CN102892172B - Seamless interface switching method for PMIPv6 (Proxy Mobile Internet Protocol v6) multi-connection mobile nodes - Google Patents

Abstract

A proxy mobile IPv6 multi-connection mobile node seamless interface switching method belongs to the field of proxy mobile IPv6, the mobile node has a plurality of network interfaces, and when the multiple network interfaces access the same proxy IPv6 domain at the same time, when a network of the mobile node When the interface (assumed to be IF1) is connected from a mobile access network (MAG1) to MAG3 in the same proxy mobile IPv6 domain, the data transmitted on this interface will first forward the data from MAG1 to the MAG connected to other network interfaces of the mobile node, Then forward it to the non-handover interface of the mobile node; when the LMA detects that the mobile node leaves MAG1, the LMA directly forwards the data stream to the MAG connected to other network interfaces of the mobile node for transmission, so as to realize data transfer during the interface handover process of the mobile node Seamless transfer.

Description

Proxy mobile IPv6 multi-connection mobile node seamless interface handover method

technical field

The invention belongs to the field of proxy mobile IPv6 (PMIPv6), and relates to a method for seamless interface switching of multiple connection mobile nodes of proxy mobile IPv6.

Background technique

With the rapid development of Internet access technology and mobile terminal equipment, network terminal equipment is often equipped with multiple network interfaces, and it has become possible for one terminal to simultaneously access multiple heterogeneous network domains. At the same time, more and more users hope to enjoy network access services anytime and anywhere, so support for mobility is an inevitable requirement for future Internet protocol development. At present, the IETF MIF (Multi-interface) working group is committed to formulating the standardization of multi-interface-related protocol mechanisms. In order to meet the needs of users to access the network anytime and anywhere, IETF has established a series of related working groups to promote the standardization of mobile IP technology. For example, the MIP4/MIP6 working group is dedicated to the standardization of mobile IPv4/IPv6 technology. The standardization of the network-side mobility management protocol PMIPv6 and so on.

Similar to the Mobile IPv4 protocol, the Mobile IPv6 protocol adds mobility support on the basis of the IPv6 protocol. However, mobile IP requires the support of the mobile node itself, and the protocol stack of the mobile node needs to be modified. In practical applications, it is difficult to determine whether the mobile node supports the mobile IP protocol. In order to ensure that the client can enjoy mobile IP services without any modification, Proxy Mobile IPv6 transfers the mobility management work that the mobile node needs to handle in the Mobile IPv6 protocol to the network, and all these tasks are handled by the network. The client can move freely in the network without any modification, and the node address always remains unchanged, and the node is completely unaware of the movement. Currently, the proxy mobile IPv6 protocol is widely concerned as a popular technology of the next generation all-IP mobile network.

RFC 5949 "Proxy Mobile IPv6 Fast Handover Technology" standardizes the proxy mobile IPv6 mobile node interface handover process. This document proposes two fast handover technologies: reactive fast handover technology and predictive fast handover technology. These two handover technologies are to forward the cached data stranded in the handover process of the mobile node to the node to be Accessed MAG to realize seamless transmission of data streams. The main difference between the two handover technologies is that the reactive fast handover technology is to establish an association with the MAG before the handover after the mobile node accesses the new MAG; and the predictive fast handover technology is to obtain the information that the mobile node is about to handover before the mobile node handover. information, establish the association between the two MAGs in advance.

Haisheng Jiang et al. proposed "Interface Handover Technology for Error Tolerance of Multi-Interface Mobile Nodes in Proxy Mobile IPv6 Networks". This handover technology makes use of the multi-interface characteristics of mobile nodes, and assists the interface to switch between MAGs with the help of other available interfaces of mobile nodes. , the main switching method is to retransmit the data cache of the interface being switched back to the Local Mobility Anchor (LMA), and then redirect the data flow to other interfaces of the mobile node through the LMA.

In general, RFC 5949 "Proxy Mobile IPv6 Fast Handover Technology" and the handover technology proposed by Haisheng Jiang et al. have greatly improved performance compared to the interface handover technology in RFC5213, but they all have certain shortcomings. For the two handover technologies in RFC 5949, the data transmitted during the handover process of the mobile node interface needs to be cached on the MAG, which increases the requirements for the storage capacity of the MAG. When there are multiple mobile nodes within the coverage of the MAG When switching at the same time, it may cause data loss due to insufficient storage capacity of the MAG. At the same time, because the data needs to be cached before forwarding, the data transmission delay will also be greatly increased, which is fatal for transmission delay-sensitive applications. The multi-interface mobile node interface handover technology that supports fault tolerance proposed by Haisheng Jiang et al. uses the characteristics of multiple interfaces of the mobile node to assist in data transmission during the interface handover process, but forwards the data packets sent to the handover interface to the LMA , and then redirecting to other interfaces of the mobile node does not effectively solve the problem that the two technologies in RFC 5949 have too high requirements for the MAG cache capability. Further, the data is first forwarded to the LMA, and then forwarded to other interfaces of the mobile node The data forwarding method may cause greater delay.

Contents of the invention

In order to overcome the deficiencies in the prior art, the object of the present invention is to provide a kind of proxy mobile IPv6 multi-connection mobile node seamless interface switching method, utilizing the characteristics of multiple network interfaces of the node to access the network, no longer need to cache data at the MAG place, This greatly reduces the requirements for the MAG data caching capability, and also reduces the data transmission delay.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A kind of proxy mobile IPv6 multi-connection mobile node seamless interface switching method, is characterized in that,

The LMA in the proxy mobile IPv6 domain assigns the same home network prefix to each interface of the multi-connection mobile node; after obtaining the home network prefix assigned by the LMA, the multi-connection mobile node obtains a global IPv6 address through configuration, and different network interfaces have different IPv6 address, that is, the mobile node interface configuration uses the same network prefix but different IP addresses;

After the MAG receives the access request of the mobile node, it sends a proxy binding update message to the LMA. After the LMA receives the proxy binding update message sent by the MAG, it first checks whether the mobile node identifier in the message exists, and if it exists, then Send the network prefix assigned to the mobile node identifier to the MAG through the proxy binding update response message, otherwise, assign a globally unique network prefix to the node;

After the MAG receives the LMA agent binding update response message, if the message contains the MAG option, the MAG obtains the home network prefix assigned to the mobile node, then sends a route broadcast to the mobile node, and increases the route to the mobile node. Routing, that is, all data packets sent to the specified home network prefix are delivered to the interface requesting access.

The MAG option includes the addresses of all MAGs associated with the mobile node, and the MAG sends a tunnel establishment request message to the address in the MAG option, and then establishes a bidirectional tunnel with it.

The LMA supports multi-interface flow mobility of the mobile node, and can route different service flows to MAGs associated with different interfaces of the mobile node.

The present invention utilizes the characteristics of multiple network interfaces of nodes to access the network in the proxy mobile IPv6 network domain, no longer needs to cache data at the MAG, greatly reduces the requirements for the MAG data cache capability, and also reduces the data transmission delay.

Description of drawings

Figure 1 is a deployment scenario of proxy mobile IPv6 multi-connection mobile nodes.

Fig. 2 is a signaling interaction process of a seamless interface handover of a proxy mobile IPv6 multi-connection mobile node.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings and embodiments.

The invention relates to a seamless interface switching method of a proxy mobile IPv6 multi-connection mobile node. In a proxy mobile IPv6 network, the mobile node uses multiple network interfaces to access the network at the same time. The deployment scenario of a multi-connection mobile node is shown in Figure 1. When the mobile node moves, when any interface of the mobile node moves from the coverage of one MAG network to the coverage of another MAG network, the interface of the mobile node will reconnect to the new MAG . During the handover process, by using the multi-interface feature of the mobile node, the present invention uses other interfaces of the mobile node to forward the data of the interface in the handover process through other interfaces, so as to realize the low-delay seamless data flow in the handover process. transmission.

As shown in Figure 2, in the case where multiple network interfaces of the proxy mobile IPv6 network domain and the mobile node are connected to the network at the same time, the specific steps of the seamless interface switching method of the multi-connection mobile node are as follows:

Step (1): In the proxy mobile IPv6 network, the mobile node has multiple network interfaces (as shown in Figure 1), assuming that the network interface 1 (IF1) of the mobile node has access to the proxy mobile IPv6 domain through MAG1, and assuming that the bidirectional data flow X (Flow X) is transmitted through this interface.

Step (2): The mobile node enters the coverage of MAG2, and decides to connect network interface 2 (IF2) to the proxy mobile IPv6 domain through MAG2.

Step (3): After MAG2 detects the access intention of the mobile node (through the layer 2 signal or receives the routing request signal sent by the mobile node), it obtains the identification (MN-ID) of the mobile node by reading the policy file, and sends it to The LMA sends a Proxy Binding Update Request signal.

Step (4): LMA receives the proxy binding update request message sent by MAG2, and detects whether the mobile node has other network interfaces connected to the network. If the mobile node has a network interface connected to the PMIPv6 domain, the LMA will give the mobile The node assigns the original home network prefix, otherwise, reassigns the home network prefix. When the LMA accepts the registration of the interface, it will send an agent binding update response message to MAG2. The difference between this message and the existing protocol is that this message contains the MAG address option. Through this option, the LMA will communicate with other MNs. The external address of the MAG connected to the network interface is notified to MAG2.

Step (5): After receiving the proxy binding update response message sent back by LMA, MAG2 first establishes a bidirectional tunnel with LMA, and then provides the home network prefix to IF2 of the mobile node through route broadcast. When MAG2 detects that the Proxy Binding Update Reply message contains the MAG address option (assuming it contains only the MAG1 address), it sends a Tunnel Request message to MAG1, which may contain one or more options in the Proxy Binding Update message, but MUST include the Mobile Node Identification option.

Step (6): When MAG1 receives the tunnel request message sent by MAG2, it first checks whether the mobile node has a network interface to establish a connection with it. If MAG1 finds that the mobile node has no network interface associated with it, it will send a tunnel to MAG2 Reply message to announce that there is no such mobile node. Otherwise, MAG1 will send a tunnel response message to MAG2, and establish a bidirectional tunnel with MAG2.

Step (7): When the mobile node IF1 moves to another access network and decides to access the proxy mobile IPv6 domain through other MAGs, it passes the decision to send the uplink data originally transmitted on IF1 through IF2.

Step (8): When MAG1 detects that the mobile node IF1 is disconnected or detects that the mobile node IF1 is about to switch, it sets the route to transmit the downlink data flow that was originally directly forwarded to the mobile node IF1 to MAG2 through the tunnel (because The home network prefix of each interface of the mobile node is the same, and the data route in the MAG is forwarded by prefix matching. Therefore, in MAG2, all the data received from MAG1 is forwarded to the mobile node IF2. At this time, the Flow X downstream forwarding path to LMA->MAG1->MAG2->IF2), and then send a Binding Update message to the LMA to de-associate the interface from MAG1.

Step (9): After receiving the proxy binding update message sent by MAG1 that contains the logout information, the LMA first decides to forward the data originally sent to the mobile node IF1 through MAG1 to MAG2 (at this time, the Flow X downstream forwarding path is determined by the LMA ->MAG1->IF1 is changed to LMA->MAG2->IF2), then cancel the binding of mobile node IF1, send a binding update response message to MAG1, and destroy the two-way tunnel established between LMA and MAG2 for mobile node IF1 .

Step (10): After receiving the proxy binding update response message sent back by the LMA, MAG1 sends a tunnel cancellation request message to MAG2.

Step (11): After receiving the tunnel withdrawal message sent by MAG1, MAG2 sends a tunnel cancellation response message to MAG1, and then destroys the tunnel created between MAG1 and MAG2 for the mobile node.

To sum up, the present invention provides a technique for realizing multi-connection mobile node interface switching in a proxy mobile IPv6 network. Compared with several existing interface switching technologies, because the present invention fully utilizes the multi-interface characteristics of the mobile node, it no longer needs to cache data at the MAG during the network interface switching process of the mobile node, which greatly reduces the The requirement for MAG caching ability, and at the same time due to the reduction of data caching time, the present invention also greatly enhances the real-time performance of data transmission.

Claims (2)

1. a kind of proxy mobile IPv6 multi-connection mobile node seamless interface switching method is characterized in that, The LMA in the proxy mobile IPv6 domain assigns the same home network prefix to each interface of the multi-connection mobile node; after obtaining the home network prefix assigned by the LMA, the multi-connection mobile node obtains a global IPv6 address through configuration, and different network interfaces have different IPv6 address, that is, the mobile node interface configuration uses the same network prefix but different IP addresses; After the MAG receives the access request of the mobile node, it sends a proxy binding update message to the LMA. After the LMA receives the proxy binding update message sent by the MAG, it first checks whether the mobile node identifier in the message exists, and if it exists, then Send the network prefix assigned to the mobile node identifier to the MAG through the proxy binding update response message, otherwise, assign a globally unique network prefix to the node; After the MAG receives the LMA agent binding update response message, if the message contains the MAG option, the MAG obtains the home network prefix assigned to the mobile node, then sends a route broadcast to the mobile node, and increases the route to the mobile node. Routing, that is, all data packets sent to the specified home network prefix are delivered to the interface requesting access; The method is implemented in the agent mobile IPv6 domain according to the following steps: Step (1): In the proxy mobile IPv6 network, the mobile node has multiple network interfaces, assuming that the mobile node network interface IF1 has been connected to the proxy mobile IPv6 domain through MAG1, and it is assumed that the bidirectional data flow X Flow X is transmitted through this interface ; Step (2): the mobile node enters the coverage area of MAG2, and decides to connect network interface 2 IF2 to the proxy mobile IPv6 domain through MAG2; Step (3): After MAG2 detects the access intention of the mobile node through the two-layer signal or the routing request signal sent by the mobile node, it obtains the identity of the mobile node by reading the policy file, and sends a proxy binding update request to the LMA Signal; Step (4): The LMA receives the proxy binding update request message sent by MAG2, and detects whether the mobile node has other network interfaces to access the network. If the mobile node has a network interface to access the PMIPv6 domain, the LMA will send the mobile node Assign the original home network prefix, otherwise, re-allocate the home network prefix; when the LMA accepts the registration of the interface, it sends an agent binding update response message to MAG2, which contains the MAG address option. Through this option, the LMA will communicate with the mobile The external address of the MAG connected to other network interfaces of the node is notified to MAG2; Step (5): After receiving the proxy binding update response message sent back by LMA, MAG2 first establishes a two-way tunnel with LMA, and then provides the home network prefix to IF2 of the mobile node through route broadcasting. When MAG2 detects the proxy binding update When the response message contains the MAG address option, it sends a tunnel request message to MAG1, which contains one or more options in the agent binding update message, but must contain the mobile node identification option; Step (6): After MAG1 receives the tunnel request message sent by MAG2, it first checks whether the mobile node has a network interface to establish a connection with it. If MAG1 finds that the mobile node has no network interface associated with it, it will send a tunnel to MAG2 A response message, notifying that there is no such mobile node, otherwise, MAG1 will send a tunnel response message to MAG2, and establish a two-way tunnel with MAG2; Step (7): When the mobile node network interface IF1 moves to other access networks and decides to access the proxy mobile IPv6 domain through other MAGs, the mobile node sends the uplink data originally transmitted on IF1 through IF2 through decision-making; Step (8): When MAG1 detects that the mobile node IF1 is disconnected or detects that the mobile node IF1 is about to switch, it transmits the downlink data flow that was originally directly forwarded to the mobile node IF1 to MAG2 through a tunnel by setting a route. At this time, the downstream forwarding path of Flow X is LMA->MAG1->MAG2->IF2, and then send a binding update message to LMA to cancel the association between the interface and MAG1; Step (9): After the LMA receives the proxy binding update message sent by MAG1 that contains the logout information, it first decides to forward the data originally sent to the mobile node IF1 through MAG1 to MAG2. >MAG1->IF1 is changed to LMA->MAG2->IF2, then cancels the binding of mobile node IF1, sends a binding update response message to MAG1, and destroys the bidirectional tunnel established for mobile node IF1 between LMA and MAG2; Step (10): MAG1 sends a tunnel cancellation request message to MAG2 after receiving the proxy binding update response message sent back by the LMA; Step (11): After receiving the tunnel withdrawal message sent by MAG1, MAG2 sends a tunnel withdrawal response message to MAG1, and then destroys the tunnel created for the mobile node between MAG1 and MAG2. 2. according to the described agent mobile IPv6 multi-connection mobile node seamless interface handover method of claim 1, it is characterized in that, described MAG option comprises the address of all the MAG associated with this mobile node, and MAG sends to the address in the MAG option and establishes Tunnel request message, with which a bidirectional tunnel is subsequently established.