Configuring and Managing T1 Digital Line Cards 255
Selecting the 4ESS Protocol
To select the 4ESS protocol:
1On the Digital Line Cards tab, select ISDN PRI Span List from the Select
Device Type drop-down list and click Apply.
2From the CO Switch Protocol drop-down list, select AT&T C ustom - 4ESS.
3Click OK to enable the 4ESS protocol and exit from the dialog box.
Otherwise click Apply to enable 4ESS, stay in the Modify Span dialog box,
and configure Call-By-Call Service. See “Configuring Call-By-Call Service”
in the next section.
Configuring Call-By-Call Service
You order the optional Call-By-Call Service from your long-distance
carrier, only if you order the 4ESS protocol. 3Com does not support
Call-By-Call Service with any other protocol.
To configure Call-By-Call Service:
1In the Modify Span dialog box, click the Enable Call-By-Call Service check
box.
2In the Carrier Identification Code text box, type the identification code for
your long-distance carrier.
Your long-distance carrier can supply this code when you order PRI
services, or you can ask the carrier for their code number. Another way to
obtain the code is to access the web site for the North American Number
Plan Administration (http://www.nanpa.com). In the menu in the left
frame, expand Number Assignments, and click Carrier Identification
Codes. Follow the instructions to download and unzip the two files
(Current Feature Group B (950-XXXX) CIC Assignments and Current
Feature Group D (101-XXXX) CIC Assignments). Search the documents to
determine the identification code for your long-distance carrier. For
example, AT&T is listed next to code 288 in the Group D document.
3From the Default Outbound Service drop-down list, select either
MEGACOM or Standard (LDS) as the service to use as the default. You
can configure the NBX system dial plan to use a particular service.
Select MEGACOM as the default service only if you purchased
MEGACOM from your long-distance carrier. You cannot select Standard
(LDS) as the default service if you purchased MEGACOM, because these
two services do not work together.
4Click OK.