I have Asterisk 188.8.131.52. I connect phone Grandstream GXP2000 to it. After registration all is OK, after 10 minutes (sometimes after 1 hour) phone dont ring. On console is:
-- Dial("SIP/511-0000072c", "SIP/892,40,Tt") in new stack
== Using SIP RTP CoS mark 5
-- Called SIP/892
[Jun 12 13:03:48] WARNING: chan_sip.c:3629 retrans_pkt: Retransmission timeout reached on transmission email@example.com:5060 for seqno 102 (Critical Request) -- See https://wiki.asterisk.org/wiki/display/AST/SIP+Retransmissions
Packet timed out after 32000ms with no response
== Everyone is busy/congested at this time (1:0/0/1)
There is missing SIP/892-xxxxxx is ringing
In sip.conf is:
type = friend
username = 892
host = dynamic
mailbox = 892
Asterisk is connected direct to Internet with own public IP.
Can you help me?
P.S. Sorry for my english.