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The slowdown only appears between two different computers. If I run it on a single computer I get 700 cps. If I run it between two separate computers but with one or two simultaneous deferreds, then there's only a very minor slowdown. I'm running on windows 2000 with Twisted-1.3.0.win32-py2.3.exe. What do you think? Is this a strange behaviour of twisted or is there something screwed up with my networking?

It is possible this is due to the immediate-write behavior of twisted 1.3 combined with the TCP Nagle algorithm. You could try calling transport.setTcpNoDelay(True) on both ends (the client and the server end) to see if that helps.

James

Ok, now I'm feeling quite clueless. I guessed that "transport" refers to myPBClientFactory.protocol.transport (for the client case). But this is set to None and never changes. Where is the underlying transport stored in PBClientFactory and PBServerFactory? Thanks, -Russ