Monitoring feature of the Cisco Agent Desktop software, which includes listening to a
live call, recording an agent call, and listening to a recorded call, has the
largest bandwidth requirements for the Cisco Agent Desktop product. Properly configuring this
feature is especially important for Unified Mobile Agents who are connected to
the main site by a WAN connection.
To access the Silent
Monitoring feature, a request is sent to a VoIP provider. The VoIP provider
captures from the network, or reads from disk, the voice streams representing
the call (two voice streams per call) and sends them back to the requestor. The
requestor receives the streams and either decodes them for listening or stores
them to disk. The bandwidth requirements detailed in this section are for the
network links between the requestor and provider.
There are three
possible VoIP providers in the Cisco Agent Desktop software:
- Cisco Agent Desktop
- VoIP Monitor service
- Recording & Playback
The Cisco Agent
Desktop application contains a module referred to as the Desktop Monitor
service, which runs on the agent’s desktop. The Desktop Monitor service processes
Silent Monitoring requests only for the agent signed in to the Cisco Agent Desktop application
on the desktop. The service captures voice packets sent to the phone or IP Communicator
software phone associated with the signed-in agent. The phone must contain an extra network port that allows the phone to be connected to a network and
also to an agent’s computer. They also support the ability of hubs and switches
to propagate network traffic through this additional port. This capability is
what allows the Desktop Monitor service to see the phone conversations on the
See the Compatibility Matrix for Unified CCE at http://docwiki.cisco.com/wiki/Compatibility_Matrix_for_Unified_CCE for a list of supported phones.
By default, this
service is active on all agent desktops when the application is started. After
initial installation of the Cisco Agent Desktop servers, all agents are already configured to
use the Desktop Monitor service for the Silent Monitoring feature.
A VoIP Monitor
service is able to handle multiple requests for Silent Monitoring
simultaneously. It captures packets directly from the switch through the
switch's Switched Port Analyzer (SPAN) configuration. An installation may have
up to five VoIP Monitor services on different machines. Off-board VoIP services
may be installed at remote office locations. In some instances, this service
may be required due to network complexity and capacity planning. Agents must be
explicitly configured to use a VoIP Monitor service if this is the method
desired for Silent Monitoring for that agent’s device.
Phone Agents who do not have a desktop must be configured to use a VoIP Monitor
service for the Silent Monitoring feature.
The Recording and
Playback service may also provide the two streams representing a phone call
when a supervisor plays back a recorded agent call. In this case, the streams
have already been stored on disk from an earlier recording session. The
Recording and Playback service reads the raw data files from the disk and sends
the RTP streams over the network to the supervisor's desktop, where they are
played through the sound card.
description indicates, the Recording and Playback service may be either the
requestor (for recording a live call) or a provider (for playing back a
A VoIP and
Recording and Playback services are usually installed along with the Cisco Agent Desktop base
services. Additional VoIP services and a second Recording and Playback service
may be installed on other boxes.
The figure below
shows a representative Unified CCE installation supporting a remote office over
a WAN. Both the main office and the remote office have a VoIP Monitor service
Figure 8. VoIP Monitor
Service at Main and Remote Sites
When you locate
the requestors and providers, you can determine where the bandwidth is required
for the Silent Monitoring feature. The following notes regarding bandwidth
- Although an administrator
can assign a specific VoIP service to an agent device, the Recording service
that is used when calls are recorded is determined at the time the request is
made. The same rule applies if two Recording services are installed to
load-balance the installation. In some cases, the provider and requestor may be
separated by a WAN and would require the bandwidth on the WAN. If a second
Recording and Playback service is to be installed, install it on a server at
the main office (on the LAN with the Cisco Agent Desktop base services).
- If the VoIP provider is a
VoIP Monitor service, if the requestor is a Recording service, and if these
services reside on the same machine, then there is no additional bandwidth used
on the network to record the call.
Regardless of who
is the requestor and VoIP provider, the bandwidth requirement between these two
points is the bandwidth of the IP call being monitored and/or recorded. For
purposes of calculating total bandwidth, you can think of each
monitoring/recording session as being a new phone call. Therefore, to calculate
bandwidth to support the Silent Monitoring feature, you can use the same
calculations used to provision the network to handle call traffic, with the
exception that the voice stream provided by the VoIP provider consists of two
streams in the same direction. Whereas a normal IP phone call has one stream
going to the phone and one stream coming from the phone, the VoIP provider has
both streams coming from the provider. Keep this difference in mind when
provisioning upload and download speeds for your WANs.
To determine the
bandwidth requirements for these voice streams, see the
Cisco Collaboration System
Solution Reference Network Designs at http://www.cisco.com/c/en/us/support/unified-communications/unified-communications-manager-callmanager/tsd-products-support-series-home.html.