Subject: [Megaco] MG Behavior on getting pending message response from MGC on ITO(Inactivity Timer) timeout

From: Rajiv Ginotra <[email-masked]>
Date: Thu, 25 Jun 2009 16:44:42 -0700

Hello All,
 
Consider the following scenario:
When the MG is sending the ITO timeout notify and the MGC sends the pending
message along with IA(Immediate Acknowledgment) in the same  message.

Question 1: After the ITO transaction retries are  finished, should MG sends
a "909 MGC Impending Failure" service change message to other MGCs
configured in the list or the send a ITO timeout notify with a new
transaction ID.
 
Question 2: Does the IA in the above reply from MGC make the behavior
different?
 
I have enclosed the call flow for reference
 
Regards
Rajiv
 
Call flow
======
[1196396 (10 ms)] !/2 [10.78.161.24]:5099 Transaction=2 {
Context = - {
Modify = ROOT {
Events = 1111 {it/ito {mit = 1000}}
}
}}
 
[10.78.161.24]:5099 [1196396 (10 ms)] !/2 [183.1.13.2]:2965 P = 2{ C = -
{mf=ROOT }}

ITO Timeout notify starts and MGC started sending pending messages:
----------------------------------------------------------------------------
--------------------------
 
[10.78.161.24]:5099 [1197496 (10 ms)] !/2 [183.1.13.2]:2965 T = 538{ C = -
{n=ROOT  { oe = 1111 { IT/ITO }  } }}
 
[1197503 (10 ms)] !/2 [10.78.161.24]:5099 Reply=538 {IA, C  =  - { n=root {
Error = 506 {"506"} }}}
 
[10.78.161.24]:5099 [1197503 (10 ms)] !/2 [183.1.13.2]:2965 k{537,538}
 
[10.78.161.24]:5099 [1198403 (10 ms)] !/2 [183.1.13.2]:2965 T = 539{ C = -
{n=ROOT  { oe = 1111 { IT/ITO }  } }}
 
[1198408 (10 ms)] !/2 [10.78.161.24]:5099 Reply=539 {IA, C  =  - { n=root {
Error = 506 {"506"} }}}
 
[10.78.161.24]:5099 [1198408 (10 ms)] !/2 [183.1.13.2]:2965 k{539}
 
[10.78.161.24]:5099 [1199408 (10 ms)] !/2 [183.1.13.2]:2965 T = 540{ C = -
{n=ROOT  { oe = 1111 { IT/ITO }  } }}
 
[1199412 (10 ms)] !/2 [10.78.161.24]:5099 Reply=540 {IA, C  =  - { n=root {
Error = 506 {"506"} }}}
 
[10.78.161.24]:5099 [1199412 (10 ms)] !/2 [183.1.13.2]:2965 k{540}
 
[10.78.161.24]:5099 [1200412 (10 ms)] !/2 [183.1.13.2]:2965 T = 541{ C = -
{n=ROOT  { oe = 1111 { IT/ITO }  } }}
 
[1200417 (10 ms)] !/2 [10.78.161.24]:5099 Reply=541 {IA, C  =  - { n=root {
Error = 506 {"506"} }}}
 
[10.78.161.24]:5099 [1200417 (10 ms)] !/2 [183.1.13.2]:2965 k{541}
 
Now the ITO retries get finished. what would be the next transaction???