![](/images/new-backgrounds/1267248/267248157x1.webp)
Grey Headline (continued)
Registration Control
TANDBERG VIDEO COMMUNICATIONS SERVER ADMINISTRATOR GUIDE
Registering Aliases
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.
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.
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”.
H.323 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 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.
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.
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.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
You can determine how the VCS will behave in this situation by configuring the Registration Conflict Mode.
To configuring the Registration Conflict Mode:
•VCS Configuration > Protocols > H.323. You will be taken to the H.323 page.
•xConfiguration H323 Gatekeeper Registration ConflictMode
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.
Introduction | Getting Started |
| Overview and |
| System | VCS | Zones and |
| Call |
| Bandwidth |
| Firewall |
| Applications |
| Maintenance |
| Appendices |
| Status |
| Configuration | Configuration | Neighbors |
| Processing |
| Control |
| Traversal |
|
|
| |||||
|
|
|
|
|
|
|
|
|
|
|
|
| |||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
D14049.04 |
|
|
|
|
|
| 79 |
|
|
|
|
|
|
|
|
|
| ||
JULY 2008 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|