WO2009018768A1

WO2009018768A1 - Method and apparatus of data package forwarding, apparatus of data package generating and communication system

Info

Publication number: WO2009018768A1
Application number: PCT/CN2008/071878
Authority: WO
Inventors: Yong Qiu; Xiaohan Liu; Min Huang; Guohua Zhou
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2007-08-07
Filing date: 2008-08-05
Publication date: 2009-02-12

Abstract

A method and apparatus of data package forwarding, an apparatus of data package generating and communication system are disclosed, wherein the method of data package forwarding includes the following steps: receiving the first data package transmitted by message sending end through the first transmission protocol signaling channel, the first data package comprising message receiving end ID and application layer message; choosing the second transmission protocol signaling channel corresponding to the message receiving end ID; transmitting the second data package to the message receiving end through the second transmission protocol signaling channel, the second data package comprising the application layer message. The apparatus of data package generating, the apparatus of data package forwarding and communication system are also provided in the invention.

Description

Packet forwarding method and device, data packet generating device and communication system

The present invention relates to the field of communications technologies, and in particular, to a data packet forwarding method and apparatus, a data packet generating apparatus, and a communication system.

Background technique

With the rapid development of Internet services and the wide application of broadband access networks and wireless networks, high-speed and convenient access to the network is the goal pursued by people. In order to make better use of the resources of existing networks and reduce the cost of network equipment operators, the 3rd Generation Partnership Project (3GPP) began research work on home base stations (HNBs). HNB refers to a small, small base station for home or office. It can be completely private. It can also be opened to the public with different priorities and permissions. Its ownership is private, not government or operation. Business. Using HNB to achieve wireless access, it can better utilize existing network resources, save more network equipment operators' costs, and combine the advantages of mobile access networks and fixed access networks.

In the System Architecture Evolution/Long Term Evolution (SAE/LTE) network, the S1 interface is an interface between an evolved radio access network (eUTRAN) and a core network node (CN Node). The control plane interface S1-CP and the user plane interface S1-UP; In practical applications, the Stream Control Transmission Protocol (SCTP) is used as a transmission protocol for transmitting point-to-point SI interface control plane signaling. The Mobility Management Entity (MME) is the entity responsible for the mobility management of the control plane in the network architecture. When the MME and the eNodeB need to communicate, it is necessary to establish SCTP Association between them (SCTP Association). The following rules are provided: (1) The common messages are identified by a pair of SCTP Stream Identifiers, that is, a downlink common signaling transmission identifier and an uplink common signaling transmission identifier; Dedicated messages are identified using at least one pair of SCTP flow identifiers, i.e., at least one downlink dedicated signaling transport identifier and at least one uplink dedicated signaling transport identifier. Each stream identification pair A stream should be coupled to SCTP.

After the introduction of HNB in eUTRAN, there will be thousands of HNBs in the communication network, and each HNB needs to establish SCTP coupling to the MME. Then, for the MME, if too many HNBs are directly connected to the MME, the number of SCTP couplings on the MME is very large, and the MME resources are seriously consumed, and the MME will be overwhelmed; and at the same time, the HNB may be powered off and restarted at any time. This will cause the SCTP coupling between the HNB and the MME to be continuously established or shut down, which will also cause a great impact on the MME and aggravate the processing load of the MME. Summary of the invention

Embodiments of the present invention provide a data packet forwarding method and apparatus, a data packet generating apparatus, and a communication system.

The embodiment of the invention uses the following technical solutions:

A data packet forwarding method includes: receiving a first data packet sent by a message sending end by using a first transmission protocol signaling channel, where the first data packet includes a message receiving end identifier and an application layer message; selecting and receiving the message The second transmission protocol signaling channel corresponding to the end identifier; the second data packet is sent to the message receiving end by using the second transmission protocol signaling channel, where the second data packet includes the application layer message.

A data packet generating apparatus includes:

a message receiving end selecting unit, configured to obtain a message receiving end identifier;

a packaging unit, configured to generate a first data packet, fill a message receiving end identifier obtained by the message receiving end selecting unit at a receiving end of the first data packet, and encapsulate an application layer message in the first In the packet.

A packet forwarding device includes:

a data packet receiving unit, configured to receive a first data packet sent by the message sending end by using a first transmission protocol signaling channel, where the first data packet includes a message receiving end identifier and an application layer message;

a channel selection unit, configured to select a second transmission protocol signaling channel corresponding to the message receiving end identifier; a data packet sending unit, configured to send, by using the second transmission protocol signaling channel, a second data packet to the message receiving end, where the second data packet includes an application layer in the data packet received by the data packet receiving unit Message.

A communication system comprising:

a packet sending device, configured to acquire a message receiving end identifier, generate a first data packet, fill the message receiving end identifier at a preset location of the first data packet, and encapsulate the application layer message in the first The data packet is further configured to send the first data packet to the data packet forwarding unit;

a packet forwarding device, configured to receive a first data packet sent by the data packet sending device by using a first transmission protocol signaling channel, where the first data packet includes a message receiving end identifier and an application layer message; The message receiving end identifies a corresponding second transmission protocol signaling channel; and sends a second data packet including the application layer message to the message receiving end by using the second transmission protocol signaling channel.

It can be seen from the above technical solution provided by the embodiment of the present invention that after the HNB is introduced in the communication system, the network node that communicates with the HNB and the forwarding are established because the transmission protocol signaling channel between the HNB and the network node that forwards the data packet is respectively established. The transport protocol signaling channel between the network nodes of the data packet does not directly establish a transport protocol signaling channel between the HNB and the network node communicating with the HNB, so that the transmission on the network node communicating with the HNB is not excessively increased. The number of protocol signaling channels, thereby reducing the signaling connection processing load of the network node communicating with the HNB; and since the HNB does not establish a transmission protocol signaling channel to the network node communicating with the HNB, the HNB frequently restarts and powers down It does not impact the network nodes that communicate with the HNB.

DRAWINGS

1 is a schematic flowchart of Embodiment 1 of a data packet forwarding method according to an embodiment of the present invention; FIG. 2 is a schematic flowchart of Embodiment 2 of a data packet forwarding method according to an embodiment of the present invention; FIG. 3 is a schematic diagram of an S1 interface according to an embodiment of the present invention; FIG. 4 is a schematic structural diagram of an SCTP protocol field according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of another embodiment of an S1 interface control plane protocol stack according to an embodiment of the present invention; Figure

6 is a schematic structural diagram of an embodiment of an X2 interface control plane protocol stack according to an embodiment of the present invention; FIG. 7 is a schematic structural diagram of an MBMS system in an evolved network according to an embodiment of the present invention;

8 is a schematic flowchart of a third embodiment of a data packet forwarding method according to an embodiment of the present invention; FIG. 9 is a schematic structural diagram of an IPv6 SCTP data packet according to an embodiment of the present invention; FIG. 10 is a schematic structural diagram of a heartbeat test request message according to an embodiment of the present invention; Schematic diagram

11 is a schematic flowchart of Embodiment 4 of a data packet forwarding method according to an embodiment of the present invention; FIG. 12 is a schematic structural diagram of a data packet generating apparatus according to an embodiment of the present invention;

FIG. 13 is a schematic structural diagram of an embodiment of a data packet forwarding apparatus according to an embodiment of the present invention;

FIG. 14 is a schematic structural diagram of an embodiment of a communication system according to an embodiment of the present invention.

detailed description

The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

As shown in FIG. 1, the first embodiment of the data packet forwarding method provided by the embodiment of the present invention includes: Step 101: Receive a data packet from a message sending end, and the data packet is transmitted through a pre-established signaling channel of the first transmission protocol with the message sending end. And including the message receiving end identifier and the application layer message; wherein, the data packet may be an SCTP data packet, a TCP data packet, or the like. When the data is an SCTP data packet, the first transmission protocol signaling channel is a first SCTP coupling, according to the SCTP data. Packets of different message types need to be sent through the first SCTP coupling corresponding to the message type. The application layer message is different according to the interface between the message sender and the message receiver. For example, it can be the S1 application layer (S1-AP) message of the S1 interface, the M2 application layer (M2-AP) message of the M2 interface, M3. M3 application layer (M3-AP) message of interface, X2 application layer (X2-AP) message of X2 interface, etc.

The message receiving end identifier may be stored in a preset position of the message receiving end of the data packet, such as: a transport network layer message of the data packet, a reserved field not used in the transport network layer message, and a Payload Protocol Identifier field (PPI). Or extend the SCTP Data Chunk Header, etc.; you can also select a partial field to save the message in the User Data field. Receiver identification. Of course, other existing fields can also be extended, and the message receiving end identifier is saved in the expanded field. It can also be encapsulated in the application layer message of the packet, and the application layer message is encapsulated in the User Data field of the packet.

The message receiving end may be an HNB, an MME, a Multi-cell/Multicast Coordination Entity (MCE), and a Multimedia Broadcast/Multicast Service Gateway (MBMS GW) in the eUTRAN system. Wait.

The identifier of the message receiving end may be an address of the message receiving end, such as an IPV4 address, an IPV6 address, etc., and may also be other information that can distinguish the receiving end of the message, such as a unique number of the message receiving end in the system. The message receiving end identifier may be an identifier that is unique in the entire communication system, or may be an identifier that is valid in a local scope, or may even be an identifier that is valid in an entity that forwards the data packet; the smaller the range, the network entity The smaller the number, the smaller the number of identifiers can be used to distinguish different network entities. Therefore, when there is not much space available for the data packet, the locally valid identifier can be preferred.

The data packet sent by the message sending end can be generated by the following process: Obtaining the message receiving end identifier of the message receiving end, filling the message receiving end identifier at the receiving end of the data packet, and packaging the application layer message into the data packet from the message sending end. The message sending end may obtain the message receiving end identifier from any network node that is identified by the message receiving end; or may obtain the message receiving end identifier from the pre-saved message receiving end list. The message receiver identifier in the message receiving list can be saved in advance or in the previous packet forwarding process.

Step 102: Select a second transmission protocol signaling channel corresponding to the identifier of the message receiving end. The data packet needs to be forwarded to the message receiving end by using the transmission protocol signaling channel. Therefore, the corresponding second transmission protocol needs to be selected according to the identifier of the message receiving end. Signaling channel

Specifically, the receiver identifier and the application layer message are encapsulated in a fixed field of the data packet, so that the data packet from the message sending end can be parsed, and the message receiving end identifier and the application layer message can be obtained after parsing; Which fixed field of the data packet can be pre-agreed, therefore, after receiving the data packet sent by the message sending end, it can directly from the pre-agreed fixed field. Extract message receiver ID and application layer messages.

After parsing the identifier of the message receiving end, the second transmission protocol signaling channel corresponding to the identifier of the message receiving end may be searched from the preset transmission protocol signaling channel information table, and the preset transmission protocol signaling channel information table is saved. There is a corresponding relationship between the message receiving end identifier and the transmission protocol signaling channel. Therefore, after the identifier of the message receiving end is parsed, the corresponding transmission protocol signaling channel can be found.

Step 103: Send, by using a second transmission protocol signaling channel, a data packet including an application layer message to the message receiving end.

The data packet sent to the message receiving end is re-encapsulated, specifically encapsulated according to the requirements of the transmission protocol used by the second transmission protocol signaling channel, where the application layer message is encapsulated in the user data field.

When the second transmission protocol signaling channel is the second SCTP coupling, the specific sending process may be: identifying the message type of the data packet, selecting a flow corresponding to the message type from the second SCTP coupling; and applying the layer message Encapsulated in a new data packet, the new data packet is sent to the message receiving end by the flow from the second SCTP coupling;

It should be noted that, in the embodiment of the present invention, the first transmission protocol signaling channel and the second transmission protocol signaling channel may be signaling transmission channels of different protocols, or may be the same signaling transmission channel, that is, the first transmission. The protocol signaling channel and the second transport protocol signaling channel may be an SCTP coupling, or a Transmission Control Protocol (TCP) signaling channel, or a combination of an SCTP coupling and a TCP signaling channel.

In order to enable different types of messages to be transmitted through different streams on the SCTP coupling, after selecting the second SCTP coupling, it is also necessary to identify the message type of the data packet, thereby selecting the second SCTP coupling corresponding to the message type. Stream. The specific identification of the packet message type may be determined according to the flow of the data packet transmitted on the first SCTP, or may be determined according to the indication of the PPI field in the data packet; if the flow identifier is included in the data packet, the data identifier may be directly The stream identifier selects the corresponding stream. After the stream on the second SCTP coupling is determined, the new data packet can be sent to the message receiving end through the stream, and the message receiving end corresponds to the message receiving end identifier. As can be seen from the above, according to the data packet forwarding method provided in this embodiment, after the ΗΝΒ is introduced in the communication system, the network node that communicates with the ΗΝΒ is established because the transmission protocol signaling channel between the network nodes that respectively ΗΝΒ and forward the data packet is established. The transport protocol signaling channel between the network nodes that forward the data packet does not directly establish the transport protocol signaling channel between the network node and the network node that communicates with the network, so that the network node on the network node that communicates with the network is not excessively increased. Transmitting the number of protocol signaling channels, thereby reducing the signaling connection processing load of the network node that communicates with the network; and because the transmission protocol signaling channel to the network node communicating with the network is not established, the frequent restart and disconnection of the network Electricity does not impact network nodes that communicate with ΗΝΒ.

The following describes the second embodiment of the data packet forwarding method of the present invention. As shown in FIG. 2, the method includes the following steps: Step 201: Receive a data packet from a message sending end, where the data packet is transmitted through a pre-established signaling channel of the first transmission protocol with the message sending end. The message receiving end identifier and the application layer message are included; Step 202: Obtain a message sending end identifier of the message sending end;

The message sender can be an HNB, MME, MCE, MBMS GW, etc. in the eUTRAN system.

When the data packet sent by the sender of the message includes the identifier of the sender of the message, the packet can be directly parsed and the identifier of the sender of the message is obtained. When the message sender identifier is stored in the transport network layer message of the data packet, such as in a reserved field such as PPI, or in the non-application layer message part of the user data field, the network layer message can be directly transmitted from the data packet. Extracting; When saving in the application layer message part of the user data field, the message sender identifier can be extracted from the application layer message. The save location of the message sender identifier may be saved in a similar location to the message receiver identifier, or may be different from the save location identified by the message receiver. When the data packet sent by the message sending end includes the message sending end identifier, the message sending end acquires the message sending end identifier when generating the data packet, and fills in the message sending end identifier in the preset position of the sending end of the data packet.

When the data packet sent by the message sending end does not include the message sending end identifier, the message sending end identifier may be obtained by: determining the message sending end identifier according to the first transmission protocol signaling channel, because each of the two ends corresponding to the coupling Are all ok, so the first transmission protocol signaling channel is connected After receiving the data packet from the message sender, it can determine the message sender identifier of the message sender. The message sender identifier may be stored in the same corresponding relationship table at the same time as the message receiver identifier and the corresponding coupled identifier.

The message receiving end can also obtain the message sending end identifier by using the common channel of the message sending end, and the common channel is independent of the transmission protocol signaling channel, and is used for transmitting the control information or the public information. The embodiment of the present invention can expand the common channel. Therefore, the message sender identifier can be obtained through the common channel of the message receiving end and the message sending end.

Of course, the manner in which the message sender end identifier is obtained is not limited in the embodiment of the present invention.

Step 203: The second transmission protocol signaling channel corresponding to the identifier of the message receiving end is selected. Step 204: Send the data packet including the application layer message and the message sending end identifier to the message receiving end by using the second transmission protocol signaling channel.

In the embodiment of the present invention, the application layer message and the message sending end identifier may be placed in the same data packet and sent to the message receiving end, and the intermediate node does not need to obtain the message sending end identifier or re-encapsulate the message sending end identifier. After receiving the data packet, the message receiving end obtains the message receiving end identifier.

In an actual application, the user data and the message sender identifier may be separately sent to the message receiving end. For example, the message sender identifier may be sent to the message receiving end through a separate data packet; The message sending end identifier may be sent to the message receiving end through the common channel of the message receiving end. Alternatively, the message sending end may directly send the message sending end identifier to the message receiving end through the common channel with the message receiving end.

In the embodiment of the present invention, the message sending end identifier is sent to the message receiving end, so that after receiving the data packet, the message receiving end can know which network entity the data packet is from, so that when the data packet needs to be sent to the message sending end, it can be determined. To which network entity is sent, the entity that forwards the data packet can determine which network entity to forward the data packet to, and improve the reliability of the communication.

When the transport protocol signaling channel is SCTP coupled, the network nodes that forward the data packets are aggregated. All SCTP couplings from the HNB to the MME can be referred to as SCTP aggregation nodes (SAGN: SCTP Aggregation Node) when the network node that forwards the data packet joins the communication network. „ After adding SAGN to the eUTRAN network architecture, it may not be directly Establish SCTP coupling between HNB and MME, and establish SCTP coupling between HNB and SAGN, and SCTP coupling between SAGN and MME, so that HNB and MME are linked by SAGN. It should be noted that in order to maintain The consistency of the macro base station, such as the macro base station in the 3rd Generation Partnership Project (3GPP), the establishment of SCTP coupling between SAGN and MME can be initiated by SAGN; and because HNB frequently restarts and powers off, between HNB and SAGN The establishment of SCTP coupling can be initiated by HNB. In practical applications, generally HNB-online will establish SCTP coupling with SAGN; similarly, SAGN will also establish MME to the MME when it can establish SCTP coupling to MME. SCTP coupling.

Since the SAGN is added to the network architecture, the original control plane protocol stack structure needs to be improved. The structure of the S1 interface control plane protocol stack is as shown in FIG. 3: The protocol stack structure of the HNB and the MME does not change; The concept of "upper entity" is introduced on the SCTP layer of SAGN. The "upper entity" can have an SCTP Control Function (SCTP Control Function) whose main purpose is to implement the SCTP protocol. Below the SCTP layer is the IP layer. User data and signaling between the MME and the SAGN and between the SAGN and the HNB are routed through the IP layer. The bottom two layers of the protocol stack, the MME and SAGN, and the LI and L2 layers between the SAGN and the HNB are the physical layer and the data link layer. Any technology capable of carrying the IP protocol can be used, for example: Ethernet, ATM or Brand rings, etc.

The Radio Access Network Application Protocol (RANAP) entity in the HNB and MME protocol stacks is a S1-CP application partial protocol. SCTP belonging to the transport layer and network layer (TNL: Transport Network Layer), SCTP belonging to the wireless control network layer _{(RNL: Radio Network Layer) 0} " layer entity" role include:

1) Implement partial SCTP control function, which means that through the primitive interaction with SCTP, each field in the SCTP packet header can be parsed, user data can be extracted; and other SCTP management functions can be completed. For example, the establishment of SCTP coupling is closed, congestion control, and the like. 2) If the upper layer entity wants to further process the application layer protocol filled in the user data, it needs to include an application layer protocol processing function, such as an evolved radio access network application protocol (eRANAP) functional entity that processes the S1-AP message. . Both the sender identifier and the receiver identifier can be encapsulated in the application layer message.

In the control plane protocol stack, for the MME and the HNB, after the two SCTP couplings between the SAGN and the MME and between the SAGN and the HNB are successfully established, the application layer information is directly exchanged between the MME and the HNB; For SAGN, after establishing SCTP coupling between SAGN and HNB, SAGN can obtain the information necessary for SCTP forwarding, such as HNB ID, etc. After establishing SCTP between SAGN and MME, SAGN can be obtained for SCTP forwarding. Required information, such as MME ID. Among them, the SAGN can obtain the information necessary for forwarding through the management class message between the SAGN and the HNB (MME), and can also obtain the information necessary for forwarding through the SCTP message.

The S1-AP message is an Initial UE Message, and the structure of the Initial UE Message carrying the identifier of the message sender is as shown in Table 1:

Table 1

The SCTP protocol field may be extended in the embodiment of the present invention. The length of the SCTP DATA Chunk Header in the SCTP DATA Chunk of the SCTP protocol is 4 bytes. The field is extended by the field, and the "Extended SCTP Data Chunk Header" field is added. As shown in Figure 4, The length of this field can be defined according to actual needs. The extension field may carry additional information (which may include, but is not limited to: the identity or address information of the message sender, the identity of the message receiver or the address information), which the SAGN can use to route the packet to the correct message receiver.

Another S1 interface control plane protocol stack structure is shown in Figure 5. The protocol stack structure of HNB, SAGN, and MME changes, on the SCTP layer of the SAGN protocol stack, and the SCTP layer and S1-AP of the HNB and MME. In the middle of the layer, the router routing layer is added. The protocol layer can carry additional information (including but not limited to: the identifier or address information of the message sending end, the identifier or address information of the message receiving end), and the SAGN can use the information to route the data packet to the correct one. The message receiving end. Functionally, the Router layer and the SCTP layer and the lower layers belong to the TNL layer in the wireless communication network, and the S1-AP still belongs to the RNL layer. The SAGN receives the SCTP data packet from the message sender, parses the additional information from the router routing layer message, determines the correct message receiver, and then repackages the data packet to the message receiver. The process of parsing the packet and encapsulating the packet by the SAGN is transparent to the S1-AP part, that is, the S1-AP packet can be transparently transmitted from the message sender to the message receiver.

The above description is the case where the MME and the HNB are S1 interfaces. In actual applications, if there are multiple LTE HNBs and LTE HNBs, or between LTE HNBs and Evolved Network Base Stations (eNBs: E-UTRAN NodeBs) When the X2 interface is connected, an intermediate forwarding node may be added between the LTE HNB and the LTE HNB or the LTE HNB and the eNB. For example, the LTE HNB and the eNB are not directly used. Establishing the coupling between the LTE HNB and the eNB, and establishing the SCTP coupling between the LTE HNB and the intermediate forwarding node, and the SCTP coupling between the intermediate forwarding node and the eNB, thereby reducing the number of SCTP couplings on the eNB, thereby The processing load of the eNB is reduced, and the collision of the LTE HNB with the eNB can be reduced.

The X2 protocol stack provided by the embodiment of the present invention is as shown in FIG. 6 after the LTE HNB and the eNB are X2 interfaces. The physical layer and the data link layer are included in the data layer. Link Layer), IP layer and SCTP layer, and X2-AP control function is introduced on the SCTP layer to implement X2-AP processing function.

An X2-AP message is a handover request (HO-REQUEST) message, at HO-REQUEST The message carrying the message sender is as shown in Table 2:

Table 2

When the intermediate forwarding node is introduced between the LTE HNB and the eNB, the message transmission between the LTE HNB and the eNB is similar to the message transmission process when the SAGN is added between the HNB and the MME, except that the interface between the LTE HNB and the eNB is an X2 interface. Therefore, the transmission and processing of the intermediate data must conform to the requirements of the X2 interface, and will not be described here.

Further, in the evolved network, for the evolved multimedia broadcast/multicast service (MBMS: Multimedia Broadcast/Multicast Service), the system structure is as shown in FIG. 7: The MBMS GW is connected to the MCE through the M3 interface, and the MCE is connected to the eNB through the M2 interface. Connected, the eNB connects to the MBMS GW through the M1 interface. The eNB may also be an LTE HNB. The following uses an eNB as an example.

The MCE may exist as an independent physical node or may be located in the eNB. At this time, the M3 interface is directly connected to the eNB. And the M2 and M3 interfaces use the SCTP protocol. There may be too many M2 interfaces between the MCE and the eNB, or there may be too many M3 interfaces between the MBMS GW and the eNB. Taking the M2 interface between the MCE and the eNB as an example, the MCE and the eNB The number of SCTP couplings between the two is also increased. Therefore, in order to reduce the processing load of the MCE and reduce the impact of the eNB on the MCE, an intermediate forwarding node may be newly added between the MCE and the eNB, and its function is similar to that of the SAGN. The information transmission process after the intermediate forwarding node is added between the MCE and the eNB is similar to the process of adding the SAGN information between the HNB and the MME, and is not described here. Only because it is an M2 interface, the intermediate message transmission and processing process needs to meet the requirements of the M2 interface. The same is true for the M3 interface as in the case of the M2 interface.

An M2-AP message is a session start (SESSION START) message, and the message sender information is carried in the SESSION START message as shown in Table 3:

table 3

Some scenarios that can be applied in the embodiments of the present invention are described above.

The process of adding SAGN to the S1 interface between the HNB and the MME is described. When applied to the X2 interface, the M2 interface, and the M3 interface, the processing procedure is similar to that of the S1 interface.

A third embodiment of the present invention is described with reference to FIG. 8. In this embodiment, the HNB sends a message to the MME as an example. The process includes:

Step 701: The HNB generates an SCTP data packet including an MME identifier and an S1-AP message, and sends the SCTP data packet to the SAGN by coupling with the first SCTP of the SAGN.

The MME identifier is the identifier of the message receiving end. The selected MME identifier can be filled in the PPI field in the SCTP data packet. The SAGN uses the PPI field to determine the structure of forwarding the data packet to the SCTP data packet using IPv6 as an example. As shown in FIG. 9, it mainly includes an IPv6 header (SC6 Header), an SCTP Common Header (SCTP Common Header), and an SCTP Data Chunk (SCTP Data Chunk), wherein the IPv6 Header includes a source address (Source Address) and a destination address (Destination Address and other information, source address and destination address occupy 128 bits (bit); SCTP Common Header includes information such as source port and destination port; SCTP Data Chunk includes stream ID (Stream Id), stream Information such as sequence number (Stream Sequence Number), PPI, and User Data; Figure 9 illustrates the case of IPv6. For IPv4 or other protocols, only the IP header or other protocol headers are different. The SCTP part is described in Figure 9. It is consistent and will not be described in this manual. In the embodiment of the present invention, the S1-AP message is encapsulated in the User Data; the HNB identifier and/or the MME identifier may be filled in the TNL layer, may be filled in the PPI field, or may be filled in the User Data; or may be filled in the RNL layer. That is, it can be encapsulated in the S1-AP message, the specific padding in which field can be preset, and the HNB identifier and the MME identifier can be filled in different fields of different layers.

The information about the SAGN needs to be obtained before the HNB sends the SCTP data packet to the SAGN. The information about the SAGN can be obtained as follows: 1) If the information of the SAGN is stored in the network management system, the HNB can be notified to the HNB by the entity in the network management system. 2) The HNB can be notified by any network node that knows the information of the SAGN in the network; 3) the information of the SAGN can be added to the configuration information of the HNB, and the configuration information can be updated; after the information of the SAGN is obtained, the corresponding information is selected. The first SCTP coupling, the SCTP data packet is sent to the SAGN by the corresponding stream on the first SCTP coupling.

Step 702: After receiving the SCTP data packet, the SAGN processes the data packet by the SCTP layer of the SAGN.

Step 703: The SCTP layer parses the SCTP data packet, extracts the MME identity from the preset location of the data packet, and extracts the S1-AP message and the flow identifier. The flow identifier corresponds to the message type.

The SCTP layer of the SAGN needs to extract the MME identifier from the SCTP data packet. Therefore, the SCTP layer of the SAGN needs to have the processing function of the SCTP data packet. If the MME identifier is encapsulated in the S1-AP message, the SCTP layer of the SAGN needs to further have the S1. - The processing function of the AP message; therefore, in order to reduce the processing load of the SAGN, the MME identity may be optionally encapsulated in a non-S1-AP message. The SCTP layer does not need to extract the HNB identifier, so the HNB identifier can be encapsulated in the S 1 -AP message; and the SCTP layer of the SAGN needs to send the HNB identifier to the MME, if the HNB The identifier is not encapsulated in the S1-AP message, and the HNB identifier needs to be extracted and re-populated in the SCTP data packet sent to the MME. However, the HNB identifier is not encapsulated in the S1-AP message, but directly By encapsulating the S 1 -AP message, the HNB identifier can be sent to the MME, which can reduce the processing steps of the SCTP layer of the SAGN. Therefore, in an actual application, the message sending end identifier (the HNB identifier in this embodiment) may be encapsulated in the S1-AP message, that is, the RNL layer; and the message receiving end identifier (the MME identifier in this embodiment) is encapsulated in In addition to the other fields of the S1-AP message, the TNL layer. Therefore, the SCTP layer of the SAGN can obtain the message receiving end identifier without parsing the S1-AP message, and then forward the data packet to the message receiving end. It can be understood that the message receiving end identifier and the message sender identifier can be filled in any field of the SCTP data packet as long as the space of the field is sufficient.

Step 704: The SCTP layer sends the MME identifier, the parsed S1-AP message, and the flow identifier to the SCTP control function layer.

The SCTP layer may use the primitive to send information such as the MME identifier to the SCTP control function layer, where the primitive is a program written by machine instructions to perform a specific function;

Step 705: The SCTP control function layer selects a second SCTP coupling corresponding between the SAGN and the MME according to the MME identifier.

After the SCTP coupling between the SAGN and the MME is established, the SAGN saves the relevant information, so that the corresponding second SCTP coupling can be determined by the MME identifier;

Step 706: The SCTP control function layer selects a corresponding stream in the second SCTP coupling according to the flow identifier. Different types of data packets are sent through different flows, so that the data packet to be forwarded may be associated with the corresponding flow according to the flow identifier. stand up;

In an actual application, the corresponding stream may be selected according to the message type indication obtained from the PPI field according to the correspondence between the pre-configured message type and the flow identifier.

Step 707: Encapsulate the S1-AP message into a user data field of the new SCTP data packet; the new data packet uses the message receiving end as a destination node.

Step 708: Send a new SCTP packet by using the selected stream in the second SCTP coupling To the MME.

Preferably, in step 701, after the HNB selects the MME, the HNB can also detect whether the MME is online, so as to determine whether the sent SCTP data packet can be received by the MME. In general, SCTP packets are generated and sent only when the MME is judged to be online. If it is determined that the MME is not online, the SCTP data packet may be processed according to a preset processing method, for example, directly discarding the SCTP data packet, or waiting for a period of time to re-detect whether the MME is online, and when detecting that the MME is online, The SCTP data packet is sent; or the SCTP data packet may be sent directly, but the identifier that detects that the MME is offline is carried in the SCTP data packet, and is processed by the SAGN; of course, other processing manners may also be used. The embodiment does not limit the manner of detecting that the MME is offline.

Specifically, the heartbeat test can be used to detect whether the MME is online, and the heartbeat test request message is sent directly to the MME. If the response message is not received after sending the test message for a period of time, or a certain number of test messages are sent, the response is not received. It is determined that the MME is not online; the heartbeat test is generally performed periodically, but the case where the heartbeat detection is triggered by an event or an event in an actual application is not excluded; it should be noted that the heartbeat test between the HNB and the MME is as specified by the SCTP protocol. The heartbeat test is different. The heartbeat test specified by the SCTP protocol is performed between the two parties that established SCTP coupling, and the two sides of the heartbeat test here do not establish SCTP coupling. The following is a method for detecting the status information of the peer node by using the node MME at the end of the S1 interface to detect whether the peer node HNB is online. The specific process is as follows:

Step 1: The SAGN checks whether the HNB is online through the heartbeat test specified by the SCTP protocol. The method for the heartbeat test is specifically as follows: The SAGN periodically sends a heartbeat message to the HNB to monitor the reachability of the HNB.

Step 2: The SAGN may report the status information of the HNB to the MME through a dedicated message, or modify the heartbeat request message defined by the SCTP protocol, and fill the HNB status information in the field to send to the MME, as shown in FIG. The length of the Sender-specific Heartbeat Info field in the Heartbeat Request message is variable. SAGN can set the preset conditions for sending this message, for example, by setting a timer. After the timer expires, the status information of the HNB is sent to the MME, or a cycle time is set, and if the number of times the HNB is offline does not exceed the preset threshold of the number of non-response, the MME is sent to the MME. The status information of the HNB is reported, where the status information of the HNB may be the information of the HNB that is not online, or the information of the online HNB, or the information of the two HNBs is sent;

The dedicated message may be a transport layer message or an application layer message, and the status information of the HNB includes the status of the HNB (online or offline), and may also include the address information of the HNB or the identifier of the HNB.

Step 3: The MME parses the dedicated message or the heartbeat request message sent by the SAGN, acquires the information of the HNB that is not online, and sends a response message to the SAGN. The sending, by the MME, the response message is an optional step. When the SAGN sends a heartbeat request message, the MME needs to determine the length of the heartbeat request message, so as to determine whether the information of the HNB is included in the message.

If the HNB wants to know whether the MME is online or not, it can also use a process similar to the above two methods, and details are not described herein again.

As can be seen from the above, in this embodiment, the data packet sent by the HNB to the MME can be forwarded through the SAGN, so that the HNB does not need to directly establish SCTP coupling with the MME, which reduces the number of SCTP coupling on the MME, and does not increase the MME. Processing load; Further, the restart and power-off of the HNB will not cause an impact on the MME. It should be noted that, in this embodiment, the HNB sends an SCTP data packet to the MME. In an actual application, the MME may send a SCTP data packet to the HNB, and may also use a process similar to the embodiment. Make a comment.

Referring to FIG. 11, a fourth embodiment of the packet forwarding method of the present invention is described. The SAGN forwards the SCTP data packet sent by the message sending end (MME in this embodiment) to the message receiving end (HNB in this embodiment). The process, wherein the embodiment describes the case where the SCTP coupling has been established, and thus the establishment process of the SCTP coupling is not described. The method includes:

Step 901: The MME generates an SCTP data packet that includes an HNB identifier and an application layer message, and sends the SCTP data packet by coupling with the first SCTP of the SAGN.

The HNB identifier is the identifier of the message receiving end. When the MME needs to send a data packet to the HNB, First, the data packet is sent to the SAGN, and then the SAGN forwards the received data packet to the HNB. Since the MME may be connected to multiple HNBs, when the MME sends a data packet to the HNB, it is necessary to include the HNB identifier in the SCTP data packet. The destination HNB may be identified by filling the selected HNB identifier in the preset location of the SCTP packet, and the SAGN determines, by using this field, which HNB the packet is forwarded to; wherein the MME obtains the information of the SAGN and the HNB The process of obtaining the information of the SAGN is similar, and is not described here. After obtaining the information of the SAGN, the MME selects the corresponding second SCTP coupling, and sends the SCTP data packet to the SAGN through the corresponding stream on the second SCTP coupling; After the HNB, it can also be judged whether the HNB is online according to the result of the heartbeat test;

Step 902: After receiving the SCTP data packet, the SAGN is handed over to the SCTP layer for processing;

Step 903: The SCTP layer parses the SCTP data packet, extracts the HNB identifier from the preset location of the receiving end, and extracts the application layer message and the flow identifier.

Step 904: The SCTP layer sends the parsed application layer message and the flow identifier to the application instance in the SCTP control function layer to process the HNB data, where the application instance may be a function module in the entity device.

In the SCTP control function layer, there is a corresponding application instance corresponding to each HNB and MME, and each application instance is corresponding to the HNB or the MME, so that the application instance can complete the SCTP data packet after receiving the corresponding data. Forwarding

Step 905: Associate a user data packet that needs to be forwarded with a second SCTP coupling between the SAGN and the HNB;

After the SCTP coupling between the SAGN and the MME is established, the SAGN saves the relevant information, so that the corresponding SCTP coupling can be determined by the MME identifier;

Step 906: The application instance that processes the HNB data selects a corresponding stream in the second SCTP coupling according to the flow identifier.

Different types of data packets are sent through different flows, so that the data packets that need to be forwarded can be associated with the corresponding flows according to the flow identifiers; In the actual application, the corresponding stream can be selected according to the message type indication obtained from the PPI and the corresponding relationship between the pre-configured message type and the flow identifier.

Step 907: Encapsulate the application layer message into the user data field in the new SCTP data packet. Step 908: Send the new SCTP data packet to the HNB by using the selected stream in the second SCTP coupling.

As can be seen from the above, in this embodiment, the data packet sent by the MME to the HNB can be forwarded through the SAGN, so that the HNB does not need to directly establish SCTP coupling with the MME, which reduces the number of SCTP coupling on the MME, and does not increase the MME. Processing load; Further, the restart and power-off of the HNB will not cause an impact on the MME. It should be noted that, in this embodiment, the MME sends the SCTP data packet to the HNB. In the actual application, the HNB sends the SCTP data packet to the MME, and the process similar to the embodiment may be used. Make a comment.

It should be noted that the foregoing embodiment only describes the case where there is only one transit node between two communication nodes. The processing when there are multiple transit nodes is similar to the processing of only one transit node, and this specification does not like it. Said.

The embodiments of the packet forwarding method provided by the embodiments of the present invention are described in detail above. The apparatus and system provided by the embodiments of the present invention are described below. Referring to FIG. 12, a first embodiment of a data packet generating apparatus according to an embodiment of the present invention is provided. The data packet generating apparatus includes:

a message receiving end selecting unit 1101, configured to acquire a message receiving end identifier;

The encapsulating unit 1102 is configured to generate a first data packet, fill the message receiving end identifier at a preset location of the first data packet, and encapsulate the application layer message in the data packet.

In order to allow the message receiving end of the received data packet to know which message transmitting end the data packet is from, the data packet generating apparatus provided by the embodiment of the present invention may further include:

The message sending end identifier obtaining unit 1103 is configured to obtain a message sending end identifier;

The encapsulating unit 1102 is further configured to fill the message sending end identifier at a preset position of the sending end of the data packet. Since different types of SCTP data packets correspond to streams on the SCTP coupling, the data packet generating unit may also stream selection unit 1104 for selecting the first SCTP coupling and in the first SCTP. Selecting, in the coupling, a stream corresponding to a message type of a data packet generated by the encapsulating unit;

In practical applications, the data packet generating apparatus may further include a data packet sending unit.

1105, configured to: when the message receiving end is online, send the generated data packet by using the stream in the first SCTP coupling selected by the stream selecting unit 1104, and also used to process the generated data according to a preset method when the message receiving end is not online. The data packet, wherein the preset processing method may be: directly discarding the SCTP data packet, or waiting for a period of time to re-detect whether the MME is online.

As can be seen from the above, the stream selection unit added in this embodiment can select the stream in the SCTP coupling for the transmission of the SCTP data packet, so that the transmission of the SCTP data packet conforms to the requirements of the SCTP protocol.

The data packet generating apparatus provided by the embodiment of the present invention may further include a message receiving end determining unit

1106, configured to determine, according to the result of the heartbeat test or the information received by the SAGN, whether the message receiving end is online; if yes, the trigger data packet sending unit 1105 sends the data packet; if not, processes the data packet according to the preset processing method. .

The message receiving end determining unit 1106 determines that the message receiving end is online and then sends the data packet, so that the message receiving end can receive the data packet, thereby improving the communication accuracy.

The data packet generating apparatus provided by the embodiment of the present invention may be an MME, an HNB, an MCE, an eNB, an MCE, an MBMS GW, and the like in the eUTRAN.

The data packet generating apparatus provided by the embodiment of the present invention causes the HNB to send a data packet through a transport protocol signaling channel between the network node of the forwarded data packet, and does not directly establish a transport protocol letter between the HNB and the network node that communicates with the HNB. The channel is so as not to excessively increase the number of transmission protocol signaling channels on the network node communicating with the HNB, reduce the signaling connection processing load of the network node that communicates with the HNB, and the HNB frequently restarts and powers off. It will impact network nodes that communicate with HNB.

Corresponding to the data packet forwarding method, the embodiment of the present invention provides a data packet forwarding device, as shown in FIG. 13, including:

a data packet receiving unit 1201, configured to receive a data packet from a message sending end, where the data packet is transmitted through a pre-established first transmission protocol signaling channel with the message sending end, including a message. Receiver identification and application layer messages;

The channel selection unit 1202 is configured to select a second transmission protocol signaling channel corresponding to the message receiving end identifier;

The channel selection unit 1202 further includes: a parsing unit 12021, configured to parse the data packet from the message receiving end, and obtain the message receiving end identifier and the application layer message;

The selecting unit 12022 is configured to search, from the preset transmission protocol signaling channel information table, a second transmission protocol signaling channel corresponding to the message receiving end identifier;

a data packet sending unit 1203, configured to send, by using a second transport protocol signaling channel, a data packet including an application layer message to a message receiving end;

The packet forwarding device provided by the embodiment of the present invention may further include:

The message sending end identifier obtaining unit 1204 is configured to obtain a message sending end identifier;

The data packet sending unit 1203 is further configured to send, by using the second transport protocol signaling channel, the data packet including the application layer message and the message sending end identifier to the message receiving end.

The node status information obtaining unit 1205 is configured to obtain status information of the message receiving end. When the preset condition is met, the notification data packet sending unit 1203 sends the status information of the message receiving end to the message sending end.

The data packet sending unit 1203 is further configured to send the status information of the message receiving end to the message sending end.

The content of the preset condition and the status information is the same as the setting in the method embodiment, and details are not described herein again.

As can be seen from the above, in the embodiment using the packet forwarding device, after the HNB is introduced in the communication system, the network node that communicates with the HNB and the forwarding are established due to the transmission protocol signaling channel between the HNB and the network node that forwards the data packet respectively. The transport protocol signaling channel between the network nodes of the data packet does not directly establish a transport protocol signaling channel between the HNB and the network node communicating with the HNB, so that the transmission on the network node communicating with the HNB is not excessively increased. The number of protocol signaling channels, which reduces The signaling connection processing load of the network node that communicates with the HNB is connected; and since the HNB does not establish a transmission protocol signaling channel to the network node that communicates with the HNB, the frequent restart and power-off of the HNB does not communicate with the HNB. Network nodes cause an impact. The packet forwarding device provided by the embodiment of the present invention may be an SAGN. It can be understood that the data packet forwarding device provided by the embodiment of the present invention can be used as a single network node; or can be integrated into an existing network node as a functional module of the existing network node. The location of the packet forwarding device provided by the embodiment of the present invention does not affect the implementation of the embodiment of the present invention. Therefore, the specific embodiment of the present invention does not limit the specific location of the packet forwarding device.

The embodiment of the invention further provides a communication system, as shown in FIG. 14, comprising:

a packet sending device 1301, configured to acquire a message receiving end identifier, generate a data packet, fill the message receiving end identifier at a preset location of the data packet, and encapsulate an application layer message in the data packet, and further Used to send the generated data packet to the packet forwarding unit 1302.

The packet forwarding device 1302 is configured to receive a data packet from the data packet sending device 1301, where the data packet is transmitted through a pre-established first transmission protocol signaling channel with the data packet sending device 1301, including a message receiving end identifier. And an application layer message; selecting a second transmission protocol signaling channel corresponding to the message receiving end identifier; and transmitting, by the second transmission protocol signaling channel, the data packet including the application layer message to the message receiving end.

The packet forwarding device may be an SAGN between the HNB and the MME, or an intermediate forwarding node between the eNB and the HNB, an intermediate forwarding node between the MCE and the eNB, an intermediate forwarding node between the MBMS GW and the eNB, and the like.

As can be seen from the present embodiment of the communication system, since the transport protocol signaling channel between the HNB and the network node that forwards the data packet can be separately established, the transport protocol between the network node communicating with the HNB and the network node forwarding the data packet The signaling channel does not directly establish a transmission protocol signaling channel between the HNB and the network node that communicates with the HNB, so that the number of transmission protocol signaling channels on the network node communicating with the HNB is not excessively increased, thereby reducing the number of transmission protocols with the HNB. The signaling connection processing load of the network node connecting the communication; and since the HNB does not establish the transmission to the network node communicating with the HNB The protocol signaling channel, so frequent restarts and power outages of the HNB do not impact the network nodes that communicate with the HNB.

The packet forwarding device 1302 is further configured to obtain a message sending end identifier of the message sending end, and send the message sending end identifier to the message receiving end by using the second SCTP coupling.

In a practical application, the communication system may further comprise a data packet receiving device for receiving a new data packet.

It can be understood that the embodiment of the present invention mainly uses the data packet transmission description between the HNB and the MME. In other scenarios, the data packet transmission process between the eNB and the HNB, the MCE and the HNB, and the data between the HNB and the MME are used. The packet transmission process is similar.

A person skilled in the art can understand that all or part of the steps of implementing the above embodiments can be completed by a program to instruct related hardware, and the program can be stored in a computer readable storage medium. , including the following steps:

Receiving a data packet from the message sending end, where the data packet is transmitted through a pre-established first transmission protocol signaling channel with the message sending end, including a message receiving end identifier and an application layer message; and selecting a corresponding to the message receiving end identifier a second transmission protocol signaling channel; transmitting, by the second transmission protocol signaling channel, a data packet including the application layer message to a message receiving end.

The above-mentioned storage medium may be a read only memory, a magnetic disk or an optical disk or the like.

The data packet forwarding method and apparatus, the data packet generating apparatus, and the communication system provided by the embodiments of the present invention are described in detail above. The foregoing description of the embodiments is only used to help understand the method of the embodiment of the present invention; The present invention is not limited to the embodiments of the present invention. The details of the present invention are not limited to the embodiments of the present invention.

Claims

Claim

A packet forwarding method, the method comprising:

Receiving, by the message sending end, the first data packet sent by the first transmission protocol signaling channel, where the first data packet includes a message receiving end identifier and an application layer message;

Selecting a second transmission protocol signaling channel corresponding to the message receiving end identifier;

Transmitting, by the second transmission protocol signaling channel, a second data packet to the message receiving end, where the second data packet includes the application layer message.

2. The method of forwarding data packets according to claim 1, wherein the method further comprises:

Obtain the sender ID of the message;

Sending the message sender identifier to the message receiving end.

3. The packet forwarding method according to claim 2, wherein:

The message sending end identifier is encapsulated in an application layer message of the first data packet.

The data packet forwarding method according to claim 2, wherein the sending the message sending end identifier to the message receiving end is:

And transmitting, by the second transmission protocol signaling channel, the message sending end identifier to the message receiving end.

5. The packet forwarding method according to claim 4, wherein:

The message sending end identifier is encapsulated in a transport network layer message of the first data packet; or

The message sending end identifier is encapsulated in a routing layer message of the first data packet.

The packet forwarding method according to claim 4, wherein the identifier of the sending message is specifically:

And obtaining, according to the first transmission protocol signaling channel, or the common channel of the message sending end, the sending end identifier.

7. A packet forwarding method according to any of claims 1-6, characterized in that The second transmission protocol signaling channel corresponding to the identifier of the message receiving end is specifically: parsing the first data packet, and acquiring the message receiving from a preset location of the receiving end of the first data packet End identifier

And obtaining, by the preset transmission protocol signaling channel information table, a second transmission protocol signaling channel corresponding to the identifier of the message receiving end.

The data packet forwarding method according to claim 7, wherein the preset location of the receiving end of the first data packet is a transport network layer message, a flow control transport protocol data block header of the transport network layer, and a routing layer. Any of the application layer messages in the message, user data, and user data.

The packet forwarding method according to claim 1, wherein the method further comprises:

Obtaining status information of the message receiving end;

Sending status information of the message receiving end to the message sending end.

The packet forwarding method according to claim 9, wherein the sending the status information of the message receiving end to the message sending end is:

Set the cycle time;

If the number of times the receiving end is offline exceeds the threshold in the period of time, the status information of the message receiving end is sent to the message sending end.

Set a timer;

If the timer expires, the status information of the message receiving end is sent to the message sending end.

The packet forwarding method according to claim 10 or 11, wherein the sending the status information of the message receiving end is:

Sending, to the message receiving end, a dedicated message, where the dedicated message includes status information of the message receiving end;

Or sending a heartbeat test request message to the message receiving end, where the heartbeat test request message Contains status information of the message receiving end.

13. The packet forwarding method according to claim 1, wherein:

The application layer message is any one of an application layer message of the S1 interface, an application layer message of the M2 interface, an application layer message of the M3 interface, and an application layer message of the X2 interface.

The data packet forwarding method according to claim 1, wherein the first transmission protocol signaling channel is any one of a flow control transmission protocol coupling, an internet protocol signaling channel, or a transmission control protocol signaling channel. ;

The second transmission protocol signaling channel is any one of a flow control transmission protocol coupling, an internet protocol signaling channel, or a transmission control protocol signaling channel.

15. A data packet generating apparatus, comprising:

a message receiving end selecting unit (1101), configured to acquire a message receiving end identifier;

The encapsulating unit (1102) is configured to generate a first data packet, fill in a message receiving end identifier obtained by the message receiving end selecting unit at a receiving end of the first data packet, and encapsulate the application layer message in the Said in the first data packet.

The data packet generating apparatus according to claim 15, further comprising: a message sending end identifier obtaining unit (1103), configured to acquire a message sending end identifier;

The encapsulating unit is further configured to fill in a message sending end identifier acquired by the message sending end identifier obtaining unit at a preset position of the sending end of the first data packet.

17. The data packet generating apparatus according to claim 15 or 16, further comprising: a stream selection unit (1104) for selecting a first SCTP coupling and selecting and cooperating in the first SCTP coupling a stream corresponding to a message type of the first data packet;

a packet sending unit (1105), configured to: when the message receiving end is online, send the first data packet by using the stream selected by the stream selecting unit, when the message receiving end is not online, according to the pre- The method of processing the first data packet.

18. A packet forwarding device, the device comprising:

a data packet receiving unit (1201), configured to receive a message sending end by using a first transmission protocol signaling channel The first data packet is sent, the first data packet includes a message receiving end identifier and an application layer message, and the channel selecting unit (1202) is configured to select a second transmission protocol signaling channel corresponding to the message receiving end identifier;

a data packet sending unit (1203), configured to send, by using the second transmission protocol signaling channel, a second data packet to the message receiving end, where the second data packet includes the data packet received by the data packet receiving unit Application layer message.

The device of claim 18, wherein the device further comprises:

a message sending end identifier obtaining unit (1204), configured to obtain a message sending end identifier;

The data packet sending unit is further configured to send, by using the second transmission protocol signaling channel, the message sending end identifier acquired by the message sending end identifier obtaining unit to the message receiving end.

20. Apparatus according to claim 18 or claim 19 wherein said channel selection unit (1202) comprises:

a parsing unit (12021), configured to parse the first data packet, to obtain the message receiving end identifier, and a selecting unit (12022), configured to search and receive the message from the preset transport protocol signaling channel information table The end identifier corresponds to a second transmission protocol signaling channel.

The packet forwarding device according to claim 18 or 19, wherein the device further includes a node state information acquiring unit (1205), configured to acquire state information of the message receiving end, when the preset condition is met, Sending a notification message to the data packet sending unit;

The data packet sending unit is further configured to send the status information to the message sending end according to the notification message sent by the node status information acquiring unit.

22. A communication system, comprising:

a packet sending device (1301), configured to acquire a message receiving end identifier, generate a first data packet, fill the message receiving end identifier at a preset location of the first data packet, and encapsulate the application layer message in the The first data packet is further configured to send the first data packet to a data packet forwarding unit;

a packet forwarding device (1302), configured to receive a first data packet sent by the data packet sending device by using a first transmission protocol signaling channel, where the first data packet includes a message receiving end identifier and an application a layer message; selecting a second transmission protocol signaling channel corresponding to the message receiving end identifier; sending, by the second transmission protocol signaling channel, a second data packet including the application layer message to the message receiving end.

The communication system according to claim 22, wherein the data packet forwarding device (1301) is further configured to acquire an identifier of the data packet sending device, and use the second transmission protocol signaling channel to The message receiving end sends the identifier of the data packet sending device.