[netperf-talk] SCTP and Nagle's Algorithm

[Rick Jones]

Chris Lydick wrote:
> List,
> 
> I am receiving an error when attempting to disable Nagle's Algorithm.
> I've read that the LKSCTP library enables Nagle by default, but I'm
> unable to disable the algorithm. Any ideas? Is this more of a LKSCTP
> issue? And, if I pass messages size larger than my MSS (ie. -m MSS*2),
> is it possible to passively bypass it?
> 
> I'm using Ubuntu 7.04 with libsctp1 and libsctp-dev libraries.
> 
> $ ./netperf -t SCTP_STREAM -H x.x.x.x -c -C -l 30 -- -m 8952 -S 16777216
> -s 16777216 -D L,R
> 
> WARNING! getaddrinfo on this platform does not accept IPPROTO_SCTP!
> Please contact your vendor for a fix to this bug in getaddrinfo().
> SCTP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to x.x.x.x
> (x.x.x.x) port 0 AF_INET : nodelay
> netperf: create_data_socket: nodelay: errno 22
> ..
> 
> I've dug through the code a bit, and the line in question is
> nettest_bsd.c:981(ish), the setsockopt() command is returning that
> error. I'm using Netperf 2.4.3.
> 
> Error 22: Invalid Argument.

First thing to do is drop the L,R since they will be ignored - the 
options parsing, upon seeing a -D option will set both loc_nodelay and 
rem_nodelay to 1 arbitrarily.

I cannot imagine why that would be the root cause, but it would be a 
cleanup.  When it still fails, then getting a system call trace of the 
behaviour would be good.  It would be nice to see exactly what values 
are being passed-in on the setsockopt() call.

rick jones

> 
> Thanks,
> Chris Lydick
> 
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