Cisco Cisco Agent Desktop 8.5

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VoIP Monitoring
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 June 21, 2004
2.0 VoIP Monitoring
In a VoIP environment, voice and data are transmitted over the network using 
well-known network protocols. 
If you know which protocols are used to package a phone call’s data, it is pos-
sible to capture (copy) those data packets as they traverse the network (often 
referred to as packet sniffing) and then unpackage and reassemble them into a 
voice stream that can be listened to in real time or stored to be listened to at a 
later time. This process is referred to as VoIP monitoring
VoIP monitoring is invisible to the persons on the phone. Agents on calls are 
not aware that they are being monitored or recorded unless the Notification fea-
ture has been enabled from within Cisco Desktop Administrator.
VoIP monitoring software looks only for Realtime Transport Protocol (RTP) 
packets. RTP is the protocol used to package and transmit voice over the net-
work. RTP packets are encapsulated by the User Datagram Protocol (UDP), 
which in turn is encapsulated by the Ethernet protocol, which is encapsulated 
by the Internet Protocol (IP). 
The VoIP monitoring software knows the Media Access Control (MAC) 
addresses of the IP phones it is monitoring/recording. It uses these MAC 
addresses to find the voice packets going to or coming from the appropriate 
device to determine whether or not to redirect the RTP packet to the receiver.
CAD software has two ways of monitoring IP phone calls: 
Desktop monitoring
Server monitoring
You may use either method or both simultaneously. The method used is based 
upon your functional requirements and the network configuration.
NOTE  
There are two types of agents: CAD agents, who use Cisco Agent 
Desktop on their PCs, and IPPA agents, who use the IP Phone Agent ser-
vice on their IP phones and who do not use PCs. CAD agents can be mon-
itored by either desktop or server monitoring; IPPA agents can be 
monitored by server monitoring only.
The method used to monitor agents is configured in Cisco Desktop Administra-
tor and stored in LDAP. When a supervisor requests a monitoring session for 
an agent, or a supervisor or agent request a recording session for a call, the 
software on their PCs reads the configuration information in LDAP to decide 
where to send the request. If the agent with the call is configured to use desk-
top monitoring, the request is sent to the Desktop Monitor service on the