Summary:ASTERISK-18058: OOH323 Fails to Identify Dead Peer and Rings Indeffinitely
Reporter:Vladimir Mikhelson (vmikhelson)Labels:
Date Opened:2011-06-22 20:48:33Date Closed:2011-07-11 15:42:11
Versions:1.8.4 Frequency of
Environment:AsteriskNOW FreePBX Asterisk 0) h323_log-no-busy
Description:When an outgoing call is placed from Asterisk to Avaya at the time the network path is not available Asterisk rings indefinitely vs. presenting a caller with busy signal.
Comments:By: Alexander Anikin (may213) 2011-06-30 15:49:10.220-0500

Vladimir, this behavior is normal except ringing. Asterisk tries 3 times to connect to opposite gateway ip, this is done for unstable network cases specially.
False ringing singal is generated by FreePBX with 'r' option in Dial options i think, chan_ooh323 don't send any alerting/progress controls.
Linux TCP stack tries to send SYN TCP packets 3 times with initial timeout of SYNACK packet is received of 3 seconds and increased twice on every attempt. This way timeout for connection is 3+6+12=21 seconds and complete connection timeout in ooh323 is 21*3 = 63 seconds.
You can decrease tcp stack retries by sysctl command down to 2 times for example:
sysctl net.ipv4.tcp_syn_retries=2
and you'll have tcp connection timeout 12 seconds per connection attempt and 36 seconds complete in ooh323 channel.