Cisco Jabber SRND – Notes
Jabber Desktop Clients – Call Control
Cisco Jabber Desktop Clients can operate in one of two modes for call control:
When a Jabber Desktop Client is in softphone mode, it is directly registered to Unified CM as a SIP endpoint for audio and video call control functionality, and it is configured on Unified CM as device type Client Services Framework.
When a Jabber Desktop Client is in deskphone control mode, it does not register with Unified CM using SIP, but instead it uses CTI/JTAPI to initiate, monitor, and terminate calls, monitor line state, and provide call history, while controlling a Cisco Unified IP Phone. The Cisco CallManager Cisco IP Phone (CCMCIP) or UDS service on Unified CM is used by the Jabber Desktop Client to retrieve a list of devices associated with each user. This list of devices is used by a client in deskphone mode to choose which Cisco IP Phone it wishes to control.
Softphone Mode
When operating in softphone mode, the Jabber Desktop Client is a SIP line-side registered device on Unified CM, utilizing all the call control capabilities and functionality of a Cisco Unified IP Phone, including configuration of registration, redundancy, regions, locations, dial plan management, authentication, encryption, user association, and so forth. The Jabber Desktop Client supports a single line appearance for the user.
The SIP registered device of the Jabber Desktop Client must be factored in as a regular SIP endpoint, as any other SIP registered endpoint, for purposes of sizing calculations for a Unified CM cluster. The Jabber Desktop Client in softphone mode uses the CCMCIP or UDS service to discover its device name for registration with Unified CM.
Deskphone Control Mode
When operating in deskphone control mode, the Jabber Desktop Client uses CTI/JTAPI to provide the ability to place, monitor, and receive calls using Cisco Unified IP Phones. When audio calls are received or placed in this mode, the audio path is through the Cisco Unified IP Phone. For video calls, the video stream can originate and terminate either on the Cisco IP Phone (if it has a camera) or on the computer using a Cisco Unified Video Advantage camera. The Jabber Desktop Client uses the CCMCIP or UDS service on Unified CM to discover the associated devices of the user.
When using deskphone control mode for the Jabber Desktop Client, factor the CTI scaling numbers into the Unified CM deployment calculations. For additional information around capacity planning, see the chapter on Collaboration Solutions Design and Deployment Sizing Considerations.
Translation Patterns
Translation patterns are used by Unified CM to manipulate the dialed digits before a call is routed, and they are strictly handled by Unified CM. Translation patterns are the recommended method for manipulating dialed numbers. For additional guidelines on translation pattern usage and dial plan management, see the chapter on Dial Plan.
Application Dialing Rules
Application dialing rules can be used as an alternative to translation patterns to manipulate numbers that are dialed. Application dialing rules can automatically strip numbers from, or add numbers to, phone numbers that the user dials. Application Dial Rules are configured in Unified CM and are downloaded to the client from Unified CM. Translation patterns are the recommended method for manipulating dialed numbers.
Directory Lookup Rules
Directory lookup rules transform caller identification numbers into numbers that can be looked up in the directory. A directory lookup rule specifies which numbers to transform based on the initial digits and the length of the number. Directory lookup rules are configured in Unified CM and are downloaded to the client from Unified CM.
Client Transformation
Before a call is placed through contact information, the client application removes everything from the phone number to be dialed, except for letters and digits. The application transforms the letters to digits and applies the dialing rules. The letter-to-digit mapping is locale-specific and corresponds to the letters found on a standard telephone keypad for that locale. For example, for a US English locale, 1-800-4UCSRND transforms to 18004827763. Users cannot view or modify the client transformed numbers before the application places the call.
Jabber Desktop Clients – Audio and Video Media
Bandwidth utilization for audio and video calls from the Jabber Desktop Client can be maintained using the Unified CM regions and locations call admission control mechanisms. Administratively placing the Jabber Desktop Client in a Region provides the ability to control the per-call voice and video bandwidth usage and the preferred audio codecs to be used for calls within and between regions. Unified CM locations-based call admission control, and/or the use of RSVP, provides intra-location and inter-location audio and video bandwidth control. The Jabber Desktop Client requires the Unified CM region per-call bandwidth settings to be sufficient to cover both the audio and video portions of the call. For example, to have a video call at a frame size of 720p and a frame rate of 30 frames per second, the session bit rate needs to be 2,000 kbps just for video; therefore, the region bandwidth for a call must account for the audio portion at 64 kbps (assuming a G.711 or G.722 codec) as well as the video portion at 2,000 kbps (assuming 720p at 30 fps). For more information on Unified CM support for regions and locations for call admission control, see the chapter on Call Processing.
