WO2012083657A1

WO2012083657A1 - Packet processing method, system and customer premises equipment

Info

Publication number: WO2012083657A1
Application number: PCT/CN2011/076120
Authority: WO
Inventors: 魏志峰
Original assignee: 刘建
Priority date: 2010-12-20
Filing date: 2011-06-22
Publication date: 2012-06-28
Also published as: CN102546362A

Abstract

The present invention discloses a packet processing method, system and a customer premises equipment. The method includes following steps: a customer premises equipment (CPE) obtains an address of a tunnel end point and establishes a tunnel by use of the Dual-Stack Lite (DS-Lite); first packets, which are upward from an equipment on the local area network (LAN) side, are encapsulated as second packets and forwarded to a carrier grade network device (CGN) via the tunnel; the second packets sent by the CGN via the tunnel are received, de-capsulated as the first packets and forwarded to the equipment on the LAN side.

Description

Message processing method, system and user front end device

Technical field

The present invention relates to communication technologies, and in particular, to a message processing method, system, and user front end device. Background technique

The rapid development of the Internet has made the current IPv4 address increasingly exhausted. It is inevitable to migrate to IPv6. In this migration process, the original solution assumes that all network nodes, user-side applications, and various application services of the server are simultaneously The dual-stack form migrates to IPv6. According to current practice, this assumption conflicts with the industrial business model, because the dual-stack technology itself also consumes IPv4 addresses, which leads to the exhaustion of IPv4 addresses during the implementation of the dual-stack migration scheme. Will be resolved. The improved network address translation (NAT) 444 is a NAT that deploys IPv4->IPv4 on the carrier side. A large number of users purchase a home gateway with NAT function because of the need for multiple terminals to access the Internet at the same time, thus interacting with the bearer-level network device. (Carrier-Grade NAT, CGN) together form a dual NAT, and it is very difficult to develop a traversal protocol for dual/multiple NAT at the network level. It can only be applied from the application through NAT User Data Protocol (UDP) Simple Traversal (STUN). The realization of NAT, as the important considerations in the development of application software and services, related equipment upgrades, re-addressing, etc. will also bring greater overhead, resulting in increased cost and complexity.

Dual-Stack Lite (DS-Lite) is mainly used for network access. It involves network layer and transport layer protocol functions. It temporarily separates IPv6 deployment at the network level from IPv6 deployment at the user level and service level. Therefore, at the network level, the problem of IPv4 address exhaustion faced by operators is concentrated, and IPv6 deployment is promoted. DS-Lite is a combination of "tunneling technology (IPv4 in IPv6 tunnel)" and "improved network address translation (NAT) technology". It implements IPv4 private network addresses for users on the local area network (LAN) side, and through IPv6 tunnels and bearer-level network devices. Double conversion of NAT on (Carrier-Grade NAT, CGN) completes access to wide area network (WAN) side (IPv4) resources. In the initial stage of the deployment of the DS-Lite solution, the main meaning of the IPv6 network connection is to provide "the tunnel of the IPv4 user to its gateway" and assist in the completion of IPv4 address sharing (Tunnel-ID based v4 NAT). But with the support side of IPv6 on the user side and the server side Gradually popular and mature, it can ensure the smooth transition of the network to IPv6.

However, the DS-Lite solution does not include the translation interworking mechanism between IPv4 and IPv6, because the access of the node to the IPv4 network and applications will be through IPv4, and the access to the IPv6 network services and applications will be through IPv6; Interworking between an IPv4 network and a WAN-side IPv4 network. Summary of the invention

In order to solve the above technical problem, the present invention provides a packet processing method, system, and user front-end device to implement interworking between a LAN-side IPv4 network and a WAN-side IPv4 network.

The present invention provides a message processing method, which includes:

The user front end device (CPE) obtains the tunnel endpoint address and uses a lightweight dual stack (DS-Lite) to establish a tunnel;

The first packet in the uplink of the local area network (LAN) device is encapsulated into a second packet, and forwarded to the bearer-level network device (CGN) through the tunnel;

Receiving a second packet sent by the CGN through the tunnel, decapsulating the second packet into a first packet, and forwarding the packet to the LAN side device.

Preferably, the above processing method can have the following characteristics:

The step of the CPE acquiring the tunnel endpoint address includes:

The CPE obtains the tunnel endpoint address through the Dynamic Host Setup Protocol (DHCP) option. Preferably, the above processing method can also have the following features:

After the first packet of the uplink of the LAN device is encapsulated into the second packet, and the packet is forwarded to the CGN through the tunnel, the method further includes:

The CGN decapsulates the received second packet into a first packet, and forwards the packet to a wide area network (WAN) side device.

Preferably, the above processing method can also have the following features:

And in the step of decapsulating the received second packet into the first packet by the CGN, and forwarding the packet to the WAN side device,

The CGN updates the address information in the address mapping table according to the first packet, and the address information packet Contains the translated source address and the unconverted destination address.

Preferably, the above processing method can also have the following features:

After the CGN is decapsulated into the first packet and forwarded to the WAN device, the method further includes:

When the CGN receives the first packet returned by the WAN device, the CGN learns the address to be forwarded according to the address mapping table, and encapsulates the first packet into a second packet, and forwards the packet to the CPE, where the CPE performs the The second packet is decapsulated into a first packet and forwarded to the LAN device corresponding to the address.

The present invention also provides a user front end device (CPE), the CPE comprising:

Establish a module, which is set to: obtain a tunnel endpoint address, and establish a tunnel by using a lightweight dual stack (DS-Lite);

a packet forwarding module, configured to: encapsulate the first packet of the uplink of the local area network (LAN) device into a second packet, and forward the packet to the bearer-level network device (CGN) through the tunnel;

And a decapsulation and forwarding module, configured to: receive the second packet sent by the CGN through the tunnel, decapsulate the second packet into a first packet, and forward the packet to the LAN device.

Preferably, the above CPE can have the following characteristics:

The CPE is set to: Obtain a tunnel endpoint address through the Dynamic Host Setup Protocol (DHCP) option.

The present invention also provides a packet processing system including the above CPE and bearer level network equipment (CGN), wherein:

The bearer-level network device (CGN) is configured to: after receiving the second packet forwarded by the CPE, decapsulate the second packet into a first packet, and forward the packet to a wide area network (WAN) side device. .

Preferably, the above processing system can have the following characteristics:

The CGN is configured to: in the process of decapsulating the second packet into the first packet, and forwarding the packet to the wide area network (WAN) device, updating the address mapping table according to the first packet Address information, the address information includes the converted source address and the unconverted destination address.

Preferably, the above processing system can also have the following features:

The CGN is further configured to: when receiving the first message returned by the WAN side device, according to The address mapping table learns the address to be forwarded, and encapsulates the first packet into a second packet and forwards the packet to the CPE, and then the CPE decapsulates the second packet into the first packet and forwards the packet to the address. Corresponding LAN side device.

The above-mentioned four-dimensional processing method, system and user front-end device can realize interworking between two networks.

BRIEF abstract

1 is a flowchart of a packet processing method according to an embodiment of the present invention;

2 is a schematic diagram of a network networking according to an embodiment of the present invention;

3 is a schematic diagram of a logical structure of an embodiment of a tunnel according to an embodiment of the present invention;

4 is a schematic diagram of a packet forwarding path according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a CPE according to an embodiment of the present invention; FIG.

FIG. 6 is a schematic structural diagram of a message processing system according to an embodiment of the present invention.

Preferred embodiment of the invention

The embodiments are described below with reference to the drawings. It should be noted that the present invention can be explained by the following embodiments, but is not limited to the following embodiments. As shown in FIG. 1 , it is a flowchart of a packet processing method according to the present invention. The method is described from a CPE side, and the method includes:

Step 101: The user front-end device (CPE) obtains the tunnel endpoint address, and uses DS-Lite to establish a tunnel.

The CPE can obtain the tunnel endpoint address through the Dynamic Host Configuration Protocol (DHCP) option to establish a tunnel such as an IPv4 in IPv6 tunnel.

Step 102: The first packet sent by the local area network (LAN) device is encapsulated into a second packet, and forwarded to the bearer-level network device (CGN) through the tunnel.

The first packet may be an IPv4 packet, and the second packet may be an IPv6 packet. The first packet and the second packet may be other types of packets, where the IPv4 packet is used. And IPv6 is only an example; After the step, the method further includes: the CGN decapsulating the received second packet into a first packet, and forwarding the packet to the wide area network (WAN) side device; where, the CGN pairs the received second packet solution In the process of being encapsulated into the first packet and forwarded to the WAN device, the CGN updates the address information in the address mapping table according to the first packet, where the address information includes the converted source address and the untransformed destination address. When the CGN receives the first packet returned by the WAN device, the IP address is obtained according to the address mapping table, and the first packet is encapsulated into a second packet and forwarded to the CPE;

Optionally, the LAN side device may be an IPv4 host that uses a private network address, and accesses an external IPv4 network through an IPv6 network composed of a CPE and a DS-Lite device.

Step 103: Receive a second packet sent by the CGN through the tunnel, and decapsulate the second packet into a first packet, and forward the packet to the LAN device.

The packet processing method establishes a tunnel between the DS-Lite and the CGN on the CPE terminal device, so that two networks, such as an IPv4 network, can communicate with each other, and an IPv6 network exists between the two IPv4 networks.

As shown in FIG. 2, it is a schematic diagram of a network networking of the present invention, where the network networking includes a LAN side PC.

(ie user host) 21, CPE 22, CGN23 and tunnel termination point (AFTR) 24; CPE as a DS-LITE client (Client), IPV4 message to and from CGN/LAN or IPV4-IN-IPV6 tunnel^ The encapsulation and decapsulation of the text enable seamless interaction between the CGN device and the LAN side device.

On the LAN side of the CPE, the IPV4 packet is mainly carried, and the WAN side link is mainly the IPV6 packet. The IPV6 packet includes the general IPV6 packet and the IPV4-IN-IPV6 packet.

As a DS-LITE server (Server), in addition to being responsible for tunneling with the CPE, the CGN also has a NAT function to implement mutual conversion of the IP V4 private network address to the public network address, thereby realizing access to the WAN-side IPV4 resource. Specifically, an address mapping table is maintained on the CGN, and the records in the address mapping table are generated by the data flow message information (the mapping record is deleted after the address aging). The CGN translates the source address in the packet sent by the CPE, and the destination address is still the public network address, and the packet is sent. When the IPv4 public network returns the data packet, the IPv4 public network can find the private network address to be forwarded by searching the table, and Forward the message to the CPE. As shown in FIG. 3, it is a schematic diagram of a logical structure of an embodiment of a tunnel according to the present invention. The tunnel logically includes two endpoints, each of which may correspond to a network device, and at the A end, the interface to the IPv4-in-IPv6 tunnel Tunl46 The IPv4 packet is encapsulated and sent to the B-end. The IPv6 header of the received IPv4-in IPv6 packet is stripped and converted to an IPv4 packet for further forwarding. The functions of the two ends of the tunnel are symmetrical. At both ends of A and B, IPV6-based communication is used. When A sends a packet to B, it knows at least the local address and the peer address of the tunnel, which are used as the source address and destination address of the IPV6 header respectively. As a DS-LITE client, the CPE implements a tunnel processing module (Tunl46) 31 functional entity in the kernel part.

As shown in FIG. 4, which is a schematic diagram of a packet forwarding path according to the present invention, first, the configuration management module 41 configures related information provided on the visual interface or remote management to the WAN connection processing module 42; the WAN connection processing module 42 creates a virtual device nbif and Creating routing information into the routing table, the tunnel configuration management module 43 obtains tunnel related information from the WAN connection processing module 42 and configures the information to the tunnel processing module 44, and then the tunnel processing module 44 establishes a tunnel based on the information; the DNS processing module 45 has a DNS The Proxy function, according to the configuration, sends the LAN-side IPV4 DNS request to the IPV6 DNS on the WAN connection from the designated or default IPV6 WAN connection, and returns the corresponding DNS response message to the LAN-side device; The packet forwarding path is as follows:

401. The LAN destination host (HOST) uplink destination IP address is the public network IP IPv4 packet: from the LAN side host host to ethx, from ethx to brO, then to the tunnel Tunl46, and then to nbif (tunl46 to nbif forwarding) Can be implemented according to the configuration of IPv6 routing), from nbif to CGN;

402. The CPE local application generates an IPv4 packet whose destination IP address is the public network IP address:

The local application APP routes to the tunnel Tunl46, and then to nbif, from nbif to CGN;

403, the CPE local application generates, the destination address global (Global) IPv6 IPv6 text: the local application APP routes to nbif, and then nbif to CGN;

404. The WAN-side downlink IPv4 destination is not an IPv4-in-IPv6 tunnel message of the CPE local address:

From CGN to nbif, the tunnel protocol receives the packet and transfers it to the tunnel Tunl46, which is routed from v4 to brO, then from brO to ethx, and finally from ethx to the LAN side host. After the tunnel packet is unblocked by the tunel46, the tunnel packet is routed to the brO through the IPv4 protocol stack and then forwarded through the bridge.

405. The WAN-side downlink IPv4 destination is an IPv4-in-IPv6 tunnel packet of the CPE local address: from CGN to nbif, the tunneling protocol receives the packet to the tunnel Tunl46, and then tunnels to the IPv4 protocol stack, and then to the local application;

406. Other IPv6 packets in the LAN side uplink or WAN side downlink:

Forwarded or submitted to the CPE for application processing between WAN/LAN according to the IPv6 protocol stack. As shown in FIG. 5, it is a schematic structural diagram of a CPE according to the present invention. The CPE includes: an establishing module 51, a package forwarding module 52, and a decapsulation forwarding module 53. The establishing module 51 is configured to obtain a tunnel endpoint address and use a lightweight The dual-stack (DS-Lite) establishes a tunnel; the encapsulation and forwarding module 52 is configured to encapsulate the first packet of the uplink of the local area network (LAN) device into a second packet, and forward the packet to the bearer-level network device (CGN) through the tunnel. The decapsulation and forwarding module 53 is configured to receive the second packet sent by the CGN through the tunnel, and decapsulate the second packet into the first packet, and forward the packet to the LAN device.

The CPE can be used to obtain a tunnel endpoint address through a Dynamic Host Setup Protocol (DHCP) option.

The CPE can have the following functions: The CPE can assign an IPv4 private network address (192.xxx) to the LAN device, and assign a gateway and a domain name server (DNS) address to it, and the default is a CPE LAN side address, such as 192.168.1.1; Supports IPv4 and IPv6 dual stacks, and obtains IPv6 global addresses and corresponding gateways, DNS addresses, etc. from the WAN side through Ethernet-based Point-to-Point Protocol (PPPoE) or Ethernet-based Internet Protocol (IPoE); CPE support An IPv4-in-IPv6 tunnel is set up to establish an IPv6 tunnel with the CGN. The IPv4 packet is forwarded to the CGN and then forwarded to the CGN. The packet is forwarded to the LAN. The side device; the CPE has a DNS proxy function, and sends the LAN side IPv4 DNS request from the specified or default IPv6 WAN connection to the IPv6 DNS on the WAN connection according to the configuration, and returns the corresponding DNS response message. For LAN side devices; CPE also has a specific DHCPV6 option (options) to get and receive specific configuration information from the WAN side (eg tunnel related information, V4 DNS) feature. The CPE of the present invention uses the DHCP V6 Options to obtain the AFTR address, and then establishes a tunnel, which improves the flexibility of the actual use of the system.

FIG. 6 is a schematic structural diagram of a 3⁄4 text processing system according to the present invention. The system includes: a CPE 61 and a bearer level network device (CGN) 62, wherein the structure of the CPE 61 is as shown in FIG. The same function has the same function and is not described here. The bearer-level network device (CGN) 62 is configured to decapsulate the second packet after receiving the second packet forwarded by the CPE 61. It is the first packet and forwarded to the wide area network (WAN) side device.

Preferably, the CGN 62 may be configured to update the address mapping table according to the first packet in the process of encapsulating the second packet into the text and forwarding to the wide area network (WAN) side device. Address information in the address information, including the converted source address and the unconverted destination address.

In addition, the CGN 62 is further configured to: when receiving the first packet returned by the WAN side device, learn the address to be forwarded according to the address mapping table, and encapsulate the first packet into the second packet to be forwarded to the second packet. The CPE 61, the CPE 61 decapsulates the second packet into a first packet and forwards the packet to the LAN device corresponding to the address.

The communication system, through the interaction of CPE 61 and CGN 62, enables the two networks to communicate.

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. It should be understood by those skilled in the art that the present invention may be modified or equivalently substituted without departing from the spirit and scope of the invention.

Industrial applicability The "^艮文 processing method, system and user front-end device of the present invention can realize interworking between two networks.

Claims

Claim

1. A text processing method, the method comprising:

2. The packet processing method according to claim 1, wherein the step of the CPE acquiring the tunnel endpoint address comprises:

The CPE obtains the tunnel endpoint address through the Dynamic Host Setup Protocol (DHCP) option.

The packet processing method according to claim 1, wherein after the first packet of the uplink of the LAN device is encapsulated into the second packet and forwarded to the CGN through the tunnel, the method further includes:

The CGN decapsulates the received second packet into a first packet, and forwards the packet to the WAN.

(WAN) side device.

The packet processing method according to claim 3, wherein in the step of decapsulating the received second packet into the first packet by the CGN, and forwarding the packet to the WAN device,

The CGN updates the address information in the address mapping table according to the first packet, and the address information includes the converted source address and the unconverted destination address.

The packet processing method according to claim 4, wherein after the CGN decapsulates the received second packet into the first packet and forwards the packet to the WAN device, the method further includes:

When the CGN receives the first packet returned by the WAN side device, the IP address is forwarded to the CPE according to the address mapping table, and the first packet is encapsulated into a second packet and forwarded to the CPE. The second packet is decapsulated by the CPE into a first packet and forwarded to the LAN device corresponding to the address.

6. A user front end device (CPE), the CPE comprising:

7. The CPE of claim 6 wherein:

The CPE is set to obtain a tunnel endpoint address through the Dynamic Host Setup Protocol (DHCP) option.

8. A message processing system comprising the user front end equipment (CPE) of claim 6 or 7, the system further comprising a bearer level network device (CGN), wherein:

9. The message processing system according to claim 8, wherein:

10. The message processing system according to claim 9, wherein:

The CGN is further configured to: when receiving the first packet returned by the WAN device, learn the address to be forwarded according to the address mapping table, and encapsulate the first packet into the second packet and forward the packet to the CPE. The second packet is decapsulated by the CPE into a first packet and forwarded to the LAN device corresponding to the address.