Max retries exceeded error on IAX channel

I have a new Asterisk 1.8.4 system with two IAX trunks and SIP phones attached. The system runs fine for a period of time and then starts to produce error messages like this.

[May 28 14:27:56] WARNING[12572] chan_iax2.c: Max retries exceeded to host 64.xx.xx.xx on IAX2/trunk_2-6001 (type = 6, subclass = 11, ts=3119938, seqno=155)

The errors increase and if Asterisk is not restarted in becomes unstable. In one case phones were unable to register and in another Asterisk crashed.

Based on this reported issue: … g_id=19285 and additional research I have changed the timing driver from to (there is a 4 port FXS card and a T1 card installed). So far the problem has not reoccured, but the next 24 hours will tell.

Has anyone else seen this problem and if so what steps were you able to take to resolve it?

Hi! i have same error

Plus sometimes all my IAX peers become unreachable

Did you solve it?

I ve just change to res_timing_dahdi only and if it works in the next week i ll write it