Registering aliases, About alias registration, H.323 alias registration – TANDBERG D14049.01 User Manual

Page 45: Sip alias registration, Attempts to register using an existing alias, H.323, H.323 alias registration sip alias registration, H.323 sip, Text goes here, Registration control

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D 14049.01
07.2007

45

TANDBERG

VIDEO COMMUNICATION SERVER

ADMINISTRATOR GUIDE

Text goes here

Introduction

Getting

Started

System

Overview

System

Configuration

H.323 & SIP

Configuration

Registration

Control

Zones and

Neighbors

Call

Processing

Firewall

Traversal

Bandwidth

Control

Maintenance

Appendices

TANDBERG

VIDEO COMMUNICATION SERVER

ADMINISTRATOR GUIDE

Registration

Control

About Alias Registration

Once the authentication process (if required) has been
completed, the endpoint will then attempt to register its
alias(es) with the VCS.

H.33

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 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

. This is done via:

VCS Configuration > Protocols > H.323

. You will be taken to the

H.323

page.

xConfiguration H323 Gatekeeper Registration ConflictMode: <Reject/Overwrite>



Registering Aliases

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”.

Registration conflict mode

Determines what will happen when an H.323
endpoint attempts to register using an alias
that has already been registered from another
IP address.

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

.

Registration Control

SIP Alias Registration

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.

H.33 Alias Registration

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.



We recommended that you do not use aliases that
reveal sensitive information. Due to the nature of
H.323, call setup information is exchanged in an

unencrypted form.

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.

We recommended that you 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.

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