CN102131233A

CN102131233A - Method and device for sending data packet based on dual-stack (DS)-LITE

Info

Publication number: CN102131233A
Application number: CN201010001019XA
Authority: CN
Inventors: 蒋陶; 周星月
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2010-01-18
Filing date: 2010-01-18
Publication date: 2011-07-20
Anticipated expiration: 2030-01-18
Also published as: CN102131233B

Abstract

The invention discloses a method and a device for sending a data packet based on a dual-stack (DS)-LITE. In the method, an uplink data packet sent from a mobile terminal is received by a carrier grade network (CGN) through a DS-LITE tunnel; the uplink data packet is analyzed by the CGN to obtain identification information of the DS-LITE tunnel and the identification information of packet data network gateway (P-GWs); and a downlink data packet is packaged by the CGN according to the identification information of the DS-LITE tunnel, and the packaged downlink data packet is sent to the mobile terminal by the P-GW corresponding to the P-GW identification information. According to the technical scheme provided by the invention, the uniqueness of DS-LITE tunnel identification on the different P-GWs connected to the identical CGN can be ensured, so that one-to-one network address translation (NAT) mapping on internet protocol (IP) connection with the identical tunnel identification on the different P-GWs can be realized.

Description

Data packet sending method and device based on DS-LITE

Technical field

The present invention relates to the communications field, in particular to a kind of at data packet sending method and device based on two stack scaled-down versions (Dual-Stack Lite abbreviates DS-Lite as).

Background technology

Third generation partner program (3rd Generation Partnership Project, abbreviate 3GPP as) grouping system (the Evolved Packet System of evolution, abbreviate EPS as) by universal mobile telecommunications system land radio access web (the Evolved UniversalTerrestrial Radio Access Network of evolution, abbreviate E-UTRAN as), mobile management unit (Mobility Management Entity, abbreviate MME as), gateway (ServingGateway, S-GW), grouped data network gateway (Packet Data Network Gateway, abbreviate P-GW or PDN GW as), home subscriber server (Home SubscriberServer, abbreviate HSS as), "Policy and Charging Rules Function (Policy and ChargingRules Function abbreviates PCRF as) entity and other support nodes are formed.

The 6th edition (IPv6) transition method of Internet protocol just begins one's study from IETFNGTRAN working group in 1994 the earliest, setting up 6Bone in 1996 experimentizes, first group of IPv6 standard request of issue in 1998 explained (Request For Comment, abbreviate RFC as), NGTRAN working group closed in 2003, thought at that time that the mainstream technology that may occur all finished, IETF does not have the RFC that produces about IPv6 in enormous quantities afterwards, the CNGI experimental network of China also was to reach first high point in 2003/2004 year, the main IPv6 transitional technology that adopted of CNGI network design all was the relevant RFC of main IPv6 that produced at that time at that time, transitional technology is at that time mainly concentrated and is comprised: two stacks, translation and the three kinds of technology in tunnel.Until 2007, along with two stack scaled-down version (Dual-Stack Lite, abbreviate DS-Lite as), carrying level network (Carrier Grade Network Address Translation, abbreviate CGN as) address translation, the address adds port (Address+Port, abbreviate A+P as), IPv6 is to NAT technology (Network Address Translation 6 to4 of IPv4, abbreviate NAT64 as) etc. the proposition of a series of novel transitional technologies, IETF reached an agreement again in 2008 and will formulate new translation and tunneling technique.

The DS-Lite technology is the focus of ipv6 migrating technology in ietf tissue, and it can be regarded as the ingenious combination of double-stack technology and traditional NAT44 technology.Its core concept is mainly reflected in following 2 points:

1. carry the packet of ipv4 by ipv6 (perhaps tunnel) technology, make and only support the application of ipv4 can operate on the bearer network of ipv6 only.

2. the NAT mechanism of traditional ipv4toipv4 has been done tiny change, increased, thereby reached the purpose of multiplexing ipv4 private net address as the prefix of the ipv6 address of bearer network or tunnel mark a parameter as the NAT translation.Identical ipv4 private net address can allow different main frames share, and distinguishes by different ipv6 prefix or Tunnel Identifier.

Fig. 1 is that DS_LITE mainly contains two kinds of deployment way, a kind of deployment way that is based on main frame, a kind of deployment way that is based on gateway based on the network structure of the DS-LITE of gateway deployment.The difference of dual mode is: the initiation point in DS-LITE tunnel is positioned on the end host or is positioned on the gateway device.Obviously, need not change, more be adapted to the mobile network for end host based on the deployment way of gateway.The network of DS_LITE mainly comprises following functional entity as can be seen from Figure 1:

DS-lite Basic Bridging BroadBand element abbreviates B4element as

The initiation point in DS_LITE tunnel, B4 network element have the ability (for example, IPv4-in-IPv6 encapsulation ability or GRE, tunnel encapsulation abilities such as LTPv3) of DS-lite tunnel encapsulation, can be that a separate equipment also can be integrated on home gateway or the main frame.

DS-lite Address Family Transition Router element abbreviates AFTR as

The destination node in IPv4-in-IPv6 tunnel, AFTR also needs to possess the IPv4-IPv4NAT function that DS_LITE defines except the function that possesses the DS_LITE tunnel, and the NAT that the NAT of this IPv4-IPv4 is based on traditional IPv4-IPv4 revises.Main change is except the parameter as the NAT mapping with source address and port numbers, also add the parameter of DS-Lite tunnel mark (prefix that can be ipv6 also can be the GRE Key of gre tunneling etc.) as the NAT mapping, like this for having identical source private net address but the IP that is encapsulated in the different DS_LITE tunnel connect, the NAT translation just can be distinguished different IP connections according to the DS_LITE Tunnel Identifier.Therefore DS_LITE be except solving ipv4 business passing through on the ipv6 bearer network, can also realize ipv4 private net address multiplexing of private network inside simultaneously.

The problem that DS_LITE can solve has demand widely in mobile core network, how to use the DS_LITE technology at 3GPP is the hot issue of studying at present, below introduces a kind of popular technical scheme of DS_LITE of using in 3GPP.

This technical scheme is called the Dual stack Lite scheme that gateway is initiated, the tunnel initiation point that is to say DS_LITE is positioned at P-GW (grouped data network gateway), and the DS_LITE tunnel terminates and dispose CGN (the Carrier Grade Network carrying rank network equipment) at the 3GPP core network with the edge of extenal grouped network.Be equivalent to the function that P-GW realizes DS_LITE B4 network element, and CGN realizes the function of AFTR.The network structure of this kind technical scheme as shown in Figure 2.

Fig. 3 is the technology schematic diagram of the Dual stack Lite scheme of gateway initiation.As can be seen from Figure 3 adopt this technical scheme, different mobile terminal under the same P-GW can distribute the private net address of identical ipv4, UE is by mobile gateway (ServingGateway, abbreviate S-GW as) and P-GW between set up mobile tunnel, set up the DS_LITE tunnel between P-GW and the CGN, different mobile terminal can the identical ipv4 address of distribution system, but DS_LITE tunnel mark difference, PGW is responsible for connecting corresponding DS_LITE tunnel of portable terminal and mobile tunnel.For the upstream data bag of portable terminal, ipv4 private net address and port numbers according to terminal on CGN are carried out the NAT translation, note the corresponding DS_LITE Tunnel Identifier of this NAT translation simultaneously in the NAT table; For downlink data packet, CGN corresponds to public network address the private net address of portable terminal in the NAT translation, simultaneously the DS_LITE Tunnel Identifier according to record in the NAT table (specifically can referring to table 1) matches corresponding DS_LITE tunnel, downlink data is encapsulated in the DS_LITE tunnel sends to P-GW, P-GW takes out packet to be encapsulated in according to the DS_LITE tunnel of setting up and the corresponding relation between the mobile tunnel and sends to UE in the mobile tunnel again from the DS_LITE tunnel.

Table 1 is the NAT translation table according to correlation technique.As shown in table 1, the content of the left hurdle record of this NAT translation table is: private net address/port numbers of DS-LITE Tunnel Identifier/IPV4, the content of right hurdle record is: public network address/port numbers of IPV4, wherein, under the situation that only has a P-GW, according to combination shown in the left hurdle and the one-to-one relationship that makes up shown in the left hurdle, can carry out man-to-man NAT mapping.

Table 1

Private net address/port numbers of DS_LITE Tunnel Identifier/IPv4	IPv4 public network address/port numbers
		DS_LITE-1/IPV4 address a, b, c, d/TCP port one	IPV4 public network address e.f.g.h/TCP port 2

DS_LITE-2/IPV4 address a, b, c, d/TCP port 3

IPV4 public network address e.f.g.h/TCP port 4

Such scheme is changed at the edge of 3GPP core net, thereby little to the influence of network, is the optimal technical scheme of 3GPP.But also there is following problem in this method:

When disposing this technical scheme, if CGN equipment of the common connection of a plurality of P-GW is arranged, CGN can be with there being DS_LITE tunnel (specifically can referring to Fig. 4) between a plurality of P-GW, therefore the DS_LITE Tunnel Identifier of different P-GW can not repeat, but distribute voluntarily by P-GW according to prior art DS_LITE Tunnel Identifier, thereby can't guarantee to be connected the uniqueness of the DS_LITE Tunnel Identifier on the different P-GW of same CGN, when CGN is NAT, the IP with same tunnel sign on the different P-GW connected like this and can't correspond to man-to-man NAT mapping.

Summary of the invention

Problem at the uniqueness that can't guarantee to be connected the DS_LITE Tunnel Identifier on the different P-GW of same CGN in the correlation technique the invention provides a kind of data packet sending method and device based on DS-LITE, one of to address the above problem at least.

According to an aspect of the present invention, provide a kind of data packet sending method based on DS-LITE.

Data packet sending method based on DS-LITE according to the present invention comprises: the upstream data bag that carrying level network C GN sends by DS-LITE tunnel mobile terminal receive; CGN resolves the upstream data bag and obtains DS-LITE tunnel identification information and P-GW identification information; CGN is according to DS-LITE tunnel identification information encapsulation downlink data packet, and the downlink data packet after will encapsulating is sent to portable terminal via the pairing P-GW of P-GW identification information.

According to a further aspect in the invention, provide a kind of packet dispensing device based on DS-LITE.

Packet dispensing device based on DS-LITE according to the present invention comprises: first receiving element is used for the upstream data bag that sends by DS-LITE tunnel mobile terminal receive; Resolution unit is used to resolve the upstream data bag and obtains DS-LITE tunnel identification information and P-GW identification information; Transmitting element be used for according to DS-LITE tunnel identification information encapsulation downlink data packet, and the downlink data packet after will encapsulating is sent to portable terminal via the pairing P-GW of P-GW identification information.

By the present invention, when CGN receives the upstream data bag, the DS-LITE tunnel identification information and the packet data gateway P-GW identification information of upstream data bag correspondence are carried out record, solved the problem of the uniqueness that can't guarantee to be connected the DS_LITE Tunnel Identifier on the different P-GW of same CGN in the correlation technique, can guarantee to be connected the uniqueness of the DS-LITE Tunnel Identifier on the different P-GW of same CGN, carry out NAT mapping one to one thereby can connect to the IP that has the same tunnel sign on the different P-GW.

Description of drawings

Accompanying drawing described herein is used to provide further understanding of the present invention, constitutes the application's a part, and illustrative examples of the present invention and explanation thereof are used to explain the present invention, do not constitute improper qualification of the present invention.In the accompanying drawings:

Fig. 1 is the system architecture diagram according to the DS_LITE network of disposing based on gateway of correlation technique;

Fig. 2 is the schematic diagram of disposing in the 3GPP core network according to the DS_LITE technology that the gateway of correlation technique is initiated;

Fig. 3 is the schematic diagram according to the DS_LITE technical scheme of the gateway initiation of correlation technique;

Fig. 4 is when disposing gateway initiation DS_LITE scheme, the network architecture diagram that a plurality of P-GW connect with a CGN;

Fig. 5 is the flow chart of data packet sending method of the DS-LITE of the embodiment of the invention;

Fig. 6 is the flow chart of example one of the present invention;

Fig. 7 is the flow chart of example two of the present invention;

Fig. 8 is the structured flowchart of packet dispensing device of the DS-LITE of the embodiment of the invention;

Fig. 9 is the structured flowchart of packet dispensing device of the DS-LITE of the preferred embodiment of the present invention.

Embodiment

Hereinafter will describe the present invention with reference to the accompanying drawings and in conjunction with the embodiments in detail.Need to prove that under the situation of not conflicting, embodiment and the feature among the embodiment among the application can make up mutually.

According to the embodiment of the invention, provide a kind of data packet sending method based on DS-Lite.

Fig. 5 is the flow chart according to the data packet sending method of the DS-LITE of the embodiment of the invention.As shown in Figure 5, the data packet sending method according to the DS-LITE of the embodiment of the invention comprises following processing (step S502-step S506):

The upstream data bag that step S502:CGN sends by DS-LITE tunnel mobile terminal receive;

Step S504:CGN resolves the upstream data bag and obtains DS-LITE tunnel identification information and packet data gateway P-GW identification information;

Step S506:CGN is according to DS-LITE tunnel identification information encapsulation downlink data packet, and the downlink data packet after will encapsulating is sent to portable terminal via the pairing P-GW of P-GW identification information.

Adopt said method, increased the identification information of distinguishing P-GW, can guarantee to be connected the uniqueness of the DS-LITE Tunnel Identifier on the different P-GW of same CGN, thereby the downlink data packet to portable terminal to be sent can be sent to this portable terminal exactly.

Preferably, above-mentioned P-GW identification information comprise following one of at least: the identification strings of the IPV6 of the IPV6 of P-GW or IPV4 address information, P-GW or IPV4 address prefix information, P-GW, the CGN equipment interface identification information that is connected with P-GW.

Preferably, after CGN parsing upstream data bag obtained DS-LITE tunnel identification information and packet data gateway P-GW identification information, this method can also comprise following processing:

(1) CGN DS-LITE tunnel identification information and P-GW identification information that parsing is obtained formed first combination with the source address and the port numbers of upstream data bag;

(2) CGN is recorded in the source information of first combination as the NAT translation in the network address translation NAT translation table.

Preferably, when CGN parsing upstream data bag obtains DS-LITE tunnel identification information and packet data gateway P-GW identification information, also comprise following processing:

(1) CGN carries out the network address translation translation to source IPV4 address information (being IPV4 private net address information) and the source port index information that carries in the upstream data bag, translates into purpose IPV4 address information and destination interface index information;

(2) CGN forms second combination with purpose IPV4 address information (being IPV4 public network address information) and destination interface index information, and second combination also is recorded in the NAT translation table.

Wherein, above-mentioned first combination is a quaternary array, above-mentioned second combination is a binary array, specifically can be referring to table 2, the content of the left hurdle record of this NAT translation table is: the interface identifier of private net address/port numbers of DS-LITE Tunnel Identifier/IPV4/P-GW, the content of right hurdle record is: public network address/port numbers of IPV4.

Table 2

The interface identifier of private net address/port numbers of DS_LITE Tunnel Identifier/IPv4/P-GW	IPv4 public network address/port numbers
		DS_LITE-1/IPV4 address a, b, c, d/TCP port one/P-GW interface 1	IPV4 public network address e.f.g.h/TCP port 2
DS_LITE-1/IPV4 address a, b, c, d/TCP port 3/P-GW interface 2	IPV4 public network address e.f.g.h/TCP port 4

IPV4 address, above-mentioned source is equivalent to the private net address of the IPV4 shown in the left hurdle of table 2, above-mentioned source port index is equivalent to the port numbers shown in the left hurdle of table 2, above-mentioned purpose IPV4 address is equivalent to the public network address of the IPV4 shown in the right hurdle of table 2, and the above-mentioned purpose port index is equivalent to the port numbers shown in the right hurdle of table 2.The interface identifier of P-GW in the table 2 promptly is the CGN equipment interface sign that is connected with P-GW.

Can get thus, have under the situation of a plurality of P-GW, carry out NAT mapping (translation), can obtain the element information that first combination is comprised.

In the specific implementation process, in the transmission of the upstream data of portable terminal, P-GW generates the Tunnel Identifier of DS_LITE, upstream data is sealed to be contained in this DS_LITE tunnel simultaneously to send to CGN equipment; After CGN receives this packet, the DS_LITE tunnel is carried out decapsulation, while is according to the IPV4 address, source of IPv4 packet, port numbers is carried out the NAT translation, public network packet after the translation is sent to the external packet data network, meanwhile in the NAT translation table, note corresponding DS_LITE Tunnel Identifier and corresponding P-GW sign.Be described below in conjunction with example one.

Example one

Fig. 6 is the flow chart of example one of the present invention.As shown in Figure 6, the upstream data bag is sent to CGN from the P-GW encapsulation and carries out the NAT translation, afterwards the upstream data bag is sent to packet data network, and this flow process specifically comprises following processing (step S602-step S606):

Step S602: packet data gateway generates the DS_LITE Tunnel Identifier, and the upstream data bag is packaged in the DS_LITE tunnel;

Step S604:CGN unties the DS_LITE tunnel, and according to the source address port numbers, Tunnel Identifier and P-GW sign are carried out the NAT translation;

Step S606:CGN carries out NAT and translates successfully back recording address and the corresponding relation of port numbers and DS_LITE Tunnel Identifier and P-GW sign of this upstream data bag correspondence in the NAT table.

Preferably, before execution in step S506, can also comprise following processing:

(1) CGN receives the downlink data packet that comes from extenal grouped network;

(2) CGN carries out the network address translation translation to purpose IPV4 address information and the destination interface index information that carries in the downlink data packet;

(3) CGN obtains first combination according to translation result.

By said process, when carrying out NAT mapping (translation),, can carry out man-to-man map addresses according to the corresponding relation of first combination of writing down in the NAT translation table with second combination.Thereby guarantee to be connected the uniqueness of the DS-LITE Tunnel Identifier on the different P-GW of same CGN, the downlink data packet to certain portable terminal to be sent is sent to this portable terminal exactly.

Preferably, step S506 may further include following processing:

(1) CGN is encapsulated in downlink data packet in the DS-LITE tunnel according to the DS-LITE tunnel identification information that comprises in first combination that gets access to;

(2) downlink data packet after CGN will encapsulate according to the P-GW identification information is sent to the P-GW of P-GW identification information correspondence;

(3) P-GW is encapsulated in downlink data packet in the mobile tunnel and is sent to portable terminal.

In the specific implementation process, in the reception of the downlink data packet of portable terminal, CGN is the packet of the extenal grouped network that receives, translate into private net address and the port numbers of IPv4 according to the NAT table, identify according to DS_LITE Tunnel Identifier in the NAT table and P-GW simultaneously, the data envelope after the NAT translation is contained in sends to corresponding P-GW in the corresponding DS_LITE tunnel.Be described below in conjunction with example two.

Example two

Fig. 7 is the flow chart of example two of the present invention.As shown in Figure 7, downlink data packet is carried out NAT conversion by CGN, is encapsulated in the different DS-LITE tunnels again and is handed down to P-GW, and this flow process specifically comprises following processing (step S702-step S708):

Step S702:CGN receives the packet that extenal grouped network sends;

Step S704:CGN is according to IP address and port numbers, and the Tunnel Identifier in the NAT table and P-GW sign are carried out the NAT translation to packet;

Step S706:CGN sends to packet data gateway with downlink data packet by the DS-LITE tunnel according to the result of NAT translation;

Step S708: packet data gateway receives after the packet, and the DS_LITE tunnel is carried out decapsulation, according to the corresponding relation in DS-LITE tunnel and mobile tunnel data envelope is contained in the mobile tunnel and is transmitted to portable terminal.

According to the embodiment of the invention, also provide a kind of packet dispensing device based on DS-Lite.

Fig. 8 is the structured flowchart according to the packet dispensing device of the DS-LITE of the embodiment of the invention.As shown in Figure 8, the packet dispensing device according to the DS-LITE of the embodiment of the invention comprises: first receiving element 1, resolution unit 2, transmitting element 3.

First receiving element 1 is used for the upstream data bag that sends by DS-LITE tunnel mobile terminal receive;

Resolution unit 2 is used to resolve the upstream data bag and obtains DS-LITE tunnel identification information and packet data gateway P-GW identification information;

Transmitting element 3 be used for according to DS-LITE tunnel identification information encapsulation downlink data packet, and the downlink data packet after will encapsulating is sent to portable terminal via the pairing P-GW of P-GW identification information.

Adopt this device, increased the identification information of distinguishing P-GW, can guarantee to be connected the uniqueness of the DS-LITE Tunnel Identifier on the different P-GW of same CGN, thereby the downlink data packet to portable terminal to be sent can be sent to this portable terminal exactly.

Preferably, as shown in Figure 9, said apparatus can also comprise: first assembled unit 4, be used for DS-LITE tunnel identification information and P-GW identification information that parsing is obtained, and form first combination with the source address and the port numbers of upstream data bag; First record cell 5 is used for the source information of first combination as the NAT translation is recorded in the network address translation NAT translation table.

Preferably, as shown in Figure 9, said apparatus also comprises: first translation unit 6, the source IPV4 address information and the source port index information that are used for the upstream data bag is carried carry out the network address translation translation, translate into purpose IPV4 address information and destination interface index information.Second assembled unit 7 is used for purpose IPV4 address information and destination interface index information are formed second combination; Second record cell 8 is used for second combination is recorded in the NAT translation table.

Preferably, as shown in Figure 9, said apparatus can also comprise: second receiving element 9 is used to receive the downlink data packet that comes from extenal grouped network; Second translation unit 10, the purpose IPV4 address information and the destination interface index information that are used for downlink data packet is carried carry out the network address translation translation; Acquiring unit 11 is used for obtaining first combination according to translation result.

Preferably, as shown in Figure 9, above-mentioned transmitting element 3 may further include: package module 30 is used for according to the DS-LITE tunnel identification information that first combination that gets access to comprises downlink data packet being encapsulated in the DS-LITE tunnel; First sending module 32, the downlink data packet after being used for will encapsulating according to the P-GW identification information is sent to the P-GW of P-GW identification information correspondence; Second sending module 34 is used for that downlink data packet is encapsulated in mobile tunnel and is sent to portable terminal.

In sum, by the foregoing description provided by the invention, solved the problem of the uniqueness that can't guarantee to be connected the DS_LITE Tunnel Identifier on the different P-GW of same CGN in the correlation technique, can guarantee to be connected the uniqueness of the DS-LITE Tunnel Identifier on the different P-GW of same CGN, can connect the IP that has the same tunnel sign on the different P-GW and carry out NAT mapping one to one, thereby the downlink data packet to portable terminal to be sent can be sent to this portable terminal exactly.

Obviously, those skilled in the art should be understood that, above-mentioned each module of the present invention or each step can realize with the general calculation device, they can concentrate on the single calculation element, perhaps be distributed on the network that a plurality of calculation element forms, alternatively, they can be realized with the executable program code of calculation element, thereby, they can be stored in the storage device and carry out by calculation element, and in some cases, can carry out step shown or that describe with the order that is different from herein, perhaps they are made into each integrated circuit modules respectively, perhaps a plurality of modules in them or step are made into the single integrated circuit module and realize.Like this, the present invention is not restricted to any specific hardware and software combination.

The above is the preferred embodiments of the present invention only, is not limited to the present invention, and for a person skilled in the art, the present invention can have various changes and variation.Within the spirit and principles in the present invention all, any modification of being done, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims

1. the data packet sending method based on two stack scaled-down version DS-LITE is characterized in that, comprising:

The upstream data bag that carrying level network C GN sends by DS-LITE tunnel mobile terminal receive;

Described CGN resolves described upstream data bag and obtains DS-LITE tunnel identification information and packet data gateway P-GW identification information;

Described CGN is according to described DS-LITE tunnel identification information encapsulation downlink data packet, and the described downlink data packet after will encapsulating is sent to described portable terminal via the pairing P-GW of described P-GW identification information.

2. method according to claim 1 is characterized in that, described P-GW identification information comprise following one of at least:

The identification strings of the IPV6 of the IPV6 of P-GW or IPV4 address information, P-GW or IPV4 address prefix information, P-GW, the CGN equipment interface identification information that is connected with P-GW.

3. method according to claim 1 and 2 is characterized in that, resolves after described upstream data bag obtains DS-LITE tunnel identification information and packet data gateway P-GW identification information at described CGN, and described method also comprises:

Described DS-LITE tunnel identification information and described P-GW identification information that described CGN obtains parsing are formed first combination with the source address and the port numbers of upstream data bag;

Described CGN is recorded in the source information of described first combination as the NAT translation in the network address translation NAT translation table.

4. method according to claim 1 and 2 is characterized in that, described CGN resolves described upstream data bag when obtaining DS-LITE tunnel identification information and packet data gateway P-GW identification information, and described method also comprises:

Described CGN carries out the network address translation translation to source IPV4 address information and the source port index information that carries in the described upstream data bag, translates into purpose IPV4 address information and destination interface index information;

Described CGN forms second combination with described purpose IPV4 address information and described destination interface index information, and described second combination is recorded in the described NAT translation table.

5. method according to claim 4 is characterized in that, before described CGN was according to described DS-LITE tunnel identification information encapsulation downlink data packet, described method also comprised:

Described CGN receives the described downlink data packet that comes from extenal grouped network;

Described CGN carries out the network address translation translation to described purpose IPV4 address information and the described destination interface index information that carries in the described downlink data packet;

Described CGN obtains described first combination according to translation result.

6. method according to claim 5, it is characterized in that, described CGN is according to described DS-LITE tunnel identification information encapsulation downlink data packet, and the described downlink data packet after will encapsulating is sent to described portable terminal via the pairing P-GW of described P-GW identification information and comprises:

Described CGN is encapsulated in described downlink data packet in the described DS-LITE tunnel according to the described DS-LITE tunnel identification information that comprises in described first combination that gets access to;

Described downlink data packet after described CGN will encapsulate according to described P-GW identification information is sent to the described P-GW of described P-GW identification information correspondence;

Described P-GW is encapsulated in described downlink data packet and is sent to described portable terminal in the mobile tunnel.

7. the packet dispensing device based on two stack scaled-down version DS-LITE is characterized in that, comprising:

First receiving element is used for the upstream data bag that sends by DS-LITE tunnel mobile terminal receive;

Resolution unit is used to resolve described upstream data bag and obtains DS-LITE tunnel identification information and packet data gateway P-GW identification information;

Transmitting element be used for according to described DS-LITE tunnel identification information encapsulation downlink data packet, and the described downlink data packet after will encapsulating is sent to described portable terminal via the pairing P-GW of described P-GW identification information.

8. device according to claim 7 is characterized in that, described device also comprises:

First assembled unit is used for described DS-LITE tunnel identification information and described P-GW identification information that parsing is obtained, forms first combination with the source address and the port numbers of upstream data bag;

First record cell is used for the source information of described first combination as the NAT translation is recorded in the network address translation NAT translation table.

9. device according to claim 8 is characterized in that, described device also comprises:

First translation unit, the source IPV4 address information and the source port index information that are used for described upstream data bag is carried carry out the network address translation translation, translate into purpose IPV4 address information and destination interface index information;

Second assembled unit is used for described purpose IPV4 address information and described destination interface index information are formed second combination;

Second record cell is used for described second combination is recorded in described NAT translation table.

10. device according to claim 9 is characterized in that, described device also comprises:

Second receiving element is used to receive the described downlink data packet that comes from extenal grouped network;

Second translation unit, the described purpose IPV4 address information and the described destination interface index information that are used for described downlink data packet is carried carry out the network address translation translation;

Acquiring unit is used for obtaining described first combination according to translation result.

11. device according to claim 10 is characterized in that, described transmitting element comprises:

Package module is used for according to the described DS-LITE tunnel identification information that described first combination that gets access to comprises described downlink data packet being encapsulated in the described DS-LITE tunnel;

First sending module, the described downlink data packet after being used for will encapsulating according to described P-GW identification information is sent to the described P-GW of described P-GW identification information correspondence;

Second sending module is used for that described downlink data packet is encapsulated in mobile tunnel and is sent to described portable terminal.