Telepresence EX90 SIP no video displayed when MTP enabled.

[Ralph John Tampilic]

Hi,

I have an issue when placing IDD or Mobile calls after dialing the PIN code.

Here is the issue, there is no problem on local calls but when we dial the IDD calls we must have to enter the PIN/authorization code and the PIN code always invalid. After we enabled the MTP required of EX90 in CUCM, the PIN was accepted and the IDD/Mobile calls successfully connected. But there is no video calls. We suspected that the MTP is the cause of this. We disabled the MTP required and test call the video is fixed.

May I know what are the configurations needed? or requirements to fixed the video calls when we needed MTP?

Highly appreciated for your help.

Thank you.

Best regards,

RJ

[deamanga]

Hi Ralph,

Your PIN issue could be related to DTMF tone from the SIP trunk, you need to make sure the SIP provider is using OOB method? This is related to RFC2833 where MTP are a required option to the CUCM for the SIP trunk, as you mentioned after you enable the MTP only audio call is working, maybe the far end codec do not support DTMF conversion? Note Cisco had a proprietary RTP, the DTMF packets are encoded differently than the media packets and use a different payload type this only applied to Cisco IOS gateway, you mentioned with no MTP required on the trunk you had video fixed, the TC SW can negotiate the use of RFC 2833 an OOB DTMF, support voice, video, and encryption; and do not anchor trunk calls to MTP resources.

Regards

Dean

[Alok Jaiswal]

Hi Ralph,

Once you enable the MTP the CUCM tries to invoke the MTP for the call.

Since the CUCM  doesn't support software MTP for the video codec and i believe the hardware MTP also is based on PVDM 2 and not the PVDM-3 dsp resources and that's the reason you will see only the audio call and no video.

As mentioned by Dean the PIN issure is realted to RFC 2833 and OOB method for DTMF signaling.

Can you tell me what type of gateway you have for PSTN calls? MGCP? H.323? SIP?

Rgds,

Alok

[Alok Jaiswal]

Ralph,

if you using the h.323 gateway then try to set this command on dial-peers

dtmf-relay h245-alphanumeric rtp-nte

and if the gateway type is MGCP then set the DTMF relay method on MGCP gateway to nte-ca

rgds

Alok

[Ralph John Tampilic]

Hi All,

Thanks for the reply.

As of now we open a TAC case and we waiting for the sniff packets logs analysis.

I will update this discussion once I have a feedback.

Thank you regards,

RJ

[Alok Jaiswal]

Hi Ralph,

i had a simillar issue with mgcp gateway and i was able to fix it with changing the dtmf realy method to nte-ca.

so this is issue is known to me.

I didn't handled issue with H.323, but to me it looks as wrong dtmf method on dial-peers.

rgds,

Alok