Hema Tahilramani Rensselaer Polytechnic Institute
Traffic Engineering (TE) deals with the issue of performance evaluation and optimization of operational IP networks. The current work in the area of intra-domain TE focuses on an indirect approach where parameters of the routing algorithm, e.g. link weights, are changed according to prevailing traffic conditions. This is undesirable because it leads to control-traffic overhead and route computations for every change in network
traffic. Moreover, the performance improvements with the indirect approach are limited by the single-path nature of underlying routing protocols.
I will present BANANAS framework for explicit, multipath routing and as a connectionless TE solution. The key idea is that a path can be encoded as a short hash (called "PathID") of a sequence of globally known identifiers. Therefore, unlike MPLS "labels", the PathID has a global significance. This property allows multipath capable nodes to autonomously compute PathIDs in a partially upgraded network without requiring an explicit signaling protocol for path-setup. We show that this framework allows the introduction of explicit routing and multipath capabilities in the context of widely deployed connectionless protocols, OSPF and BGP. BANANAS has been evaluated using both SSFNet simulations and Linux/Zebra implementation on Utah's
Emulab testbed facility. This work has been accepted for ACM SIGCOMM 2003 workshop on Future Directions in Network Architecture (FDNA-2003), Karlsruhe, Germany.