Webex registered devices with Hybrid call services routing URI's into Expressway

[Steve Boyd]

I have Webex site with Hybrid calendar and call services enabled for Cloud registered Room Kit's, and when dialing a complete URI to any non webex.com or cisco.com domain the call fails.  Troubleshooting it I saw the call routing into the Expressway's, where it's getting forwarded to the CUCM which is rejecting the call (as expected).   Audio only calls to on-prem extensions or even PSTN destinations do complete fine, as expected too.   

I see the URI calls in the EXP-E logs for any external or 3rd party URI dialed, and I wasn't aware this is even possible with only the Hybrid call service (voice only) configured.  It's as if the cloud is default routing any unknown video URI inbound to the Expressway instead of directly as it should be.   Once I disable the call service from the endpoint (in Control Hub), it then functions and routes the video call fine.   It's not hitting the Exp-E at this point either.   Same with dialing a full Webex meeting URI - it works fine always, and I never see it hitting the Exp.

Anyone seen this issue or any ideas?

[Mike_Brezicky]

I am pretty sure this is the default and expected result. hybrid call services, while you mention voice only - SIP traffic is just that. So when you have Hybrid call and an endpoint setup to use it, WCH is going to default all non registered addresses to the Call Service Connect address. I even believe in the settings, it calls it a Default SIP destination.

[Steve Boyd]

Yea I was aware it was all URI routing, but docs and presentations I've seen show number routing will go through the expressways, where a URI dialed (anything with the @ in the address) will route directly through the cloud service.  So I'm sort of figuring out that's not the case, but unless someone can point to documentation explicitly stating this limitation then please do.  There's some vague language in the deployment guide about Teams clients, but none of the design guides I can find that say if you take a customer with cloud registered endpoints and deploy hybrid services to these endpoints (so they can have CUCM extensions) that your B2B IP/video calls will now hair-pining through the Expessway pair and require traversal licenses.  But apparently that's the case...