Cisco Cisco Customer Response Solution Downloads Guide D’Installation Rapide
Accessing Audio Streams
November 2013
17
Desktop Capture Method
The desktop capture method relies upon the fact that many Cisco IP phones contain a
small internal switch and a second network port on the back of the phone to which a
computer can be daisy-chained.
small internal switch and a second network port on the back of the phone to which a
computer can be daisy-chained.
with either a hard or soft IP phone.
In this configuration, the IP phone and the computer are sharing a single network
cable for their network configuration. When a hard phone is used, the phone and the
computer are separate network endpoints with their own unique IP and MAC
addresses. When a soft IP phone is used, the computer and the phone are a single
network endpoint that share a MAC and IP address.
cable for their network configuration. When a hard phone is used, the phone and the
computer are separate network endpoints with their own unique IP and MAC
addresses. When a soft IP phone is used, the computer and the phone are a single
network endpoint that share a MAC and IP address.
When a hard phone is used, the phone must be configured to send its network traffic
down the line to the desktop in order for the NIC on the computer to see the traffic
meant for the phone. This is a setting that is accessed through the Unified CM
administration application. This allows the audio data for phone calls (as well as other
traffic sent to/from the phone) to hit the computer's NIC. But, by definition, the
computer's NIC will not pass this data up to an application on the computer because it
is not addressed for the computer's NIC. It is addressed to the IP phone. In order to
see this traffic, the NIC needs to use promiscuous mode.
down the line to the desktop in order for the NIC on the computer to see the traffic
meant for the phone. This is a setting that is accessed through the Unified CM
administration application. This allows the audio data for phone calls (as well as other
traffic sent to/from the phone) to hit the computer's NIC. But, by definition, the
computer's NIC will not pass this data up to an application on the computer because it
is not addressed for the computer's NIC. It is addressed to the IP phone. In order to
see this traffic, the NIC needs to use promiscuous mode.
NICs that support the Network Driver Interface Specification (NDIS), which includes
almost all NICs for PCs, will also support a packet capture feature called promiscuous
mode. In this mode, the NIC passes packets up to the software on the machine even if
they are not addressed to the machine’s NIC. Cisco monitoring and recording software
uses a packet sniffing driver that opens a NIC adapter and puts it into promiscuous
mode so it can see the daisy-chained IP phone’s audio traffic when the agent is on a
call. With this configuration, the software is able to capture both of the agent's phone
call audio streams and process them for live monitoring or recording.
almost all NICs for PCs, will also support a packet capture feature called promiscuous
mode. In this mode, the NIC passes packets up to the software on the machine even if
they are not addressed to the machine’s NIC. Cisco monitoring and recording software
uses a packet sniffing driver that opens a NIC adapter and puts it into promiscuous
mode so it can see the daisy-chained IP phone’s audio traffic when the agent is on a
call. With this configuration, the software is able to capture both of the agent's phone
call audio streams and process them for live monitoring or recording.
Cisco monitoring and recording software also supports the use of approved
software-based IP phones. Soft IP phones are applications that run on the agent's PC.
software-based IP phones. Soft IP phones are applications that run on the agent's PC.
Figure 7.
Desktop capture hardware configurations