MS Teams with SBC Forking Call

[Faisal Saoud]

Hello,

We have a Ribbon device acting as an SBC between CUCM and MS Teams. On the Ribbon, there is a call forking feature, which means that when a call comes from MS Teams, the Ribbon forks the call—sending one leg to CUCM and another to the MS Teams destination. This allows the call to ring on both the Cisco phone and MS Teams simultaneously.

We are planning to replace the Ribbon with a Cisco 8300 SBC. Does the Cisco 8300 SBC support a similar call-forking feature? If not, can MS Teams handle this functionality?

[Roger Kallberg]

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@Faisal Saoud wrote:

Hello,

We have a Ribbon device acting as an SBC between CUCM and MS Teams. On the Ribbon, there is a call forking feature, which means that when a call comes from MS Teams, the Ribbon forks the call—sending one leg to CUCM and another to the MS Teams destination. This allows the call to ring on both the Cisco phone and MS Teams simultaneously.

We are planning to replace the Ribbon with a Cisco 8300 SBC. Does the Cisco 8300 SBC support a similar call-forking feature? If not, can MS Teams handle this functionality?

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If the call comes from Teams should it not then already ring on the destination in Teams? I mean the call shouldn't need to pass via an SBC to ring on the destination in Teams as that call should be kept within the platform.

[Faisal Saoud]

Hello @Roger Kallberg , I understand your point, but in our case, we need something like SNR (Simultaneous Ring) on Cisco CUCM. This would allow both the destination Cisco phone and MS Teams to ring simultaneously when someone on Teams calls another person. The called person can then pick up the call from either device.

[Nithin Eluvathingal]

AFAIK, the call forking feature on the Ribbon is mainly to send calls from the Enterprise PBX to MS Teams, primarily for calls coming from the PSTN, focusing on migrating enterprise users to Teams.

As @Vaijanath Sonvane mentioned, when using the 8200, you need to make use of the SNR. For my customer, I have enabled the SNR on the CUCM as all the calls land on the CUCM, and the customer's requirement is that they want the calls landing on the CUCM to ring on MS Teams.

Forking on the CUBE serves a different functionality.

[Faisal Saoud]

@Nithin Eluvathingal If we want the opposite scenario also, where someone from MS Teams places a call, and the call rings simultaneously on the desk phone and MS Teams of the called person, can this be achieved through SNR from the CUCM side?

[Nithin Eluvathingal]

I have this scenario for our customer where Teams users call the CUCM desk phones of their colleagues, and the call rings on both the CUCM desk phone and Teams, as this user has SNR enabled with RDP as the Teams number.

[Faisal Saoud]

Thanks @Nithin Eluvathingal Is there any tips you would like to tell in the configuration to avoid call looping

[Roger Kallberg]

Use COR or DPG would be my suggestion for loop avoidance. With DPG you can control that calls coming from Teams for example can not route back to Teams, at least not until it touches something in CM and that sends it to Teams. For that there would be pretty hard to protect from as that in my book would be a misconfiguration that shouldn't be there in the first place.

[Nithin Eluvathingal]

Make the calls land on one place and enable SNR on that device. If you enable it on both, as @Vaijanath Sonvane  mentioned, it creates a loop. Additionally, if you need to call Teams and CUCM as extension calling, I would suggest having a prefix to make it simple and not complex.

[Vaijanath Sonvane]

Hi @Faisal Saoud,

Yes, you need SNR configuration on CUCM to allow calls to ring simultaneously on both CUCM device and MS Teams Client. The best practice is to enable SNR on only one platform (either CUCM or MS Teams) otherwise it will create a calling loop. 

The decision on where to enable SNR depends largely on the direction of your inbound calling traffic and the specific needs of your organization. If most of your inbound calls are directed to CUCM devices (e.g., desk phones), you may want to enable SNR on CUCM so that the call rings both the CUCM phone and the Teams client. 

Media Forking is supported on Cisco 8000 Series Routers but it is mainly used for recording functionality. Please see below URL for more details:

https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube/ios-xe/config/ios-xe-book/m_voi-cube-sip-rec-recorder.html

[Faisal Saoud]

@Vaijanath Sonvane If we want the opposite scenario, where someone from MS Teams places a call, and the call rings simultaneously on the desk phone and MS Teams of the called person, can this be achieved through SNR from the CUCM side?