Description Page 49 of 378
ITG Trunk 2.0 ISDN Signaling Link (ISL) Description, Installation and Operation
Dialing plans
Dialing plan configuration allows customers to set up routing tables to route
calls to the appropriate destination, based on dialed digits. The dialing plan is
configured through the Electronic Switched Network (ESN) feature, using
overlays in the Meridian 1 or MAT. With ESN configurat ion, the Mer idian 1
can route outgoing calls to the ITG ISL Trunk card. Address translation
allows the ITG ISL Trunk card call processing to translate the called party
number to the IP address of the terminating ITG node, and to deliver calls to
the destination through the IP network.
The Meridian 1 ITG ISL Trunk card supports the following dialing plans:
• Nort h Ame rican dialing plan
• Flexible Numbering Plan
Customer-defined Basic Automatic Route Selection (BARS) and Network
Alternate Route Selec tion (NARS) Access Codes are used to access the
dialing plans.
The ITG Trunk dialing plan supports a single Meridian 1 customer per ITG
node and multiple ITG nodes per Meridian 1. A customer may have mult ipl e
nodes in a Meridian 1, but each node can only support the dialing plan of a
single customer. Multiple Meridian 1 customers will require multiple nodes
per Meridian 1.

Multi-node configuration

The following example explains a possible configuration between two
Meridian 1 switches to achieve both resiliency into the IP network and load
balancing.
Meridian 1 switch A has two ITG nodes, A1 a nd A2, fo r t he desti na tion NP A
613. A Route List Block (RLB) is created, in order to have two route entries
(one for each ITG node). If the trunks of node A1 are all in use or node A1 is
down, call traffic is routed to node A2. This provi des resil iency by preve nting
failure of a single ITG node (for example, DCH failure or Leader s ubnet fai ls)
from completely eliminating VoIP service for a Meridian 1 system.
It is desirable to distribute calls to multiple nodes at a remote destination
Meridian 1. The configuration of multiple dialing plan ent ries at t he local ITG
node allows routing based on the dialed digits.