Max retries exceeded error on IAX channel

Hi all, I’ve an Asterisk 1.4.26 (but I see the same issue with 1.4.18) on a Debian 4.0 with some IAX trunk to other Asterisk all connected with 100Mb ethernet LAN.
After some days of activities (about 1 or 2 month) all calls on IAX2 channel give me this error:

[Jul 23 18:09:16] WARNING[13542]: chan_iax2.c:2047 __attempt_transmit: Max retries exceeded to host 172.18.0.3 on IAX2/trixbox-1 (type = 6, subclass = 11, ts=10032, seqno=5)

The only way to fix is restarting Asterisk, so I think it’s not related to the O.S. or network problem. Seems that Asterisk lock all IAX2 connections.

Now every 15 days I restart Asterisk with when convenience option with a cron command but isn’t a good solution :smile:

Any suggestion to solve this issue?

Thanks

Pasqu