Call Processing Language (CPL) is an XML-based language for defining call handling. This Appendix
gives details of the VCS’s implementation of the CPL language and should be read in conjunction
with the CPL standard

RFC 3880 [5]

and the

Guide to writing CPL [22]

The VCS has many powerful inbuilt transform features so CPL should be required only if advanced
call handling rules are required.
The VCS supports most of the CPL standard along with some TANDBERG-defined extensions. It
does not support the top level actions

<incoming> and <outgoing> as described in RFC 3880.

Instead it supports a single section of CPL within a

<taa:routed> section.

When Call Policy is implemented by uploading a CPL script to the VCS, the script is checked against
an XML schema to verify the syntax. There are two schemas - one for the basic CPL specification
and one for the TANDBERG extensions. Both these schemas can be

downloaded from the web

interface

and used to validate your script before uploading to the VCS.

The following example shows the correct use of namespaces to make the syntax acceptable:

<?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>
<address-switch field="destination">
<address is="reception@example.com">
<proxy/>
</address>
</address-switch>
</taa:routed>
</cpl>

Overview of CPL on the Cisco VCS

address-switch

Overview

The address-switch node allows the script to run different actions based on the source or
destination aliases of the call. It specifies which fields to match, and then a list of address nodes
contains the possible matches and their associated actions.
The address-switch has two node parameters:

field

and

subfield

address

The address construct is used within an address-switch to specify addresses to match. It supports
the use of Regular Expressions (see the

Regular expression reference

Appendix for further

information).
Valid values are:

is=string

Selected field and subfield exactly match the given string.

contains=string

Selected field and subfield contain the given string.
Note: The CPL standard only allows for this matching on the
display subfield; however the VCS allows it on any type of
field.

subdomain-of=string

If the selected field is numeric (e.g. the tel subfield) then
this matches as a prefix; so

address subdomain-of="555" matches 5556734 etc.
If the field is not numeric then normal domain name
matching is applied; so

address subdomain-of="company.com" matches

nodeA.company.com etc.

regex="regular expression" Selected field and subfield match the given regular

expression.

All address comparisons ignore upper/lower case differences so

address is="Fred" will also

match

fred, freD etc.