IPv6 address distribution method in 3GPP network
Technical field
The invention belongs to network communication field, particularly relate to the IPv6 address distribution method in a kind of 3GPP network.
Background technology
Compared with 2G, 3G network, except providing except speech business, can also provide all kinds of high-speed data service.In the near future.Replacement access in radio is become main Internet access method by wireless access, and the wireless terminal of huge number brings huge IP address need.IPv6 has enough address spaces to ensure that each terminal obtains publicly-owned address, need not use NAT (network address translation), and this simple connection mode is end to end of value to carrying out of value-added service.In addition, the advantage of IPv6 in mobility and fail safe is also the reason of its attraction 3G standardization tissue.
3GPP is one of main now 3G standardization tissue.It is paid much attention to the application of IPv6 in 3G network and it is considered as the basis of following complete IP network.In complete IP network, comprise all business of voice all packetized after be placed on IPv6 and transmit.Various piece in network be all unified in one relatively stable and under widely used network layer protocol, this is by greatly simplified network structure and create the platform of an opening for carrying out various value-added service.Consider the particularity of wireless network environment, the IPv6 address assignment in 3GPP network is more more complex than general network.
Identical with general network in step of IPv6 address allocation procedure in 3GPP network, all first use an interface identifier link generation local address, then the communication in link range is started, from generate after router obtains network prefix global range can IPv6 address, complete Address Autoconfiguration.Because the bandwidth resources of wireless network are nervous especially, although 3GPP some details to Address Autoconfiguration are revised, but the IPv6 address allocation plan of amended 3GPP and existing standard is incompatible, a lot of IPv6 can be caused to apply cannot use in 3GPP network, the deployment of serious obstruction IPv6 in 3GPP network.
IETF proposes its improvement project, although the scheme of IETF solves the problem that former 3GPP scheme is brought.But it is excessive to the consumption of IPv6 address space.The feasibility of relevant criterion maker to its scheme of IETF is also analyzed, and drawn the promising results that address space enough uses, but along with the fast development of various networking technology, the various equipment comprising household electrical appliance all will become a member of internet, it seems now that address space more than sufficient may be just enough till that time, to think that 3GPP network seeks more meticulous address allocation plan be necessary.
Summary of the invention
The problem that the consumption of address allocation plan to IPv6 address space proposed for the incompatibility problem about former 3GPP scheme mentioned in background technology and IETF is excessive, the present invention proposes the IPv6 address distribution method in a kind of 3GPP network.
An IPv6 address distribution method in 3GPP network, is characterized in that, described method specifically comprises step:
Step 1: when user equipment (UE) needs to connect external network APN, described user equipment (UE) sends activation message by link PDP Context to the GPRS serving GPRS support node SGSN of position, points to corresponding external network APN;
Step 2:GPRS serving GPRS support node SGSN resolves this external network APN, and sends establishment message to corresponding GPRS Support Node gateway GGSN;
Step 3:GPRS support node gateway GGSN distributes multiple 64bit network prefix to each link PDP Context, and existing 64bit network prefix is further divided, the network prefix producing 2n 64+n bit distributes to link PDP Context, the size of n is decided in its sole discretion according to network condition by operator, then sends establishment response message by link PDP Context to GPRS serving GPRS support node SGSN;
Step 4:GPRS serving GPRS support node SGSN sends activation by link PDP Context to user equipment (UE) and accepts message;
Step 5: user equipment (UE) receives activation by link PDP Context and accepts message, for link PDP Context produces the interface identifier of 64-n bit voluntarily, link PDPContext completes activation since then, and user equipment (UE) begins through the communication that link PDP Context and GPRS Support Node gateway GGSN carries out link range;
Step 6: user equipment (UE) obtains network prefix from GPRS Support Node gateway GGSN, obtain after combining with interface identifier global range can IPv6 address; Complete the Address Autoconfiguration for this link PDPContext, user equipment (UE) begins through IPv6 address and accesses the external network be connected with GPRS Support Node gateway GGSN.
It is different from each other that described GPRS Support Node gateway GGSN distributes multiple 64bit network prefix to each link PDP Context.
Described method does not use the fixed boundary of 64bit.
Although the address assigning step of the program meets standard completely, owing to not using the fixed boundary of 64bit, so Virtual network operator also needs to carry out some amendments to the IPv6 on UE.Below by illustrate this amendment cost and impact be all very little:
1) common IPv6 main frame can convert by the MAC Address of its Ethernet card the interface identifier obtaining 64bit easily, but the 3GPP data terminal of the overwhelming majority does not have Ethernet interface.They can adopt other algorithm to produce the interface identifier of different length.Virtual network operator only needs that its interface identifier is produced algorithm and is solidificated in SIM card.The appropriate section of the IPv6 of standard in replacement data terminal, SIM card capacity is now increasing, and this point is not difficult to accomplish.
2) whether the makers of IPv6 standard are always with regard to adopting the various piece in fixing boundary separates IPv6 address to have dispute, change to prevent future noise policy.Existing IPv6 realizes all should based on variable boundary.The present invention realizes doing experiment to the IPv6 on windows platform and Linux platform, and they all can accept the network prefix of variable-length.
3) current router is to the process of IP message and routing all based on longest prefix match, and whether it and the hierarchical structure be indifferent in IP address, adopt fixed boundary not affect it.
The invention has the beneficial effects as follows, the address allocation plan of proposition, both without the problem consuming address space excessively, achieves with existing standard compatible with less cost again.
Accompanying drawing explanation
Fig. 1 is the network structure of universal mobile telecommunications system UMTS;
Fig. 2 is packet switched ps domain structure;
Fig. 3 is the corresponding relation figure between PDP Context and IP link.
Embodiment
Below in conjunction with accompanying drawing, preferred embodiment is elaborated.It should be emphasized that following explanation is only exemplary, instead of in order to limit the scope of the invention and apply.
An IPv6 address distribution method in 3GPP network, is characterized in that, described method specifically comprises step:
Step 1: when user equipment (UE) needs to connect external network APN, described user equipment (UE) sends activation message by link PDP Context to the GPRS serving GPRS support node SGSN of position, points to corresponding external network APN;
Step 2:GPRS serving GPRS support node SGSN resolves this external network APN, and sends establishment message to corresponding GPRS Support Node gateway GGSN;
Step 3:GPRS support node gateway GGSN distributes multiple 64bit network prefix to each link PDP Context, and existing 64bit network prefix is further divided, the network prefix producing 2n 64+n bit distributes to link PDP Context, the size of n is decided in its sole discretion according to network condition by operator, then sends establishment response message by link PDP Context to GPRS serving GPRS support node SGSN;
Step 4:GPRS serving GPRS support node SGSN sends activation by link PDP Context to user equipment (UE) and accepts message;
Step 5: user equipment (UE) receives activation by link PDP Context and accepts message, for link PDP Context produces the interface identifier of 64-n bit voluntarily, link PDPContext completes activation since then, and user equipment (UE) begins through the communication that link PDP Context and GPRS Support Node gateway GGSN carries out link range;
Step 6: user equipment (UE) obtains network prefix from GPRS Support Node gateway GGSN, obtain after combining with interface identifier global range can IPv6 address; Complete the Address Autoconfiguration for this link PDP Context, user equipment (UE) begins through IPv6 address and accesses the external network be connected with GPRS Support Node gateway GGSN.
It is different from each other that described GPRS Support Node gateway GGSN distributes multiple 64bit network prefix to each link PDP Context.
Described method does not use the fixed boundary of 64bit.
Fig. 1 is the network structure of universal mobile telecommunications system UMTS.In Fig. 1, UMTS network is divided into two parts, wireless access network and core net, wherein the structure of core net and the identical of GPRS, and therefore it can connect the wireless access network of UMTS, also can connect the wireless access network of GSM.Core net is logically divided into circuit-switched CS domain and packet switched ps domain, is respectively speech business and data service service.PS territory can carry multiple packet data protocol, and IP is wherein in occupation of dominant position.In order to the various multimedia services comprising VoIP can be provided.3GPP constructs IMS (IP multimedia subsystem) on PS territory, and IMS adopts SIP (session initiation protocol) to carry out Call-Control1 and network layer protocol only uses IPv6, and it is that 3GPP network is marched toward the first step of all-IP structure.In the complete IP network of 3GPP conception, no longer include CS territory, the speech business after packetizing is transmitted by the functional unit given in PS territory, and such as the connection between net of other different type network is responsible for conversion by special media gateway.
Fig. 2 is packet switched ps domain structure.In Fig. 2, in PS territory, there are two functional unit: SGSN and GGSN.Wherein SGSN is responsible for the certification of data service customers, charging and mobile management.GGSN is then the router connecting PS territory and external network.
Fig. 3 is the corresponding relation figure between PDP Context and IP link.First need to be illustrated this key concept of PDP Context.UE (subscriber equipment) is the function modeling of data terminal, is connected to external network by GGSN, and PDP Context is then a link between UE and GGSN.Be used for transmitting grouped data.PDP Context is divided into primary and secondary two class.Elementary PDP Context defines the link of a point-to-point between UE and GGSN, and GGSN for this reason elementary PDP Context distributes an IP address.Multiple secondary PDP Context can be set up again on this elementary PDPContext.They share an IP address.But different connection performances can be had.An elementary PDP Context and the secondary PDP Context that sets up thereon is considered as a link between UE and GGSN by 3GPP, just creates and give IP address when there being connection requirement, without then deleting during connection requirement and reclaiming IP address.
The above; be only the present invention's preferably embodiment, but protection scope of the present invention is not limited thereto, is anyly familiar with those skilled in the art in the technical scope that the present invention discloses; the change that can expect easily or replacement, all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection range of claim.