Placing the ISDN Order Through Your Telephone Company A-4
AT&T 5ESS Custom Switch To order ISDN service for the AT&T 5ESS Custom switch,
supply the telephone company with the information
provided in Table A-3.
* The Directory Number, Circuit-switched Voice, and Circuit-switched Voice Limit
parameters should be set to 2 to allow both analog ports to be used simultaneously.
Otherwise, if those parameters are set to 1, the ISDN line can only place or receive one
call at a time.
†FCO (also referred to as Additional Call Offering) allows you to receive an incoming call
while a dual-channel Multilink PPP call is active. If you do not want this feature, which
may cost extra, FCO is not required.
Table A-3 Line Configuration for AT&T 5ESS Custom
Required Information Specification
Line Type Standard (2B+D) ISDN line with
point-to-point configuration
Line Code 2B1Q
Interface Type U interface with an RJ-45 jack
Directory Numbers 2*
Maximum Terminals 1
Maximum B Channels 2
Actual User Yes
Circuit-switched Voice 2*
Circuit-switched Voice Channel Any
Circuit-switched Data 2
Circuit-switched Data Channel Any
Terminal Type A (Basic Terminal)
Display Yes
Circuit-switched Voice Limit 2*
Circuit-switched Data Limit 2
Voice or Data Both
Call Appearance Preference Idle
Flexible Call Offering (FCO) Yes†