[ixp1200] IXP1200 SOSP Paper

[Scott C. Karlin]

For those interested in what we have been up to with regard to the
IXP1200 processor, you might want to check out our latest paper,
available at

      http://www.cs.princeton.edu/nsg/papers/ixp-sosp.ps

The abstract is given below.

Scott

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Building a Robust Software-Based Router Using Network Processors
Tammo Spalink, Scott Karlin, Larry Peterson, Yitzchak Gottlieb

Recent efforts to add new services to the Internet have increased 
interest in software-based routers that are easy to extend and 
evolve.  This paper describes our experiences using emerging network 
processors---in particular, the Intel IXP1200---to implement a 
router.  We show it is possible to combine an IXP1200 development 
board and a PC to build an inexpensive router that forwards 
minimum-sized packets at a rate of 3.47 Mpps.  This is nearly an 
order of magnitude faster than existing pure PC-based routers, and 
sufficient to support 1.77 Gbps of aggregate link bandwidth.  At 
lesser aggregate line speeds, our design also allows the excess 
resources available on the IXP1200 to be used robustly for extra 
packet processing.  For example, with 8 x 100 Mbps links,
240 register operations and 96 bytes of state storage are available 
for each 64-byte packet.  Using a hierarchical architecture we can 
guarantee line-speed forwarding rates for simple packets with the 
IXP1200, and still have extra capacity to process exceptional packets 
with the Pentium.  Up to 310 Kpps of the traffic can be routed 
through the Pentium to receive 1510 cycles of extra per-packet 
processing.