TANDBERG Security Camera About Alternates Configuring Alternates, VCS Configuration Alternates

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Alternates

TANDBERG VIDEO COMMUNICATIONS SERVER ADMINISTRATOR GUIDE

About Alternates Configuring Alternates

The purpose of an Alternate is to provide extra reliability in the rare case that a VCS fails.

Each VCS can be part of a pool of up to 6 Alternate VCSs that act as backups to each other in case one becomes unavailable (for example, due to a network or power outage).

All the Alternates in a pool are configured similarly and share responsibility for their H.323 endpoint community. When an H.323 endpoint registers with the VCS, it is given the IP addresses of all the VCS’s Alternates. If the endpoint loses contact with the initial VCS, it will seek to register with one of the Alternates. This may result in your H.323 endpoint community’s registrations being spread over all the Alternates.

When the VCS receives a Location Request, it checks its own registration database along with that of each of its Alternates before responding. This allows the pool of endpoints to be treated as if they were registered with a single VCS.

You must configure all Alternates in a ! pool identically for all registration and call features such as authentication,

bandwidth control and policy. If you do not do this, endpoint behavior will vary unpredictably depending on which Alternate it is currently registered with. Alternates should also be deployed on the same LAN as each other so that they may be configured with the same routing information such as local domain names and local domain subnet masks.

Alternates are not used to increase the

capacity of your network; they are to provide redundancy. To increase

capacity, add one or more additional VCSs to your network and neighbor them together.

Alternates are periodically interrogated

to ensure that they are still functioning. In order to prevent delays during call

setup, any non-functioning Alternates will not receive Location Requests.

If you have Alternates configured, you

should change the registration Time to live on the primary VCS and on each of

its alternates from the default 30 minutes to just a few minutes. This setting determines how often endpoints are required to re-register with their VCS, and changing this to just a few minutes will ensure that if the primary VCS has failed, the endpoint will quickly failover to one of its Alternates.

When configuring your VCS with the

details of the system it will be using as a traversal server, you are given the

opportunity to include details of any Alternates of that traversal server. Adding this information to your VCS will ensure that, if the original traversal server becomes unavailable, your VCS can use one of its Alternates instead.

Each VCS can be configured with the IP addresses of up to five other VCSs that will act as Alternates should the current VCS become unavailable.

To configure Alternate VCSs:

•VCS Configuration > Alternates.

You will be taken to the Alternates page.

•xConfiguration Alternates

!	Systems that are configured as	Failover re-registration to an Alternate
	Alternates must not be configured as	applies to H.323 re-registrations only.
	neighbors to each other.	SIP currently has no equivalent.

Save	Alternate 1 to Alternate 5 IP address
Click Save to save your	To configure another VCS as an Alternate, enter its IP address.
changes.	Up to 5 Alternates may be configured.

Introduction	Getting Started	Overview and	System	VCS	Zones and	Call	Bandwidth	Firewall	Maintenance	Appendices
		Status	Configuration	Configuration	Neighbors	Processing	Control	Traversal
D14049.03					89
MAY 2008