When users picked up their phone handset, there was a noticeable delay before dial tone. Delayed dial tone is a classic symptom of an overworked CallManager.
The Cisco UCS C210M2 servers were more than adequate for the load. Each UCS-C210M2 hosted VMware VMs of CallManager, Unity Connection, and UCCX. All of the VMs were deployed using the Cisco prescribed OVA templates.
|Cisco UCS C210M2|
So what is “VMware Tools”?
According to docwiki.cisco.com/wiki/VMware_Tools:
VMware Tools are specialized drivers for virtual hardware that is installed in the UC applications when they are running virtualized.
Now I understand Drivers. Up to date drivers are a good thing. Docwiki goes on to state:
It is very important that the VMware tools version running in the UC application be in sync with the version of ESXi being used.
Anyone who has read Cisco documentation before should realize, Cisco doesn’t often use the phrase “it is very important”. This is as close as Cisco gets to saying “you have to do this”.
So we installed VMware tools on all of the VMs and the Cisco voice system has been stable ever since.
Cisco has 3 methods for installing VMware Tools on Unified Communications Application VMs dependent on the UC Application version. Visit DocWiki-VMware Tools to find the appropriate method.
Please Note: VMware Tools will have to be re-installed anytime VMware ESXi is patched or upgraded.