In order for an endpoint to use the TANDBERG VCS, the
endpoint must first register with the VCS. The VCS can be
configured to control which devices are allowed to register with
it. Two separate mechanisms are provided:

authentication process

based on the username and

password supplied by the endpoint
a simple Registration Restriction Policy that uses

Allow

Lists or Deny Lists

to specify which aliases can and cannot

It is possible to use both mechanisms together. For example,
you can use authentication to verify an endpoint’s identity from
a corporate directory, and registration restriction to control
which of those authenticated endpoints may register with a
particular VCS.
This section gives an overview of how endpoints and other
devices register with the VCS, and then describes the two
mechanisms by which registrations can be restricted.

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Registration Control

Registration Overview

MCU, Gateway and Content Server Registration

H.323 systems such as gateways, MCUs and Content Servers
can also register with a VCS. They are known as locally
registered services. These systems are configured with their
own prefix, which they provide to the VCS when registering. The
VCS will then know to route all calls that begin with that prefix
to the gateway, MCU or Content Server as appropriate. These
prefixes can also be used to control registrations.
SIP devices cannot register prefixes. If your dial plan dictates
that a SIP device should be reached via a particular prefix, then
you should add the device as a neighbor zone with a pattern
match equal to the prefix to be used.

Registrations on a VCS Border Controller

If a traversal-enabled endpoint registers directly with
a VCS Border Controller, the VCS Border Controller will
provide VCS services to that endpoint in addition to firewall
traversal. Traversal-enabled endpoints include all TANDBERG
Expressway™ endpoints and third party endpoints which
support the ITU H.460.18 and H.460.19 standards.
Endpoints that are not traversal-enabled can still register with a
VCS Border Controller, but they may not be able to make and/or
receive calls through the firewall successfully. This will depend
on a number of factors:

whether the endpoint is using SIP or H.323
the endpoint’s position in relation to the firewall
whether there is a NAT in use
whether the endpoint is using a public IP address

For example, if an endpoint is behind a NAT and/or firewall. it
may not be able to receive incoming calls and may not be able
to receive media for calls they have initiated.

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