From the Platform Ref Guide for UC560: http://www.cisco.com/en/US/partner/prod/collateral/voicesw/ps6788/vcallcon/ps7293/reference_guide_c07-566560.html
Voice Resource Utilization
The Cisco UC 560 includes eight digital signal processors (DSPs) that enable digitized voice processing on the platform. The DSP resources available on the platform are used for various unified communications features, namely support of analog and digital VICs, prescheduled or ad hoc voice conference calls, and translation of digitized voice from a less complex codec (such as g711) to a more complex codec (such as g729)-typically used for deployments that use IP trunking (SIP or H.323) for PSTN access or multisite interconnection.
Each DSP can support 16 g711 channels or 8 g729 channels. This enables a total of 64 g711 channels on the Cisco UC 560. Table 8 indicates the DSP resource utilization for each feature. Tables 9 and 10 show a few deployment scenarios based on combinations of these features.
