Cisco TelePresence Administrator's Manual page 375

Reference material
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="urn:ietf:params:xml:ns:cpl cpl.xsd">
<taa:routed>
<taa:rule-switch>
<taa:rule originating-zone="TraversalZone" destination="9(.*)">
<!-- Calls coming from the traversal zone are not allowed to use this gateway -->
<!-- Reject call with a status code of 403 (Forbidden) -->
<reject status="403" reason="Denied by policy"/>
</taa:rule>
<taa:rule origin="(.*)" destination="(.*)">
<!-- All other calls allowed -->
<proxy/>
</taa:rule>
</taa:rule-switch>
</taa:routed>
</cpl>
CPL example: redirecting failed calls based on status code
The output from a proxy node allow actions to be taken based on the result of the proxy operation. In base
CPL a single failure output is allowed which is invoked if the call attempt fails for any reason (see section 6.1
of RFC 3880 for details).
The VCS supports an extension to the base CPL specification that allows a status code to be specified so
that the failure action is only invoked if the call attempt fails for the specified reason. In addition the VCS
allows multiple failure outputs to be specified within a single proxy node. This allows a script to redirect the
call to different locations (such as different recorded messages) based on the exact reason for call failure.
For example:
<?xml version="1.0" encoding="UTF-8" ?>
<cpl xmlns="urn:ietf:params:xml:ns:cpl"
xmlns:taa="http://www.tandberg.net/cpl-extensions"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="urn:ietf:params:xml:ns:cpl cpl.xsd">
<taa:routed>
<!-- Proxy the call normally, but redirect to different recorded messages based on --
>
<!-- the particular error response we get -->
<proxy>
<failure status="403">
<!-- Call attempt failed with 403 (Forbidden) -->
<taa:location url="forbidden-message@example.com" clear="yes">
<proxy/>
</taa:location>
</failure>
<failure status="404">
<!-- Call attempt failed with 404 (Not Found) -->
<taa:location url="notfound-message@example.com" clear="yes">
<proxy/>
</taa:location>
</failure>
<failure>
<!-- General catch-all failure handler for all other error responses -->
<taa:location url="failed-message@example.com" clear="yes">
<proxy/>
</taa:location>
Cisco VCS Administrator Guide (X8.1.1)
CPL reference
Page 375 of 507