[asterisk-users] Diagnosing poor call quality

[Chris Bagnall]

> Beware that ADSL uses vastly more bandwidth than you expect on small
> packets, eg if you are classifying using a cheap router then you
> probably need to at least half your claimed bandwidth in order to
> make the prioritisation work correctly.  I added some (hack) patches
> to fix the linux calculation for HTB on the linux QOS list a year or
> two back. If you have a linux router you could use those to improve
> the calculation quality for QOS - or else I found a Draytek router
> does impressively well at getting it right for small sites...      

Each site is using an old PIII-era PC running m0n0wall (www.m0n0.ch/wall) as
a router. Network cards are all decent-quality Intel Pro/100+ cards.

I've not had any complaints from either site today - I made the RTP change
on the SPA942s yesterday, and last night changed some of the QoS settings on
m0n0wall at the ip290 site.

> Very likely you will find that the issue is variable jitter on the
> line.  The link above should help you figure this out 

If this is the case, would upgrading to 1.4 with the new SIP jitter buffer
help at all?

Regards,

Chris
-- 
C.M. Bagnall, Director, Minotaur I.T. Limited
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