Yes, the PC running OVS would have to be used as a switch. If one of your requirements is that you need more than the number of Ethernet ports you can conveniently put in a PC chassis (which is often 6 to 10 ports), then it's not a good way to go.
Presumably the hardware switch's performance drops because the ASIC can't do what you are asking and every packet has to be sent to the switch CPU. Switch CPUs are usually quite slow and often the channel from ASIC to CPU is ratelimited too. With OVS, every packet already goes up to the CPU (that's a NIC's job after all) and there's very little incremental cost to modifying a few headers. On Sun, Jun 26, 2011 at 03:15:48PM -0400, Aaron Rosen wrote: > But in order to use OVS in this manor I would need a box running OVS > that everyone first sent their traffic to first right? Is the reason > why OVS can perform a factor of 1000 faster is because the > implementation is better or because the hardware of a commodity PC is > better for this than that of the OF switch that is doing the > modifying? Just curious. > > On Sun, Jun 26, 2011 at 3:00 PM, Ben Pfaff <b...@nicira.com> wrote: > > On Sun, Jun 26, 2011 at 02:54:13PM -0400, Aaron Rosen wrote: > >> Thanks for your reply. I just tested this on the same HP just > >> rewriting the DL_DST and the performance is the same there too so it > >> must be done in software completely on these switches :( > > > > You mentioned a "high" rate of 683 Mbit/sec. If that's a good rate for > > you, you don't need switching ASIC for that. Open vSwitch can handle > > several gigabits per second on commodity PC server hardware. And its > > performance won't drop by a factor of 1000 when you start modifying > > headers. _______________________________________________ openflow-discuss mailing list openflow-discuss@lists.stanford.edu https://mailman.stanford.edu/mailman/listinfo/openflow-discuss
