[Asterisk-Users] asterisk grandstream aleatory error

[interopen]

Hello all,

It just start happening a week ago on a handytone 286, sip extension, every 
time i call to this extension it rings one time and it hungs, in the asterisk 
console this error repeats:

Jul  7 00:19:32 WARNING[98311]: chan_sip.c:471 retrans_pkt: Maximum retries 
exceeded on call 09d5668135ce80e86d50c8f47c4dcf47 at 10.0.0.6 for seqno 102 
(Request)

I change the ip of the handytone and work for a couple of days but start 
again.

Any solution or trick.

Thanks in advanced,

Ivan