CUCM call sequence and flow

[Bekzod Fakhriddinov]

Hi. If there is route pattern X  and it has RL with route groups A and B , also RP  X has Local route group C . By order in route list : A is first choice, B second, X is 3rd .

How CUCM will re-route calls (will it ?) in case of when not all calls failed on trunk A, but to specific prefixes ?? 

I have this problem when calls to some international numbers dropped via primary sip trunk but didn't go trough backup PRI (different Carrier ). 

Thank you

[Gregory Brunn]

What code/ sip message are you getting back from carrier on the sip trunk?

Also what are your service parameters set to for user busy and unallocated number?

[Bekzod Fakhriddinov]

SIP/2.0 404 Not Found from carrier. Then the CUBE then hunts to dial-peer 92 and sends a INVITE to second ip of same Carrier ->Received:SIP/2.0 404 Not Found

Then CUBE sends "No matching outgoing dial-peer" to CUCM and CUCM terminates call and doenst try our backup PRI ...

Why ? Is it because of not all calls dropped and SIP trunk was running ? Is there any percent should be dropped to switch to second-backup link (on CUCM route list )?

[Gregory Brunn]

What are you service parameters on CUCM set to?

[Bekzod Fakhriddinov]

I attached sip serv parameters

[Gregory Brunn]

Stop routing on unallocated number flag

[Bekzod Fakhriddinov]

is True, screen shot is attached.

[Gregory Brunn]

Change to false, then try.

[Bekzod Fakhriddinov]

Is "No matching outgoing dial-peer"  equal “unallocated number” ?  I see it may also cause call routing loop ? 

[Gregory Brunn]

Loop avoidance is best done with more than just this feature. IE calling search spaces on the sip trunk pointing in that don't have access to your outsides numbers etc. As far as I understand sip 404 will match to unallocated.

[Bekzod Fakhriddinov]

"Loop avoidance is best done with more than just this feature. IE calling search spaces on the sip trunk pointing in that don't have access to your outsides numbers etc"    

I have that SIP trunk with  inbound CSS which has partition Global-PSTN with prefixes to Local, Long Distance, International .

Which means my sip trunk does have access to outside number , and I will have a loop correct ?  if correct then how calling search spaces on the sip trunk pointing in that don't have access to your outsides numbers AND will be able to get inbound calls ?

Thank you 

[Gregory Brunn]

Why does your inbound sip trunk need access to outside numbers?

I typically restrict my sip trunks on cucm to have internal access only.

[Bekzod Fakhriddinov]

do you mean inbound CSS ? It was programmed this way by vendors.

Are you able to get calls from PSTN/ LD/International when you restrict it to internal only ? 

[Bekzod Fakhriddinov]

resolved

[Gregory Brunn]

Yes I am talking the inbound calling search space on your sip trunk configuration in CUCM. This I would only normally create a CSS called internal that would only have access to the internal partition where DNs would be placed.

Can you walk me through the situation you are worried about creating a loop, understand I don't know you environment looks like do you have ICT to other CUCM clusters that are blind pointing back and forth?