Internet Engineering Task Force R. Despres Internet-Draft RD-IPtech Intended status: Standards Track September 21, 2011 Expires: March 24, 2012 Analysis of Stateless Solutions for IPv4 Service across IPv6 Networks - A synthetic Analysis Tool draft-despres-softwire-stateless-analysis-tool-00 Abstract This document proposes a discussion tool for the Softwire interim meeting of 2011/09/26-27. Its contains tables in which the most significant and differentiating functional features of different solutions are identified. Status of this Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. 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Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as Despres Expires March 24, 2012 [Page 1] Internet-Draft Stateless Analysis Tool September 2011 described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Referenced Solutions. . . . . . . . . . . . . . . . . . . . . . 4 3. Port-set Features . . . . . . . . . . . . . . . . . . . . . . . 5 4. IPv6-Address-format Features . . . . . . . . . . . . . . . . . 6 5. Traversal-method Features . . . . . . . . . . . . . . . . . . . 7 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 7 7. Informative References . . . . . . . . . . . . . . . . . . . . 7 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 7 Despres Expires March 24, 2012 [Page 2] Internet-Draft Stateless Analysis Tool September 2011 1. Introduction A debate on stateless solutions, for residual IPv4 service across IPv6-only networks, is in the agenda of the Softwire interim meeting on 2011/09/26-27. This document proposes a tool to facilitate common understanding during these discussions. It is intended to contribute to the decision-making process when time comes to decide what to standardize. It contains tables in which, for each of the major proposed solutions, the most significant differentiating functional features are listed. Separate tables are proposed for: o features that depend on how port-sets of shared IPv4 addresses are specified; o features that depend on how IPv6 destination addresses used to traverse IPv6 networks are constructed; o features that depend on whether IPv4 packets are encapsulated or twice translated. For each table, discussion can be in two steps: 1. get common enough understanding of each functional feature; 2. Check that authors of each proposed solution agree on what applies to their solutions, with caveats if appropriate. After that, a discussion on which solution(s) the WG recommends to standardize should be more effective. There is no claim that the current state of these tables is exhaustive, or that it reflects an accurate understanding of all solutions. It is proposed only as a temporary tool for the meeting. Clarification questions and proposed amendments are naturally welcome. Despres Expires March 24, 2012 [Page 3] Internet-Draft Stateless Analysis Tool September 2011 2. Referenced Solutions. +-------------+-----------------------------------------------------+ | Name in | Document | | this draft | | | and date | | +-------------+-----------------------------------------------------+ | Port range | draft-boucadair-behave-ipv6-portrange-04 | | 2009-10-20 | | | ----------- | -------------------------------------------------- | | NAT Bypass | draft-zhou-softwire-b4-translated-ds-lite-01 | | 2011-07-01 | | | ----------- | -------------------------------------------------- | | dIVI - PD | draft-xli-behave-divi-pd-00 | | 2011-07-02 | | | ----------- | -------------------------------------------------- | | 4rd - a | draft-murakami-softwire-4rd-00 - section 5 | | 2011-07-04 | | | ----------- | -------------------------------------------------- | | 4v6T | draft-murakami-softwire-4v6-translation-00 | | 2011-07-04 | | | ----------- | -------------------------------------------------- | | dIVI | draft-xli-behave-divi-03 | | 2011-07-10 | | | ----------- | -------------------------------------------------- | | Lightweight | draft-cui-softwire-b4-nat-02 | | 4over6 | | | 2011-07-11 | | | ----------- | -------------------------------------------------- | | Port range | draft-bsd-softwire-stateless-port-index-analysis-00 | | - NC | sec 2.1.2 | | 2011-09-05 | | | ----------- | -------------------------------------------------- | | 4rd - b1 | draft-despres-softwire-4rd-addmapping-00 | | 2011-08-19 | | | ----------- | -------------------------------------------------- | | 4rd - b2 | draft-despres-softwire-4rd-addmapping-01 | | 2011-09-21 | | +-------------+-----------------------------------------------------+ Despres Expires March 24, 2012 [Page 4] Internet-Draft Stateless Analysis Tool September 2011 3. Port-set Features +---+-----------------+-------+--------+-------+------+------+------+ | | Port-set | Port | Port | dIVI | 4rd | 4rd | 4rd | | | related | range | range | and | - a | - b1 | - b2 | | | Features | | - NC | dIVI | | | | | | | | | - pd | | | | +---+-----------------+-------+--------+-------+------+------+------+ | A | Minimum-length | no | no | no | YES | YES | YES | | | Port-set IDs (k | | | | | | | | | bits => 2^k | | | | | | | | | sets) | | | | | | | | - | --------------- | ---- | ---- | ---- | ---- | ---- | ---- | | B | RTP/RTCP | YES | YES | no | YES | YES | YES | | | odd-even port | | (*) | | | | | | | pairs in port | | | | | | | | | sets | | | | | | | | - | --------------- | ---- | ---- | ---- | ---- | ---- | ---- | | C | Scattered port | no | YES | YES | no | YES | no | | | sets for UPnP | | | | | | (**) | | | frienliness | | | | | | | | - | --------------- | ---- | ---- | ---- | ---- | ---- | ---- | | D | WK ports | YES | no | no | YES | YES | YES | | | excluded from | (*) | | | | | | | | assigned | | | | | | | | | restricted port | | | | | | | | | sets | | | | | | | +---+-----------------+-------+--------+-------+------+------+------+ (*) Possible by avoiding to assign some Port-set-ID values. (**) Not kept in view of a partially heuristic effect, and for the sake of simplicity. Despres Expires March 24, 2012 [Page 5] Internet-Draft Stateless Analysis Tool September 2011 4. IPv6-Address-format Features +---+-------------------+--------+------+------+------+------+------+ | | Features related | Port | dIVI | dIVI | 4rd | 4rd | 4rd | | | to formats of | range | | - pd | - a | - b1 | - b2 | | | IPv6 addresses | and | | | | | | | | | Port | | | | | | | | | range | | | | | | | | | - NC | | | | | | +---+-------------------+--------+------+------+------+------+------+ | 1 | Address sharing | no | no | YES | YES | YES | YES | | | possible with /32 | | | | | | | | | ISP prefixes | | | | | | | | - | --------------- | ----- | ---- | ---- | ---- | ---- | ---- | | 2 | Routing toward | YES | no | YESo | YES | YES | YES | | | CPEs based on | | | | | | | | | prefixes up to 64 | | | | | | | | | bits | | | | | | | | - | --------------- | ----- | ---- | ---- | ---- | ---- | ---- | | 3 | IPv6 routing plan | no | no | no | YES | YES | YES | | | independent from | | | | | | | | | IPv4 | | | | | | | | - | --------------- | ----- | ---- | ---- | ---- | ---- | ---- | | 4 | Sizes of CPE | no | no | no | no | YES | YES | | | address spaces | | | | | | | | | expressed for | | | | | | | | | both IPv6 and | | | | | | | | | IPv4 by | | | | | | | | | IPv6-prefix | | | | | | | | | lengths | | | | | | | | - | --------------- | ----- | ---- | ---- | ---- | ---- | ---- | | 5 | Multiple BR | no | no | no | YES | YES | YES | | | addresses for | | | | | | | | | Ingress Fltering | | | | | | | | - | --------------- | ----- | ---- | ---- | ---- | ---- | ---- | | 6 | CPE-cascades | no | no | no | YES | YES | no | | | support (ISP | | | | | | (*) | | | suffix in CPE | | | | | | | | | IPv6 prefixes) | | | | | | | +---+-------------------+--------+------+------+------+------+------+ (*) No longer covered in view of limited information on the use case, and for the sake of simplicity, but possible with a separately documented option. Despres Expires March 24, 2012 [Page 6] Internet-Draft Stateless Analysis Tool September 2011 5. Traversal-method Features +---+----------------+--------------------+-------------------------+ | | Features | Double translation | Encapsulation (NAT | | | related to | (dIVI, dIVI-PD, | bypass, 4v6E, | | | traversal | 4v6T) | Lightweight 4over6) | | | methods | | | +---+----------------+--------------------+-------------------------+ | x | Full | no | YES | | | transparency | | | | | to IPv4 | | | | - | -------------- | ------------------ | ----------------------- | | y | Optimized | YES | no | | | header length | | | +---+----------------+--------------------+-------------------------+ 6. Acknowledgements Wojciech Dec et al.[1] and Mohamed Boucadair [2] have analyzed with more details several solutions covered above. Their drafts have been quite helpful to prepare these tables. Nejc Skoberne has shared on the WG list an early comparison table which usefully influenced this work [3]. Also, Alain Durand expressed interest to have this type of tools in I-D format. Thanks to all of them. 7. Informative References [1] "draft-dec-stateless-4v6-02". [2] "draft-bsd-softwire-stateless-port-index-analysis-00". [3] "www.ietf.org/mail-archive/web/softwires/current/msg02520.html". Author's Address Remi Despres RD-IPtech 3 rue du President Wilson Levallois, France Email: despres.remi@laposte.net Despres Expires March 24, 2012 [Page 7]