[Asterisk-Users] IAX2 Sporadic TX/RX retries

[Steve Rodgers]

Hi,

I'm trying to track down why I'm getting calls dropped on an infrequent basis 
between two asterisk servers which are at the same physical location and 
connected to each other with UTP ethernet. Here is the connection diagram

Asterisk Server 1 ===UTPENET== Switch  ====UTPENET==== Asterisk Server 2

I see sporadic RX and TX frame retries when I enable iax2 debugging on either 
box. Here's some sample output:

   Timestamp: 30016ms  SCall: 00005  DCall: 00001 [192.168.17.200:4569]
Rx-Frame Retry[ No] -- OSeqno: 012 ISeqno: 010 Type: IAX     Subclass: LAGRP
   Timestamp: 30016ms  SCall: 00001  DCall: 00005 [192.168.17.200:4569]
Tx-Frame Retry[-01] -- OSeqno: 010 ISeqno: 013 Type: IAX     Subclass: ACK
   Timestamp: 30016ms  SCall: 00005  DCall: 00001 [192.168.17.200:4569]
Rx-Frame Retry[ No] -- OSeqno: 013 ISeqno: 010 Type: IAX     Subclass: LAGRQ
   Timestamp: 30010ms  SCall: 00001  DCall: 00005 [192.168.17.200:4569]
Tx-Frame Retry[000] -- OSeqno: 010 ISeqno: 014 Type: IAX     Subclass: LAGRP
   Timestamp: 30010ms  SCall: 00005  DCall: 00001 [192.168.17.200:4569]
Rx-Frame Retry[ No] -- OSeqno: 014 ISeqno: 011 Type: IAX     Subclass: ACK
   Timestamp: 30010ms  SCall: 00001  DCall: 00005 [192.168.17.200:4569]
 
I get a burst of these retries every 2-30 seconds on both ends. 

Given the two servers are hardwired to each other, I would think retries 
should be more infrequent and that this could be the "smoking gun" for the 
dropped calls.


Besides the iax2 debug CLI command, what other tricks can be used to help to 
track this problem down to its root cause?

Steve.