draft-ietf-v6ops-3gpp-analysis-06.txt   draft-ietf-v6ops-3gpp-analysis-07.txt 
Internet Draft J. Wiljakka (ed.) Internet Draft J. Wiljakka (ed.)
Document: draft-ietf-v6ops-3gpp-analysis-06.txt Nokia Document: draft-ietf-v6ops-3gpp-analysis-07.txt Nokia
Expires: March 2004 Expires: April 2004
September 2003 October 2003
Analysis on IPv6 Transition in 3GPP Networks Analysis on IPv6 Transition in 3GPP Networks
Status of this Memo Status of this Memo
This document is an Internet-Draft and is in full conformance with This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC2026. all provisions of Section 10 of RFC2026.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that Task Force (IETF), its areas, and its working groups. Note that
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1.1 Scope of this Document....................................3 1.1 Scope of this Document....................................3
1.2 Abbreviations.............................................3 1.2 Abbreviations.............................................3
1.3 Terminology...............................................4 1.3 Terminology...............................................4
2. Transition Mechanisms and DNS Guidelines......................4 2. Transition Mechanisms and DNS Guidelines......................4
2.1 Dual Stack................................................5 2.1 Dual Stack................................................5
2.2 Tunneling.................................................5 2.2 Tunneling.................................................5
2.3 Protocol Translators......................................5 2.3 Protocol Translators......................................5
2.4 DNS Guidelines for IPv4/IPv6 Transition...................6 2.4 DNS Guidelines for IPv4/IPv6 Transition...................6
3. GPRS Transition Scenarios.....................................6 3. GPRS Transition Scenarios.....................................6
3.1 Dual Stack UE Connecting to IPv4 and IPv6 Nodes...........6 3.1 Dual Stack UE Connecting to IPv4 and IPv6 Nodes...........6
3.2 IPv6 UE Connecting to an IPv6 Node through an IPv4 Network 7 3.2 IPv6 UE Connecting to an IPv6 Node through an IPv4 Network 8
3.3 IPv4 UE Connecting to an IPv4 Node through an IPv6 Network 9 3.3 IPv4 UE Connecting to an IPv4 Node through an IPv6 Network 10
3.4 IPv6 UE Connecting to an IPv4 Node.......................10 3.4 IPv6 UE Connecting to an IPv4 Node.......................10
3.5 IPv4 UE Connecting to an IPv6 Node.......................11 3.5 IPv4 UE Connecting to an IPv6 Node.......................11
4. IMS Transition Scenarios.....................................11 4. IMS Transition Scenarios.....................................12
4.1 UE Connecting to a Node in an IPv4 Network through IMS...11 4.1 UE Connecting to a Node in an IPv4 Network through IMS...12
4.2 Two IMS Islands Connected over IPv4 Network..............13 4.2 Two IMS Islands Connected over IPv4 Network..............14
5. About 3GPP UE IPv4/IPv6 Configuration........................13 5. About 3GPP UE IPv4/IPv6 Configuration........................14
6. Security Considerations......................................14 6. Security Considerations......................................15
7. References...................................................15 7. References...................................................15
7.1 Normative................................................15 7.1 Normative................................................15
7.2 Informative..............................................16 7.2 Informative..............................................16
8. Contributors.................................................17 8. Contributors.................................................18
9. Authors and Acknowledgements.................................17 9. Authors and Acknowledgements.................................18
10. Editor's Contact Information................................18 10. Editor's Contact Information................................19
11. Changes from draft-ietf-v6ops-3gpp-analysis-05.txt..........18 11. Changes from draft-ietf-v6ops-3gpp-analysis-06.txt..........19
12. Intellectual Property Statement.............................18 12. Intellectual Property Statement.............................19
13. Copyright...................................................19 13. Copyright...................................................19
Appendix A - On the Use of Generic Translators in the 3GPP Networks Appendix A...................................................20
.................................................................20
1. Introduction 1. Introduction
This document describes and analyzes the process of transition to This document describes and analyzes the process of transition to
IPv6 in Third Generation Partnership Project (3GPP) General Packet IPv6 in Third Generation Partnership Project (3GPP) General Packet
Radio Service (GPRS) packet networks. The authors can be found in Radio Service (GPRS) packet networks. The authors can be found in
Authors and Acknowledgements section. Authors and Acknowledgements section.
This document analyzes the transition scenarios in 3GPP packet This document analyzes the transition scenarios in 3GPP packet
data networks that might come up in the deployment phase of IPv6. data networks that might come up in the deployment phase of IPv6.
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(using a TCP/UDP proxy) or Layer 7 (using application relays). (using a TCP/UDP proxy) or Layer 7 (using application relays).
2.4 DNS Guidelines for IPv4/IPv6 Transition 2.4 DNS Guidelines for IPv4/IPv6 Transition
[DNStrans] provides guidelines to operate DNS in a mixed world of [DNStrans] provides guidelines to operate DNS in a mixed world of
IPv4 and IPv6 transport. The recommendations (including the IPv4 and IPv6 transport. The recommendations (including the
keywords) are copied verbatim from [DNStrans]: keywords) are copied verbatim from [DNStrans]:
"In order to preserve name space continuity, the following "In order to preserve name space continuity, the following
administrative policies are RECOMMENDED: administrative policies are RECOMMENDED:
- every recursive DNS server SHOULD be either IPv4-only or - every recursive DNS server SHOULD be either IPv4-only or dual
dual stack, stack,
- every single DNS zone SHOULD be served by at least one IPv4 - every single DNS zone SHOULD be served by at least one IPv4
reachable DNS server. reachable DNS server.
This rules out IPv6-only DNS server performing full recursion and This rules out IPv6-only DNS server performing full recursion and
DNS zones served only by IPv6-only DNS servers. This approach DNS zones served only by IPv6-only DNS servers. This approach
could be revisited if/when translation techniques between IPv4 and could be revisited if/when translation techniques between IPv4 and
IPv6 were to be widely deployed. IPv6 were to be widely deployed.
In order to enforce the second point, the zone validation process In order to enforce the second point, the zone validation process
SHOULD ensure that there is at least one IPv4 address record SHOULD ensure that there is at least one IPv4 address record
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activates the appropriate PDP context depending on the type of activates the appropriate PDP context depending on the type of
application it has started or depending on the address of the peer application it has started or depending on the address of the peer
host it needs to communicate with. If IPv6 PDP contexts are host it needs to communicate with. If IPv6 PDP contexts are
available and IPv6-in-IPv4 tunneling is needed, it is recommended available and IPv6-in-IPv4 tunneling is needed, it is recommended
to activate an IPv6 PDP context and perform tunneling in the to activate an IPv6 PDP context and perform tunneling in the
network. This case is described in more detail in section 3.2. network. This case is described in more detail in section 3.2.
However, the UE may attach to a 3GPP network, in which the Serving However, the UE may attach to a 3GPP network, in which the Serving
GPRS Support Node (SGSN), the GGSN, and the Home Location Register GPRS Support Node (SGSN), the GGSN, and the Home Location Register
(HLR) support IPv4 PDP contexts, but do not support IPv6 PDP (HLR) support IPv4 PDP contexts, but do not support IPv6 PDP
contexts. If the 3GPP network does not support IPv6 PDP contexts, contexts. This may happen in early phases of IPv6 deployment. If
and an application on the UE needs to communicate with an IPv6(- the 3GPP network does not support IPv6 PDP contexts, and an
only) node, the UE may activate an IPv4 PDP context and encapsulate application on the UE needs to communicate with an IPv6(-only)
IPv6 packets in IPv4 packets using a tunneling mechanism. This node, the UE may activate an IPv4 PDP context and encapsulate IPv6
might happen in very early phases of IPv6 deployment. To generally packets in IPv4 packets using a tunneling mechanism.
solve this problem (IPv6 not available in the 3GPP network), this
document strongly recommends the 3GPP operators to deploy basic The use of private IPv4 addresses in the UE depends on the support
IPv6 support in their GPRS networks, which can in most cases be of these addresses by the tunneling mechanism and the deployment
handled by making software upgrades in the network elements. scenario. In some cases public IPv4 addresses are required, but if
the tunnel endpoints are in the same private domain, or the
tunneling mechanism works through IPv4 NAT, private IPv4 addresses
can be used. One deployment scenario example is using a laptop
computer and a 3GPP UE as a modem. IPv6 packets are encapsulated in
IPv4 packets in the laptop computer and IPv4 PDP context is
activated. The used tunneling mechanism (automatic or configured)
in that case depends on the support of tunneling mechanisms in the
laptop computer.
To generally solve this problem (IPv6 not available in the 3GPP
network), this document strongly recommends the 3GPP operators to
deploy basic IPv6 support in their GPRS networks. That also makes
it possible to burden the transition effects in the network and
make the 3GPP UEs simpler.
As a general guideline, IPv6 communication is preferred to IPv4 As a general guideline, IPv6 communication is preferred to IPv4
communication going through IPv4 NATs to the same dual stack peer communication going through IPv4 NATs to the same dual stack peer
node. node.
When analyzing a dual stack UE behavior, an application running on An application running on a UE can identify whether the endpoint is
a UE can identify whether the endpoint required is an IPv4 or IPv6 an IPv4 or IPv6 capable node by examining the destination address.
capable node by examining the address to discover what address Alternatively, if a user supplies a name to be resolved, the DNS
family it falls into. Alternatively, if a user supplies a name to may contain records sufficient to identify which protocol should be
be resolved, the DNS may contain records sufficient to identify used to initiate the connection with the endpoint. In dual stack
which protocol should be used to initiate the connection with the networks, one of the main concerns of an operator is the correct
endpoint. Since the UE is capable of native communication with both
protocols, one of the main concerns of an operator is the correct
address space and routing management. The operator must maintain address space and routing management. The operator must maintain
address spaces for both protocols. Public IPv4 addresses are often address spaces for both protocols. Public IPv4 addresses are often
a scarce resource for the operator and typically it is not possible a scarce resource for the operator and typically it is not possible
for a UE to have a globally unique IPv4 address continuously for a UE to have a globally unique IPv4 address (continuously)
allocated for its use. Use of private IPv4 addresses means use of allocated for its use. Use of private IPv4 addresses means use of
NATs when communicating with a peer node outside the operator's NATs when communicating with a peer node outside the operator's
network. In large networks, NAT systems can become very complex, network. In large networks, NAT systems can become very complex,
expensive and difficult to maintain. expensive and difficult to maintain.
For DNS recommendations, we refer to section 2.4. For DNS recommendations, we refer to section 2.4.
3.2 IPv6 UE Connecting to an IPv6 Node through an IPv4 Network 3.2 IPv6 UE Connecting to an IPv6 Node through an IPv4 Network
The best solution for this scenario is obtained with tunneling, The best solution for this scenario is obtained with tunneling,
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the operator / ISP deployment scenario and only generic the operator / ISP deployment scenario and only generic
recommendations can be given in this document. recommendations can be given in this document.
The following subsections are focused on the usage of different The following subsections are focused on the usage of different
tunneling mechanisms when the peer node is in the operator's tunneling mechanisms when the peer node is in the operator's
network or outside the operator's network. The authors note that network or outside the operator's network. The authors note that
where the actual 3GPP network ends and which parts of the network where the actual 3GPP network ends and which parts of the network
belong to the ISP(s) also depends on the deployment scenario. The belong to the ISP(s) also depends on the deployment scenario. The
authors are not commenting how many ISP functions the 3GPP operator authors are not commenting how many ISP functions the 3GPP operator
should perform. However, many 3GPP operators are ISPs of some sort should perform. However, many 3GPP operators are ISPs of some sort
themselves. ISP transition scenarios are documented in [ISP-scen]. themselves. ISP networks' transition to IPv6 is analyzed in [ISP-
scen] and [ISP-an].
3.2.1 Tunneling inside the 3GPP Operator's Network 3.2.1 Tunneling inside the 3GPP Operator's Network
Many GPRS operators already have IPv4 backbone networks deployed Many GPRS operators already have IPv4 backbone networks deployed
and they are gradually migrating them while introducing IPv6 and they are gradually migrating them while introducing IPv6
islands. IPv6 backbones can be considered quite rare in the first islands. IPv6 backbones can be considered quite rare in the first
phases of the transition. If the 3GPP operator already has IPv6 phases of the transition. If the 3GPP operator already has IPv6
widely deployed in its network, this subsection is not so relevant. widely deployed in its network, this subsection is not so relevant.
In initial IPv6 deployment, where a small number of IPv6-in-IPv4 In initial IPv6 deployment, where a small number of IPv6-in-IPv4
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Connection redundancy should also be noted as an important Connection redundancy should also be noted as an important
requirement in 3GPP networks. Static tunnels on their own don't requirement in 3GPP networks. Static tunnels on their own don't
provide a routing recovery solution for all scenarios where an IPv6 provide a routing recovery solution for all scenarios where an IPv6
route goes down. However, they may provide an adequate solution route goes down. However, they may provide an adequate solution
depending on the design of the network and in presence of other depending on the design of the network and in presence of other
router redundancy mechanisms. On the other hand, routing protocol router redundancy mechanisms. On the other hand, routing protocol
based mechanisms can provide redundancy. based mechanisms can provide redundancy.
3.2.2 Tunneling outside the 3GPP Operator's Network 3.2.2 Tunneling outside the 3GPP Operator's Network
This subsection includes the case when the peer node is outside the This subsection includes the case in which the peer node is outside
operator's network. In that case the IPv6-in-IPv4 tunnel starting the operator's network. In that case IPv6-in-IPv4 tunneling can be
point can be in the operator's network - encapsulating node can be necessary to obtain IPv6 connectivity and reach other IPv6 nodes.
e.g. the GGSN or the edge router.
The case is pretty straightforward if the upstream ISP provides
native IPv6 connectivity to the Internet. If there is no native
IPv6 connectivity available in the 3GPP network, an IPv6-in-IPv4
tunnel should be configured from e.g. the GGSN to the dual stack
border gateway in order to access the upstream ISP.
If the ISP only provides IPv4 connectivity, then the IPv6 traffic Tunnel starting point can be in the operator's network depending on
initiated from the 3GPP network should be transported tunneled in how far the 3GPP operator has come in implementing IPv6. If the
IPv4 to the ISP. 3GPP operator does not have an IP backbone, or has not implemented
IPv6 in it, the encapsulating node can be the GGSN. If the 3GPP
operator has an IP backbone, and has implemented IPv6 in it, but
the upstream ISP does not provide IPv6 connectivity to the
Internet, the encapsulating node can be the edge router.
Usage of configured IPv6-in-IPv4 tunneling is recommended. As the The case is pretty straightforward if the upstream ISP provides
number of the tunnels outside of the 3GPP network is limited, no IPv6 connectivity to the Internet and the operator's backbone
more than a couple of tunnels should be needed. network supports IPv6. Then the 3GPP operator does not have to
configure any tunnels, since the upstream ISP will take care of
routing IPv6 packets. If the upstream ISP does not provide IPv6
connectivity, an IPv6-in-IPv4 tunnel should be configured e.g. from
the edge router to a dual stack border gateway operated by another
ISP which is offering IPv6 connectivity.
ISP transition scenarios are described in [ISP-scen]. In the tunneling scenarios above, usage of configured IPv6-in-IPv4
tunneling is recommended. As the number of the tunnels outside of
the 3GPP network is limited, no more than a couple of tunnels
should be needed.
3.3 IPv4 UE Connecting to an IPv4 Node through an IPv6 Network 3.3 IPv4 UE Connecting to an IPv4 Node through an IPv6 Network
3GPP networks are expected to support both IPv4 and IPv6 for a long 3GPP networks are expected to support both IPv4 and IPv6 for a long
time, on the UE-GGSN link and between the GGSN and external time, on the UE-GGSN link and between the GGSN and external
networks. For this scenario, it is useful to split the end-to-end networks. For this scenario, it is useful to split the end-to-end
IPv4 UE to IPv4 node communication into UE-to-GGSN and GGSN-to- IPv4 UE to IPv4 node communication into UE-to-GGSN and GGSN-to-
v4NODE. An IPv6-capable GGSN is expected to support both IPv6 and v4NODE. An IPv6-capable GGSN is expected to support both IPv6 and
IPv4 UEs. Therefore an IPv4-only UE will be able to use an IPv4 IPv4 UEs. Therefore an IPv4-only UE will be able to use an IPv4
link (PDP context) to connect to the GGSN without the need to link (PDP context) to connect to the GGSN without the need to
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external IPv4 networks either. In the longer run, 3GPP operators external IPv4 networks either. In the longer run, 3GPP operators
may need to phase out IPv4 UEs and the IPv4 transport network. This may need to phase out IPv4 UEs and the IPv4 transport network. This
would leave only IPv6 UEs. would leave only IPv6 UEs.
Therefore, overall, the transition scenario involving an IPv4 UE Therefore, overall, the transition scenario involving an IPv4 UE
communicating with an IPv4 peer through an IPv6 network is not communicating with an IPv4 peer through an IPv6 network is not
considered very likely in 3GPP networks. considered very likely in 3GPP networks.
3.4 IPv6 UE Connecting to an IPv4 Node 3.4 IPv6 UE Connecting to an IPv4 Node
As a general guideline, IPv6-only UEs are not recommended in the Generally speaking, IPv6-only UEs may be easier to manage, but that
early phases of transition until the IPv6 deployment has become so would require all services to be used over IPv6, and that may not
prevalent that direct communication with IPv4(-only) nodes will no be realistic in the near future. Dual stack implementation requires
longer be necessary. It is assumed that IPv4 will remain useful for management of both IPv4 and IPv6 networks and one approach is that
quite a long time, so in general, dual-stack implementation in the "legacy" applications keep using IPv4 for the foreseeable future
UE can be recommended. This recommendation naturally includes and new applications requiring end-to-end connectivity (for
manufacturing dual-stack UEs instead of IPv4-only UEs. example, peer-to-peer services) use IPv6. As a general guideline,
IPv6-only UEs are not recommended in the early phases of transition
until the IPv6 deployment has become so prevalent that direct
communication with IPv4(-only) nodes will no longer be necessary.
It is assumed that IPv4 will remain useful for quite a long time,
so in general, dual-stack implementation in the UE can be
recommended. This recommendation naturally includes manufacturing
dual-stack UEs instead of IPv4-only UEs.
However, if there is a need to connect to an IPv4(-only) node from However, if there is a need to connect to an IPv4(-only) node from
an IPv6-only UE, it is possible to use specific translation and an IPv6-only UE, it is possible to use specific translation and
proxying techniques; generic IP protocol translation is not proxying techniques; generic IP protocol translation is not
recommended. There are three main ways for IPv6(-only) nodes to recommended. There are three main ways for IPv6(-only) nodes to
communicate with IPv4(-only) nodes (excluding avoiding such communicate with IPv4(-only) nodes (excluding avoiding such
communication in the first place): communication in the first place):
1. the use of generic-purpose translator (e.g. NAT-PT [RFC2766]) 1. the use of generic-purpose translator (e.g. NAT-PT [RFC2766])
in the local network (not recommended as a general solution), in the local network (not recommended as a general solution),
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not discussed further here. not discussed further here.
For many applications, application proxies can be appropriate (e.g. For many applications, application proxies can be appropriate (e.g.
HTTP proxies, SMTP relays, etc.). Such application proxies will not HTTP proxies, SMTP relays, etc.). Such application proxies will not
be transparent to the UE. Hence, a flexible mechanism with minimal be transparent to the UE. Hence, a flexible mechanism with minimal
manual intervention should be used to configure these proxies on manual intervention should be used to configure these proxies on
IPv6 UEs. Within the 3GPP architecture, application proxies can be IPv6 UEs. Within the 3GPP architecture, application proxies can be
placed on the GGSN external interface (Gi), or inside the service placed on the GGSN external interface (Gi), or inside the service
network. network.
The authors note that NAT-PT applicability statement work is being The authors note that [NATPTappl] discusses the applicability of
done in the v6ops wg. The problems related to NAT-PT usage in 3GPP NAT-PT. The problems related to NAT-PT usage in 3GPP networks are
networks are documented in appendix A. documented in appendix A.
3.5 IPv4 UE Connecting to an IPv6 Node 3.5 IPv4 UE Connecting to an IPv6 Node
The legacy IPv4 nodes are mostly nodes that support the The legacy IPv4 nodes are mostly nodes that support the
applications that are popular today in the IPv4 Internet: mostly e- applications that are popular today in the IPv4 Internet: mostly e-
mail and web-browsing. These applications will, of course, be mail and web-browsing. These applications will, of course, be
supported in the future IPv6 Internet. However, the legacy IPv4 UEs supported in the future IPv6 Internet. However, the legacy IPv4 UEs
are not going to be updated to support the future applications. As are not going to be updated to support the future applications. As
these applications are designed for IPv6, and to use the advantages these applications are designed for IPv6, and to use the advantages
of newer platforms, the legacy IPv4 nodes will not be able to of newer platforms, the legacy IPv4 nodes will not be able to
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- a specific mechanism for SIP signalling and media translation - a specific mechanism for SIP signalling and media translation
These (except for the last one, naturally) have relatively well- These (except for the last one, naturally) have relatively well-
known security considerations, which are also discussed in the known security considerations, which are also discussed in the
specific documents. However, in particular one should note that a specific documents. However, in particular one should note that a
proper configuration of locally-deployed relays and proxies is very proper configuration of locally-deployed relays and proxies is very
important, so that the outsiders will not have access to them, to important, so that the outsiders will not have access to them, to
be used for abuse, laundering attacks, or circumventing access be used for abuse, laundering attacks, or circumventing access
controls. controls.
In particular, this memo does not recommend the following In particular, this memo does not recommend the following technique
techniques which each have a number of security issues, not further which has security issues, not further analyzed here:
analyzed here:
- NAT-PT or other translator as a generic-purpose transition - NAT-PT or other translator as a generic-purpose transition
mechanism, mechanism,
- the use of IPv6 transition mechanisms (except dual stack) at
the UEs.
7. References 7. References
7.1 Normative 7.1 Normative
[RFC2026] Bradner, S.: The Internet Standards Process -- Revision [RFC2026] Bradner, S.: The Internet Standards Process -- Revision
3, RFC 2026, October 1996. 3, RFC 2026, October 1996.
[RFC2663] Srisuresh, P., Holdrege, M.: IP Network Address [RFC2663] Srisuresh, P., Holdrege, M.: IP Network Address
Translator (NAT) Terminology and Considerations, RFC 2663, August Translator (NAT) Terminology and Considerations, RFC 2663, August
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[RFC3314] Wasserman, M. (editor): Recommendations for IPv6 in 3GPP [RFC3314] Wasserman, M. (editor): Recommendations for IPv6 in 3GPP
Standards, September 2002. Standards, September 2002.
[RFC3315] Droms, R. et al.: Dynamic Host Configuration Protocol for [RFC3315] Droms, R. et al.: Dynamic Host Configuration Protocol for
IPv6 (DHCPv6), July 2003. IPv6 (DHCPv6), July 2003.
[RFC3319] Schulzrinne, H., Volz, B.: Dynamic Host Configuration [RFC3319] Schulzrinne, H., Volz, B.: Dynamic Host Configuration
Protocol (DHCPv6) Options for Session Initiation Protocol (SIP) Protocol (DHCPv6) Options for Session Initiation Protocol (SIP)
Servers, July 2003. Servers, July 2003.
[3GPPtr] El Malki K., et al.: "IPv6-IPv4 Translators in 3GPP [3GPPtr] El Malki K., et al.: "IPv6-IPv4 Translation mechanism for
Networks", June 2003, draft-elmalki-v6ops-3gpp-translator-00.txt, SIP-based services in Third Generation Partnership Project (3GPP)
work in progress. Networks", October 2003, draft-elmalki-sipping-3gpp-translator-
00.txt, work in progress.
[DHCP-DNS] Droms, R. (ed.): "DNS Configuration options for DHCPv6", [DHCP-DNS] Droms, R. (ed.): "DNS Configuration options for DHCPv6",
August 2003, draft-ietf-dhc-dhcpv6-opt-dnsconfig-04.txt, work in August 2003, draft-ietf-dhc-dhcpv6-opt-dnsconfig-04.txt, work in
progress. progress.
[DHCP-SL] Droms, R.: "A Guide to Implementing Stateless DHCPv6 [DHCP-SL] Droms, R.: "A Guide to Implementing Stateless DHCPv6
Service", April 2003, draft-ietf-dhc-dhcpv6-stateless-00.txt, work Service", October 2003, draft-ietf-dhc-dhcpv6-stateless-01.txt,
in progress. work in progress.
[DNStrans] Durand, A. and Ihren, J.: "DNS IPv6 transport [DNStrans] Durand, A. and Ihren, J.: "DNS IPv6 transport
operational guidelines", June 2003, draft-ietf-dnsop-ipv6- operational guidelines", June 2003, draft-ietf-dnsop-ipv6-
transport-guidelines-00.txt, work in progress. transport-guidelines-00.txt, work in progress.
[ISP-an] Ksinant, V. (ed.): " Analysis of Transition Mechanisms for
Introducing IPv6 into ISP Networks", October 2003, draft-ksinant-
v6ops-isp-analysis-00.txt, work in progress.
[ISP-scen] Lind, M. (Editor): "Scenarios for Introducing IPv6 into [ISP-scen] Lind, M. (Editor): "Scenarios for Introducing IPv6 into
ISP Networks", June 2003, draft-lind-v6ops-isp-scenarios-00.txt, ISP Networks", October 2003, draft-lind-v6ops-isp-scenarios-01.txt,
work in progress. work in progress.
[NATPTappl] Satapati, S., Sivakumar, S., Barany, P., Okazaki, S.,
Wang, H.: " NAT-PT Applicability ", October 2003, draft-satapati-
v6ops-natpt-applicability-00.txt, work in progress.
[NATPT-DNS] Durand, A.: "Issues with NAT-PT DNS ALG in RFC2766", [NATPT-DNS] Durand, A.: "Issues with NAT-PT DNS ALG in RFC2766",
January 2003, draft-durand-v6ops-natpt-dns-alg-issues-00.txt, work January 2003, draft-durand-v6ops-natpt-dns-alg-issues-00.txt, work
in progress, the draft has expired. in progress, the draft has expired.
[v4v6trans] van der Pol, R., Satapati, S., Sivakumar, S.: [v4v6trans] van der Pol, R., Satapati, S., Sivakumar, S.:
"Issues when translating between IPv4 and IPv6", January 2003, "Issues when translating between IPv4 and IPv6", January 2003,
draft-vanderpol-v6ops-translation-issues-00.txt, work in progress, draft-vanderpol-v6ops-translation-issues-00.txt, work in progress,
the draft has expired. the draft has expired.
[3GPP-24.008] 3GPP TS 24.008 V5.8.0, "Mobile radio interface Layer [3GPP-24.008] 3GPP TS 24.008 V5.8.0, "Mobile radio interface Layer
skipping to change at page 17, line 39 skipping to change at page 18, line 18
Pekka Savola has contributed both text and his IPv6 experience to Pekka Savola has contributed both text and his IPv6 experience to
this document. He has provided a large number of helpful comments this document. He has provided a large number of helpful comments
on the v6ops mailing list. on the v6ops mailing list.
9. Authors and Acknowledgements 9. Authors and Acknowledgements
This document is written by: This document is written by:
Alain Durand, Sun Microsystems Alain Durand, Sun Microsystems
<alain.durand@sun.com> <Alain.Durand@sun.com>
Karim El-Malki, Ericsson Radio Systems Karim El-Malki, Ericsson Radio Systems
<Karim.El-Malki@era.ericsson.se> <Karim.El-Malki@era.ericsson.se>
Niall Richard Murphy, Enigma Consulting Limited Niall Richard Murphy, Enigma Consulting Limited
<niallm@enigma.ie> <niallm@enigma.ie>
Hugh Shieh, AT&T Wireless Hugh Shieh, AT&T Wireless
<hugh.shieh@attws.com> <hugh.shieh@attws.com>
skipping to change at page 18, line 4 skipping to change at page 18, line 31
<Karim.El-Malki@era.ericsson.se> <Karim.El-Malki@era.ericsson.se>
Niall Richard Murphy, Enigma Consulting Limited Niall Richard Murphy, Enigma Consulting Limited
<niallm@enigma.ie> <niallm@enigma.ie>
Hugh Shieh, AT&T Wireless Hugh Shieh, AT&T Wireless
<hugh.shieh@attws.com> <hugh.shieh@attws.com>
Jonne Soininen, Nokia Jonne Soininen, Nokia
<jonne.soininen@nokia.com> <jonne.soininen@nokia.com>
Hesham Soliman, Flarion Hesham Soliman, Flarion
<h.soliman@flarion.com> <h.soliman@flarion.com>
Margaret Wasserman, Wind River Margaret Wasserman, Nokia
<mrw@windriver.com> <margaret.wasserman@nokia.com>
Juha Wiljakka, Nokia Juha Wiljakka, Nokia
<juha.wiljakka@nokia.com> <juha.wiljakka@nokia.com>
The authors would like to thank Heikki Almay, Gabor Bajko, Ajay The authors would like to thank Heikki Almay, Gabor Bajko, Ajay
Jain, Jarkko Jouppi, Ivan Laloux, Janne Rinne, Pedro Serna, Fred Jain, Jarkko Jouppi, Ivan Laloux, Jasminko Mulahusic, Janne Rinne,
Templin, Anand Thakur and Rod Van Meter for their valuable input. Andreas Schmid, Pedro Serna, Fred Templin, Anand Thakur and Rod Van
Meter for their valuable input.
10. Editor's Contact Information 10. Editor's Contact Information
Comments or questions regarding this document should be sent to the Comments or questions regarding this document should be sent to the
v6ops mailing list or directly to the document editor: v6ops mailing list or directly to the document editor:
Juha Wiljakka Juha Wiljakka
Nokia Nokia
Visiokatu 3 Phone: +358 7180 48372 Visiokatu 3 Phone: +358 7180 48372
FIN-33720 TAMPERE, Finland Email: juha.wiljakka@nokia.com FIN-33720 TAMPERE, Finland Email: juha.wiljakka@nokia.com
11. Changes from draft-ietf-v6ops-3gpp-analysis-05.txt 11. Changes from draft-ietf-v6ops-3gpp-analysis-06.txt
- Handled issues from: - 3.2.2 edited based on wg last call comments
http://danforsberg.info:8080/draft-ietf-v6ops-3gpp-
analysis/index
- Security considerations section updated
- Editorial / textual changes in many sections - Editorial / textual changes in many sections
- Appendix A created
12. Intellectual Property Statement 12. Intellectual Property Statement
The IETF takes no position regarding the validity or scope of any The IETF takes no position regarding the validity or scope of any
intellectual property or other rights that might be claimed to intellectual property or other rights that might be claimed to
pertain to the implementation or use of the technology described in pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights this document or the extent to which any license under such rights
might or might not be available; neither does it represent that it might or might not be available; neither does it represent that it
has made any effort to identify any such rights. Information on the has made any effort to identify any such rights. Information on the
IETF's procedures with respect to rights in standards-track and IETF's procedures with respect to rights in standards-track and
skipping to change at page 19, line 16 skipping to change at page 19, line 47
copyrights, patents or patent applications, or other proprietary copyrights, patents or patent applications, or other proprietary
rights which may cover technology that may be required to practice rights which may cover technology that may be required to practice
this standard. Please address the information to the IETF Executive this standard. Please address the information to the IETF Executive
Director. Director.
13. Copyright 13. Copyright
The following copyright notice is copied from [RFC2026], Section The following copyright notice is copied from [RFC2026], Section
10.4. It describes the applicable copyright for this document. 10.4. It describes the applicable copyright for this document.
Copyright (C) The Internet Society September 26, 2003. All Rights Copyright (C) The Internet Society October 26, 2003. All Rights
Reserved. Reserved.
This document and translations of it may be copied and furnished to This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain others, and derivative works that comment on or otherwise explain
it or assist in its implementation may be prepared, copied, it or assist in its implementation may be prepared, copied,
published and distributed, in whole or in part, without restriction published and distributed, in whole or in part, without restriction
of any kind, provided that the above copyright notice and this of any kind, provided that the above copyright notice and this
paragraph are included on all such copies and derivative works. paragraph are included on all such copies and derivative works.
However, this document itself may not be modified in any way, such However, this document itself may not be modified in any way, such
as by removing the copyright notice or references to the Internet as by removing the copyright notice or references to the Internet
skipping to change at page 20, line 25 skipping to change at page 20, line 44
GGSN external (Gi) interface, typically separate from the GGSN. GGSN external (Gi) interface, typically separate from the GGSN.
NA(P)T-PT can be installed, for example, on the edge of the NA(P)T-PT can be installed, for example, on the edge of the
operator's network and the public Internet. NA(P)T-PT will operator's network and the public Internet. NA(P)T-PT will
intercept DNS requests and other applications that include IP intercept DNS requests and other applications that include IP
addresses in their payloads, translate the IP header (and payload addresses in their payloads, translate the IP header (and payload
for some applications if necessary) and forward packets through its for some applications if necessary) and forward packets through its
IPv4 interface. IPv4 interface.
NA(P)T-PT introduces limitations that are expected to be magnified NA(P)T-PT introduces limitations that are expected to be magnified
within the 3GPP architecture. Some of these limitations are listed within the 3GPP architecture. Some of these limitations are listed
below (notice that some of them are also relevant for IPv4 NAT). We below (notice that some of them are also relevant for IPv4 NAT).
note here that [v4v6trans] analyzes the issues when translating [NATPTappl] discusses the applicability of NAT-PT in more detail.
between IPv4 and IPv6. NAT-PT applicability statement document
(currently being written in v6ops wg) will also be used as a
reference in this document.
1. NA(P)T-PT is a single point of failure for all ongoing 1. NA(P)T-PT is a single point of failure for all ongoing
connections. connections.
2. There are additional forwarding delays due to further 2. There are additional forwarding delays due to further
processing, when compared to normal IP forwarding. processing, when compared to normal IP forwarding.
3. There are problems with source address selection due to the 3. There are problems with source address selection due to the
inclusion of a DNS ALG on the same node [NATPT-DNS]. inclusion of a DNS ALG on the same node [NATPT-DNS].
 End of changes. 

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