A mobile ipv4 data packet processing method, device and system thereof

Abstract

The present invention provides a method and device for forwarding mobile IPv4 data in communication network access equipment and a corresponding access communication network system. The system includes mobile nodes, network access equipment, and some or all of them with external agent functions. Several edge routers, wherein the network access device listens to the mobile IPv4 control message between the mobile node and the edge router, analyzes the control message, establishes a corresponding data forwarding table, and uploads the , The downlink mobile IP data packet is forwarded to the corresponding edge router or mobile node. The invention effectively solves the problem of supporting mobile IPv4 in the existing access network system.

Description

technical field [0001] The invention relates to the technical field of communication, in particular to a method, device and system for processing data packets supporting mobile IPv4 in an access network communication system. Background technique [0002] With the continuous development of Internet applications and the widespread use of portable and handheld computers, people's requirements for mobility support are also increasing. Mobile IP (such as Mobile IPv4) is proposed to provide the mobility of hosts. figure 1 Contains the following functional entities involved in the Mobile IPv4 standard proposed by IETF (Internet Engineering Task Force): Mobile Node (MN) 101, a host that can move on the Internet, such as network devices such as notebook computers, mobile phones, and PDAs , and can maintain ongoing communication sessions during the moving process; peer node (CN) 102, a peer host or other network device that communicates with MN; home agent (HA) 103, a router that mai...

AI Technical Summary

Problems solved by technology

Layer 2 / 3 network access devices 121 such as DSLAM (Digital Subscriber Office Equipment) usually listen to DHCP (Dynamic Host Configuration Protocol) messages, and extract MAC address information, IP addresses, And other network parameters (such as the default router) and record port information, establish and maintain the corresponding FIB (Forwarding Information Base) and forward the uplink and downlink IP data packets according to the FIB, but the DHCP snooping method is very important to the mobile There will be the following problems when the IPv4 data packet is forwarded: when the mobile node 101 moves to the visited network 120, obtains a foreign agent care-of address FACOA by receiving an agent advertisement message from the FA 104 and registers with the FA 104, the aforementioned DHCP snooping method obtains The FIB of the mobile node does not include the mapping relationship between the current port of the mobile node and the HoA (home address), so that the mobile IPv4 data packet from the foreign agent FA cannot be correctly forwarded to the mobile node 101

[0004] In addition, with the development of mobile services, the number of mobile nodes will increase day by day. figure 2 In the illustrated mobile IP communication network system structure, the new foreign agent 204b and the edge router 204c will be deployed at the edge of the access network. Registration or data exchange, or when the mobile node 201b with a configured care-of address CoCoA expects to register and exchange data with the home agent through the foreign agent 204b (or edge router 204c), the mobile IPv4 control message sent by the mobile node 201a, 201b And the IP data packet will first be forwarded to the default router 204a by the network access device 221 according to the FIB established in the aforementioned DHCP snooping mode, rather than directly forwarding to the foreign agent 204b, which the mobile node 201a data packet destination IP address points to. And the foreign agent 204b (or edge router 204c) that mobile node 201b data packet destination IP address points to, will make the default router 204a in the access network system 220 be in overload state (shown in figure 20A) like this; Another problem is, in In the communication network access system, the allocation of IP address pools (subnet space) is generally adjusted according to specific usage conditions. When an IP address pool is exhausted, it is allocated to another new address pool. The address pool space owned by default router 204a, foreign agent 204b, and edge router 204c may be different and non-continuous. Network access equipment 221 such as DSLAM forwards the destination network address issued by mobile node 201a to foreign agent During the mobile IPv4 control message and IP data packet of 204b, or when forwarding the destination network address that mobile node 201b sends is the mobile IPv4 control message and IP data packet of foreign agent 204b (or edge router 204c), if the default router 204a is set "Secured ARP option" does not respond to ARP requests that are not in the same subnet range, and the network access device 221 cannot obtain the MAC address corresponding to the default router 204a interface, and will not be able to forward the aforementioned data packets and discard them (Fig. Show 22A)

Images