CUCM nodes in multi-location to form a cluster latency issue.

[osw200051]

Hi Expert,

I had one CUCM Publisher node in location A and one CUCM Subscriber node in location B.

I tested (Ping test) the round trip latency is about 60-70 ms from Location A to location B.

From Cisco documentation, the round trip latency for this two nodes in multi location should smaller than 80 ms. So, it seems my situation can meet the target.

But I wanna to ask, if sometime the latency from location A to location B is suddenly high than 80 ms for a moment such or unstable for peak hours, what would be the result of the two node?  Would the two nodes disconnect the database sync and then resume?

Although the  latency is suddenly go higher than the requirement, I suppose all IP Phones in these location still can work normally, right?

Thanks all

[Manish Gogna]

Hi,

80 ms is recommended but the phones and database communication would continue to work 'normally' till about 150 ms or even a bit higher in some cases. Beyond that the users might start experiencing issues with voice or video quality on calls but IP phone registrations and other functions should still be okay.

As per the CUCM SRND

"The influence of latency on design varies, based on the type of Unified Communications service considered for remote deployment. If a voice service is hosted across a WAN where the one-way latency is 200 ms, for example, users might experience issues such as delay-to-dialtone or increased media cut-through delays. For other services such as presence, there might be no problem with a 200 ms latency."

http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/srnd/collab10/collab10/models.html

Manish