[erlang-questions] gen_tcp:send(Sock, SmallPacket) issue

Matthias Lang <>
Thu Jun 21 11:55:56 CEST 2007


Fredrik Thulin writes:

 > The complexity comes from having to implement retransmissions
 > yourself, and even though SIP has done just that, it hasn't solved
 > all issues with flow control and messages larger than your typical
 > MTU.

I'm aware of two MTU issues. One is that a fragmented UDP packet
stands an uncomfortably high chance of being dropped (if any one of
the fragments gets dropped, you lose the whole UDP packet). The other
is that some networks discard fragmented packets. I never really
understood why that is (paranoid firewalls?). Is there more?

At this point, it may also be worth mentioning SCTP, a relatively new
protocol which is probably a better fit for many applications. The
downside is that it's probably not supported on older machines and
windows boxes, at least not out of the box.

  http://www.erlang.org/doc/man/gen_sctp.html
  http://en.wikipedia.org/wiki/SCTP

Matt



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