3com SuperStack 3 NBX Manual De Usuario

These sections tell you how to add an E1 Digital Line Card to an NBX 
system:

■

■

■

Before you insert the E1 Digital Line Card into the chassis, order an E1 
line, with the specifications you want, from your telephone carrier, and 
have them install the line.

When you order E1 with DID, CLIP, or MSN services, the local telephone 
carrier assigns a block of telephone numbers to you. Usually, you can 
request a specific range of numbers, but sometimes the carrier assigns 
numbers other than the ones you request.

You may be able to request that the local telephone carrier pass you a 
specific number of digits for each incoming telephone call. Sometimes 
the carrier does not offer any choice. In either situation, you need to 
know how many digits the carrier passes.

Example: Carriers commonly pass either the last three digits or last four 
digits of the number for each incoming call.

Sometimes the last digits of the telephone numbers the carrier assigns to 
you do not match the telephone extension numbers you want to use for 
internal calls. You can create entries in your Dial Plan configuration file to 
translate the incoming numbers into the corresponding extension 
numbers.

Example: You want to use internal extensions from 4000 through 4999, 
but the local telephone carrier assigns you numbers from 617-555-3500 
through 617-555-4499. You can create translator entries in the Dial Plan 
configuration file to translate an incoming digit sequence such as 3795 
into extension number 4295, and a sequence such as 4213 into 4713. 
The configuration would require several translator entries to handle 
subsets of the total range. A unique set of entries would handle incoming 
digit sequences from 3500 through 3599, from 3600 through 3699, and 
each of the other sequences in which the first two digits were unique in 
the range from 37XX through 44XX.