By: Aaron Falk
Date: February 7, 2009
Here are a few items on Internet Research Task Force (IRTF) developments since IETF 72:
- The composition of the Internet Research Steering Group (IRSG) has been made public and can be seen at www.irtf.org/chair.
- The document defining the IRTF publication stream has been finalized and is enqueued at the RFC Editor.
- Four IRTF RFCs have been published since IETF 72. Three are from the Delay-Tolerant Networking Research Group (dtnrg) on Licklider Transmission Protocol (LTP), and one is from the Network Management Research Group on Simple Network Management Protocol measurements.
- Draft-irtf-asrg-dnsbl (DNS Blacklists and Whitelists), which received substantial discussion on the IETF mailing list leading up to IETF 72, will be published as an IRTF RFC to document current practices. In response to the IETF list comments, it will include security considerations reflecting the IETF lastcall comments.
In a departure from the usual IRTF reporting, the presentation at IETF 73 included introductions to two IRTF Research Groups: the Delay-Tolerant Networking Research Group (dtnrg) and the Peer-to-Peer Research Group (p2prg).
Delay-tolerant networking (DTN, sometimes called disruption-tolerant or disconnection-tolerant networking) is based on a model that makes no assumption that the sender and receiver are concurrently connected to the network. Data transfer is achieved using a multiparty communications model, wherein helpers provide a store-carry-forward mechanism for messages using extensible (Uniform Resource Identifier-based) naming. DTN supports multipath routing and caching to address connectivity disruptions. The dtnrg has been encouraging development, testing, and deployment of DTN protocols.
The exciting news from dtnrg is that the Bundle Protocol (BP) is now being tested in space. The code was uploaded to the United Kingdom’s Disaster Monitoring Constellation satellite, which is operated by Surrey Satellite Technology Ltd. (SSTL). SSTL, Cisco Systems, and NASA Glenn conducted a test by downloading a 150-megabyte fragmented image of Earth by using the dtnrg’s BP. In addition, NASA’s Jet Propulsion Laboratory recently completed an experiment with DTN that involved using BP and LTP out to a distance of 15 million to 25 million kilometres. A report on results was presented at the dtnrg session.
The IRTF report at the IETF 73 plenary also included an introduction to the Peer-to-Peer Research Group. Peer-to-peer (P2P) networks exhibit a symmetric relationship between hosts. They are distributed, they scale to large numbers of nodes and users, they are autonomous, and they support anonymity. Well-known P2P systems include Usenet and BGP. BitTorrent and Skype are examples of new P2P systems.
The p2prg has been developing a new charter that will encourage (1) research on P2P/network traffic optimization (beyond ALTO (Application-Layer Traffic Optimization)); (2) security, privacy, anonymity, and trust; (3) improving interoperation between different P2P systems; (4) information storage, reliability, and retrieval in P2P systems; and (5) gaining a better understanding of P2P system performance and user behaviour “in the wild.”
Additionally, five research groups met during the week of IETF 73. The dtnrg was summarized earlier, and notes from the other research group meetings follow.
Host Identity Protocol Research Group (hiprg)
The HIPRG met at IETF 73 and discussed two individual submissions. The first was a proposal to generalize HIP to include object-to-object (and not strictly host-to-host) communications. The second draft proposed to carry geolocation data explicitly in the HIP protocol. The meeting also received implementation updates from Boeing’s HIP-based overlay deployment and the HIP for Linux project’s recent work.
IP Mobility Optimizations Research Group (mobopts)
The meeting focussed on current documents, including IP Location Privacy, Multicast Mobility, and Media Independent Preauthentication. The latter two are completing research group last call, and the IP Location Privacy document is in IRSG review.
Also discussed at the meeting was a framework for benchmarking mobility models. The purpose is to be able to evaluate models used in literature by using a common reference that outlines what to look for. In addition, there was lively debate over what approach to take for multicast mobility solutions. One camp argued that multicast needs to be extended, while the other contended that without extensions to mobility protocols, handover would not provide the performance necessary for multicast traffic.
Internet Congestion Control Research Group (iccrg)
The ICCRG meeting covered two main topics. The first was an exploration of alternative start-up mechanisms, and the second was the basis of Internet congestion control on TCP-friendly sending rates. Two sets of experimental data were presented on the evaluation of different start-up mechanisms that attempt to improve on standard TCP slow start. Matt Mathis then led a discussion on Rethinking TCP-Friendly, and the research group accepted that it should write a vision statement document to increase architectural discussion on whether TCP friendliness should still be used as a strict criterion for evaluation of new Internet protocols.
Routing Research Group (rrg)
The Routing Research Group met to continue to discuss next-generation routing architectures. The research group heard six separate presentations on different aspects of a new architecture and continued to discuss the many alternatives at hand. The group plans to draft a preliminary recommendation for an architecture in the coming months.
For more information about the Internet Research Task Force, visit www.irtf.org.