Exam 300-820 topic 1 question 76 discussion

Local reachable Video Mesh resources are tried first, in order of lowest SRT delay. When all local resources are exhausted, the participant connects to the cloud. https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cloudCollaboration/wbxt/videomesh/cmgt_b_webex-video-mesh-deployment-guide/cmgt_b_hybrid-media-deployment-guide_chapter_010.html

Learned reachability information is provided to the Webex cloud every time a call is set up. This information allows the cloud to select the best resource (cluster or cloud), depending on the relative location of the client to available clusters and the type of call. If no resources are available in the preferred cluster, additional clusters are tested for availability based on SRT delay. A preferred cluster is chosen with the lowest SRT delay. Calls are served on premises from a secondary cluster when the primary cluster is busy. Local reachable Video Mesh resources are tried first, in order of lowest SRT delay. When all local resources are exhausted, the participant connects to the cloud. https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cloudCollaboration/wbxt/videomesh/cmgt_b_webex-video-mesh-deployment-guide/cmgt_b_hybrid-media-deployment-guide_chapter_010.html

I agree, B is right. Cluster 2 from on-premise has STUN Round-Trip Delay (SRT) lower than 250ms. I that case Cluster 2 will be selected. If Cluster 2 had for example SRT =300 (>250) then cloud US-EAST will be chosen.

I Agree, B is right. Cloud Cluster Selection for Overflow Based on 250 ms or Higher STUN Round-Trip Delay https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cloudCollaboration/wbxt/videomesh/cmgt_b_webex-video-mesh-deployment-guide/cmgt_b_hybrid-media-deployment-guide_chapter_010.html

The correct answer is B - Video Mesh Cluster-2. Local Webex Video Mesh resources are always tried first (unless the round-trip delay is not greater than 250 then the lower cloud resource would be used.) Source: Official Cert Guide

https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cloudCollaboration/wbxt/videomesh/cmgt_b_webex-video-mesh-deployment-guide/cmgt_b_hybrid-media-deployment-guide_chapter_010.html "Which cluster is used also depends on latency rather than just location. For example, a cloud cluster with lower STUN round-trip (SRT) delay than a Webex Video Mesh cluster may be a better candidate for the meeting. This logic prevents a user from landing on a geographically far cluster with a high SRT delay"

From my point of view, the answer will be C US-East based on the lowest SRT, because the question says The Webex Teams Endpoint, not SIP endpoint registered to CUCM. Based on the registration procedure, Webex Teams endpoint upon registration retrieves a list of nodes from Cloud, and make connectivity test to chouse VMN based on the lowest SRT.

A preferred cluster is chosen with the lowest SRT delay. Calls are served on premises from a secondary cluster when the primary cluster is busy. Local reachable Webex Video Mesh resources are tried first, in order of lowest SRT delay. When all local resources are exhausted, the participant connects to the cloud.