Fast address look-up for internet routers

We consider the problem of organizing address tables for internet routers to enable fast searching. Our proposal is to to build an efficient, compact and easily searchable implementation of an IP routing table by using an LC-trie, a trie structure with combined path and level compression. The depth of this structure increases very slowly as function of the number of entries in the table. A node can be coded in only four bytes and the size of the main search structure never exceeds 256 kB for the tables in the US core routers. We present a software implementation that can sustain approximately half a million lookups per second on a 133 MHz Pentium personal computer, and two million lookups per second on a more powerful SUN Sparc Ultra II workstation.

[1]  Günter Karjoth,et al.  Routing on longest-matching prefixes , 1996, TNET.

[2]  Bernhard Plattner,et al.  Scalable high speed IP routing lookups , 1997, SIGCOMM '97.

[3]  Arne Andersson,et al.  Faster Searching in Tries and Quadtrees - An Analysis of Level Compression , 1994, ESA.

[4]  Arne Andersson,et al.  Improved Behaviour of Tries by Adaptive Branching , 1993, Inf. Process. Lett..

[5]  Peter Newman,et al.  IP switching and gigabit routers , 1997, IEEE Commun. Mag..

[6]  Philippe Jacquet,et al.  Limiting Distribution for the Depth in Patricia Tries , 1993, SIAM J. Discret. Math..

[7]  C. M. Ozveren,et al.  The GIGAswitch control processor , 1995 .

[8]  W. David Sincoskie.  Viewpoint: broadband ISDN is happening—except it's spelled IP , 1997 .

[9]  Martina Zitterbart,et al.  On the Design of a Multigigabit IP Router , 1994, J. High Speed Networks.

[10]  D. B. Davis,et al.  Sun Microsystems Inc. , 1993 .

[11]  G. H. Gonnet,et al.  Handbook of algorithms and data structures: in Pascal and C (2nd ed.) , 1991 .

[12]  Stephen E. Deering,et al.  IP Version 6 Addressing Architecture , 1995, RFC.

[13]  Svante Carlsson,et al.  Small forwarding tables for fast routing lookups , 1997, SIGCOMM '97.

[14]  Vince Fuller,et al.  Classless Inter-Domain Routing (CIDR): an Address Assignment and Aggregation Strategy , 1993, RFC.

[15]  C. Zukowski,et al.  Putting routing tables in silicon , 1992, IEEE Network.

[16]  Gaston H. Gonnet,et al.  Handbook Of Algorithms And Data Structures , 1984 .

[17]  H. V. Jagadish,et al.  Towards a Gigabit IP Router , 1992, J. High Speed Networks.

[18]  Edward Fredkin,et al.  Trie memory , 1960, Commun. ACM.