Abstract: Two of the largest issues facing the Internet today are the problems of providing quality-of-service to applications that require some form of "guarantee" of bandwidth availability and/or end-to-end delay, and the problem of avoiding congestion between traditional best-effort flows. The Internet research community is promoting active queue management in routers as a means of addressing both of these issues. Active queue management refers to managing the length of an outbound queue in a router by selectively dropping packets to bias the behavior and performance of connections transiting the router during times of congestion.
In this seminar we will review the congestion control and quality-of-service problems for the Internet and discuss how active queue management (AQM) has become a key component of proposals for advanced congestion control and better-than-best-effort forwarding services. We'll study several AQM algorithms including RED (Random Early Detection), RED with ECN (Explicit Congestion Notification) and their myriad variants. Included will be a discussion of the impact that new traffic types such as real-time audio and video and the protocols used to carry these data types have on the traditional traffic mix on the Internet. The seminar will culminate in a presentation of the differentiated services architecture ("diffserv") for the Internet and its deployment in the Internet 2 Qbone testbed.