Call recording using Cisco Forked Audio is an elegant solution to replace traditional passive recording methods that use packet sniffing technology. Not only does the new solution provide a tighter integration with Cisco UCM but it also eliminates the need for complicated port mirroring (SPAN) setup on network elements across the organization.
Network Administrators that have configured port mirroring for huge organizations with complicated networks would agree that setting up port mirroring to record all phones can often be a challenging and costly exercise.
Telrex's implementation of Call Recording using Cisco Forked Audio aims to eliminate this hardship for network administrators to enable devices for recording in a user-friendly and cost-effective manner.
The forked audio solution uses a Cisco IP Phone's internal DSP resource called a built-in-bridge that enables the audio from the phone to be streamed directly to the Quality Management Server via a SIP Trunk.
Note that the SIP Trunk to the Quality Management Server is setup by the CUCM but the audio flows from the phone in question directly to the Quality Management Server. The audio from both the ends of the call are sent separately and simultaneously via two separate SIP sessions. Call Recording would also receive call control details via TAPI. The tow audio streams are mixed together, tagged with the call control information received and merged into a single recording by the Quality Management Server. Quality Management supports recording audio in G.711 and G.729A codec formats.
On the CUCM, a directory number is assigned to the Quality Management Server and a route pattern is configured for the SIP Trunk pointing to it.
On the Quality Management Server, the Cisco TSP application needs to be installed to receive TAPI notifications of device specific events. The application user authorized to use the TSP on the Quality Management Server should have recording capabilities enabled. It should also have the list of all users that need to be recorded in its list of controlled devices.
For further details on how to setup the CUCM for Forked Audio Recording, visit the Guide to Configure Silent Monitoring and Recording on Cisco's web site.
The following are necessary steps to equip CallRex 4.2 for recording via Cisco Forked Audio:
Download the Cisco TSP from the UCM interface and install it on the Quality Management Server.
From the Start menu, navigate to Control Panel > Phone and Modem Options > Advanced tab.
Select the appropriate Cisco TSP and select Configure.
In the User tab, enter the username and password of the application user created in UCM interface.
In the CTI Manager tab, enter the IP address of the UCM.
In Quality Management Client, under Services > Call Recording, select Cisco Forked Audio as the PBX type.
In Client, under Services > Call Control, select Cisco Forked Audio as the PBX type.
IP Addresses for the Users in the Client need not be added as they are populated during recording.
Quality Management provides the capability to monitor all calls in progress regardless of whether they are being recorded on Quality Management or not. Every device in a call in progress that is not set to automatically record shows up as On Phone and the user can monitor or record the call on-demand.
CPU: 2 GHz Pentium 4 or better - see the Quality Management Server specifications on the Quality Management datasheet for details
Operating System: Windows 2008 32 bit
Note: Windows 2008 64 bit edition will be supported only in 8.5 versions
CUCM Version: Cisco Unified Communications Manager 7.0 or above
Supported Devices: The following devices are supported according to Cisco: 7906G, 7911G, 7931G, 7941G, 7941G-GE, 7961G, 7961G-GE, 7970G, 7970G-GE, and Cisco IP Communicator 7.0 and above
Check with Cisco or your hardware vendor for specific devices that have the Built-in-Bridge capability.
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