/mcpBandwidth Management Bandwidth allocations for audio and video calls are managed through regions and locations that you configure in Cisco Unified Communications Manager Administration. The amount of bandwidth available for a specific call must be able to manage the combination of all media streams that are associated with the session, including voice, video, signaling, and any extra media, such as a BFCP presentation. Cisco Unified Communications Manager contains features able to manage bandwidth. Enhanced Locations Call Admission Control Enhanced Locations Call Admission Control (CAC) enables you to control the audio and video quality of calls over a wide-area (IP WAN) link by limiting the number of calls that are allowed on that link at the same time. For example, you can use call admission control to regulate the voice quality on a 56-kb/s frame relay line that connects your main campus and a remote site. CAC verifies whether there is sufficient bandwidth available to complete a call. CAC can reject calls due to insufficient bandwidth. In Unified Communications Manager, locations-based call admission control works in conjunction with regions to define the characteristics of a network link. Regions and locations work in the following manner: • Regions allow the bandwidth of video calls to be set. The audio limit on the region may result in filtering out codecs with higher bit rates. However, for video calls, the video limit constrains the quality (resolution and transmission rate) of the video. • Locations define the amount of total bandwidth available for all calls on that link. When a call is made on a link the regional value for that call must be subtracted from the total bandwidth allowed for that link. For more information about call admission control, see chapter 'Configure Enhanced Locations Call Admission Control' in System Configuration Guide for Cisco Unified Communications Manager . Session Level Bandwidth Modifiers Unified Communications Manager provides location call admission control support for handling session level bandwidth modifiers. Session level bandwidth modifiers are communicated as part of the parameters in the SDP portion of the initial SIP signaling. These parameters indicate the maximum amount of bandwidth each endpoint will support for that type of call. These parameters are used, along with regions and locations settings, to set the bandwidth for each call. During the initial call setup, both parties communicate to Unified Communications Manager their maximum allowed bandwidth for the call. Unified Communications Manager passes this communication to the other endpoint, but if the bandwidth that is specified by the endpoint is greater than the region setting, Unified Communications Manager replaces the value with the region bandwidth value. Unified Communications Manager uses the following rules to determine the amount of bandwidth to allocate to a specific call: • When Unified Communications Manager receives an Offer or Answer from an endpoint, it checks whether there is a session level bandwidth modifier in the SDP: Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs 876 SIP Interoperability Bandwidth Management