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D14049.05
February 2009
Grey Headline
(continued)
TANDBERG
VIDEO COMMUNICATIONS SERVER
ADMINISTRATOR GUIDE
Introduction
Getting started
Overview and
status
System
configuration
VCS
configuration
Zones and
neighbors
Call
processing
Bandwidth
control
Firewall
traversal
Appendices
Applications
Maintenance
Clustering and peers
A VCS can be part of a cluster of up to six VCSs. Each VCS in the cluster is a peer of every other
VCS in the cluster.
The purpose of a cluster is twofold:
to increase the capacity of your VCS deployment compared with a single VCS
1.
to provide redundancy in the rare case that a VCS becomes unavailable (for example, due to a
2.
network or power outage).
Peers have identical configuration, and share information with each other about their use of
bandwidth, registrations, and FindMe users. This allows the cluster to act as one large VCS Local
Zone.
The diagram opposite shows four peers clustered together to form one large Local Zone.
About the configuration master
All peers in a cluster must be configured identically for subzones, zones, links, pipes,
authentication, bandwidth control and call policy. To achieve this, one peer is nominated as
the configuration master. Every minute or so all other peers in the cluster request updated
configuration information from the master, and overwrite their existing configuration with these new
settings.
”Alternate” is an H.323 term for a system used to provide redundancy to a Primary
gatekeeper, and prior to version X3.0 the VCS supported Alternates. From X3.0 onwards,
redundancy (along with other features) is provided by clusters of peers, which support both
H.323 and SIP and work as equals. However, peers may sometimes be referred to as Alternates.
About clustering
LOCAL
ZONE
Traversal
Subzone
Default
Subzone
DNS
Zone
ENUM
Zone
Neighbor
Zone
Traversal
Client Zone
Subzone
Default
Zone
PEER 3
PEER 2
PEER 1
PEER 4
Cluster
Subzone
VCS CLUSTER
