3025 Feature Group D (Bell Atlantic Region Specific)

Category 1 - Circuit Switched BSA

A circuit switched basic serving arrangement (BSA) provides an enhanced service
provider (ESP) with a connection to the circuit switched network.  This BSA is 
capable of supporting analog signals of approximately 300 to 3000 Hz.  Voice 
grade analog data may also be transmitted.  The transmission interface may 
be 2-wire or 4-wire voice grade, or may be derived from a variety of 
multiplexing alternatives (e.g., DS-1 or DS-3).

This BSA may support one-way or two-way directionality.  Calls are set up and 
taken down on a call by call basis.  The transport/usage element could be 
intra-office or inter-office.

Route diversity may be available with this serving arrangement.

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Category 1, Type B - Circuit Switched Trunk BSA

A circuit switched trunk BSA provides an enhanced service provider (ESP) with a
trunk-side connection to the circuit switched network.

Alternative types of network connection, address signaling and supervisory 
signaling are available.  Examples of network connections are direct trunk,
or tandem connection.  Examples of address signaling are multi-frequency CAMA 
or exchange access address signaling protocol.  Examples of supervisory 
signaling are loop reverse battery or E&M.  This BSA may support one-way or 
two-way directionality.

Calls are set up and taken down on a call by call basis.  Different access
arrangements, based on the North American Numbering Plan, may be available 
alternatives.

Generic Name of BSA
 	Regional Company BSA Name
==========================================================================
Category 1, Type B - Circuit Switched Trunk BSA
	AM - Circuit Switched Trunk
     	BA - Feature Group B
     	BA - Feature Group D
     	BS -  Circuit Switched Trunk
     	NX - Circuit Switched - Trunk
     	PB - Voice Grade - Trunk - Circuit Switched
     	SWB - Switched Access - Feature Group B
     	SWB - Switched Access - Feature Group D
     	SWB - Switched Access - Feature Group K
     	USW - Voice Grade - Trunk - Circuit Switched

Reference:  TR-NPL-000334, Section 5.7, Voice Grade Switched Access Service - 
Transmission Parameter Limits and Interface Combinations, Issue 1, June 1986,
Revision 1, November 1987.  Also see TR-TSY-000698 Feature Group B FSD
20-24-0300, Issue 1, June 1989 (replaces FSD 20-24-0300 in TR-TSY-000530, 
Issue 2, July 1987).  Also see LSSGR (TR-TSY-000064), FSD 20-24-0000, InterLATA
Carrier/International Carrier Interconnection (Feature Group D), Issue 2, 
July 1987, Module TR-TSY-000530.  Also see TR-NPL-000258 Compatibility 
Information for Feature Group D Switched Access Service, Issue 1, October 1985.  
