A good limitation on packet switching is related to an issue regarding linux soft-net and "irq livelocking". A very useful and powerful approach is to use the "NAPI" patches for the linux kernel which seem to work very very well in alleviating this problem.
I was able to route/forward without loss around 120-130kpps on my p3-600 256mb ram linux-router with the NAPI patches (without them the box crapped out around 30kpps, quite a difference indeed!). On April 2, 2002 02:09 am, Patrick Schaaf wrote: > On Tue, Apr 02, 2002 at 11:31:30AM +0530, Mehul Vora wrote: > > does linux switch packets at wire speed while using netfilter to do > > stateful firewalling? > > No. > > BTW, what wire speeds do you have in mind? 64kbit/s, 100mbit/s, 10gbit/s? > And on what hardware platform (processor, I/O busses). > > Probably the 'No' will change when you tell us. > > Gratuitious General Advise: any switching or routing facility with internal > queues transmits packets up to some maximum packet rate saturating the I/O > busses or CPU. If the aggregate outgoing "wire speed" packet rate, however > that is defined, does not exceed the maximum CPU/IO saturating packet rate, > the system can be said to do "wire speed switching". > > By varying the parameters I ask in the first paragraph above, over the > range of currently supported Linux systems, I'm sure that you will find > a 'Yes' solution for a two-ports-only situation at 1gbit/s speeds, and > you will find that 10gbit/s is not yet available. > > best regards > Patrick
