Configuring X.25 8-21
Subscriber Addressing
Subcriber IDs are the called and calling addresses that ar e placed in call packets. Each
Subscriber ID record also defines routing for calls to the subscriber. Each subscriber
ID, or address, consists of up to 15 digits, including (if desired) question marks and/
or asterisks used as wildcards. (See "Wildcards in Subscriber Addresses.")
Subscribers using a public data network (PDN) must conform to the format used by
the PDN. For example, CCITT Recommendation X.121 specifies this format: a one-
digit international code, followed by a four-digit Data Network Identification Code
(DNIC), followed by up to 10 digits of Network Terminal Number (NTN).
A private network (that will not communicate with other networks) does not need to
follow the format—any or all of the digits can be u sed as desired, following the guide-
lines in this chapter.

Wildcards in Subscrib er Addresses

Each subscriber is assign ed to a SmartSwi tch 1800 p ort, and more than on e subscr iber
device can use a port. To eliminate the need to specify the complete ID of every sub-
scriber on the port, the question mark and the asterisk can be used as “wildcard” char-
acters.
A question mark in an address matches any single digit. For example,
3110?????????? is any 14-digit address that begins with 3110.
An asterisk matches any combination of digits, including none at all. For example,
3110*00 is any address that starts with 3110 an d en d s wit h 00, including 311000 (but no t
31100—overlapping is not allowed). Note that * by itself is very important, because it
matches any address.
Wildcards can be combined. The address 3110??* is any address beginning with 3110
and containing at least two more digits.
The following figure shows an example of wildcard addressing.
Figure 8-7 Wildcard Addressing Example
Node 1
Node 2
00100
12301
12302
12303
12304
P1
P3 - Subscriber ID 123*
L1,P0 L0,P0
L0,P1
L0,P2
L0,P3