As of SAP enhancement package 3 (SP03) for SAP CRM 7.0, the Interaction Center (IC) utilizes ABAP Push Channel (APC) for
detail information on APC refer to blog http://scn.sap.com/community/abap/connectivity/blog/2013/11/18/websocket-communication-using-abap-push-channels. When the APC is active, the server informs the Web browser about events like an incoming phone call immediately and directly - using a permanent WebSocket connection. This way APC provides an alternative to the polling mechanism of the IC context area.
Example: A communication event like “new phone call is altering” arrives on the CRM server. Now it has to be transferred to the IC Session in the Web browser of the respective agent. In the past, this was done by a polling mechanism (“SAM polling”): the browser polls at regular intervals (typically once per second) to the server and will thus get the information that the new event (alerting phone call) has occurred. With APC there will be no need for polling: the CRM server can directly push the information that there is a new communication event to the Web browser. This way the CRM server, the network and the browser session are freed up from the permanent polling traffic. And also the agent benefits from the better response times: the event (alerting phone call) will - on average - arrive faster on the agent’s UI because the polling interval (e.g. 1 second) is avoided.
It is by the way not only the communication events that benefit from the new push mechanism. Also Alerting and Broadcast Messaging rely on the new push channel as soon as you switch on the APC option in the context area profile.
As prerequisite you need a Web browser that supports WebSockets (e.g. IE10). If temporary network connection problems occur, or if the Web browser used by an agent does not support WebSockets, the system launches the classic polling mechanism instead.
If you are interested, you can activate the APC in the Customizing activity Define Context Area Profile and check out SAP note 1962301 for more technical details.
For further information check the RKT material of SAP enhancement package 3 or the release information.