In the external definition, multiple user agents received from client side devices can be mapped to the configured channel handler, which means that the handlers can be reused for several user agents or devices.

To associate the user agents from a client device with a reusable channel handler, configure the mapping in the server configuration file btt.xml as follows:

The id="opera" is the browser that is used by existing devices belonging to any communication provider. In this example, a channel handler named html should be added in the channelHandlers section. If you define description="equals", then the user agent that comes in the request must exactly match the specified id. If you define description="contains", then the user agent that comes in the request can just contain the specified id. This feature allows the system to assign multiple versions of a client device user agent to a specific channelHandler.