[Asterisk-bsd] IAX2 long latency

[Dr. Rich Murphey]

Hmm.. does 'netstat -in' report any collisions or in/out errors?  That would
help rule out issues with the NIC or drivers.

Does linux do any priority queueing (in the firewall or elsewhere) of
UDP/RTP packets per the TOS flags or port numbers?  That would certainly
account for differences in latency of RTP traffic if/when the WAN link is
saturated.  I've switched to using TOS=0x10 in sip/iax.conf just to be on
the safe side in this regard.

FreeBSD's 'uname -m' will report i386 on various machines on which linux
will report 'i686', so there can be differences in compiler optimization
that could affect codec performance.  That shouldn't be more than about %5
in general, but the codecs could possibly be tuned such that it would have a
greater impact.

So, you could try building with PROC=i686 in various makefiles for the xeon,
and see if it has any effect.

Rich

> -----Original Message-----
> From: asterisk-bsd-admin@lists.digium.com [mailto:asterisk-bsd-
> admin@lists.digium.com] On Behalf Of Chris Stenton
> Sent: Tuesday, June 29, 2004 12:03 PM
> To: asterisk-bsd@lists.digium.com
> Subject: Re: [Asterisk-bsd] IAX2 long latency
> 
> I tested both using GSM.
> 
> Both machines are on the same subnet and identical in the way asterisk is
> used.
> 
> I checked into this because I have been having a few dropped packet
> problems
> connecting to voiptalk from the FreeBSD box but not the Linux box which
> must
> be due to the longer latency.
> 
> Chris
> 
> ----- Original Message -----
> From: "Dr. Rich Murphey" <Rich@WhiteOakLabs.com>
> To: <asterisk-bsd@lists.digium.com>
> Sent: Tuesday, June 29, 2004 3:57 PM
> Subject: RE: [Asterisk-bsd] IAX2 long latency
> 
> 
> > Which codecs?
> >
> > I've noticed differences in latency between xten and firefly, but
> haven't
> > taken the time to reproduce it using identical codec choices.
> >
> > 400ms is indeed quite long if the components are all on the same subnet.
> >
> > Diagnostic output (e.g set verbose 9) can cause audio delay, even when
> > obtaining output using remote asterisk (asterisk -r) to a server at high
> > priority (asterisk -p).
> >
> > Rich
> >
> > > -----Original Message-----
> > > From: asterisk-bsd-admin@lists.digium.com [mailto:asterisk-bsd-
> > > admin@lists.digium.com] On Behalf Of Chris Stenton
> > > Sent: Tuesday, June 29, 2004 3:53 AM
> > > To: asterisk-bsd@lists.digium.com
> > > Subject: [Asterisk-bsd] IAX2 long latency
> > >
> > > I have just done some crude latency testing on an iax2 soft phone and
> > > compared the latency on my Linux Box to that produced by my FreeBSD
> box
> > > via
> > > the simple echo test. The latency under FreeBSDis very long maybe
> 400ms.
> > > The
> > > latency is not so noticable under Linux. The Linux box is a 1.4GHz P
> IV
> > > while the FreeBSD box is a dual 2.4GHz  Xeon.
> > >
> > > Same test with an XTEN SIP phone showed no difference in latency.
> > >
> > > Chris
> > >
> > > _______________________________________________
> > > Asterisk-BSD mailing list
> > > Asterisk-BSD@lists.digium.com
> > > http://lists.digium.com/mailman/listinfo/asterisk-bsd
> > >
> >
> >
> >
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> 
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