Cisco Cisco E-Mail Manager Unity Integration Option Leaflet

Cisco Unified Presence contains not only a presence server, but also a SIP proxy server, and both are 
required for Unified Expert Advisor deployments. The proxy server has two purposes in a Unified 
Expert Advisor deployment: first, as a way to define the entire SIP dial plan in one place, and second, 
as an integral element in the Unified Expert Advisor failover strategy.

Although the Cisco Unified Presence 6.x server does not offer failover support, the proxy server does. 
In addition, Unified Expert Advisor can currently be configured to point to only one such proxy server; 
failover among SIP proxy servers is not supported.

If Unified CVP is part of the deployment, you might prefer for Unified CVP to use the Cisco Unified 
Presence publisher as one of its SIP proxy servers, so that you have to configure the dial plan only once. 
However, this benefit should be weighed against the performance impact that is incurred by making one 
Cisco Unified Presence server responsible for IM and presence services, SIP proxy services, and (in 
Microsoft Office Communicator deployments) federation overhead to Microsoft Office 
Communications Server (OCS), on top of its existing publisher responsibilities.

Runtime servers may be either simplexed or duplexed. In a simplexed configuration, both simplexed and 
duplexed Unified ICM PGs are supported, but duplexed Runtime servers require duplexed 
Unified ICM PGs as well.

The following considerations apply to these types of configurations:

Any component that is simplexed becomes a single point of failure in the deployment.

If the expert advisor PIM is co-resident with another PIM (such as a Cisco Unified Communications 
Manager PIM) that is duplexed, then the Expert Advisor PIM must also be duplexed even if the 
Runtime Server itself is simplexed. However, there is no machine count penalty for following this 
requirement because no new machines are being introduced to carry the expert advisor PIMs in this 
scenario.

In order to reduce server count for small deployments, it is possible for PIMs to share Unified ICM PGs 
and for multiple PGs to be hosted on the same physical machine, as long as all Unified ICM sizing 
guidelines, co-residency rules, and physical proximity rules are observed. Most Unified Expert Advisor 
installations include a VRU peripheral (for Unified CVP), a Cisco Unified CM peripheral, and an Expert 
Advisor peripheral. Cisco Unified CM and Expert Advisor PGs are best located physically near their 
respective peripherals, but VRU PGs need not be.

The co-residency rules are as follows:

One machine can host no more than two PGs.

One PG can host no more than two types of peripherals (types of PIMs).

In order for one PG to host two types of peripherals:

It must be configured as a Generic PG; and

One of the types must be a VRU PG.