Around the IETF Other IETF Work Of-Interest to ICCRG Wesley Eddy MTI Systems Internet Congestion Control Research Group (ICCRG) IETF 77, Anaheim, March 21-26, 2010

Goals Raise awareness of work going on in the IETF which ICCRG might be interested in – Some WG’s products require congestion control mechanisms and they can benefit from review & guidance – Some WG’s products may interact with congestion control mechanisms at other points in the stack or path in interesting or unforeseen ways Not exhaustive; based just on personal review There are also several BoFs of interest, but the goals of those are often fluffier, so I’ve left them out for now …

Applications Area A lot of things that simply use TCP … probably not so interesting to ICCRG Application-Layer Traffic Optimization (ALTO) WG – From charter: “… provide applications with information to perform better-than-random initial peer selection. ALTO services may take different approaches at balancing factors such as maximum bandwidth, minimum cross-domain traffic, lowest cost to the user, etc.” – Since P2P traffic is a large bandwidth consumer in many networks, ALTO’s work may have an impact on large-scale traffic patterns and network loading / congestion profiles

Internet Area Locator/ID Separation Protocol (lisp) WG – developing experimental mechanisms for routing system scalability – May cause interesting packet delays or reordering as mappings are resolved for initial packets – See “data probe” concept discussed in LISP+ALT Pseudowire Emulation Edge to Edge (pwe3) WG – developed “pseudowire” technology for emulating a point-to-point or point-to-multipoint link perceived by users as an unshared link/circuit over an IP/MPLS network. – ICCRG open-issues document discusses multi-domain pseudowires – There is a pseudowire congestion control framework: See: draft-ietf-pwe3-congestion-frmwk-02

Operations & Management Area Nothing in particular … Interesting high-level questions ICCRG might think about could include how congestion is detected, measured, and responded to by network management (having different visibility, timescales, and mechanisms available than a transport protocol has, for instance)

Real-time Applications & Infrastructure Area The question of “overload protection” or “overload control”, which differs from what congestion control classically considers, is relevant to some of the RAI WGs.

Routing Area The Bidirectional Forwarding Detection (BFD) WG defined a protocol that signals liveness; the specification requires congestion control for use over multihop paths: – See draft-ietf-bfd-base-11 Congestion control for MANET has been a popular subject in the research realm

Security Area Nothing that I know of …

Transport Area Datagram Congestion Control Protocol (DCCP) – Maintains TFRC and the DCCP protocol capable of incorporating new/alternative congestion control mechanisms Low Extra Delay Background Transport (ledbat) – Specifying a congestion control mechanism rather than a transport protocol itself – Goal includes a responsiveness to delays beyond a threshold; intended use includes P2P file transfer, e.g. BitTorrent – See: draft-ietf-ledbat-congestion-00 Multipath TCP (mptcp) WG is working on experimental mechanisms to allow TCP to use multiple paths Congestion & Pre-Congestion Notification (PCN) WG – Focused on protecting QoS for flows within a DiffServ domain – Detecting, signaling, ingesting, exporting, and reacting to congestion information within the network TCP Maintenance & Minor Extensions (TCPM) WG