News from the IRTF

A BoF session on path-decoupled signalling for data (OFFPATH) was held to discuss creation of a research group (RG) on signalling between end-systems and components in the network, such as firewalls.

The purpose of the group is to develop a flexible framework around a simple protocol. Initial work includes a SIP-based implementation from Cornell University.

Delay-Tolerant Networking (DTN) RG

The DTN RG met in Berkeley, California, in May in addition to conducting a review with the IAB. New work has begun on bundle-in-bundle encapsulation and on defining new bundle headers/blocks.

End-to-End (End2End) RG

The End2End RG is planning a meeting in summer 2006 to discuss, among other things, the re-evaluation of the state of work on congestion control. The re-evaluation will be coordinated with the Internet Congestion Control (ICC) RG.

Host Identity Protocol (HIP) RG

The HIP RG met at the past two IETF meetings. The HIP over NAT problem statement is currently in the RFC Editor queue. The experimental report is progressing. Internet-Drafts on the following topics are in preparation:

  • Simultaneous multi-access
  • Service discovery
  • TCP piggybacking

Internet Measurement (IM) RG

The IM RG is considering two workshops: one on techniques for application identification and the other on IM RG bandwidth estimation, at which the RG will determine whether the techniques are ready for standardisation.

IP Mobility Optimization (MobOpts) RG

The document on “Route Optimization Enhancements” will be published as the first IRTF RFC. The RG is further investigating the effect of mobility on transport protocol performance, with measurements on operational networks as well as simulation. The RG has access to a testbed and has developed a draft on Layer-2 abstractions for Layer-3 handover.

Internet Congestion Control (ICC) RG
In May, Michael Welzl joined S. Keshav as co-chair of the ICC RG. A wiki page has been developed and the RG is now working on an online bibliography. There has also been discussion of one or more “survey” documents. The surveys will catalog the IETF RFCs on congestion control in addition to experimental congestion control protocols.

Network Management (NM) RG

The Network Management RG met during IETF 66 to discuss SNMP trace collection and analysis. A workshop is planned to identify network-management research challenges and to draft a five-year research agenda.

Routing Research Group (RRG)

The Routing Research Goup met in Barcelona in April during InfoCom and is currently searching for a new co-chair. The documents “Routing Requirements” and “History of Routing Requirements” are awaiting final updates. The RG is planning to meet at the IETF in November in San Diego.

Scalable Adaptive Multicast (SAM) RG

The SAM RG had its first meeting at IETF 66 in Montreal. A couple of Internet-Drafts are in preparation (see for a full bibliography). SAM RG co-chair John Buford gave a short review of IP Multicast and explained why it is needed. For example, multicast achieves bandwidth savings over unicast. Certain applications, such as real-time video-streaming, are difficult or impossible to deploy without it. The goal of the SAM RG is to enhance the benefits of multicast by offering flexible and incremental deployment options.

With three different types of Multicast available – Application Layer Multicast (ALM), Overlay Multicast (OM) and Hybrid approaches – the group is attempting to create a unified framework that enables interoperability of different multicast protocols based on network, traffic, and group properties. The group is hoping for a dynamic transition between protocols and mechanisms to optimise performance. There are, however, challenges with this approach. For example, determining multicast support by region may require significant awareness of the network topology. For another example, constructing trees across regions will require mapping between different protocols for tree construction and group membership.

The RG has prepared two Internet-Drafts. As next steps the SAM RG will prepare a problem statement and driving scenarios, requirements for a SAM framework, and a survey of ALM/OM/Hybrid technologies and performance metrics. For more information, see the SAM web site:

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