1005 Closed User Groups - Packet

Closed User Group (CUG) is a Public Packet Switched Network feature that 
controls communication between Data Terminal Equipment (DTEs) belonging to the 
same CUG. Various CUG feature options are designated by the user such as:
  o Incoming Calls Barred With CUG, allows a member of a CUG to originate
    calls to other members of the CUG, but cannot receive incoming calls.
  o CUG With Incoming Access, allows a member of a CUG to receive incoming 
    calls from any DTE not in the CUG.
  o Outgoing Calls Barred With CUG, allows a member of a CUG to receive calls 
    from other members of that CUG, but cannot originate any calls.
  o CUG With Outgoing Access, allows a member of a CUG to make outgoing calls
    to any DTE.

A DTE can be a member of more than one CUG.  

Generic Name of ONA Service 	Product Name			BSE or CNS
===========================================================================
Closed User Groups - Packet	AM - Closed User Group		BSE 
                           	AM - Closed User Group		CNS 
                           	BA - Closed User Groups		BSE or CNS
                           	BS - Closed User Group 		BSE or CNS
                           	NX - Closed User Group		BSE or CNS
                           	PB - Closed User Group		BSE 
                           	SWB - Restricted User Group	BSE 
                           	USW - Closed User Group		BSE 

FEATURE OPERATION:
Closed User Groups provide a mechanism for controlling communication that
is defined by the client/user when the service is requested.  A preferential
CUG may be chosen at subscription and the preferential CUG will automatically
be selected if a specific CUG is not designated in the call request packet.
Screening of the CUG may be performed at the originating and terminating
interfaces as well as the PPSN X.75 interface.  The call request is cleared if
found invalid at any screening point.

TECHNOLOGICAL AND FEATURE INTERACTION CONSIDERATIONS:
1. The PPSN and ISDN Packet Handling Facility (PHF) should be capable of 
   supporting more than 100 CUGs on an X.25 interface.

2. The PPSN Access Concentrator should be capable of supporting up to 10 CUGs
   on an X.25 interface.

3. The PPSN X.75 interface should support 100 CUG codes.

4. References:
   o PPSNGR TR-TSY-301, Issue 2, December 1988, Sections 3.2.6.10.  Closed
     User Group facility code indicator, CUG Index and Interlock Code tables
     are found in B-10, B-11 and B-12.

This service, if offered as a BSE, is associated with the Packet Switched
X.25 and X.75 basic serving arrangements.
