Z-iteration for CBQ TCP/IP Networks
Catalin Popescu and A. Udaya Shankar
December 15, 1999Introduction
A CBQ TCP/IP network is one where TCP connections have class attributes and routers do class-based queueing (CBQ) of packets on some or all links. The Z-iteration technique is being extended to such networks, and we present preliminary results below. Specifically, we present the time evolution of some performance metrics for three examples of class-based TCP/IP networks and compare against ns simulations.
Network 1
There are two classes of traffic, namely class A and class B, in addition to best-effort traffic. All TCP connections are from node N1 to nodes N3 and N4. Class A has 30% bw allocation and priority 9. Class B has 50% bw allocation and priority 9. The best-effort traffic has priority 9 (and zero bw allocation).
Network 2
This network has class A, class B, and best-effort traffic. On each link, A has 30% with priority 7, B has 40% with priority 9, and the best-effort has priority 9.
Network 3
There are three traffic classes, A, B and C, in addition to best-effort. For the orange links, A has 20% and priority 3, B has 20% and priority 5, C has 20% and priority 9, and best- effort has priority 9. The red links do not implement CBQ.