Call forward issue - no answer to voicemail - CUCM & CUC

[Rody_VB]

Hello everyone,

We are facing an issue regarding call forwarding on no answer to voicemail.

---

About the lab :

We have a CUCM cluster connect to a CUC cluster through a SIP trunk.

• CUCM version 12.5.1.10000-22
  • @ ip Call manager : 192.168.1.1

• CUC version 12.5.1.10000-23
  • @ ip CUC : 192.168.1.2
  • Voice Mail Pilot = 123

We use G729.

Three third party SIP end-point are configured with theses parameters :

• DN=1001 ; @ ip 192.168.2.18
• DN=1002 ; @ ip 192.168.2.10
• DN=1003 ; 

The IP phone with DN 1001 has an operational voicemail.

There is no Voice GW on the network. Everything is in a local area.

---

About test :

• [NOK] 1001 > Call Forward no answer (5sec) to voicemail
  • 1002 call 1001
  • 1001 is ringing but does not answer
    After 5 sec (DN configuration), 1001 stop ringing
  • 1002 still get in the call (for 10 sec)
  • Then i get an error message : Service Unavailable

On RTMT, i see :

47 = Resource unavailable, unspecified. Explanation : A resource unavailable event occured and no other cause in the resource unavailable class applies

On CUCM logs, i did not really understand what it is happening (why 1002 is not forwarded to voicemail through SIP trunk).

I did not see codec/DTMF mismatchs.

I do not need MTP i guess (MTP resources are also registered on call manager - with IP Voice Media Streaming App activated on other cucm nodes - May i have an issue due to this MTP only support G711 if necessary).

I tried to troubleshoot this with the https://cway.cisco.com/csa/ but i did not see something.

---

Other tests :

1. [OK] 1001 > Forward All to voicemail
   • 1002 call 1001
   • 1002 is forwarded to voicemail
2. [OK] 1001 > Call Forward Busy to voicemail
   • 1003 call 1001
   • 1001 answers
   • 1002 call 1001
   • 1002 is forwarded to voicemail
3. [OK] 1001 > Call Forward Unregistered to voicemail
   • 1002 call 1001 (unregistered)
   • 1002 is forwarded to voicemail
4. [OK] 1001 > Call Forward No Answer (5 sec) to DN=1003
   • 1002 call 1001
   • 1001 is ringing but does not answer
   • After 5 sec (DN configuration), 1002 is forwarded to 1003

---

Questions :

• Did i miss something in SIP trunk configuration (or SIP profile / about early offer etc. ?)
• Or is it something in CUC configuration ?

---

Attached :

You will find CUCM logs for call forwarding to voicemail (rebuild from CSA) :

• [00:27:18.185] 1002 call 1001
• [00:27:23.428] Forward to voicemail on no answer (5sec)

---

Thank you very much for your next reply and support !

Rody

[Maren Mahoney]

Do I understand your situation correctly that only Call Forward No Answer to Voicemail is not working, that all other forms of Call Forwarding are working correctly? That is an interesting problem!

What I see in the trace is that the UPDATE at 01101383.001 |00:27:23.461] is showing a CSeq of 101 where the original INVITE has a CSeq of 1. This means that your SNOM D305 phone is seeing the UPDATE as a update to a call that has not yet been established.

In the CFA, CFUR, and CFB situations (assuming the busy trigger on 1001 is 1), the call is not extended to the 1001 phone in the first place so the situations are different so the signaling flow would be different.

Can you provide a trace of the CFNA=1003 call? That would be a closer match to this scenario.

Now all of that said, I don't understand yet why this is happening. I'm hoping that the trace of the CFNA=1003 call will help. (Or that someone else on this forum can provide an explanation.)

Maren

[Rody_VB]

Hi Maren,
Thank you so much for your analisys.
You absolutly right ! CFNA to voicemail does not working.
All other cases are working well (CFA, CFUR & CFB ; and CFNA to other DN on phone).
I'll provide very soon call logs from CFNA to 1003 (as soon as i have access to customer infrastructure).
I'll keep you updated.
Rody

[Rody_VB]

Hello Maren,

About CFNA to a DN=1003,

It finaly does not work, It is the same issue between CFNA to voicemail or to a DN.

What really happening during call forwarding on no answer to 1003 is :

1. 1002 call 1001
2. After 5 sec CFNA is activated to 1003
3. 1003 is ringing
4. BUT when 1003 off hook
   1002 still calling
5. Then 1002 get an error message : Service Unavailable

CUCM version 12.5.1.10000-22 :

• @ ip Call manager : 192.168.1.1

Third party SIP end-point :

• DN=1001 ; @ ip 192.168.2.18
• DN=1002 ; @ ip 192.168.2.10
• DN=1003 ; @ ip 192.168.2.16

Attached logs from a CFNA to 1003.

[Rody_VB]

To keep topic updated :

I get some Cisco SIP phones to test CFNA to DN/Voicemail.

It works perfectly.

I need to investigate on the third-party SIP phone (snom D305) or the device SIP profile.

[Maren Mahoney]

I apologize for letting this slip. It was on my list to investigate this morning. However, since we are talking about 3rd party phones I'm not sure I'm going to be able to help much more. It would be worth digging through the configuration guides for your 3rd party phones to see if they have more information.

Maren

[Vaijanath Sonvane]

Hi,

Have you tried your scenario using G.711 codec for all three phones and Unity Connection SIP Trunk? If yes, can you please share your results.

Also, please post the screenshots of SIP Trunk Security Profile, SIP Profile and SIP Trunk configured for Unity Connection. 

[Rody_VB · Accepted solution]

New update :

The third-party SIP phone (Snom D305) is sending a bad reply to the update of the callmanager regarding the CFNA to DN/voicemail (call flow attached) :

Snom D305 is sending a "491 Request Pending" instead of a "200 OK".

With anoter SIP phone, everything works (CFNA to DN or voicemail as well).

This is a bug from Snom phones and we will contact Snom support.

Many thanks Maren, Vaijanath for your help !