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diff --git a/doc/rfc/rfc5344.txt b/doc/rfc/rfc5344.txt new file mode 100644 index 0000000..7dece45 --- /dev/null +++ b/doc/rfc/rfc5344.txt @@ -0,0 +1,507 @@ + + + + + + +Network Working Group A. Houri +Request for Comments: 5344 IBM +Category: Informational E. Aoki + AOL LLC + S. Parameswar + Microsoft Corporation + October 2008 + + + Presence and Instant Messaging Peering Use Cases + +Status of This Memo + + This memo provides information for the Internet community. It does + not specify an Internet standard of any kind. Distribution of this + memo is unlimited. + +Abstract + + This document describes several use cases of peering of non-VoIP + (Voice over IP) services between two or more Service Providers. + These Service Providers create a peering relationship between + themselves, thus enabling their users to collaborate with users on + the other Service Provider network. The target of this document is + to drive requirements for peering between domains that provide the + non-VoIP based collaboration services with presence and, in + particular, Instant Messaging (IM). + + Table of Contents + + 1. Introduction ....................................................2 + 2. Use Cases .......................................................2 + 2.1. Simple Interdomain Subscription ............................2 + 2.2. List Based Interdomain Subscription ........................3 + 2.3. Authorization Migration ....................................3 + 2.4. Pager Mode IM ..............................................4 + 2.5. Session Based IM ...........................................4 + 2.6. Other Services .............................................4 + 2.7. Federation and Clearing House ..............................5 + 3. Security Considerations .........................................5 + 4. Acknowledgments .................................................6 + 5. Informative References ..........................................6 + + + + + + + + + +Houri, et al. Informational [Page 1] + +RFC 5344 Presence and IM Peering Use Cases October 2008 + + +1. Introduction + + This document uses the terminology as defined in [1] unless otherwise + stated. + + Real Time Collaboration (RTC) services have become as prevalent and + essential for users on the Internet as email. While RTC services can + be implemented directly by users in a point-to-point fashion, they + are often provided for, or on behalf of, a Peer Network of users + within an administrative domain. As the use of these services grows, + users increasingly have the need to communicate with users not only + within their own Peer Network but with those in other Peer Networks + as well (similar to the old Public Switched Telephony Network (PSTN) + that enabled global reachability). In practice, each Peer Network is + controlled by some domain, and so there is a need to provide for + easier establishment of connectivity between Peer Networks and for + the management of the relationships between the Peer Networks. This + document describes a set of use cases that describe how peering + between Peer Networks may be used in non-VoIP RTC services. The use + cases are intended to help in identifying and capturing requirements + that will guide and then enable a secure and easier peering between + Peer Networks that provide non-VoIP RTC services. The use cases for + the VoIP RTC services are described in [2]. + + Note that this document does not define requirements for a new + protocol or for protocol extensions. It captures the way that + presence and Instant Messaging are currently used within enterprises + and operator domains. + +2. Use Cases + +2.1. Simple Interdomain Subscription + + Assume two Peer Networks, Peer Network A and Peer Network B. User + Alice@example.com (hosted in Peer Network A) wants to subscribe to + user Bob@example.net (hosted in Peer Network B) and get his presence + information. In order to do so, Alice@example.com could connect + directly to example.net and subscribe to Bob's presence information. + However, Peer Network B is willing to accept subscriptions and route + IMs only when they are coming from its users or from other Peer + Networks that Peer Network B trusts. + + In reality, what will happen is Peer Network A will connect to Peer + Network B and send Alice's subscription to Bob via Peer Network B. + When Peer Network B has new information on Bob, it will send + notifications to Peer Network A, which will pass them to Alice. + + + + + +Houri, et al. Informational [Page 2] + +RFC 5344 Presence and IM Peering Use Cases October 2008 + + +2.2. List-Based Interdomain Subscription + + This is similar to the simple interdomain subscription use case, + except in this case Alice subscribes to a Uniform Resource Identifier + (URI) [8] that represents a list of users in Peer Network B [9] [3]. + + There are several types of lists that Alice may subscribe to: + + o Personal group - a list that is created and maintained by Alice + and includes Alice's watch list. + + o Public group - a list that is created and maintained by an + administrator. Public groups usually contain a list of specific + people that have some common characteristic, e.g., support group + of a company. + + o Ad-hoc group - a list that is short lived and is usually created + in the context of some activity that Alice is doing. An ad-hoc + group may be created by Alice or by some application. Typical + examples may be the list of people that participate with Alice in + a conference or a game. + +2.3. Authorization Migration + + If many users from one Peer Network watch presentities [6] in + another Peer Network, it may be possible that many watchers [6] + from one Peer Network will subscribe to the same user in the other + Peer Network. However, due to privacy constraints that enable a + user to provide different presence documents to different + watchers, each Peer Network will have to send multiple copies of + the watched-presence document. The need to send multiple copies + between the Peer Networks is very inefficient and causes redundant + traffic between the Peer Networks. + + In order to make the subscription between Peer Networks more + efficient there needs to be a way to enable Peer Networks to agree + to share privacy information between them. This will enable + sending a single copy (the full copy) of the presence document of + the watched user and letting the receiving Peer Network be + responsible for sending the right values to the right watchers + according to the delegated privacy policies of the watched users. + + Instead of sharing the watched user's privacy policies between the + Peer Networks, it is also possible to send different copies of the + presence document with a list of the watchers the presence + document is intended for. For example, if there is a set of + watchers in one Peer Network that may see the location of the + presentity and another set of users in the same Peer Network that + + + +Houri, et al. Informational [Page 3] + +RFC 5344 Presence and IM Peering Use Cases October 2008 + + + may not see the location information, two presence documents will + be sent--each associated with a list of watchers that should + receive it. One presence document will contain the location + information and will be associated with a list of users that may + see it, and the other presence document will not contain the + location information and will be associated with a list of users + that may not see the location information. See [11]. + +2.4. Pager Mode IM + + In this use case, a user from one Peer Network sends a pager mode + [7] IM to a user on another Peer Network. + +2.5. Session Based IM + + In this use case, a user from one Peer Network creates a Message + Session Relay Protocol (MSRP) [10] session with a user from + another Peer Network. + +2.6. Other Services + + In addition to VoIP sessions, which are out of scope for this + document, only presence and IM have been ratified as RFCs. In + addition to presence and IM, there are many other services that + are being standardized or that may be implemented using minimal + extensions to existing standards. These include: + + o N-way chat - enable a multi-participant textual chat that will + include users from multiple Peer Networks. See [4] for more + details. + + o File transfer - send files from a user in one Peer Network to a + user in another Peer Network. See [5] for more details. + + o Document sharing - sharing and editing a document between users in + different Peer Networks. + + Note: Document sharing is mentioned in this document only for + completeness of use cases. It is not being standardized by the + IETF and will not be included in the requirements document that + will result from this document. + + The list above is of course not exhaustive, as new developments in + the world of non-VoIP RTC will surface new services. Enabling + peering between networks for some of the services will create a basis + for enabling peering for future services also. + + + + + +Houri, et al. Informational [Page 4] + +RFC 5344 Presence and IM Peering Use Cases October 2008 + + +2.7. Federation and Clearing House + + A federation as defined in [1] enables peering between multiple Peer + Networks. A federation may be implemented by means of a central + service providing a hub for the Peer Networks or, alternatively, Peer + Networks may connect to each other in a peer-to-peer fashion. One of + the most important services that this hub type of federation should + provide is authorized interconnection that enables each Peering + Network to securely identify other Peering Networks. Other services + that might be provided include an N-way chat server, lawful + interception, logging, and more. This hub type of federation is also + known as a "Clearing House". + + As non-VoIP services are usually text-based and consume less + bandwidth, they may benefit from having a central service that will + do central services such as logging for them. For example, instead + of requiring each Peer Network to log all messages that are being + sent to the other Peer-Network, this service can be done by the + Clearing House. + +3. Security Considerations + + When Peer Network A peers with Peer Network B, there are several + security issues for which the administrator of each Peer Network will + need mechanisms to verify: + + o All communication channels between Peer Networks and between each + Peer Network and the Clearing House have their authenticity and + confidentiality protected. + + o The other Peer Network is really the Peering Network that it + claims to be. + + o The other Peer Network is secure and trustworthy, such that + information that is passed to it will not reach a third party. + This includes information about specific users as well as + information about the authorization policies associated with user + information. + + o The other Peer Network is secure and trustworthy, such that it + will not modify or falsify data that it presents to its users + except as required by the authorization policy provided. + + o If there is a third party (e.g., a Clearing House) involved in the + connection between the two Peering Networks that element is also + secure. + + + + + +Houri, et al. Informational [Page 5] + +RFC 5344 Presence and IM Peering Use Cases October 2008 + + + The same issues of security are even more important from the point of + view of the users of the Peer Networks. Users will be concerned + about how their privacy is being adhered to when their presence + information is sent to the other Peer Network. Users today are + concerned about providing their email address to a third party when + they register to a domain; presence contains much more sensitive + information, and the concern of users here will be even greater. + + The privacy issue is even harder when we take into account that, in + order to enable scalable peering between big Peer Networks, there are + some optimizations that may require migration of the privacy + definitions of users between Peer Network (see Section 2.3). We can + imagine the fiasco that would ensue if a user of one Peer Network + were able to see the privacy information and learn he/she is listed + in the block list of a close friend. + + This document discusses use cases for peering between Peer Networks. + It is out of the scope of this document to provide solutions for + security. Nevertheless, it is obvious that the protocols that will + enable the use cases described here will have to provide for the + security considerations also described here. + +4. Acknowledgments + + We would like to thank Jonathan Rosenberg, Jon Peterson, Rohan Mahy, + Jason Livingood, Alexander Mayrhofer, Joseph Salowey, Henry + Sinnreich, and Mohamed Boucadir for their valuable input. + +5. Informative References + + [1] Malas, D. and D. Meyer, "SPEERMINT Terminology", Work in + Progress, February 2008. + + [2] Uzelac, A. and Y. Lee, "VoIP SIP Peering Use Cases", Work in + Progress, May 2008. + + [3] Camarillo, G. and A. Roach, "Framework and Security + Considerations for Session Initiation Protocol (SIP) URI-List + Services", Work in Progress, November 2007. + + [4] Niemi, A., Garcia-Martin, M., and G. Sandbakken, "Multi-party + Instant Message (IM) Sessions Using the Message Session Relay + Protocol (MSRP)", Work in Progress, February 2008. + + [5] Garcia-Martin, M., Isomaki, M., Camarillo, G., Loreto, S., and + P. Kyzivat, "A Session Description Protocol (SDP) Offer/Answer + Mechanism to Enable File Transfer", Work in Progress, May 2008. + + + + +Houri, et al. Informational [Page 6] + +RFC 5344 Presence and IM Peering Use Cases October 2008 + + + [6] Day, M., Rosenberg, J., and H. Sugano, "A Model for Presence + and Instant Messaging", RFC 2778, February 2000. + + [7] Campbell, B., Ed., Rosenberg, J., Schulzrinne, H., Huitema, C., + and D. Gurle, "Session Initiation Protocol (SIP) Extension for + Instant Messaging", RFC 3428, December 2002. + + [8] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform + Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986, + January 2005. + + [9] Roach, A., Campbell, B., and J. Rosenberg, "A Session + Initiation Protocol (SIP) Event Notification Extension for + Resource Lists", RFC 4662, August 2006. + + [10] Campbell, B., Ed., Mahy, R., Ed., and C. Jennings, Ed., "The + Message Session Relay Protocol (MSRP)", RFC 4975, September + 2007. + + [11] Rosenberg, J., Donovan, S., and K. McMurry. "Optimizing + Federated Presence with View Sharing", Work in Progress, July + 2008. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Houri, et al. Informational [Page 7] + +RFC 5344 Presence and IM Peering Use Cases October 2008 + + +Authors' Addresses + + Avshalom Houri + IBM + 3 Pekris Street + Science Park + Rehovot, + Israel + + EMail: avshalom@il.ibm.com + + Edwin Aoki + AOL LLC + 401 Ellis Street + Mountain View, CA 94043 + USA + + EMail: aoki@aol.net + + Sriram Parameswar + Microsoft Corporation + One Microsoft Way + Redmond, WA 98052 + USA + + EMail: Sriram.Parameswar@microsoft.com + + + + + + + + + + + + + + + + + + + + + + + + + +Houri, et al. Informational [Page 8] + +RFC 5344 Presence and IM Peering Use Cases October 2008 + + +Full Copyright Statement + + Copyright (C) The IETF Trust (2008). + + This document is subject to the rights, licenses and restrictions + contained in BCP 78, and except as set forth therein, the authors + retain all their rights. + + This document and the information contained herein are provided on an + "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS + OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND + THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS + OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF + THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED + WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. + +Intellectual Property + + The IETF takes no position regarding the validity or scope of any + Intellectual Property Rights or other rights that might be claimed to + pertain to the implementation or use of the technology described in + this document or the extent to which any license under such rights + might or might not be available; nor does it represent that it has + made any independent effort to identify any such rights. Information + on the procedures with respect to rights in RFC documents can be + found in BCP 78 and BCP 79. + + Copies of IPR disclosures made to the IETF Secretariat and any + assurances of licenses to be made available, or the result of an + attempt made to obtain a general license or permission for the use of + such proprietary rights by implementers or users of this + specification can be obtained from the IETF on-line IPR repository at + http://www.ietf.org/ipr. + + The IETF invites any interested party to bring to its attention any + copyrights, patents or patent applications, or other proprietary + rights that may cover technology that may be required to implement + this standard. Please address the information to the IETF at + ietf-ipr@ietf.org. + + + + + + + + + + + + +Houri, et al. Informational [Page 9] + |