Nortel Networks NN43001-314 User Manual

Page 293

Introduction

293

select trunks at the main office, Branch Office, or other branch offices as
required. Therefore, the user can route calls to gateways that minimize
long-distance costs, minimize bandwidth usage, or meet other criteria.

On-net dialing plan options

Depending upon customer dialing preferences and configuration
management requirements, many on-net dialing plans are available:

•

Coordinated Dialing Plan (CDP) — Each location is allocated one or
more Steering Codes that are unique within a CDP domain.

•

Uniform Dialing Plan (UDP) — Each location is assigned a Location
Code (LOC). Each telephone has a unique Directory Number (DN).

•

Group Dialing Plan (GDP) — Each group has an LOC that has to be
dialed from outside the group as a prefix to the group CDP. Members
in the group may dial only the CDP number. Effectively, GDP is a
combination of CDP and UDP.

•

Transferable Directory Numbers (TNDN) — Each user is given a unique
DN, that does not change even if it moves to a different Call Server.
The NRS keeps track of each TNDN in the network so that it knows to
which endpoint (Call Server or MG 1000B Core) to return when asked to
resolve a TNDN address.

For more information, refer to Dialing Plans Reference (NN43001-283)

Nortel recommends that customers use Coordinated Dialing Plan (CDP)
between the main office and its branch offices since it enables all users, at
the main office or Branch Office, to call each other using just an extension
number. CDP enables consistent dialing between the main office and MG
1000B IP Phones and devices.

Examples of on-net configurations are given in

Appendix "On-net dialing

plan configuration examples" (page 383)

Off-net dialing plan

When dialing to the PSTN, the Call Server determines that the call
destination is off-net by analyzing the digits that must be pre-configured at
major Call Servers in the network.

If routed over a Virtual Trunk, a request is sent to the NRS to determine
the location of public E.164 numbers. The NRS is configured with a list
of potential alternate routes that can be used to reach a certain dialed
number. Each route is configured with a unique "route cost" to determine
the least-cost route.

Nortel Communication Server 1000

Branch Office Installation and Commissioning

NN43001-314

01.02

Standard

Release 5.0

20 June 2007