WO2013178014A1 - Site communication method, rtr and tunnel router - Google Patents

Abstract

A site communication method, Re-encapsulating Tunnel Router (RTR) and tunnel router are disclosed in the embodiment, wherein the site communication method comprises: after receiving the data packet, the RTR ensuring the source node and the destination node of the data packet are behind the same Network Address Translator (NAT) device, then sending an information notice message to the tunnel router (xTR) of the site in which the source node or the destination node is located, wherein the information notice message contains the information of the opposite site; and the RTR receiving the information notice response message returned from the xTR.

Description

 Site communication method, RTR and tunnel router

Technical field

 The present invention relates to the field of mobile communications and the Internet, and more particularly to a method for communicating a station, a repackaged tunnel router (RTR), and a tunnel router. Background technique

 In order to solve the problem of increasing the size of the routing table and better meet the needs of users for technologies such as mobility support, multi-homed network deployment and traffic engineering deployment, the network architecture design of identity and location separation has become a hot spot in the industry.

 The Locator/ID Separation Protocol (LISP) technology is a popular solution for separating the host identity from the host location identity. As shown in Figure 1, it is the basic logical architecture of the LISP network. The way is as follows:

 The site network (usually referred to as the user network) is separated from the transport network (usually referred to as the carrier network), and the address space is divided into an endpoint identifier (EID, which represents an address within the site network) address space and a route location identifier (Routing Locator) , RLOC , which represents the reachability of the border router network) address space. The routing information inside the site network in the network, that is, the EID address information, is not advertised to the transmission network. The two site networks pass between the Ingress Tunnel Router (ITR) and the Egress Tunnel Router (ETR). Establish a tunnel that traverses the transport network to connect. The site network implements the maintenance of mapping information from EID to RLOC through a separate mapping system.

 As shown in Figure 1, the LISP network architecture includes a data plane and a mapping plane.

The data plane implements the forwarding and transmission of data packets. As shown in Figure 1, the source node that generated the packet in the LISP site sends the packet to the ingress tunnel router ITR at the site. The ITR encapsulates the data packet according to the mapping relationship between the destination node EID address obtained by the cache plane or the mapping plane and the RLOC address of the ETR of the site where the destination node is located, and then sends the encapsulated data packet to the ETR of the destination site. After the ETR removes the outer LISP encapsulation of the data packet, the EDR forwards the data packet to the destination node in the site according to the EID address of the data packet. The mapping plane can help the ITR find the site ETR corresponding to the destination node and obtain mapping information. As shown in Figure 1, the ETR registers the mapping information of the EID to RLOC in the site to the mapping server (MS). When the ITR in the LISP site needs to find the destination node mapping information, the mapping request packet is forwarded to the MS through the mapping plane, thereby further finding the corresponding destination site ETR. After the ITR caches the mapping information of the MS or the destination station ETR response, the packet forwarding of the data packet is performed.

 If the LISP site is deployed on a private network and is behind a network address translation (NAT) device, the site is referred to as a post-NAT site. According to the basic procedure of LISP mapping registration, the ETR of the post-NAT site registers the obtained private RLOC address to the MS. Since the RLOC address is a private address, the external node cannot communicate with the nodes in the site. To solve the problem of communication through the NAT device, a Re-encapsulating Tunnel Router (RTR) is introduced in the LISP mechanism, as shown in Figure 2.

 Control plane angle, the RTR receives the encapsulation mapping register message sent by the ETR after the NAT, and caches the related information in the registration message, and then re-encapsulates the mapping registration message and sends it to the MS. When the communication peer node searches for mapping information of the nodes in the intra-NAT after the NAT, the MS or the site ETR responds to the communication peer with the RLOC address of the RTR.

 Data plane angle, RTR is used as a relay device for communication between the site and the external peer after NAT. When the external peer sends a message to the node in the post-NAT site, the external peer obtains the RLOC address pointing to the RTR through the mapping search, and the RTR receives the data packet, and after decapsulating the data packet, according to the saved post-NAT site related information, The data packet encapsulation and forwarding is performed. When the packet is sent out by the site after the NAT, the site ITR does not perform the peer mapping information search, but the packet is directly encapsulated and sent to the RTR device, and the RTR searches the peer mapping information. Perform packet encapsulation and forwarding again.

 The relay encapsulation and forwarding based on the RTR device can well solve the problem of interworking between the post-NAT and the external public network. However, in some special scenarios, the forwarding process may cause unnecessary routing detours.

As shown in Figure 3, Site 1 and Site 2 are located behind the same NAT device, and both sites are registered by the same RTR device. Based on the related technology, when the source node in Site1 sends a data packet to the destination node in Site2, Siter's ITR needs to first send the data packet to the RTR. After the data packet passes through the NAT device and arrives at the RTR, the RTR stores the Site2 based on its own. information, The data packet is re-encapsulated, and the encapsulated data packet is sent to the ETR in Site2 through the NAT. Because the ITR does not perform the mapping information search, the ITR cannot know the RLOC information of the ETR in Site2. Therefore, the data packet cannot be directly encapsulated or sent to the ETR through the NAT device, thereby causing the route to be bypassed.

 As shown in Figure 4, if multiple levels of NAT are deployed in the network topology, NAT2 (secondary NAT device) and Site1 are both behind NAT1 (primary NAT device), and Site2 is behind NAT2. In this scenario, according to the related technology, when Sitel communicates with Site2, the data packet needs to pass through NAT1 to reach the RTR, and then encapsulates and forwards again, and then passes through NAT1 and NAT2 to reach Site2, and the scenario also has a route bypass. There are also scenarios where the source site is located on a multi-level NAT device, the destination site is located behind a primary NAT device, or the two sites are located behind a multi-level NAT device. The problem is similar to the scenario in Figure 4.

 It should be noted that the LISP mobile node (LISP MN) can be regarded as a LISP site, and the MN performs the functions of the ITR and the ETR at the same time. Therefore, the special scenario of routing bypass includes the two LISP MNs behind the same NAT device communicating with each other, or the LISP site and the LISP MN communicating with each other after the same NAT device. Summary of the invention

 The embodiment of the invention provides a communication method of a station, an RTR and a tunnel router, to solve the problem of route detour caused by re-encapsulation and forwarding of an RTR that is forwarded to a NAT device.

 An embodiment of the present invention provides a method for communication of a station, where the method includes:

 After receiving the data packet, the repackage tunneling router (RTR) determines that the source node and the destination node of the data packet are located behind the same network address translation (NAT) device, and the tunnel to the source node or the site where the destination node is located. The router (xTR) sends an information advertisement message, where the information advertisement message includes the peer site information;

 The RTR receives the information notification response message returned by the xTR.

 Preferably, the sending, by the RTR, the information advertisement message to the xTR of the source node or the site where the destination node is located includes:

The RTR sends the letter to an ingress tunnel router (ITR) of a site where the source node is located Information notification message; or,

 The RTR sends the information advertisement message to an egress tunnel router (ETR) of the site where the destination node is located.

 Preferably, the peer site information includes: a local routing location identifier (RLOC) of the peer site xTR, a local port number, a global RLOC, a global port number, and an endpoint identity (EID) address prefix information.

 Preferably, after the RTR receives the information notification response message returned by the xTR, the method further includes:

 The RTR is configured to indicate that the RTR only performs the packet encapsulation and forwarding between the source node or the site where the destination node is located and the peer site thereof after receiving the information advertisement response message. length of time.

 The embodiment of the invention further provides a method for communication of a site, the method comprising:

 The tunnel router (xTR) of the source node or the site where the destination node is located receives the information advertisement message that is sent by the re-encapsulation tunnel router (RTR) and contains the information of the opposite site;

 The xTR obtains the peer site information from the information advertisement packet, determines that the peer site is reachable according to the peer site information, and directly sends the data packet to the peer site.

 Preferably, the xTR of the site where the source node is located is an ingress tunnel router (ITR), and the xTR of the site where the destination node is located is an egress tunnel router (ETR).

 Preferably, the determining, by the xTR, the peer site reachable according to the peer site information, that: the ITR sends a probe message to the ETR, and receives a probe response message returned by the ETR; or

 The ETR sends a probe message to the ITR, receives a mapping request message sent by the ITR after receiving the probe message, and returns a mapping response to the ITR.

 Preferably, after the xTR determines that the peer site is reachable according to the peer site information, the method further includes:

The xTR sends a data packet to the peer site through Network Address Translation (NAT). Preferably, the determining, by the xTR, the peer site reachability according to the peer site information includes: The ITR sends a probe message to the ETR through the NAT device, and receives a probe response message returned by the ETR through the NAT device; or

 The ETR sends a probe message to the ITR through the NAT device, and receives a mapping request message sent by the ITR after receiving the probe message by using the NAT device, and The ITR returns a mapping response message.

 The embodiment of the present invention further provides a repackage tunneling router (RTR), where the RTR includes: a determining module, configured to: after receiving the data packet, determining that the source node and the destination node of the data packet are in the same network address translation (NAT) ) behind the device, triggering the channel module;

 The notification module is configured to send an information advertisement message to the tunnel node (xTR) of the source node or the site where the destination node is located, where the information advertisement message includes the peer site information; and the receiving module is set as the receiving station The information returned by the xTR announces the response message.

 Preferably, the notification module is set to:

 Sending the information advertisement message to an ingress tunnel router (ITR) of the site where the source node is located; or

 Sending the information advertisement message to an egress tunnel router (ETR) of the site where the destination node is located.

 Preferably, the peer site information includes: a local routing location identifier (RLOC) of the peer site xTR, a local port number, a global RLOC, a global port number, and an endpoint identity (EID) address prefix information.

 Preferably, the RTR further includes:

 a setting module, configured to: after the receiving module receives the information notification response message returned by the xTR, set a time interval, where the time interval is used to indicate that the RTR only performs the information after receiving the information notification response message The length of time that the source node or the site where the destination node is located and its peer site is encapsulated and forwarded.

 The embodiment of the present invention further provides a tunnel router, where the tunnel router includes:

The transceiver module is configured to receive an information advertisement message that is sent by the re-encapsulation tunneling router (RTR) and that includes a peer station information, and return a message notification response message to the RTR. The data processing module is configured to obtain the peer site information from the information advertisement packet, determine that the peer site is reachable according to the peer site information, and directly send the data packet to the peer site.

 Preferably, the tunnel router is an ingress tunnel router (ITR) or an egress tunnel router (ETR).

 Preferably, when the tunnel router is the ITR, the data processing module is configured to: send a probe message to the ETR, receive a probe response message returned by the ETR, or receive the ETR transmission. After the packet is probed, the mapping request message is sent, and the mapping response message returned by the ETR is received. When the tunnel router is the ETR, the data processing module is configured to: send a probe to the ITR. And receiving a mapping request message sent by the ITR after receiving the probe message, and returning a mapping response message to the ITR, or receiving the probe message sent by the ITR, to the The ITR returns the probe response message.

 Preferably, the data processing module is further configured to: after determining that the peer site is reachable according to the peer site information, send a data packet to the peer site by using network address translation (NAT).

 Preferably, when the tunnel router is the ITR, the data processing module is configured to: send, by the NAT device, a probe packet to the ETR, and receive a probe response packet returned by the ETR by the NAT device. Or, after receiving the probe packet sent by the ETR by the NAT device, sending a mapping request packet, and receiving a mapping response packet returned by the ETR by the NAT device; or, the tunnel router is When the ETR is described, the data processing module is configured to: send, by the NAT device, a probe packet to the ITR, and receive a mapping request packet sent by the ITR after receiving the probe packet by using the NAT device. And returning, by the NAT device, a mapping response message to the ITR, or receiving the probe packet sent by the ITR through the NAT device, and returning the probe to the ITR by using the NAT device. Respond to 4 essays.

 In the embodiment of the present invention, when multiple LISP sites or LISP mobile nodes located behind the same NAT device can communicate with each other, the device can transmit along the optimized path to prevent the data packet from being forwarded to the RTR outside the NAT device for rerouting and forwarding. Reduce the burden on RTR devices. BRIEF abstract

1 is a related art LISP network architecture diagram; 2 is a schematic diagram of NAT traversal deployment in a related art LISP network architecture; FIG. 3 is a schematic diagram of multi-site or multi-LISP MN deployment after NAT in a related art LISP network architecture;

 4 is a schematic diagram of multi-level NAT deployment in a related art LISP network architecture;

 5 is a signaling flow chart of Embodiment 1 of the optimized post-NAT station communication method of the present invention; FIG. 6 is a signaling flow chart of Embodiment 2 of the optimized post-NAT station communication method of the present invention; FIG. 7 is an optimized NAT of the present invention. FIG. 8 is a schematic structural diagram of an RTR embodiment of the present invention; FIG.

 FIG. 9 is a schematic structural diagram of an embodiment of a tunnel router according to the present invention. Preferred embodiment of the invention

 Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, in the case of no conflict, the features in the embodiments and the embodiments in the present application may be arbitrarily combined with each other.

 In order to more clearly describe the contents of the embodiments of the present invention, the related concepts involved in the embodiments are as follows:

 Post-NAT site: The LISP site is deployed on the private network, behind the NAT device, and is called the post-NAT site. When the LISP MN accesses the private network behind the NAT device, the LISP MN can also be regarded as a post-NAT site.

 Local RLOC address: After the NAT, the site xTR (including ITR and ETR) obtains the private network address as the RLOC, which is called the local RLOC address.

 Global RLOC address: After the NAT sends the data packet sent by the site xTR through the NAT device, the NAT device replaces the external source address and port number of the data packet, and replaces the local RLOC address as the source address with the public network. Address, which is called the global RLOC address.

 An embodiment of the present invention provides a method for communication of a station. The embodiment is described from the perspective of an RTR, and the method includes:

Step 11: After receiving the data packet, the re-encapsulation tunneling router (RTR) determines whether the source node and the destination node of the data packet are located behind the same network address translation (NAT) device; Step 12: The RTR determines that the source node and the destination node are located in the same NAT device, and sends an information advertisement message to the tunnel node (xTR) of the source node or the site where the destination node is located, where the information notification message is sent. Contains the peer site information;

 In the step 12, the RTR sending the information advertisement message to the xTR of the source node or the site where the destination node is located may include: sending, by the RTR, the information notification to an ingress tunnel router (ITR) of a site where the source node is located. Or the RTR sends the information advertisement message to an egress tunnel router (ETR) of the site where the destination node is located;

 Step 13. The RTR receives the information notification response message returned by the xTR.

 After the step 13, the method may further include: setting, by the RTR, a time interval, where the RTR receives the information notification response message, and only executes the source node or the destination node and the site The length of time that the packet between the peer sites is encapsulated and forwarded.

 The above communication method, by transmitting the information of the opposite site to the tunnel router, lays a foundation for optimizing the path transmission of the packet edge and avoiding route detour.

Correspondingly, an embodiment of the present invention further provides a method for communication of a station, which is described from the perspective of an xTR, and the method includes:

 Step 21: The tunnel router (xTR) of the source node or the site where the destination node is located receives the information advertisement message that is sent by the re-encapsulation tunnel router (RTR) and contains the information of the peer site.

 The xTR of the site where the source node is located is an ingress tunnel router (ITR), and the xTR of the site where the destination node is located is an egress tunnel router (ETR);

 Step 22: The xTR obtains the peer site information from the information advertisement packet, determines that the peer site is reachable according to the peer site information, and directly sends the data packet to the peer site.

 Determining the peer site reachability according to the peer site information includes: the ITR sending a probe message to the ETR, and receiving a probe response message returned by the ETR; or the ETR to the ITR Sending a probe message, and receiving a mapping request message sent by the ITR after receiving the probe message, and returning a mapping response message to the ITR.

In addition, in order to overcome the path rounding problem occurring in the scenario shown in FIG. 4, after the xTR determines that the peer site is reachable according to the peer site information, the method may further include: Address translation (NAT) sends a packet to the peer site.

 In this case, the xTR 4 determines that the peer site is reachable according to the peer site information:

 The ITR sends a probe message to the ETR by using the NAT device, and receives a probe response message returned by the ETR by the NAT device; or

 The ETR sends a probe message to the ITR through the NAT device, and receives a mapping request message sent by the ITR after receiving the probe message by using the NAT device, and The ITR returns a mapping response message.

 Based on the foregoing method, when communication is performed between multiple LISP sites or LISP MNs behind the same NAT device, all the data packets need not be sent to the RTR for encapsulation and forwarding, thereby avoiding route detour during the data packet transmission process, and Reduce the burden of RTR.

The following describes the embodiments of the present invention from the perspective of interaction between the RTR and the xTR: Embodiment 1

 As shown in FIG. 5, it is a signaling flowchart of Embodiment 1 of the post-NAT communication method of the present invention. The present embodiment is applicable to the mapping of the mapping information of the same RTR after the same NAT device is used. When the RTR forwards the data packet between the two sites, it notifies the two sites of the information about the peer site; the following steps are included:

 Step 501: The Sitel ITR encapsulates the data packet sent by the source node in Site1 to the destination node in Site2. The encapsulated data packet, the source address of the inner layer is the source node EID, the destination address is the destination node EID in Site2, the source address of the outer header is the local RLOC address of the ITR, and the destination address is the RLOC address of the RTR;

 Step 502: When receiving the data packet, the NAT device replaces the external source address and port number of the data packet with the global RLOC address and the global port number corresponding to the ITR according to the locally stored address translation information.

 Step 503: The NAT device sends the replaced data packet to the RTR.

Step 504: The RTR determines, according to the locally cached information on the Sitel and the Site2, whether the source site and the destination site of the sent data packet are located behind the same NAT device, and is determined to be located in the same NAT. After the device, perform the next steps;

 The related information includes at least a local RLOC, a local port number, a global RLOC, a global port number, and an intra-site EID address prefix information used by the two sites xTR to establish a connection with the RTR;

 If the corresponding NAT device is associated with the RTR, the RTR may also cache the type information of the NAT device corresponding to the site and the global RLOC address pool configured on the NAT device.

 It should be noted that the RTR determines whether the source site and the destination site are located in the same NAT device by comparing whether the global RLOC addresses registered by the two sites are the same or similar. If the global RLOC address pool information of the NAT device is cached on the RTR, it can be determined by comparing whether the global RLOC address of the two sites belongs to the global RLOC address pool of the same NAT device.

 Step 505a: The RTR sends an information advertisement message to the Iter site ITR, where the message includes information about the Site2 site, and the information includes at least the local RLOC, the local port number, the global RLOC, the global port number, and the site of the Site2 site ETR. EID address prefix information;

 Step 505b: The RTR sends an information advertisement message to the Site 2 ETR, where the message includes

Information about the Sitel site, which should include at least the local RLOC, local port number, global RLOC, global port number, and site EID address prefix information of the Sitel site ITR;

 It should be noted that the RTR device may perform one of the steps 505a and 505b, or both steps may be performed. If the above two steps are performed, the order of execution of the steps may be performed indefinitely or simultaneously.

 Step 506a: After receiving the information advertisement message of the RTR, the Site1 ITR sends a message notification response to the RTR.

 Step 506b: After receiving the information advertisement message of the RTR, the Site 2 ETR sends an information notification response to the RTR.

It should be noted that the RTR device can set a time value after receiving the information notification response from the Sitel ITR and the Site2 ETR. During the valid time, when the RTR device receives the data packet sent by the Sitel ITR to the Site2 ETR, only the packet encapsulation and forwarding is performed, and the information notification message is not sent to the two sites; Step 507: After receiving the data packet, the RTR searches for the information about the locally cached Site2 site, and re-encapsulates the data packet. The outer source address of the data packet is the RLU address of the RTR, and the destination address is the global RLOC address of the ETR of the Site2 site.

 Step 508: The RTR sends the repacked data packet to the NAT, and the NAT device replaces the outer address and destination port number of the data packet with the local RLOC and port number of the Site2 site ETR, and then sends the data packet to the ETR in Site2.

 It should be noted that the steps 507 and 508 are prior art, and the execution sequences of the steps 504, 505a, and/or 505b and the steps 507 and 508 are performed in sequence, or may be performed simultaneously.

 Based on the above process, when the RTR determines that the two sites of the communication are located on the same NAT device, the information about the peer site can be notified to the post-NAT site.

Embodiment 2

 As shown in FIG. 6 , it is a signaling flowchart of Embodiment 2 of the optimized post-NAT station communication method of the present invention. This embodiment is applicable to related operations after the source station Sitel ITR receives the information about the destination site sent by the RTR. Steps:

 Step 601: After receiving the relevant information in the destination site Site2 sent by the RTR, the ITR in the source site Site1 sends the probe packet to the Site2 ETR by using the local RLOC of the ETR in Site2 as the destination address.

 It should be noted that, in the existing LISP mechanism, a data probe packet is defined, and the reachability of the RLOC address of the communication peer can be detected. In step 601, the Sitel ITR can select to use the existing data probe packet to probe the Site2. ETR corresponds to the reachability of the local RLOC;

 Step 602: After receiving the probe packet sent by the Site1 ITR, the Site2 ETR sends a probe response packet to the Site1 ITR, where the packet may include mapping information of the EID address prefix to the local RLOC in the Site2 ETR.

 Step 603: After receiving the probe response message of the Site2 ETR, the Sitel ITR uses the local RLOC of the Site2 ETR as the destination address of the outer package of the data packet to directly send the data packet to the Site2 ETR;

If the Sitel ITR performs step 601, it does not receive the probe of the Site2 ETR within the set time. In response to the message or the probe message sent by the Site2 ETR, the following steps may be performed: Step 604: The ITR in the source station uses the global RLOC of the ETR in Site2 as the destination address, and sends a probe message to the Site2 ETR.

 Step 605: The probe packet is routed to the NAT device. The NAT device finds that the destination address of the packet is the global RLOC address of a device that is allocated to the NAT. If the NAT device supports the hairpin translation function, the NAT device pairs the data. Replace the source address, source port number, destination address, and destination port number of the packet;

 Step 606: The NAT device sends the probe message after the address and port number replacement to the Site2 ETR. Step 607: After receiving the probe message sent by the Sitel ITR, the Site2 ETR uses the Sitel ITR global RLOC as the destination address to the Sitel ITR. Sending a probe response message, where the message includes mapping information of the EID address prefix to the local RLOC in the Site2 ETR;

 Step 608: The NAT device performs the address and port number replacement of the probe response packet.

 Step 609: The NAT device sends the probe response message after the address and the port number are replaced to Sitel.

ITR;

 Step 610: After receiving the probe response message of the Site2 ETR, the Site1 ITR uses the global RLOC of the Site2 ETR as the destination address of the outer package of the data packet when the data packet is subsequently sent. Step 611: The NAT device replaces the address of the data packet. The port number;

 Step 612: The NAT device sends the data packet to the Site2 ETR.

 It should be noted that the Sitel ITR performs the optional steps 604-612 because, in some special scenarios, although the source site and the destination site are located behind the same NAT device, the two sites may not be able to communicate using the local RLOC of the peer.

 For example, in the scenario shown in Figure 4, the destination site Site2 is located behind the NAT2 (secondary NAT) device, and Sitel obtains the local RLOC of Site2 as the private network address of Site2 behind the NAT2 device. If the Sitel ITR uses the address to initiate to Site2. Active communication, packets cannot pass through NAT2 and reach ETR. Application Steps 604-609, the Sitel ITR sends a probe packet to the Site2 ETR through NAT1. After the packet is successfully sent, the actual forwarding path of the data packet between the Sitel ITR and the Site2 ETR is: ITR NAT1 NAT2 ETR.

The above-mentioned probe method using the peer global RLOC address as the destination address is also applicable to the source station. Both the point and destination sites are located behind a multi-level NAT device.

 During the execution of the above probe step, before receiving the probe response from the Site2 ETR, the Sitel ITR may continue to send the packet with the destination address pointing to the EID in Site2 to the RTR to avoid the impact of the probe process on data forwarding.

Embodiment 3

 As shown in FIG. 7 , it is a signaling flowchart of the third embodiment of the post-NAT communication method of the present invention. The embodiment is applicable to the related operations after the destination site Site 2 ETR receives the information about the source site sent by the RTR. The following steps:

 Step 701: After receiving the information about the source site Site1 sent by the RTR, the ETR of the destination site Site2 sends the probe packet to the Sitel ITR by using the local RLOC of the ITR in the Site1 as the destination address.

Request, trigger mapping request message), trigger the communication peer ITR sends a mapping request to itself. In step 701, the Site2 ETR may select an existing SMR packet to detect the reachability of the local RLOC corresponding to the ETR in the Site2.

 Step 702: After receiving the probe message sent by the Site2 ETR, the Sitel ITR may send a mapping request to the Site2 ETR, and the destination address points to the local RLOC of the Site2 ETR;

 Step 703: The Site2 ETR returns a mapping response message to the Sitel ITR, where the packet includes mapping information of the Site2 EID prefix information and the Site2 ETR local RLOC.

 Step 704: After receiving the mapping response message of the Site2 ETR, the Sitel ITR uses the local RLOC of the Site2 ETR as the destination address of the outer package of the data packet to directly send the data packet to the Site2 ETR.

 If the Site2 ETR does not receive the mapping request message of the Sitel lTR or the probe packet sent by the Sitel ITR within the set time, the following steps are performed: Step 705: ETR in the destination site Site2 Sending a probe message to the Sitel ITR by using the global RLOC of the ITR in the Sitel as the destination address;

Step 706: The probe packet is routed to the NAT device, and the NAT device discovers the destination address of the packet. If the NAT device supports the hairpin conversion function, the NAT device replaces the source address, source port number, destination address, and destination port number of the data packet.

 Step 707: The NAT device sends the probe packet with the address and the port number to the Sitel ITR. Step 708: After receiving the probe packet sent by the Site2 ETR, the Site1 ITR sends the probe message to the Site2 ETR by using the Site2 ETR global RLOC as the destination address. Mapping request message;

 Step 709: The NAT device performs the mapping of the address and the port number of the mapping request packet, and sends the replaced packet to the Site2 ETR.

 Step 710: After receiving the Sitel ITR mapping request message, the Site2 ETR sends a mapping response message to the Site1 ITR, where the packet includes the mapping information of the Site2 EID prefix information and the Site2 ETR local RLOC.

 Step 711: The NAT device performs the mapping of the address and port number of the mapping response packet, and sends the replaced packet to the Sitel ITR.

 Step 712: After receiving the mapping response message of the Site2 ETR, the Site1 ITR uses the global RLOC of the Site2 ETR as the destination address of the outer package of the data packet when the data packet is subsequently sent. Step 713: The NAT device replaces the address of the data packet. The port number and the packet is sent to the Site2 ETR.

 It should be noted that the Site2 ETR performs the optional steps 705-713 because, in some special scenarios, although the source site and the destination site are located behind the same NAT device, the two sites may not be able to communicate using the local RLOC of the peer. For specific reasons, refer to the related description in the second embodiment.

 During the execution of the above-mentioned probe step, before receiving the mapping response message from the Site2 ETR, the Sitel ITR can continue to send the data packet with the destination address pointing to the EID in Site2 to the RTR, so as to avoid the impact of the probe process on data forwarding.

 The foregoing embodiments are described by taking a LISP site located behind a NAT device as an example. The embodiments are also applicable to the communication between the LISP MNs after the NAT device, and the LISP sites behind the NAT device and the LISP MN.

FIG. 8 is a schematic structural diagram of an RTR embodiment of the present invention, where the RTR includes a prediction mode. Block 81, an announcement module 82, and a receiving module 83, wherein:

 The judging module is configured to: after receiving the data packet, determine that the source node and the destination node of the data packet are located behind the same network address translation (NAT) device, and trigger the notification module;

 The notification module is configured to send an information advertisement message to the tunnel node (xTR) of the source node or the site where the destination node is located, where the information notification message includes the peer site information;

 The receiving module is configured to receive the information notification response message returned by the xTR.

 The notification module is configured to: send the information advertisement message to an ingress tunnel router (ITR) of the site where the source node is located; or send to an egress tunnel router (ETR) of a site where the destination node is located The information is an advertisement message.

 In addition, the RTR further includes: a setting module 84, configured to: after the receiving module receives the information notification response message returned by the xTR, setting a time interval, where the time interval is used to indicate that the RTR receives the information notification After the response packet, only the length of time for the data packet encapsulation and forwarding between the source node or the site where the destination node is located and its peer site is performed.

 The above RTR, by transmitting the peer site information to the tunnel router, lays a foundation for realizing the packet path along the optimized path transmission and avoiding route detour.

As shown in FIG. 9, it is a schematic structural diagram of an embodiment of a tunnel router according to the present invention. The tunnel router includes a transceiver module 91 and a data processing module 92, wherein:

 The transceiver module is configured to receive an information advertisement message that is sent by the re-encapsulated tunneling router (RTR) and that includes a peer station information, and return a message notification response message to the RTR.

 The data processing module is configured to obtain the peer site information from the information advertisement packet, determine that the peer site is reachable according to the peer site information, and directly send the data packet to the peer site.

The tunnel router may be an ingress tunnel router (ITR) or an egress tunnel router (ETR). The data processing module is specifically configured to: when the tunnel router is the ITR, send a probe packet to the ETR. Receiving the probe response message returned by the ETR, or after receiving the probe message sent by the ETR, sending a mapping request message, and receiving a mapping response message returned by the ETR; or, the tunnel router is When the ETR is described, the probe message is sent to the ITR, and the mapping request message sent by the ITR after receiving the probe message is received, and The ITR returns a mapping response message, or receives the probe message sent by the ITR, and returns the probe response message to the ITR.

 In addition, the data processing module is further configured to: after determining that the peer site is reachable according to the peer site information, send a data packet to the peer site by using network address translation (NAT). At this time, when the tunnel router is the ITR, the data processing module is configured to: send, by the NAT device, a probe message to the ETR, and receive a probe response report that is returned by the ETR by the NAT device. Or, after receiving the probe message sent by the ETR by the NAT device, sending a mapping request message, and receiving a mapping response message returned by the ETR by the NAT device; or, the tunnel router is In the ETR, the data processing module is configured to: send, by the NAT device, a probe packet to the ITR, and receive a mapping request that is sent by the ITR after receiving the probe packet by using the NAT device. And returning, by the NAT device, a mapping response message to the ITR, or receiving the probe message sent by the ITR by using the NAT device, and returning, by the NAT device, the Probe response messages.

 The above tunnel router can obtain the same information by obtaining the information of the opposite site.

When multiple LISP sites or LISP mobile nodes behind the NAT device communicate with each other, they can transmit along the optimized path, which avoids the route bypass caused by the RTR retransmission and forwarding of the data packet to the RTR outside the NAT device, which reduces the burden on the RTR device.

One of ordinary skill in the art will appreciate that all or a portion of the above steps may be accomplished by a program that instructs the associated hardware to be stored in a computer readable storage medium, such as a read only memory, a magnetic disk, or an optical disk. Alternatively, all or part of the steps of the above embodiments may also be implemented using one or more integrated circuits. Correspondingly, each module/unit in the above embodiment may be implemented in the form of hardware or in the form of a software function module. The invention is not limited to any specific form of combination of hardware and software.

The above embodiments are only intended to illustrate the technical solutions of the present invention and are not to be construed as limiting the invention. A person skilled in the art should understand that the technical solutions of the present invention may be modified or equivalent, without departing from the spirit and scope of the present invention, and should be included in the scope of the claims of the present invention. Industrial Applicability The embodiments of the present invention can implement multiple RISP sites or LISP mobile nodes located behind the same NAT device, and can transmit along the optimized path to prevent the data packets from being forwarded to the RTR outside the NAT device for re-encapsulation and forwarding. Roundabout, reducing the burden on RTR devices.

Claims

claims 1. A site communication method, the method includes: After receiving the data packet, the re-encapsulation tunnel router (RTR) determines that the source node and the destination node of the data packet are located behind the same network address translation (NAT) device, and then sends a request to the site where the source node or the destination node is located. The tunnel router (xTR) sends an information notification message, and the information notification message contains the peer site information; The RTR receives the information notification response message returned by the xTR. 2. The method according to claim 1, wherein: The RTR sends an information notification to the xTR of the site where the source node or the destination node is located. The text includes: The RTR sends the information notification message to the ingress tunnel router (ITR) of the site where the source node is located; or, The RTR sends the information notification message to the egress tunnel router (ETR) of the site where the destination node is located. 3. The method of claim 1, wherein: The peer site information includes: the local routing location identifier (RLOC), local port number, global RLOC, global port number and endpoint identity identifier (EID) address prefix information of the xTR of the peer site. 4. The method according to any one of claims 1-3, wherein: After the RTR receives the information notification response message returned by the xTR, the method further includes: The RTR sets a time interval. This time interval is used to indicate that after the RTR receives the information notification response message, it only performs data packet encapsulation and forwarding between the source node or the site where the destination node is located and its opposite end site. length of time. 5. A site communication method, the method includes: The tunnel router (xTR) of the site where the source node or destination node is located receives the information advertisement message containing the peer site information sent by the re-encapsulation tunnel router (RTR); The xTR obtains the opposite site information from the information notification message, determines that the opposite site is reachable based on the opposite site information, and directly sends a data packet to the opposite site. 6. The method according to claim 5, wherein: The xTR of the site where the source node is located is an ingress tunnel router (ITR), and the xTR of the site where the destination node is located is an egress tunnel router (ETR). 7. The method according to claim 6, wherein: The xTR determining that the peer site is reachable based on the peer site information includes: The ITR sends a probe message to the ETR, and receives the probe response message returned by the ETR; or The ETR sends a probe message to the ITR, receives a mapping request message sent by the ITR after receiving the probe message, and returns a mapping response message to the ITR. 8. The method according to claim 5 or 6, wherein: After the xTR determines that the opposite site is reachable based on the opposite site information, the method further includes: The xTR sends data packets to the peer site through Network Address Translation (NAT). 9. The method according to claim 8, wherein: The xTR determining that the peer site is reachable based on the peer site information includes: The ITR sends a probe message to the ETR through the NAT device, and receives a probe response message returned by the ETR through the NAT device; or The ETR sends a probe message to the ITR through the NAT device, receives a mapping request message sent by the ITR through the NAT device after receiving the probe message, and, sends a mapping request message to the ITR through the NAT device. The ITR returns a mapping response message. 10. A re-encapsulation tunnel router (RTR), the RTR includes: The judgment module is configured to, after receiving the data packet, judge that the source node and destination node of the data packet are located behind the same network address translation (NAT) device, and trigger the channel module; The notification module is configured to send an information notification message to the tunnel router (xTR) of the site where the source node or the destination node is located, where the information notification message contains the opposite end site information; as well as The receiving module is configured to receive the information notification response message returned by the xTR. 11. The RTR according to claim 10, wherein: The notification module is set to: Send the information notification message to the ingress tunnel router (ITR) of the site where the source node is located; or, Send the information notification message to the egress tunnel router (ETR) of the site where the destination node is located. 12. The RTR according to claim 10, wherein: The peer site information includes: the local routing location identifier (RLOC), local port number, global RLOC, global port number and endpoint identity identifier (EID) address prefix information of the peer site xTR. 13. The RTR according to any one of claims 10 to 12, the RTR further comprising: a setting module configured to set a time interval after the receiving module receives the information notification response message returned by the xTR. , this time interval is used to indicate the length of time that the RTR only performs data packet encapsulation and forwarding between the source node or the site where the destination node is located and its opposite end site after receiving the information announcement response message. 14. A tunnel router, the tunnel router includes: The transceiver module is configured to receive an information notification message containing peer site information sent by a re-encapsulation tunnel router (RTR), and to return an information notification response message to the RTR; The data processing module is configured to obtain the peer site information from the information notification message, determine that the peer site is reachable based on the peer site information, and directly send a data packet to the peer site. 15. The tunnel router according to claim 14, wherein: The tunnel router is an ingress tunnel router (ITR) or an egress tunnel router (ETR). 16. The tunnel router according to claim 15, wherein: When the tunnel router is the ITR, the data processing module is configured to: send a probe message to the ETR, and receive a probe response message returned by the ETR, or receive the probe response message from the ETR. After sending the probe message, send a mapping request message, and receive the mapping response message returned by the ETR; or, when the tunnel router is the ETR, the data processing module is set to: send to the ITR Probe message, and receive the mapping request message sent by the ITR after receiving the probe message, and return a mapping response message to the ITR, or, receive the probe message sent by the ITR, and send the probe message to the ITR. The ITR returns the probe response text. 17. The tunnel router according to claim 14 or 15, wherein: The data processing module is further configured to: after determining that the opposite site is reachable based on the opposite site information, send a data packet to the opposite site through network address translation (NAT). 18. The tunnel router according to claim 17, wherein: When the tunnel router is the ITR, the data processing module is set to: via the The NAT device sends a probe message to the ETR, and receives a probe response message returned by the ETR through the NAT device, or, after receiving the probe message sent by the ETR through the NAT device, sends a mapping request. message, and receives the mapping response message returned by the ETR through the NAT device; or, when the tunnel router is the ETR, the data processing module is set to: send to the ITR through the NAT device Probe message, receive the mapping request message sent by the ITR through the NAT device after receiving the probe message, and return a mapping response message to the ITR through the NAT device, or, receive the ITR The probe response message is sent by the NAT device, and the probe response message is returned to the ITR by the NAT device.