Technical information

Integrators’ Reference Manual for ViewStation EX, ViewStation FX, and VS4000
56 www.polycom.com
Service prefixes are short numeric strings that identify the services
being requested, such as call speed and zone.
An H.323 dial plan allows you to associate a numeric alias to the
network address of each H.323 entity. This is the calling plan that
you develop for H.323 deployments.
In large deployments, the dial plan also helps to manage resources
by segmenting user populations.
The dial plan defines the following elements of the deployment:
❑ Services — these include system services, gateway and MCU
services.
❑ Routing and policies — these include the default group policy
and least-cost routing tables.
❑ Network topology — includes private numbering plans (E.164
provisioning) or a public dialing plan (ISDN alias assignment).
❑ Neighbor gatekeepers — these are gatekeepers that manage
other H.323 zones within an organization.
❑ Addressing — specifies the requirements for assigning zone
and service prefixes and endpoint addresses.
Before you design a dial plan, you should document:
❑ Current telephone number dialing patterns
❑ Planned router locations
❑ Traffic routing requirements
Because no standard protocol defines the dynamic routing of E.164
addresses, H.323 dial plans must be configured statically and
managed on gateway and gatekeeper platforms.
To reduce the complexity of the configuration, confine H.323
addresses to one portion of the dial plan.