Cisco Cisco TelePresence Video Communication Server Expressway
Enabling Calls Between Endpoints Registered on the VCS Control
VCS Control Configuration
Configuration of the VCS Control to enable calls to be made between devices that register to it can be broken down
into the following steps:
into the following steps:
■
Setting up the SIP domain of the VCS Control. This is needed for SIP registration.
■
Creating a transform to ensure that domain information is added to dialed numbers that do not include a
domain. This forces dialed number information from SIP and H.323 endpoints into a common format:
number@domain.
domain. This forces dialed number information from SIP and H.323 endpoints into a common format:
number@domain.
Setting up the SIP Domain of the VCS Control
SIP endpoints register with the VCS with an AOR (Address Of Record) in the format 4_digit_number@vcs.domain. The
VCS must be configured with the SIP domain information so that it will accept these registrations.
VCS must be configured with the SIP domain information so that it will accept these registrations.
1.
Go to Configuration > Domains.
2.
Click New.
3.
Enter the domain Name, for example vcs.domain.
4.
Click Create domain.
Creating Transforms
In this deployment scenario, users want to be able to dial other endpoints registered to the VCS using a 4xxx
extension number. Unified CM endpoints are to be dialed using a 3xxx number. This dialing model can be supported
by H.323 (if the endpoint registers the 4-digit E.164 alias), however, SIP does not support dialing by numbers alone. If
a number (without a domain appended) is dialed from a SIP endpoint the endpoint will automatically append its own
domain.
extension number. Unified CM endpoints are to be dialed using a 3xxx number. This dialing model can be supported
by H.323 (if the endpoint registers the 4-digit E.164 alias), however, SIP does not support dialing by numbers alone. If
a number (without a domain appended) is dialed from a SIP endpoint the endpoint will automatically append its own
domain.
For consistency with both SIP and H.323 dialing, this deployment scenario always uses the URI form for routing calls
(that is, dialed_digits@domain). When the VCS receives a call request, the dialed number:
(that is, dialed_digits@domain). When the VCS receives a call request, the dialed number:
■
will contain the 4 digit extension number that identifies the specific endpoint to route to
■
may or may not include a domain (only included when a SIP endpoint is making the call)
Thus, a transform is needed to ensure that the dialed number is transformed into a consistent form, in this case to add
the domain (vcs.domain) if required. To achieve this, a regex is used:
the domain (vcs.domain) if required. To achieve this, a regex is used:
([^@]*)
transforms to
\1@vcs.domain
(any dialed
information which does not contain a domain – does not contain an ‘@’ – has the ‘@vcs.domain’ added.)
alternatively search the internet for the term “Regular Expression”.
To create the transform:
1.
Go to Configuration > Dial plan > Transforms.
2.
Click New.
9
Cisco VCS SIP Trunk to Unified CM Deployment Guide
Enabling Calls Between Endpoints Registered on the VCS Control