Scheduled System Maintenance:
On May 6th, single article purchases and IEEE account management will be unavailable from 8:00 AM - 5:00 PM ET (12:00 - 21:00 UTC). We apologize for the inconvenience.
By Topic

SPAL: a speedy packet lookup technique for high-performance routers

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

1 Author(s)
Tzeng, N.-F. ; Center for Adv. Comput. Studies, Univ. of Louisiana, Lafayette, LA, USA

This work introduces and evaluates a technique for speedy packet lookups, called SPAL, in high-performance routers, realized by fragmenting the BGP routing table into subsets. Such a router contains multiple line cards (LCs), each of which is equipped with a forwarding engine (FE) to perform table lookups locally based on its forwarding table (which is a fragmented subset). The number of table entries in each FE drops as the number of LCs in a router grows. This reduction in the forwarding table size drastically lowers the amount of SRAM (e.g., L3 data cache) required in each LC to hold the trie constructed according to the matching algorithm. SPAL calls for caching the lookup result of a given IP address at its home LC (denoted by LCho, using the LR-cache), such that the result can satisfy the lookup requests for the same address from not only LCho but also other LCs quickly, when the switching fabric for interconnecting LCs has a low latency. Lookup results obtained from remote LCs are also held in the LR-cache of a local LC. Our trace-driven simulation reveals that SPAL indeed leads to substantial improvement in mean lookup performance. SPAL may possibly shorten the worst-case lookup time (thanks to fewer memory accesses during longest-prefix matching search) when compared with a current router without partitioning the routing table. It takes no specific traffic into consideration when selecting the partitioning bits, promising good scalability and a small mean lookup time per packet.

Published in:

Parallel Processing, 2004. ICPP 2004. International Conference on

Date of Conference:

15-18 Aug. 2004