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Facilities, Reverse charging: r, Network user identification (nui) – Northern UTA220/UTA220k User Manual

Page 87: Closed user group (cug)

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UTA220/UTA220k

12-11

D-Channel X.25

FACILITIES

The following facilities and corresponding code formats are
supported by the TA.

Reverse Charging: R

Reverse Charging is a facility analogous to “collect” calls. All
connect charges are charged to the remote DTE. This facility
works in conjunction with the Reverse Charging Acceptance
facility. If the remote DTE does not subscribe to Reverse
Charging Acceptance, the local DTE's call with the reverse
charging request is cleared.

Format: R

Network User Identification (NUI)

This facility provides a way for the user to be identified by the
network for the purpose of billing, security, or network
management.

Format: N

A character string of up to 16 decimal characters from 33 to
126 of the ASCII character table (see Appendix F) except for
characters 43 to 45 (hyphen, comma, and plus sign). Spaces
can be included in the specification of the NUI string but are
discarded by the PAD.

Echo to the local DTE is turned off upon entering the N until
a comma or hyphen is entered. The comma signifies the end
of the NUI string and indicates that more facilities are to
follow. The hyphen signifies the ending of the facility block.
The P or D designator used for the beginning of the user data
call does not end the NUI string because it is considered a valid
NUI string character.

Closed User Group (CUG)

The Closed User Group (CUG) facility permits users to
essentially establish a private network on a public network by
restricting communications to only those who are designated
to be in the group. Access by anyone outside the group is
denied. The CUG number is assigned by the network provider
at subscription time.

Format: G

: two decimal digits ranging from 00 - 99. If two decimal
digits are not specified, the response ERR displays.