Distributed Communications System B Private Networking
Administration for Network Connectivity
CID: 77730 555-233-504 — Issue 1 — April 2000
346
Extension Number Portability
Extension Number Portability (ENP) gives you the ability to assign any extension to
any switch in an ENP subnetwork. Stations can be moved across switches while
retaining the original extension number, as long as the switches are part of the ENP
subnetwork. EPN is used in conjunction with Automatic Alternate Routing (AAR)
and Uniform Dial Plan (UDP).
How to administer ENP
•
AAR Digit Conversion form — Assign all 3-digit ENP codes as home, and if using
a 5-digit UDP, associate the ENP codes with the leading, or 10 thousands, digit
(that is, the fifth digit of the extension). For example, for extension number 73446,
“7” is the 10 thousands digit.
• ENP Numbering Plan form — Associate the leading one or two digits of
extensions in the ENP subnetwork with a 3-digit ENP code, used to construct a
7-digit AAR-like ENP number.
• Node Number Routing form — Associate a route pattern with each node in the
ENP subnetwork.
• Uniform Dialing Plan form — Enter the number of digits in the plan (4 or 5) and
the Extension Codes for non-home extensions in the ENP subnetwork as
ENPNode (node number routed).
Detailed description The ENP Numbering Plan allows you to set 4- or 5-digit extensions in the ENP
subnetwork to a 7-digit AAR-like number that is sent to other nodes in the network.
Only the first 1 or 2 leading digits of the extension are significant.
ENP Codes are distinguished from AAR location codes because ENP Codes are home
on every node within the ENP subnetwork, and ENP Codes are administered in the
ENP Numbering Plan table as well as in the AAR Analysis table. Since ENP Codes
are home on every node, they cannot be used as AAR location codes.
UDP extensions are converted to ENP numbers if node number routing is specified
for the extensions in the UDP table.
Note: One ENP code is required for a 4-digit ENP subnetwork. A 5-digit
UDP requires one ENP code for each leading digit of extensions
used within the ENP subnetwork.
DCS message signaling links are not required to support ENP. As a result, many
multiple switch configurations are possible with ENP. Typically the ENP network
will be a subnetwork of a UDP or Electronic Tandem Network (ETN).
Form Field
AAR and ARS Digit Conversion Table
• All
Extension Number Portability Numbering
Plan
• All
Node Number Routing
• All
Uniform Dialing Plan
• Ext Code