DIVA T/A ISDN Modem Reference Guide ◆ Page 49
Always On / Dynamic ISDN AT Commands

The following table describes the Always On/ D ynamic ISDN AT commands.

AT!X1 =n X.25 Version. Specifies the X.25 version you are using. There are two X.25 CCITT
recommendations available for selection, 1984 and 1988. This information is
provided by your Service Provider and should match the X.25 recommendation
supported on the switch you are connecting to.
n=0 1984 (default).
n=1 1988.
AT!X2 =n X.25 DTE Address. Specifies the X.25 DTE address. An X.25 DTE Address identifies a
node on an X.25 network. Every X.25 node has an X.25 address. Your Service provider
assigns this value at subscription time.
This number is your 7, 10, or 11 digit X.25 Directory number (11=with leading 1). For
example, if 214-111-1234 is your DN, the following combinations are possible:
AT!X2=1111234
AT!X2=2141111234
AT!X2=12141111234
Maximum Length: 5 digits; digits can be from 0-9 inclusive.
Default: none.
AT!X3 =n X.25 Facilities. Specifies the X.25 facilities that are to be included each time a call is
made.
X.25 facilities are optional network services that let you perform tasks such as
reversing charges on your calls, accessing a Close User Group, or specifying a
Network User Identification (NUI).
Enter facilities as hexadecimal octets (eight-bit bytes).
For example, if your X.25 long distance provider is AT&T (AT&T=3134), you should
specify AT!X3=443134. To specify a Throughpu t Class of 9600, enter AT!X3=02AA (or
in Canada enter AT!X3=02aa420707430707).
Maximum Length = 28 characters; characters can be any combination of numbers
from 0 to 9, and letters from A to F (lower and upper case). Default: none.
AT!X4 =n Local ISDN Pref ixes. Specifies the local ISDN prefixes to be used on phone numbers
received with BACP enabled.
For example, AT!X4=9 will place a 9 in front of the number you are dialing for
situations where you need to dial 9 for an outside line (PBX). AT!X4=1 will place a 1 in
front of the number in situations where you are making a long distance call. Default:
none.
Max Length: 9 characters. Characters can be numbers in the range 0 to 9, or the
*and# symbols.
AT!X5 =n X.25 Default Window S ize. Specifies the X.25 default window size. This is the
window size used if no window size is specified in the X.25 Facilities field when a call
is made.
Default: 2.
Window sizes of 1 to 7 are standard. A value of 0 is not allowed.