Configuring Wideband Codec

Chapter 6 Customizing the Cisco Unified IP Phone

Note Cisco recommends that you also store backup copies of custom image files in another location. You can use these backup copies if the customized files are overwritten when you upgrade Cisco Unified Communications Manager.

Step 4 Use a text editor to edit the List.xml file. See the “List.xml File Format Requirements” section on page 6-4for the location of this file, formatting requirements, and a sample file.

Step 5 Save your modifications and close the List.xml file.

Note When you upgrade Cisco Unified Communications Manager, a default List.xml file will replace your customized List.xml file. After you customize the List.xml file, make a copy of the file and store it in another location. After upgrading Cisco Unified Communications Manager, replace the default List.xml file with your stored copy.

Step 6 To cache the new List.xml file, stop and start the TFTP service by using Cisco Unified Serviceability or disable and reenable the Enable Caching of Constant and Bin Files at Startup TFTP service parameter (located in the Advanced Service Parameters).

If Cisco Unified Communications Manager has been configured to use G.722 (G.722 is enabled by default for the Cisco Unified IP Phone 7975G) and if the far endpoint supports G.722, the call connects by using the G.722 codec in place of G.711. This situation occurs regardless of whether the user has enabled a wideband headset or wideband handset, but if either the headset or handset is enabled, the user may notice greater audio sensitivity during the call. Greater sensitivity means improved audio clarity but also means that more background noise can be heard by the far endpoint—noise such as rustling papers or nearby conversations. Even without a wideband headset or handset, some users may prefer the additional sensitivity of G.722. Other users may be distracted by the additional sensitivity of G.722.

The following parameters in Cisco Unified Communications Manager Administration affect whether wideband is supported for this Cisco Unified Communications Manager server or a specific phone:

•Advertise G.722 Codec—From Cisco Unified Communications Manager Administration, choose System > Enterprise Parameters. The default value of this enterprise parameter is True, which means that all Cisco Unified IP Phone Series that are registered to this Cisco Unified Communications Manager advertise G.722 to Cisco Unified Communications Manager. If each endpoint in the attempted call supports G.722 in its capabilities set, Cisco Unified Communications Manager chooses that codec for the call.

•Advertise G.722 Codec—From Cisco Unified Communications Manager Administration, choose Device > Phone. The default value for this product-specific parameter is the value that is specified in the enterprise parameter. If you want to override this on a per-phone basis, choose Enabled or Disabled in the Advertise G.722 Codec parameter on the Product Specific Configuration area of the Phone Configuration window.

Cisco Unified IP Phone 7975G Administration Guide for Cisco Unified Communications Manager 7.0 (SCCP and SIP)

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