With legacy system, the Telephony Control Server provides specific video service support allowing video calls to be identified and handled separately if required in the server. With this feature the Lotus Sametime Unified Telephony will be able to enable users for Video support and allow routing of calls based on the video media type.
Figure 1. Video Service Landscape for the Lotus Sametime Unified Telephony solution
Video Characteristics in CDR's
Once a video call had been negotiated end to end, the Telephony Control Server will record as part of the internal CDR records, information regarding the Media Type and the bit-rate used for the call.
For this purpose the following existing fields in the CDR will be used:
Field # 20 "Bearer Capability Request" - to save the bit- rate for the call.
If video call is made field 20 will show "3 (Circuit mode 64 Kbps)".
Field # 104 "Media Type" that is a bitwise data and reflects audio, audio/video or video depending how it is set by the component using its method in the CDR
If video call is made field 104 will show "3 (Audio, Video)".
Routing Calls Based on Video Capabilities
Gateway Routes for destinations on the Telephony Control Server will be provisioned such that they are identified as preferred gateways supporting video calls. Based on the SDP offer indicating as video call, the Lotus Sametime Unified Telephony will be able to route the call over a preferred gateway for video if the route is configured as such.
Such a provisioning will allow Lotus Sametime Unified Telephony to prioritize and dynamically route calls for video over preferred gateways connected to the server.
In order to achieve preferred gateway routes for video calls, firstly gateways that will handle video calls will be identified. Next routes will be configured with destinations pointing to such gateways with their bearer capabilities set to "Unrestricted" (Data64KB).
When a video call is made, Lotus Sametime Unified Telephony will identify the call to be a video call and set the call to the same bearer capabilities value such that the preferred gateway routes for the call can be identified by selecting a preferred gateway for the matched route.
This will ultimately ensure that the call is routed over the preferred gateway.
Enable Video Service for Subscribers
The Video Call Allowed
feature allows or dis-allows an subscriber to make or receive video calls.
Figure 2. Overview of Lotus Sametime Unified Telephony Filtering out Video from the Call
The Video Call Allowed
attribute is available on a per subscriber endpoint basis and available to all contacts of that subscriber. The default is "allow video calls for all subscribers", but the administrator can block video calls from/to a particular subscriber:
If the Video Call Allowed check mark is turned ON, then the Lotus Sametime Unified Telephony will allow video calls across the server.Parent topic: CAC (Call Admission Control)
If the Video Call Allowed check mark is turned OFF, then even if subscriber makes video calls, the port of all video m-lines will be set to zero by the Telephony Control Server before routing the call to intended receiver.
How to Configure Subscriber Attributes