Media flow for Cisco webex phones

[carl_townshend]

Hi Guys

We are currently in process of installing Cisco webex phones, physical and software on our sites.

Can anyone tell me the media flow of the phones, does the RTP stream all go via Webex, or does it go direct from phone to phone once the call has been setup?

Many thanks

[b.winter]

If the phones can reach each other directly, then ICE will establish a direct media connection between the entpoints. Otherwise, the media will be hairpinned via the cloud.
https://help.webex.com/en-us/article/nt6eyxb/Webex-Calling-media-optimization-with-Interactive-Connectivity-Establishment(ICE)

[carl_townshend]

Hi

thanks for the reply, so how does it know they would be able to talk direct to each other ? Does phone A try to establish a direct connection to phone B? if it fails does it revert back to hairpinning ?

[b.winter]

If you wanna know how it works, you should check out, how ICE (interactive connectivity establishment) works.

And yes, if it cannot establish a direct connection, it falls back to a hairpinning connection via cloud.

[Shalid Kurunnan Chalil]

You may also find it useful to understand the media flow from the below reference. It’s a troubleshooting guide but explain in details different call flow scenarios.

Troubleshoot Webex Calling Media Quality in Control Hub 

regards

Shalid

[Kathy N.]

I think media flow is also dependent on which type of SIP connection you have.  From what I've read ICE is only needed if you have an on-premise gateway. If you use Cloud Connect or a Cisco calling plan, the media stream stays on prem for devices on the same local network.  Here's a link to some basic information about it.
https://www.webex.com/content/dam/wbx/us/aag/webex_calling_pstn_options_cm-5770.pdf

If you have time, I'd recommend the Webex Calling for Customer Administrators course in Webex Academy.  It has more detailed information about Webex Calling and it's administration.  Here's a link to that course:
https://academy.webex.com/learn/courses/1610/webex-calling-for-customer-administrators