Cisco Cisco Agent Desktop 8.5

You must make many decisions when planning for a VoIP Monitor service 
deployment. These decisions will dictate how many VoIP Monitor service instal-
lations will be needed, where they will be deployed, and how the switches will 
be configured. 

Table 1 summarizes the major decisions/features that must be taken into 
account when planning a deployment. These are expanded upon in 
Section 5.0.

Number of Agents

The VoIP Monitor service can support the phone traffic of 
400 simultaneous calls. Loads greater than this cause 
performance degradation. 

As a general equation, use 

APT × N = X

where

APT = average peak talk time

N = number of agents

X ≤ 400

This is a simplified formula. Real-world planning is more 
complex and should use Erlang tables to calculate the 
number of VoIP Monitor services needed to support a 
given contact center.

VLANs

Voice and data must be separated by using voice and 
data VLANs. This improves VoIP Monitor service capacity 
because it is not sniffing network traffic that is not related 
to calls. If the switch does not support VSPAN, or is con-
strained to sniffing only a single VLAN, the placement of 
the VoIP Monitor service will be limited.

LCCs

A single LCC can contain multiple VoIP monitor services 
(monitor domains). This implies multiple subnets and mul-
tiple VLANs, which can all affect how the VoIP Monitor 
services are deployed.

Router Placement

There can be no routers between the ports being moni-
tored and the IP phones. Doing so causes the speech 
packet MAC addresses to be changed, becoming invisi-
ble to the VoIP Monitor service.

Switch Capabilities

Different Catalyst switches have differing SPAN and 
RSPAN capabilities. These capabilities (or lack thereof) 
dictate where the VoIP Monitor service can be deployed.