Registering Aliases; About Alias Registration; Attempts To Register Using An Existing Alias; Blocking Registrations - Cisco TelePresence Administrator's Manual

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Registration control

About alias registration

After the authentication process (if required) has been
completed, the endpoint will then attempt to register its alias(es)
with the VCS.
H.323
When registering, the H.323 endpoint presents the VCS with one
or more of the following:
•
one or more H.323 IDs
•
one or more E.164 aliases
•
one or more URIs
Users of other registered endpoints can then call the endpoint
by dialing any of these aliases.
You are recommended to register your H.323 endpoints
using a URI. This facilitates interworking between SIP
and H.323, as SIP endpoints register using a URI as
standard.
You are recommended to not use aliases that reveal
sensitive information. Due to the nature of H.323, call
setup information is exchanged in an unencrypted form.
SIP
When registering, the SIP endpoint presents the VCS with its
contact address (IP address) and logical address (Address of
Record). The logical address is considered to be its alias, and
will generally be in the form of a URI.
Overview and System
Introduction
status configuration
D14049.08
November 2010

Registering aliases

Attempts to register using an existing alias

An endpoint may attempt to register with the VCS using an alias that is already registered to the system. How this is managed
depends on how the VCS is configured and whether the endpoint is SIP or H.323.
H.323
An H.323 endpoint may attempt to register with the VCS using an alias that has already been registered on the VCS from another IP
address. The reasons for this could include:
•
two endpoints at different IP addresses are attempting to register using the same alias
•
a single endpoint has previously registered using a particular alias. The IP address allocated to the endpoint, or the port the
endpoint uses to communicate with the VCS, then changes, and the endpoint is attempting to re-register using the same alias.
You can determine how the VCS will behave in this situation by configuring the Registration Conflict Mode, using either:
•
VCS configuration > Protocols > H.323
You will be taken to the H.323 page.
xConfiguration H323 Gatekeeper Registration ConflictMode
•
The options are:
Reject: the registration from the new IP address will be rejected. This is useful if your priority is to prevent two users registering with
the same alias.
Overwrite: the existing registration will be overwritten using the new IP address. This is useful if your network is such that endpoints
are often allocated new IP addresses, because it will prevent unwanted registration rejections.
The default is Reject.
SIP
A SIP endpoint will always be allowed to register using an alias that is already in use from another IP address. When a call is received
for this alias, all endpoints registered using that alias will be called simultaneously. This SIP feature is known as "forking".

Blocking registrations

If you have configured the VCS to use a Deny
Name; or Status > Registrations > by Alias and click an Alias; or Status > Registrations > History and click an Alias) you will have an
option to block the registration. This will add all the aliases used by that endpoint to the Deny List.
Cisco VCS Zones and Clustering and
configuration neighbors peers
List, from the Registration details page (Status > Registrations > by Device and click a
Call Bandwidth
processing control
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