WO2014063606A1 - Packet forwarding method and corresponding device - Google Patents

Abstract

Disclosed is a packet forwarding method, and also disclosed are a CE and a CGN device. The method comprises: a CE receiving a first IP packet sent by a user equipment, the first IP packet comprising a source private port and a source private IP address; the CE processing the first IP packet to obtain a second IP packet, the processing comprising: replacing the source private port in the first IP packet with a public port, and replacing the source private IP address with a public IP address; the CE sending the second IP packet to a CGN device so that after receiving the second IP packet, the CGN device forwards the second IP packet to a network device on a network side according to a destination IP address of the second IP packet. According to the present invention, conversion between a source private IP address and a public IP address and between a source private port and a public port can be performed on a CE, and for application level packet information, an ALG may be executed once on the CE, and the ALG does not need to be executed on both the CE and the CGN, thereby reducing network device overheads.

Description

 Method for forwarding texts and corresponding equipment The present application claims priority to Chinese patent application filed on October 25, 2012 by the Chinese Patent Office, application number 201210411849.9, and the invention titled "message forwarding method and corresponding equipment". The entire contents of this application are incorporated herein by reference. Technical field

 The present invention relates to the field of communications technologies, and in particular, to a packet forwarding method and corresponding device. Background technique

 At present, IPv4 address resources are becoming more and more tense globally. IPv4 uses private network addresses and Network Address Translation (NAT) technology is inevitable.

 Provided in Prior Art 1 (IETF Working Group Document Name: draft-penno-softwire-sdnat-01; see: http:〃 tools.ietf.org/id/draft-penno-softwire-sdnat-01.txt) In a stateless network address translation scheme, different user edge devices (CEs) use different private network addresses and private network transmission control protocol/Internet Protocol (Transmission Control Protocol/Internet Protocol, TCP/IP) family. Transport layer port segment. This kind of scheme has a small change to the traditional CE, but it has the following defects: Carrier Grade NAT (CGN) devices must translate addresses and ports at the same time; In the process of network address translation, it needs to be on the CE side. The source IP address and the private network port of the user equipment are translated/translated between the private IP address and the private network port of the CE. The private IP address and private network port of the CE are configured on the CGN device. The conversion and translation between the public IP address and the public network port, and the two-layer NAT processing method requires the application layer gateway to be executed on the CE and CGN devices separately for the application layer packet information related to the specific service. (Application Level Gateway, ALG) processing increases the overhead of network devices.

In the prior art 2 (IETF working group manuscript name: draft-tsou-stateless-nat44-01; see http:〃 tools.ietf.org/id/draft-tsou-stateless-nat44-01.txt) In a stateless network address translation scheme, different CE devices are assigned different private network addresses and different public network port segments. The mapping between the private network address of the CE and the IP address of the public network is established by the CGN device. Shooting relationship (refer to Figure 1, where Private IPv4_Prefix is the private network address network segment, Public IPv4_Prefix is the public network IP address network segment, and Public IPv4_suffix is the suffix of the public network IP address obtained from the private network address of the CE through the mapping rule) , forming a stateless address translation. Because the CE uses the public network port segment, the CGN device does not perform port translation. However, the CGN device also needs to use the source private IP address of the user equipment and the source private network port and the corresponding private IP address of the CE and the public network port. The ALG processing is performed on the CE and the CGN device separately, which increases the overhead of the network device for the application layer packet information related to the specific service. Summary of the invention

 The technical problem to be solved by the embodiments of the present invention is to provide a packet forwarding method and a corresponding device, which are used to solve the problem in the prior art. When a private network user accesses the public network through the CE device, the CE and the CGN device need to be respectively configured. NAT processing is performed, and ALG processing is performed on the CE and CGN devices respectively, which increases the problem of network equipment overhead.

 In order to solve the above technical problem, the first aspect provides a packet forwarding method, including:

 The user edge device receives the first IP packet sent by the user equipment, where the first IP packet includes the source private network port and the source private network IP address.

 The CE processes the first IP packet to obtain a second IP packet, where the processing includes: replacing the source private network port of the first IP packet with a public network port, and the source private Replace the network IP address with the public IP address.

 Transmitting, by the CE, the second IP packet to the carrier-level network address translation CGN device, so that the CGN device receives the second IP packet according to the destination IP address of the second IP packet The address forwards the second IP packet to the network device on the network side.

In a first possible implementation manner of the first aspect, the public network port is obtained by the CE from the CGN device by means of active acquisition, passive reception, or manual configuration, the public network IP address. Corresponding relationship between the private network IP address of the CE and the public network IP address, where the first correspondence is obtained by the CE according to the private network IP address and the first correspondence, the first The correspondence is sent to the CE in advance by the CGN device. In the first aspect or the first possible implementation manner of the first aspect, the second possible implementation manner of the first aspect is further provided, where the CE is in the second IP packet The packet header is encapsulated with a new packet header. The destination IP address of the new packet header is the IP address of the CGN device, and the source IP address is the private IP address of the CE. The CGN device sends the second IP packet encapsulating a new packet header.

 In a first possible implementation of the first aspect or a second possible implementation of the first aspect, a third possible implementation manner of the first aspect is further provided, where the CE receiving station a third IP packet sent by the CGN device, where the third IP packet is obtained by the CGN device processing the fourth IP packet received by the network device on the network side, and the fourth IP packet is processed by the CGN device. The destination IP address of the fourth IP packet is the public network IP address, and the destination port is the public network port, where the network device of the network side responds to the second IP packet. The processing of the fourth IP packet by the CGN device includes:

 When the destination IP address of the fourth IP packet is the public network IP address, the destination IP address of the fourth IP packet is replaced with the private IP address of the CE according to the first correspondence. address.

 In a third possible implementation manner of the first aspect, the fourth possible implementation manner of the foregoing first aspect is further provided, the CE processing the third IP packet to obtain a fifth IP address. The packet processing, the CE processing the third IP packet includes: when determining that the destination IP address of the third IP packet is the private network IP address of the CE, and the destination port is the public network port And replacing, by the second corresponding relationship, the destination IP address of the third IP packet with the source private network IP address, and replacing the destination port of the third IP packet with the source private network port; The CE sends the fifth IP packet to the user equipment according to the destination IP address of the fifth IP packet.

In a first possible implementation of the first aspect or a second possible implementation of the first aspect, a fifth possible implementation manner of the first aspect is further provided, where the CE receiving a sixth IP packet sent by the CGN device, where the sixth IP packet is obtained by the CGN device processing the fourth IP packet received by the network device on the network side, and the fourth IP packet is processed by the CGN device. The destination IP address of the fourth IP packet is the public network IP address, and the destination port is the public network port, where the network device of the network side responds to the second IP packet. CGN The processing of the fourth IP packet by the device includes:

 When it is determined that the destination IP address of the fourth IP packet is the public network IP address, and the destination port is the public network port, the new packet is encapsulated before the packet header of the fourth IP packet. The destination IP address of the outer packet header of the fourth IP packet is the private IP address of the CE, and the source IP address is the IP address of the CGN device, and the fourth IP packet is external. The destination IP address of the layer header is obtained according to the first correspondence.

 In a fifth possible implementation manner of the first aspect, the sixth possible implementation manner of the foregoing first aspect is further provided, the CE processing the sixth IP packet to obtain a seventh IP address. The packet processing, the CE processing the sixth IP packet includes: when determining that the sixth IP packet includes a two-layer packet header, stripping the outer packet header, and determining the sixth IP address. The destination IP address of the inner packet header of the packet is the public network IP address, and when the destination port is the public network port, the inner layer packet of the sixth IP packet is sent according to the second correspondence. The destination IP address of the header is replaced with the source private network IP address, and the destination port is replaced with the source private network port; the CE sends the seventh IP packet according to the destination IP address of the seventh IP packet. Send to the user equipment.

 The second aspect provides a method for packet forwarding, including:

 The carrier-level network address translation CGN device receives the second IP packet sent by the CE, and the second IP packet is obtained by the CE processing the first IP packet, where the first IP packet is the The receiving, by the CE, the first IP packet includes the source private network port and the source private network IP address, and the processing includes: replacing the source private network port of the first IP address with the public network Port, replacing the source private network IP address with a public network IP address;

 The CGN device forwards the second IP packet to the network device on the network side according to the destination IP address of the second IP packet.

 In a first possible implementation manner of the second aspect, the public network port is obtained by the CE from the CGN device by means of active acquisition, passive reception, or manual configuration, where the public network IP address is obtained. Corresponding relationship between the private network IP address of the CE and the public network IP address, where the first correspondence is obtained by the CE according to the private network IP address and the first correspondence, the first The correspondence is sent to the CE in advance by the CGN device.

In the second aspect or the first possible implementation manner of the second aspect, the second possible implementation manner of the second aspect is further provided, where the CGN determines the second IP The packet includes a two-layer packet header, and the outer packet header of the second IP packet is stripped, and is forwarded according to the destination IP address of the inner packet header of the second IP packet, and includes two layers of packets. The second IP packet of the header is obtained by the CE encapsulating a new packet header before the original packet header of the second IP packet, where the destination IP address of the new header is The IP address of the CGN device, and the source IP address is the private IP address of the CE.

 In a second possible implementation of the second aspect or a second possible implementation of the second aspect, a third possible implementation manner of the second aspect is further provided, where the CGN device receives a fourth IP packet, where the fourth IP packet is a response of the network device on the network side to the second IP packet, and the destination IP address of the fourth IP packet is the public IP address. Address, the destination port is the public network port; the CGN device processes the fourth IP packet to obtain a third IP packet, and the CGN device processes the fourth IP packet, including: When the destination IP address of the fourth IP packet is the public network IP address, the destination IP address of the fourth IP packet is replaced with the private IP address of the CE according to the first correspondence. And forwarding the third IP packet to the CE according to the destination IP address of the third IP packet.

 In a second possible implementation of the second aspect, or a second possible implementation of the second aspect, a fourth possible implementation manner of the second aspect is further provided, where the CGN device receives a fourth IP packet, where the fourth IP packet is a response of the network device on the network side to the second IP packet, and the destination IP address of the fourth IP packet is the public IP address. The destination port is the public network port; the CGN device processes the fourth IP packet to obtain a sixth IP packet, and the CGN device processes the fourth IP packet, including: The destination IP address of the fourth IP address is the public network IP address, and when the destination port is the public network port, a new packet header is encapsulated in front of the packet header of the fourth IP packet. The destination IP address of the new packet header is the private network IP address of the CE determined by the first correspondence, and the source IP address of the new packet header is the IP address of the CGN device. According to the destination IP address of the outer packet header of the sixth IP packet, the first IP packets sent to the CE.

 In a third aspect, a user edge device CE is provided, including:

 a first receiving unit, configured to receive a first IP packet sent by the user equipment, where the first IP packet includes a source private network port and a source private network IP address;

a first processing unit, configured to process the first IP packet to obtain a second IP packet, where The process includes: replacing the source private network port of the first IP packet with a public network port, and replacing the source private network IP address with a public network IP address;

 a first sending unit, configured to send the second IP packet to the carrier-level network address translation CGN device, so that the CGN device receives the second IP packet according to the second IP packet The destination IP address forwards the second IP packet to the network device on the network side.

 In a first possible implementation manner of the third aspect, the first processing unit includes: an acquiring subunit, configured to acquire the public from the CGN device by means of active acquisition, passive reception, or manual configuration. a storage port unit, configured to store a first correspondence, where the first correspondence includes a correspondence between a private network IP address of the CE and the public network IP address, where the first correspondence is The determining, by the CGN device, the determining unit, configured to determine the public network IP address according to the private network IP address of the CE and the first correspondence stored by the storage subunit.

 In the third aspect or the first possible implementation manner of the third aspect, a second possible implementation manner of the third sending surface is further provided, where the first sending unit includes: a package a unit, configured to encapsulate a new packet header before the packet header of the second IP packet, where the destination IP address of the new header is the IP address of the CGN device, and the source IP address is The private IP address of the CE; the sending subunit, configured to send, to the CGN device, the second IP packet encapsulated by the encapsulating subunit.

 In a second possible implementation of the third aspect or a second possible implementation of the third aspect, a third possible implementation manner of the third aspect is further provided, where the CE further includes a second receiving unit, configured to receive a third IP packet sent by the CGN device, where the third IP packet is a fourth IP packet processing received by the CGN device from a network device on the network side The destination IP address of the fourth IP packet is the public network IP address, and the destination port is the public network port, and the processing of the fourth IP packet by the CGN device includes: When the destination IP address of the fourth IP packet is the public network IP address, the destination IP address of the fourth IP address is replaced with the private IP address of the CE according to the first correspondence.

 In a third possible implementation manner of the foregoing third aspect, the fourth possible implementation manner of the third sending surface is further provided, where the CE further includes:

a storage unit, configured to save the public network port and the source private network IP address of the user equipment a second mapping unit, configured to process the third IP packet to obtain a fifth IP packet, and a second sending unit, configured to perform, according to the fifth Sending, by the destination IP address of the IP packet, the fifth IP address to the user equipment;

 The second processing unit includes: a determining subunit, configured to determine a destination IP address and a destination port of the third IP packet, where the destination IP address of the third:^>3⁄4 text is The private network IP address of the CE, the packet processing sub-unit is triggered when the destination port is the public network port, and the packet processing sub-unit is configured to send the third IP packet according to the second correspondence. The destination IP address is replaced with the source private network IP address, and the destination port of the third IP packet is replaced with the source private network port.

 In a second possible implementation of the third aspect, or a second possible implementation manner of the third aspect, a fifth possible implementation manner of the third Also includes:

 a third receiving unit, configured to receive a sixth IP packet sent by the CGN device, where the sixth IP packet encapsulates a new packet by the CGN device before the packet header of the fourth IP packet The destination IP address of the new packet header is the private IP address of the CE, and the source IP address is the IP address of the CGN device. The storage unit is configured to save the public network port and the user. The source IP address of the device and the second correspondence of the source private network port; the third processing unit is configured to process the sixth IP packet to obtain a seventh IP packet, where the processing includes When the sixth IP packet is included in the packet, the outer packet header is stripped, and the destination IP address of the inner packet header of the sixth IP packet is determined to be a public IP address. When the port is a public network port, the destination IP address of the inner packet header of the sixth IP packet is replaced with the source private IP address of the user equipment according to the second correspondence stored in the storage unit. Replacing the destination port with the source private network of the user equipment The third sending unit is configured to send the seventh IP packet to the user equipment according to the destination IP address of the seventh IP packet.

In a fourth aspect, a carrier-level network address translation CGN device is provided, including: a first receiving unit, configured to receive a second IP packet sent by a user edge device CE, where the second IP packet is the CE And processing the first IP packet, the first IP packet is received by the CE from the user equipment, and the first IP packet includes a source private network port and a source private network IP address, and the processing is performed. The method includes: replacing the source private network port of the first IP packet with a public network port. Replace the source private network IP address with a public network IP address.

 The first sending unit is configured to forward the second IP packet to the network device on the network side according to the destination IP address of the second IP packet.

 In a first possible implementation of the fourth aspect, the device further includes: a first pre-processing unit, configured to send the first correspondence to the CE in advance, where the first correspondence includes The CE is configured to obtain the public network IP address according to the private network IP address and the first correspondence relationship, where the private network IP address of the CE is associated with the public network IP address.

 In a first possible implementation manner of the fourth aspect, the second possible implementation manner of the fourth aspect is further provided, where the device further includes:

 And a second pre-processing unit, configured to set the public network port for the CE in advance.

 In the fourth aspect or the first possible aspect of the fourth aspect or the second possible implementation of the fourth aspect, a third possible implementation manner of the fourth aspect is also provided , the first sending unit includes:

 a first determining sub-unit, configured to determine the second IP packet, and when the second IP packet includes a two-layer packet header, triggering the following first packet processing sub-unit, including two layers of packets The second IP packet of the header is obtained by the CE encapsulating a new packet header before the original packet header of the second IP packet, where the destination IP address of the new packet header is The IP address of the CGN device, the source IP address is the private network IP address of the CE, and the first packet processing subunit is configured to: when the second IP packet includes two layer headers, the second packet The outer packet header of the IP packet is stripped, and is forwarded according to the destination IP address of the inner packet header of the second IP packet.

 In a second possible implementation of the fourth aspect, or a third possible implementation of the fourth aspect, a fourth possible implementation manner of the fourth aspect is further provided, where the device further includes :

a second receiving unit, configured to receive a fourth IP packet, where the fourth IP packet is a response packet of the network device on the network side to the second IP packet, where the fourth IP packet is The destination IP address is the public network IP address, and the destination port is the public network port; the processing unit is configured to process the fourth IP packet to obtain a third IP packet; and the second sending unit is configured to The destination IP address of the third IP packet forwards the third IP packet to the CE; where the processing unit includes: a second determining sub-unit, configured to determine the fourth IP packet, and trigger the following second packet processing sub-unit when the destination IP address of the fourth IP packet is the public IP address; The second packet processing sub-unit is configured to replace the destination IP address of the fourth IP packet with the private network IP address of the CE according to the first correspondence.

 In a second possible implementation of the fourth aspect, or a third possible implementation manner of the fourth aspect, a fifth possible implementation manner of the foregoing fourth aspect is further provided, where the device further includes :

 a third receiving unit, configured to receive the fourth IP packet, and a packet encapsulating unit, configured to process the fourth IP packet to obtain a sixth IP packet, where the processing includes: when determining the The destination IP address of the four IP packets is the public network IP address. When the destination port is the public network port, a new packet header is encapsulated before the packet header of the fourth IP packet. The destination IP address of the header is the private IP address of the CE, and the source IP address is the IP address of the CGN device, where the CGN device is based on the destination IP address of the fourth IP packet (that is, the public network) And determining, by the first address, the destination IP address of the new packet header; the third sending unit, configured to: according to the destination IP address of the outer packet header of the sixth IP packet, The sixth IP packet is forwarded to the CE.

 The implementation of the embodiment of the present invention has the following beneficial effects: The user edge device CE processes the packet sent by the user equipment, replaces the source private network port of the packet with the public network port, and replaces the source private network IP address. For the public network IP address, the NAT is implemented on the CE, so that the CGN device does not need to perform NAT, and according to the first correspondence and the obtained public network port, for the application layer packet information, the ALG processing can be performed only on the CE, without ALG processing is performed on the CE and CGN devices respectively, which reduces the overhead of network devices. DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description For some embodiments of the present invention, other drawings may be obtained from those skilled in the art without departing from the drawings. 1 is a public network IP address used by a user edge device CE and a private network of a CE

Schematic diagram of the mapping relationship of IP addresses;

 2 is a schematic flowchart of a method for packet forwarding according to an embodiment of the present invention; FIG. 3 is a schematic flowchart of a method for packet forwarding according to an embodiment of the present invention; FIG. 4 is a diagram of a method according to an embodiment of the present invention. FIG. 5A is a schematic structural diagram of a user edge device CE according to an embodiment of the present invention; FIG. 5B is a schematic structural diagram of a first processing unit of a user edge device CE according to an embodiment of the present invention;

 FIG. 5C is a schematic diagram of a first sending unit structure of a user edge device CE according to an embodiment of the present invention; FIG.

 FIG. 6 is a schematic structural diagram of a user edge device CE according to an embodiment of the present invention; FIG. 7 is a schematic structural diagram of a user edge device CE according to an embodiment of the present invention; FIG. 8A is a CGN device structure according to an embodiment of the present invention; Schematic diagram

 FIG. 8B is a schematic structural diagram of a first transmitting unit of a CGN device according to an embodiment of the present invention; FIG.

 9 is a schematic structural diagram of a CGN device according to an embodiment of the present invention;

 FIG. 10 is a schematic structural diagram of a CGN device according to an embodiment of the present invention; FIG.

 11 is a schematic structural diagram of a user edge device CE according to an embodiment of the present invention; and FIG. 12 is a schematic structural diagram of a CGN device according to an embodiment of the present invention. detailed description

 The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

 FIG. 2 is a schematic flowchart of a packet forwarding method according to an embodiment of the present invention. Referring to FIG. 2, the method includes:

200: The user edge device CE receives the first IP packet sent by the user equipment, where the first IP address is The packet contains the source private network port and the source private network IP address.

 202: The CE processes the first IP packet to obtain a second IP packet, where the processing includes: replacing the source private network port of the first IP address with a public network port, The source private network IP address is replaced with a public network IP address.

 204: The CE sends the second IP packet to the carrier-level network address translation CGN device, so that the CGN device receives the second IP packet according to the second IP packet after receiving the second IP packet. The destination IP address forwards the second IP packet to the network device on the network side.

 The user equipment is a user equipment on the private network side of the CE, and the source private network port included in the first IP packet is a TCP/IP port, and the private network port can only be connected to the CE. The private network side is valid and cannot be used for the CGN public network side network forwarding. For convenience of description, in the embodiment of the present invention, the source port in the first IP address is defined as the private network source port, and the CGN is the CE source. The assigned port for forwarding on the public network side of the CGN is defined as the public network port.

 Optionally, the public network port is obtained by the CE from the CGN device by means of active acquisition, passive reception, or manual configuration. For example, if the CE obtains the public network port from the CGN device by means of active acquisition, the dynamic host configuration protocol (DHCP) or the Neighbor Discovery Protocol (NDP) may be adopted. To achieve, if the CE obtains the public network port from the CGN device by means of passive acquisition, the BroadBand Forum Technical Report 069 (BBF TR-069) or the single network management protocol can be obtained through the broadband forum technical report No. 069 (Broadband Forum Technical Report 069, BBF TR-069) (Simple Network Management Protocol, SNMP) or Port Control Protocol (PCP).

Optionally, the public network IP address is obtained by the CE according to the private network IP address and the first correspondence, and the first corresponding relationship holds the private network IP address of the CE and the public network. Corresponding relationship of the IP address, the first correspondence is sent to the CE by the CGN device in advance. The private network IP address of the CE is allocated by the CGN device, and when the CGN allocates a private network IP address to the CE, the public network address that the CE needs to use is also allocated, and the CGN is Establishing the first correspondence between the private network IP address of the CE and the public network IP address, and the CGN device may send the first correspondence to the CE by using DHCP or NDP or SNMP or PCP protocol. . Optionally, the CE may replace the source private network port of the first IP packet with a public network port, and replace the source private network IP address with a public network IP address. Performing ALG processing on the IP address includes: converting/translating the address and port information in the payload information of the first IP packet. For example, in a case where a user on the private network side accesses a File Transfer Protocol (FTP) server, the payload information of the first packet includes a destination IP address specified by the user on the private network side for the FTP data connection ( That is, the source private network IP address and the destination port (that is, the source private network port), at this time, the CE specifies the load information of the first IP packet according to the first correspondence. The destination IP address and destination port are translated/translated into the public network IP address and the public network port. Because the CE device performs ALG processing on the first IP packet, the CGN device does not need to perform ALG processing on the first IP packet.

 Optionally, when the CE has a default route to the CGN device, the CE directly forwards the second IP packet to the CGN according to the default route.

 Optionally, the sending, by the CE, the second IP address to the CGN device may further include: the CE encapsulating a new packet header before the packet header of the second IP packet, the new The destination IP address of the header is the IP address of the CGN device, the source IP address is the private IP address of the CE, and the CE sends the encapsulated new header to the CGN device. The second IP packet.

 The packet forwarding method provided in this embodiment may be configured to convert the source private network IP address and the source private network port of the first message transmitted by the user equipment to the public network IP address and the public on the CE. The network port, according to the first correspondence and the obtained public network port, only needs to perform ALG processing on the application layer packet information related to the specific service, and does not need to perform ALG processing on the CE and the CGN device respectively. The network equipment overhead is fixed.

 FIG. 3 is a schematic flowchart of a method for packet forwarding according to an embodiment of the present invention. Referring to FIG. 3, the method includes:

300: The CGN device receives the second IP packet sent by the CE, where the second IP packet is obtained by the CE processing the first IP packet, where the first IP packet is the CE slave user equipment. Receiving, the first IP packet includes a source private network port and a source private network IP address, and the processing includes: replacing the source private network port of the first IP packet with a public network port, and the source Replace the private network IP address with the public IP address. 302: The CGN device forwards the second IP packet to the network device on the network side according to the destination IP address of the second IP packet.

 Optionally, the public network port is obtained by the CE from the CGN device by means of active acquisition, passive reception, or manual configuration. For example, the CE obtains the public network port through the DHCP, NDP, SNMP, or PCP protocol, or the BBF TR-069 technology.

 Optionally, the public network IP address is obtained by the CE according to the private network IP address and the first correspondence, and the first corresponding relationship holds the private network IP address of the CE and the public network. Corresponding relationship of the IP address, the first correspondence is sent to the CE by the CGN device in advance. The private network IP address of the CE is allocated by the CGN device, and when the CGN allocates a private network IP address to the CE, the public network address that the CE needs to use is also allocated, and the CGN is Establishing the first correspondence between the private network IP address of the CE and the public network IP address, and the CGN device may send the first correspondence to the CE by using DHCP or NDP or SNMP or PCP protocol. .

 Optionally, the CGN device forwards the second IP packet to the network device on the network side by:

 The CGN device determines that the second IP packet includes a two-layer packet header, and the outer packet header of the second IP packet is stripped by 10,000, according to the inner packet header of the second IP packet. The destination IP address is forwarded, and the second IP packet that includes the two-layer packet header is obtained by the CE encapsulating a new packet header before the original packet header of the second IP packet. The destination IP address of the new packet header is the IP address of the CGN device, and the source IP address is the private IP address of the CE.

 In the packet forwarding method provided in this embodiment, the CGN device decapsulates and sends the packet, does not perform port translation, and does not need to perform ALG processing on the application layer packet information, thereby reducing device overhead.

 FIG. 4 is a schematic flowchart of a method for packet forwarding according to an embodiment of the present invention. Referring to FIG. 4, the method includes:

 400: The CE receives the first IP packet sent by the user equipment, where the first IP packet includes a source private network port and a source private network ip address.

401: The CE processes the first IP packet to obtain a second IP packet, where the processing includes: replacing the source private network port of the first IP address with a public network port, The source private Replace the network IP address with the public IP address.

 The CE sends the second IP packet to the carrier-level network address translation CGN device, so that the CGN device receives the second IP packet according to the second IP packet after receiving the second IP packet. The destination IP address forwards the second IP packet to the network device on the network side.

 403: The CGN device receives the sent second IP packet.

 404: The CGN device forwards the second IP packet to the network device on the network side according to the destination IP address of the second IP packet.

 For the description of 400 to 402, please refer to the description of the embodiment shown in FIG. 2. For the description of 403 and 404, refer to the description of the embodiment shown in FIG. 3, which will not be described herein.

 405: The CGN device receives a fourth IP packet, where the fourth IP packet is a response packet of the network device on the network side to the second IP packet, and the destination of the fourth IP packet is The IP address is the public network IP address, and the destination port is the public network port.

 406: The CGN device processes the fourth IP packet to obtain a third IP packet, and forwards the third IP packet to the CE according to the destination IP address of the third IP packet. The processing of the fourth IP packet by the CGN device includes: when determining that the destination IP address of the fourth IP packet is the public network IP address, the fourth IP according to the first correspondence The destination IP address of the packet is replaced with the private IP address of the CE. The third IP packet is forwarded to the CE according to the destination IP address of the third IP address.

 The private network IP address of the CE is allocated by the CGN device, and when the CGN allocates a private network IP address to the CE, the public network address that the CE needs to use is also allocated, and the CGN is Establishing the first correspondence between the private network IP address of the CE and the public network IP address.

 407: The CE receives a third IP packet sent by the CGN device.

408: The CE processes the third IP packet to obtain a fifth IP packet, and the processing, by the CE, the third IP packet includes: determining a destination IP address of the third IP packet If the destination port is the public network port, the destination IP address of the third IP packet is replaced with the destination private IP address by using the second corresponding relationship. The destination port of the third IP address is replaced with the source private network port. The CE stores the source network IP address of the public network port and the user equipment, and the second corresponding relationship of the source private network port. Optionally, the second correspondence is established when the CE obtains the public network port by using a DHCP, NDP, SNMP, or PCP protocol, or by using the BBF TR-069 technology.

 409: The CE sends the fifth IP packet to the user equipment according to the destination IP address of the fifth IP packet.

 An embodiment of the present invention further provides a method for packet forwarding, the method comprising 400 to 405 in the embodiment shown in FIG. 4, and the following steps:

 1) The CGN device processes the fourth IP packet to obtain a sixth IP packet, and the processing, by the CGN device, the fourth IP packet includes: determining a destination of the fourth IP packet The IP address is the public network IP address, and the destination port is the public network port, and a new packet header is encapsulated in front of the packet header of the fourth IP packet, and the destination IP address of the new packet header is The source IP address of the new IP address is the IP address of the CGN device according to the private network IP address of the CE determined according to the first correspondence, and the outer layer of the sixth IP packet is The destination IP address of the packet header is sent to the CE by the sixth IP packet.

 The private network IP address of the CE is allocated by the CGN device, and when the CGN allocates a private network IP address to the CE, the public network address that the CE needs to use is also allocated, and the CGN is Establishing the first correspondence between the private network IP address of the CE and the public network IP address.

 2) The CGN device sends the sixth IP packet to the CE according to the destination IP address of the outer packet header of the sixth IP packet.

3) The CE receives the sixth IP packet sent by the CGN device, and processes the sixth IP packet to obtain a seventh IP packet, where the CE processes the sixth IP packet, including When it is determined that the sixth IP packet includes two layer headers, the outer packet header is stripped, and the destination IP address of the inner layer 4 header of the sixth IP address is determined to be The public network IP address, when the destination port is the public network port, the destination IP address of the inner packet header of the sixth IP packet is replaced with the source private network IP address according to the second correspondence. The destination port is replaced with the source private network port; the CE sends the seventh IP packet to the user equipment according to the destination IP address of the seventh IP packet. The CE stores the source network IP address of the public network port and the user equipment, and the second corresponding relationship of the source private network port. Optionally, the second correspondence is established when the CE obtains the public network port by using a DHCP, NDP, SNMP, or PCP protocol, or by using the BBF TR-069 technology.

 Optionally, in this step, the CE may further perform an ALG process, for example, converting/translating address and port information in the payload information of the sixth IP packet according to the first correspondence.

 4) The CE sends the seventh IP packet to the user equipment according to the destination IP address of the seventh IP packet.

 In this embodiment, the conversion between the source private network IP address, the source private network port, the corresponding public network IP address, and the public network port is implemented on the CE, and the CGN device performs tunnel encapsulation and decapsulation. Text processing and sending. For the processing of application layer packet information, ALG processing can be performed on the CE without performing on the CGN device.

 FIG. 5A is a schematic structural diagram of a user edge device CE according to an embodiment of the present invention. Referring to FIG. 5A, the CE50 includes:

 The first receiving unit 52 is configured to receive a first IP packet sent by the user equipment, where the first IP packet includes a source private network port and a source private network IP address.

 The first processing unit 54 is configured to process the first IP packet to obtain a second IP packet, where the processing includes: replacing the source private network port of the first IP address with the public network Port, replace the source private network IP address with the public network IP address.

 The first sending unit 56 is configured to send the second IP packet to the CGN device, so that the CGN device receives the second IP packet according to the destination IP address of the second IP packet. Forwarding the second IP packet to a network device on the network side.

 In an implementation manner of this embodiment, referring to FIG. 5B, the first processing unit 54 includes: an obtaining subunit 542, configured to acquire the public network from the CGN device by means of active acquisition, passive reception, or manual configuration. The port obtains the public network port by, for example, receiving information sent by the DHCP server.

The storage sub-unit 544 is configured to store a first correspondence, where the first correspondence includes a correspondence between a private network IP address of the CE50 and the public network IP address (the first in the embodiment shown in FIG. 6) When the processing unit 50 includes the storage subunit 544, the first correspondence includes the correspondence between the private network IP address of the CE60 and the public network IP address, and the change of the implicit device number is in the embodiment shown in the other figures. A similar situation in the unit/subunit is also applicable, and is not specifically described. The first correspondence is that the CGN device is previously sent to the CE 50.

 The determining subunit 546 is configured to determine the public network IP address according to the private network IP address of the CE50 and the first correspondence stored by the storage subunit 544.

 In an implementation manner of this embodiment, referring to FIG. 5C, the first sending unit 56 includes: a packaging sub-unit 562, configured to encapsulate a new packet header before the packet header of the second IP packet. The destination IP address of the new header is the IP address of the CGN device, and the source IP address is the private IP address of the CE50.

 The sending subunit 564 is configured to send, to the CGN device, the second IP packet encapsulated by the encapsulating subunit 562 into a new packet header.

 The CE50 provided in this embodiment can implement the conversion of the source private network IP address of the user equipment, the source private network port to the public network IP address, and the public network port, and only needs to execute the ALG once for the application layer packet information.

 FIG. 6 is a schematic structural diagram of a user edge device CE according to an embodiment of the present invention. Referring to FIG. 6, the CE 60 includes, in addition to the first receiving unit 52, the first processing unit 54, and the first sending unit 56, the following:

 The second receiving unit 62 is configured to receive a third IP packet that is sent by the CGN device, where the third IP packet is a fourth IP packet that is received by the CGN device from the network device on the network side. The destination IP address of the fourth IP address is the public network IP address, and the destination port is the public network port, and the processing of the fourth IP packet by the CGN device includes:

 When it is determined that the destination IP address of the fourth IP packet is the public network IP address, the destination IP address of the fourth IP packet is replaced with the private network IP address of the CE60 according to the first correspondence.

 The storage unit 64 is configured to save a second correspondence between the public network port and the source private network IP address of the user equipment and the source private network port.

The second processing unit 66 is configured to process the third IP packet to obtain a fifth IP packet. The second sending unit 68 is configured to: according to the destination IP address of the fifth IP packet, the first Five IP packets are sent to the user equipment.

 In an implementation manner of this embodiment, the second processing unit 62 may include:

 a determining subunit, configured to determine a destination IP address and a destination port of the third IP packet, where the destination IP address of the third IP address is a private network IP address of the CE60, and the destination port is the The following packet processing subunit is triggered when the public network port is used;

 a message processing subunit, configured to replace the destination IP address of the third IP packet with the source private network IP address according to the second correspondence, and replace the destination port of the third IP packet with The source private network port.

 FIG. 7 is a schematic structural diagram of a user edge device CE according to an embodiment of the present invention. Referring to FIG. 7, the CE 70 includes, in addition to the first receiving unit 52, the first processing unit 54, and the first sending unit 56, the following:

 The third receiving unit 72 is configured to receive a sixth IP packet that is sent by the CGN device, where the sixth IP packet is encapsulated by the CGN device before the packet header of the fourth IP packet. The destination IP address of the new packet header is the private IP address of the CE70, and the source IP address is the IP address of the CGN device.

 The saving unit 74 is configured to save a second correspondence between the public network port and the source private network IP address and the source private network port of the user equipment.

 The third processing unit 76 is configured to process the sixth IP packet to obtain a seventh IP packet. Specifically, when it is determined that the sixth IP packet includes a two-layer packet header, the outer packet header is stripped; the destination IP address of the inner header is determined as the public network IP address, and the destination port is the public port. And replacing the destination IP address of the inner packet header of the sixth IP packet with the source private IP address of the user equipment according to the second correspondence stored by the storage unit 74, The destination port of the inner packet header of the sixth IP packet is replaced with the source private network port of the user equipment.

 The third sending unit 78 is configured to send the seventh IP packet to the user equipment according to the destination IP address of the seventh IP packet.

It can be seen that, by using the CE provided by the embodiment of the present invention, the CE is implemented in the CE, so that the CGN device does not need to perform NAT, and according to the first correspondence and the obtained public network port, for application layer packet information, ALG processing can be performed only on the CE without performing ALG processing on the CE and the CGN device separately, which reduces the overhead of the network device. FIG. 8A is a schematic structural diagram of a CGN device according to an embodiment of the present invention. Referring to FIG. 8A, the CGN device 80 includes:

 The first receiving unit 82 is configured to receive a second IP packet sent by the user edge device CE. The second IP packet is obtained by the CE processing the first IP packet, where the first IP packet is received by the CE from the user equipment, and the first IP packet includes the source private network. The port and the source private network IP address, the process includes: replacing the source private network port of the first IP packet with a public network port, and replacing the source private network IP address with a public network IP address.

 The first sending unit 84 is configured to forward the second IP packet to the network device on the network side according to the destination IP address of the second IP packet.

 Optionally, in an implementation manner of this embodiment, the CGN device 80 may further include: a first pre-processing unit 86, configured to send the first correspondence to the CE in advance, so that the CE is configured according to the CE The private network IP address and the first corresponding relationship are corresponding to the public network IP address, and the first correspondence relationship includes a correspondence between the private network IP address of the CE and the public network IP address.

 The second pre-processing unit 88 is configured to set the public network port for the CE in advance.

 In the packet forwarding system composed of the CE and the CGN device, the CGN device 80 provided in this embodiment does not need to perform the ALG function, and can also perform network translation without port translation.

 In an implementation manner of this embodiment, referring to FIG. 8B, the first sending unit 84 includes: a first determining subunit 842, configured to determine, by the second IP packet, the second IP packet. The first message processing sub-unit 844 is triggered when the two-layer header is included. The second IP packet that includes the two-layer packet header is obtained by the CE encapsulating a new packet header before the original packet header of the second IP packet, where the new header is The destination IP address is the IP address of the CGN device 80, and the source IP address is the private IP address of the CE.

 The first packet processing sub-unit 844 is configured to: when the second IP packet includes a two-layer packet header, strip the outer packet header of the second IP packet, according to the second IP packet The destination IP address of the inner packet header is forwarded.

FIG. 9 is a schematic structural diagram of a CGN device according to an embodiment of the present invention. Referring to FIG. 9, the CGN device 90 includes, in addition to the first receiving unit 82 and the first sending unit 84, the following: The second receiving unit 92 is configured to receive a fourth IP packet, where the fourth IP packet is a response packet of the network device on the network side to the second IP packet, and the fourth IP packet is The destination IP address is the public network IP address, and the destination port is the public network port.

 The processing unit 94 is configured to process the fourth IP packet to obtain a third IP packet. The second sending unit 96 is configured to forward the third IP packet to the CE according to the destination IP address of the third IP packet.

 In an implementation manner of this embodiment, the processing unit 94 includes:

 a second determining sub-unit, configured to determine the fourth IP packet, and triggering the following second packet processing sub-unit when the destination IP address of the fourth IP packet is the public IP address;

 The second packet processing sub-unit is configured to replace the destination IP address of the fourth IP packet with the private network IP address of the CE according to the first correspondence.

 FIG. 10 is a schematic structural diagram of a CGN device according to an embodiment of the present invention. Referring to FIG. 10, the CGN device 100 includes: a first receiving unit 82 and a first sending unit 84, and a third receiving unit 102, configured to receive a fourth IP packet, where the fourth IP packet is a response packet of the network device on the network side to the second IP packet, and the destination IP address of the fourth IP packet is the public network IP address, the destination port is the public network port.

 The packet encapsulating unit 104 is configured to process the fourth IP packet to obtain a sixth IP packet. Specifically, when it is determined that the destination IP address of the fourth IP packet is the public network IP address, and the destination port is the public network port, the packet is encapsulated before the packet header of the fourth IP packet. The destination IP address of the new packet header is the private IP address of the CE, and the source IP address is the IP address of the CGN device 100. The CGN device 100 may determine the destination of the new packet header of the fourth IP packet according to the destination IP address of the fourth IP packet, that is, the public network IP address, and the first correspondence. IP address.

 The third sending unit 106 is configured to forward the sixth IP packet to the CE according to the destination IP address of the outer packet header of the sixth IP packet.

It can be seen that, by using the CGN provided by the embodiment of the present invention, the CE is implemented in the CE, so that the CGN device does not need to perform NAT, and according to the first correspondence and the obtained public network port, for application layer packet information, ALG processing can be performed only on the CE, without performing ALG processing on the CE and the CGN device, respectively, reducing network equipment Overhead.

 FIG. 11 is a schematic structural diagram of a user edge device CE according to an embodiment of the present invention. Referring to FIG. 11, the CE 110 includes: a transceiver 111 and a processor 112. among them:

 The transceiver 111 is configured to receive a first IP packet sent by the user equipment, where the first IP packet includes a source private network port and a source private network IP address.

 The processor 112 is configured to process the first IP packet to obtain a second IP packet, where the processing includes: replacing the source private network port of the first IP address with a public network port, The source private network IP address is replaced with a public network IP address.

 The transceiver 111 is further configured to send the second IP packet to the carrier-level network address translation CGN device, so that the CGN device receives the second IP packet according to the second IP after receiving the second IP packet. The destination IP address of the packet forwards the second IP packet to the network device on the network side.

 Optionally, the transceiver 111 is further configured to obtain the public network port from the CGN device by means of active acquisition, passive reception, or manual configuration, where the CE 100 further includes:

 The storage unit 113 is configured to store a first correspondence, where the first correspondence includes a correspondence between a private network IP address of the CE and the public network IP address, where the first correspondence is sent in advance by the CGN device. To the CE;

 The processor 112 is further configured to determine the public network IP address according to the private network IP address of the CE and the first correspondence stored by the memory 113.

 Optionally, the processor 112 is further configured to encapsulate a new packet header before the packet header of the second IP packet, where a destination IP address of the new packet header is an IP address of the CGN device. Address, source IP address is the private network IP address of the CE110;

 The transceiver 111 is further configured to send, to the CGN device, the second IP packet encapsulated by the processor 112 into a new packet header.

 Optionally, the transceiver 111 is further configured to receive a third IP packet sent by the CGN device, where the third IP packet is received by the CGN device from a network device on the network side. The destination IP address of the fourth IP packet is the public network IP address, and the destination port is the public network port, and the CGN device processes the fourth IP packet, including the four IP packets. :

When it is determined that the destination IP address of the fourth IP address is the public network IP address, The first correspondence replaces the destination IP address of the fourth IP packet with the private network IP address of the CE.

 Optionally, the processor 112 is further configured to save the source private network IP address of the public network port and the user equipment, and the second corresponding relationship of the source private network port;

 The processor 112 is further configured to process the third IP packet to obtain a fifth IP packet, where the processing, by the CE, the third IP packet includes:

 When it is determined that the destination IP address of the third IP address is the private network IP address of the CE, and the destination port is the public network port, the third IP packet is used according to the second correspondence. The destination IP address is replaced with the source private network IP address, and the destination port of the third IP packet is replaced with the source private network port.

 The transceiver 111 is configured to send the fifth IP packet to the user equipment according to the destination IP address of the fifth IP packet.

 It can be seen that, by using the CE provided by the embodiment of the present invention, the CE is implemented in the CE, so that the CGN device does not need to perform NAT, and according to the first correspondence and the obtained public network port, for application layer packet information, ALG processing can be performed only on the CE without performing ALG processing on the CE and the CGN device separately, which reduces the overhead of the network device.

 FIG. 12 is a schematic structural diagram of a CGN device according to an embodiment of the present invention. Referring to FIG. 12, the CGN device 120 includes:

 The transceiver 121 is configured to receive a second IP packet sent by the user edge device CE, where the second IP packet is obtained by the CE processing the first IP packet, where the first IP packet is The receiving, by the user equipment, the first IP packet includes the source private network port and the source private network IP address, and the processing includes: replacing the source private network port of the first IP address with the public IP address The network port replaces the source private network IP address with a public network IP address.

 The transceiver 121 is further configured to forward the second IP packet to the network device on the network side according to the destination IP address of the second IP packet.

 Optionally, the CGN device 120 further includes:

 The storage unit 122 is configured to store a first correspondence, where the first correspondence includes a correspondence between a private network IP address of the CE and the public network IP address.

The transceiver 121 is further configured to send the first correspondence to the CE in advance. Optionally, the CGN device 120 further includes a processor 123, configured to preset the public network port for the CE.

 Optionally, the processor 123 is further configured to: determine, by the second IP packet, the second IP packet, where the second IP packet includes a two-layer packet header, and the outer layer of the second IP packet is reported. The header is stripped, and the second IP packet that includes the two-layer packet header is obtained by the CE encapsulating a new packet header before the original packet header of the second IP packet, where the new packet is obtained. The destination IP address of the header is the IP address of the CGN device 120, and the source IP address is the private IP address of the CE.

 The transceiver 121 is further configured to forward according to a destination IP address of an inner packet header of the second IP packet.

 Optionally, the transceiver 121 is further configured to receive a fourth IP packet, where the fourth IP packet is a response packet of the network device on the network side to the second IP packet, where the The destination IP address of the four IP packets is the public network IP address, and the destination port is the public network port.

 The processor 123 is further configured to process the fourth IP packet to obtain a third IP packet, where the processing includes: determining that the destination IP address of the fourth IP address is the public IP address In the address, the destination IP address of the fourth IP packet is replaced with the private IP address of the CE according to the first correspondence.

 The transceiver 121 is further configured to forward the third IP packet to the CE according to the destination IP address of the third IP packet.

 It can be seen that, by using the CGN provided by the embodiment of the present invention, the CE is implemented in the CE, so that the CGN device does not need to perform NAT, and according to the first correspondence and the obtained public network port, for application layer packet information, ALG processing can be performed only on the CE without performing ALG processing on the CE and the CGN device separately, which reduces the overhead of the network device. A person skilled in the art can understand that all or part of the process of implementing the above embodiment method can be completed by a computer program to instruct related hardware, and the program can be stored in a computer readable storage medium. In execution, the flow of an embodiment of the methods as described above may be included. The storage medium may be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM).

What has been disclosed above is only a preferred embodiment of the present invention, and of course, it cannot be limited thereto. The scope of the invention is therefore intended to be embraced within the scope of the invention.

Claims

Rights request 1. A message forwarding method, characterized by including: The user edge device CE receives the first IP message sent by the user device, where the first IP message includes the source private network port and the source private network IP address; The CE processes the first IP message to obtain a second IP message. The processing includes: replacing the source private network port of the first IP message with a public network port, and replacing the source private network port with a public network port. Replace the network IP address with the public IP address; The CE sends the second IP message to the carrier-level network address translation CGN device, so that after receiving the second IP message, the CGN device can, according to the destination IP of the second IP message, The address forwards the second IP packet to the network device on the network side. 2. The method according to claim 1, characterized in that, the public network port is obtained by the CE from the CGN device through active acquisition, passive reception or manual configuration, and the public network IP address is The CE is obtained based on the private IP address and the first correspondence. The first correspondence stores the correspondence between the private IP address of the CE and the public IP address. The first correspondence The relationship is sent by the CGN device to the CE in advance. 3. The method according to claim 1 or 2, wherein the CE sending the second IP message to the CGN device includes: The CE encapsulates a new message header before the message header of the second IP message, the destination IP address of the new IP message header is the IP address of the CGN device, and the source IP address is the The CE's private network IP address sends the second IP message encapsulated with a new IP header to the CGN device. 4. The method according to claim 2 or 3, characterized in that, the method further includes: the CE receiving a third IP message sent by the CGN device, the third IP message being the CGN device. The device processes the fourth IP message received from the network device on the network side, and the fourth IP message is the response message of the network device on the network side to the second IP message, so The destination IP address of the fourth IP message is the public network IP address, and the destination port is the Public network port, the CGN device's processing of the fourth IP message includes: When it is determined that the destination IP address of the fourth IP message is the public network IP address, replace the destination IP address of the fourth IP message with the private network IP of the CE according to the first correspondence relationship. address. 5. The method according to claim 4, wherein the CE stores a second corresponding relationship between the public network port, the source private network IP address of the user equipment, and the source private network port. , the method also includes: The CE processes the third IP message to obtain a fifth IP message. The CE processes the third IP message including: When it is determined that the destination IP address of the third IP message is the private network IP address of the CE and the destination port is the public network port, the destination IP address of the third IP message is changed according to the second correspondence relationship. Replace the destination IP address with the source private network IP address, and replace the destination port of the third IP message with the source private network port; The CE sends the fifth IP message to the user equipment according to the destination IP address of the fifth IP message. 6. A message forwarding method, characterized by including: The carrier-grade network address translation CGN device receives the second IP message sent by the CE. The second IP message is obtained by the CE processing the first IP message. The first IP message is the The first IP packet received by the CE from the user equipment includes a source private network port and a source private network IP address. The processing includes: replacing the source private network port of the first IP packet with a public network. Port, replace the source private network IP address with the public network IP address; The CGN device converts the second IP message according to the destination IP address of the second IP message.

7. The method according to claim 6, wherein the public network port is obtained by the CE from the CGN device through active acquisition, passive reception or manual configuration, and the public network IP address is The CE is obtained based on the private network IP address and the first corresponding relationship, The first correspondence relationship stores the correspondence relationship between the private network IP address of the CE and the public network IP address, and the first correspondence relationship is sent to the CE in advance by the CGN device. 8. The method according to claim 6 or 7, characterized in that, the CGN device forwarding the second IP message to the network device on the network side according to the destination IP address of the second IP message includes: The CGN device determines that the second IP message contains two layers of headers, peels off the outer header of the second IP message, and based on the inner header of the second IP message The destination IP address is forwarded, and the second IP message containing the two-layer message header is obtained by the CE encapsulating a new message header before the original message header of the second IP message, the The destination IP address of the new message header is the IP address of the CGN device, and the source IP address is the private IP address of the CE. 9. The method according to claim 7 or 8, characterized in that, the method further includes: the CGN device receives a fourth IP message, the fourth IP message is for the network device on the network side. In the response message of the second IP message, the destination IP address of the fourth IP message is the public network IP address, and the destination port is the public network port; The CGN device processes the fourth IP message to obtain a third IP message. The CGN device processes the fourth IP message including: When it is determined that the destination IP address of the fourth IP message is the public network IP address, replace the destination IP address of the fourth IP message with the private network IP of the CE according to the first correspondence relationship. address; Forward the third IP message to the CE according to the destination IP address of the third IP message. 10. A user edge device CE, which is characterized by including: The first receiving unit is configured to receive the first IP message sent by the user equipment, where the first IP message includes the source private network port and the source private network IP address; A first processing unit, configured to process the first IP message to obtain a second IP message. The processing includes: replacing the source private network port of the first IP message with a public network port, The source private network IP address is replaced with a public network IP address; The first sending unit is configured to send the second IP message to the carrier-level network address translation CGN device, so that after receiving the second IP message, the CGN device can send the second IP message according to the second IP message. The second IP message is forwarded to the network device on the network side according to the destination IP address of the message. 11. The CE according to claim 10, wherein the first processing unit includes: An acquisition subunit, configured to acquire the public network port from the CGN device through active acquisition, passive reception or manual configuration; A storage subunit, configured to store a first correspondence relationship. The first correspondence relationship includes the correspondence relationship between the private network IP address of the CE and the public network IP address. The first correspondence relationship is the predetermined relationship between the CGN device and the private network IP address of the CE. Sent to the CE; The determining subunit is configured to determine the public network IP address according to the private network IP address of the CE and the first correspondence stored by the storage subunit. 12. The CE according to claim 10 or 11, characterized in that the first sending unit includes: An encapsulation subunit, configured to encapsulate a new message header before the message header of the second IP message, where the destination IP address of the new IP message header is the IP address of the CGN device, and the source IP address is the private IP address of the CE; A sending subunit, configured to send the second IP message in which a new message header is encapsulated by the encapsulation subunit to the CGN device. 13. The CE according to claim 11 or 12, characterized in that, the CE further includes: a second receiving unit, configured to receive the third IP message sent by the CGN device, the third IP message It is obtained by the CGN device processing the fourth IP message received from the network device on the network side. The destination IP address of the fourth IP message is the public network IP address, and the destination port is the public network IP address. network port, the processing of the fourth IP message by the CGN device includes: When it is determined that the destination IP address of the fourth IP message is the public network IP address, the destination IP address of the fourth IP message is replaced with the destination IP address according to the first correspondence relationship. Specifies the private IP address of the CE. 14. The CE according to claim 13, wherein the CE further includes: a storage unit configured to store the public network port and the source private network IP address of the user equipment, and the source private network IP address. The second corresponding relationship of network ports; The second processing unit is used to process the third IP message to obtain a fifth IP message; the second sending unit is used to send the fifth IP message according to the destination IP address of the fifth IP message. Send the text to the user device; Wherein, the second processing unit includes: The judgment subunit is used to judge the destination IP address and destination port of the third IP message. When the destination IP address of the third IP message is the private network IP address of the CE, the destination port is When the public network port is used, the following message processing subunit is triggered; A message processing subunit is used to replace the destination IP address of the third IP message with the source private network according to the second correspondence relationship. IP address, and replace the destination port of the third IP message with the source private network port. 15. A carrier-grade network address translation CGN device, characterized in that it includes: a first receiving unit, configured to receive a second IP message sent by a user edge device CE, where the second IP message is the CE message The first IP message is obtained by processing the first IP message. The first IP message is received by the CE from the user equipment. The first IP message includes the source private network port and the source private network IP address. The processing The method includes: replacing the source private network port of the first IP message with a public network port, and replacing the source private network IP address with a public network IP address; The first sending unit is configured to forward the second IP message to the network device on the network side according to the destination IP address of the second IP message. 16. The device according to claim 15, characterized in that the device further includes: a first pre-processing unit, configured to send a first correspondence to the CE in advance, the first correspondence including the There is a corresponding relationship between the private network IP address of the CE and the public network IP address, and the CE obtains the public network IP address based on the private network IP address and the first corresponding relationship. 17. The device according to claim 16, characterized in that the device further includes: a second pre-processing unit, configured to pre-set the public network port for the CE. 18. The device according to any one of claims 15 to 17, characterized in that the first sending unit includes: The first judgment sub-unit is used to judge the second IP message. When the second IP message contains a two-layer message header, the following first message processing sub-unit is triggered, including a two-layer message. The second IP packet in the header is obtained by the CE encapsulating a new packet header before the original packet header of the second IP packet, and the destination IP address of the new packet header is the The IP address of the CGN device, and the source IP address is the private IP address of the CE; The first message processing subunit is configured to peel off the outer message header of the second IP message when the second IP message contains two layers of message headers. According to the second IP message The destination IP address of the inner header of the message is forwarded. 19. The device according to claim 17 or 18, characterized in that the device further includes: The second receiving unit is configured to receive a fourth IP message. The fourth IP message is a response message of the network device on the network side to the second IP message. The fourth IP message The destination IP address is the public network IP address, and the destination port is the public network port; A processing unit, used to process the fourth IP message to obtain a third IP message; A second sending unit, used to forward the third IP message according to the destination IP address of the third IP message. to the CE; Wherein, the processing unit includes: The second judgment subunit is used to judge the fourth IP message, and trigger the following second message processing subunit when the destination IP address of the fourth IP message is the public network IP address; The second message processing subunit is configured to replace the destination IP address of the fourth IP message with the private IP address of the CE according to the first corresponding relationship.