Date: Sun, 4 Feb 1996 20:40:54 -0500 From: dennis@etinc.com (dennis) To: Matt Thomas <matt@lkg.dec.com> Cc: hackers@freebsd.org Subject: Re: High speed Routing (was Re: Multi-Port Async Cards) Message-ID: <199602050140.UAA27888@etinc.com>
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> >In <Pine.BSI.3.91.960202115948.8158A-100000@ivory.lm.com> , you wrote: > >> That's right; and you can't add a 100Mbp/s port to a PC that will >> actually route that many packets for $134, or for any price. Reference >> the very interesting TCP performance tests at Usenix which showed that at >> Ethernet MTUs, Pentium boxes running TCP/IP over the loopback interface >> could only reach about 40Mb/s (this number went up if you increased the >> MTU ... the cost is in the packet processing, not the raw byte speed). > ># ifconfig lo0 mtu 1536 ># ./ttcp -f m -t -s -n 8192 0 >ttcp-t: buflen=8192, nbuf=8192, align=16384/0, port=5001 tcp -> 0 >ttcp-t: socket >ttcp-t: connect >ttcp-t: 67108864 bytes in 7.61 real seconds = 67.24 Mbit/sec +++ >ttcp-t: 8192 I/O calls, msec/call = 0.95, calls/sec = 1075.83 >ttcp-t: 0.0user 4.1sys 0:07real 55% 26i+263d 250maxrss 0+2pf 1330+4920csw > >I just did that on my P90 (running 2.1.0-RELEASE) using the loopback device >and an Ethernet MTU. That seems to be a bit more that 40Mb/s. > >However, I do agree that FreeBSD as it is today is not suitable as a high >speed router. While the system does have the raw processing power to do >high-speed routing, the network infrastructure is not up to the task. >Not surprisingly (given its history), the IP networking code is heavily >oriented to being a host, not a router. Depends on what you mean by "high speed routing". When you figure the cost of a Cisco 4500 with 4 or 6 T1 ports and a lot of ram and a 10 or 100Mbs interface....freebsd boxes do just fine in this scenario. As with most hardware architectures, there is a point of density where is become unsuitable. But its at a point that is higher than the majority of requirements. For T1 to T1 or T1 to LAN switching it is just fine. As fast or faster than much of what is being used. Certainly it can't compete with "backplane optimized routers"....but there are a few million routers out there that are not as fast as FreeBSD can be. dennis ---------------------------------------------------------------------------- Emerging Technologies, Inc. http://www.etinc.com Synchronous Communications Cards and Routers For Discriminating Tastes. 56k to T1 and beyond. Frame Relay, PPP, HDLC, and X.25 for BSD/OS, FreeBSD and LINUX
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