[Asterisk-Users] IAX2 tolerance on packet losses

Ernest Raspberry eraspberry at gmail.com
Wed Dec 15 01:42:33 MST 2004


Hello,

I'm experiencing some problems with running IAX2 protocol on quite
reliable link with G729A codec. My customer has 2mb FR link to the
Internet used in about 20%. Ping statistics:

50 packets transmitted, 49 received, 2% packet loss, time 49496ms
rtt min/avg/max/mdev = 9.308/13.126/33.307/4.851 ms

Everything would be great, but the quality isn't good enough. I have
2mb/512kb DSL line,
on which voice calls are working muuch better.

I've checked it on many ways. Hping tells me, that the average UDP
packet loss rate is about 8-15%. Is that too much for IAX
retransmissions ability? I've setup jitter with default settings
from iax.conf, but the quality remains almost the same - it's still
tooo jiiiiitttteery every few seconds.

I ran out of ways to test it. The conclusion remains the same - delays
and delay changes should be good enough, but the packet losses remain
too. I see some VNAK requests in
my log files, but no more than 3-4 during ~40 seconds connection.

So should I fight the packet losses or tune my iax.conf options?

--
Redargs,
Ernest Raspberry



More information about the asterisk-users mailing list