CUCM 10.5 , Silent ringtone on Call-Waiting call

[Ahmed Khalefa]

Hello All,

Recently , one of our customers purchased a 3rd Party SIP Phones , and they are registered to the CUCM as 3rd Pary Basic SIP Phones ,

Phones are working normally , without any issue , till the customer discovered an interesting issue ..

When Phone A , calls Phone B ... and we have an established call ..

Now Phone C , tries to call Phone A ..

- Phone A : hears a beep tone ( which is the one for waiting )

- Phone C : hears nothing .. complete emptiness .. and this is the issue

they raised a Ticket with the 3rd party vendor , and they said that the Phone A sends a SIP Message 182 ( Queued ) to the CUCM

but after checking the CUCM Traces , the CUCM didn't sends any ACK or any message to reply ..

I tried changing the "SIP Rel1XX Options" from Disabled to "Send PRACK for all 1XX messages" , but that didn't change any thing ..

also , googled the issue and found that CUCM chooses to ignore this message ... as per this document :

http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/sip_msg/line_std/10_0_1/CUCM_BK_CC69BCF6_00_cucm-sipline-messaging-std-100/CUCM_BK_CC69BCF6_00_cucm-sipline-messaging-std-100_chapter_01.html#CUCM_CN_S33CFD74_00__table_2433D78BFB80416EAE12B4734...

Can any one help with such issue ?

Thanks A lot,
Ahmed Salah

[vasank · Accepted solution]

Hi Ahmed,

What is the expectation here? 182 is a provisional message indicating the proxy that call is in queue, which does not necessarily translate to 180 ringing or 183 session progress, if the third party sip phone sends a 183 session progress after 182 then it would make sense to perform audio cut through.

Thanks,

Vasanth

[Ahmed Khalefa]

Hello Vasanth,

it seems that your answer says all .. as i took a SIP Trace from  a working Cisco SIP Phone 99xx , and the message i sent as 180 Ringing , instead of 182 ...

So , i believe that the issue is related to the 3rd party vendor ..

Thanks A lot,
Ahmed Salah

[vasank]

Thanks Ahmed, glad it helped.

Regards,

Vasanth

[Vivek Batra]

Can you please share the SIP traces of second call on both the call legs viz from C to CUCM and CUCM to A?

By the way, third party SIP phones are from which vendor?

- Vivek

[Ahmed Khalefa]

Hello Mohamed, Vivek,

traces are in the attachment below .
i took a trace from the CUCM , with below scenario :

1722 : 10.1.35.252 >> Phone A
1000 : 10.1.30.107 >> Phone B ( VM System : not Cisco )
1718 : 10.1.35.236 >> Phone C

I used TranslatorX and found that when the 1722 is having an established call with 1000 , and 1718 tries to call to 1722 , 1722 sends a 182 SIP Message ( Queued ) to the CUCM .. that's all ...

Thanks A lot,
Ahmed Salah

[Ahmed Khalefa]

Hello All,

any luck finding any thing inside CUCM Traces?

[Mohammed al Baqari]

Please get SIP real time trace from CUCM using RTMT and share a snapshot. This will help us to understand the call flow. This might be related to voice cutthough and early-media but lets see