1002 Category 2, Type B - X.75 Packet Switched BSA

Category 2 - Packet Switched Basic Serving Arrangement

A packet switched (BSA) provides an ESP with a connection to the packet switched
network.  This BSA is capable of supporting analog or digital signals of various
transmission rates.  The transmission interface may be 2-wire or 4-wire, or
derived from a variety of multiplexing alternatives (e.g., DS-1 or DS-3).

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Category 2, Type B - X.75 Packet Switched BSA

The Type B Packet Switched BSA provides an ESP with X.75 access to the BOC 
packet switching network.  The X.75 interface conforms to CCITT 
Recommendation X.75.

X.75 supports physical, link and packet level procedures.  At the physical
level data signaling rates of 9.6 kbps are supported over analog or digital 
facilities.  Speeds of 56 kbps are supported over digital facilities only.  
The link level protocol supported at the interface is LAPB procedures.  The 
main function of the link level protocol is to ensure that the packets cross 
the network interface essentially error free.  The network level access protocol
provides the procedures required to set up, maintain and clear virtual calls. 

Generic Name of BSA
 	Regional Company BSA Name
==========================================================================
Category 2, Type B - X.75 Packet Switched BSA
	AM - Packet Switched (X.75)
     	BA - Public Data Network: X.75
     	BS - PulseLink(R) Packet Switching - X.75
     	NX - Packet Switched - Trunk
     	PB - Public Packet Switching (X.75)
     	SWB - Packet Switched - MicroLink II(sm) (X.75 Version)
     	USW - Packet Switching (X.75)

Reference:  PPSNGR TR-TSY-301 Public Packet Switched Network Generic
Requirements, Issue 2, December 1988.  TR-NPL-000011 Asynchronous Terminal
and Host Interface Reference, Issue 1, March 1985.  TR-TSY-000461 X.75
Interfaces to BOC/IDC Network, Issue 1, June 1987.  
Ameritech TR-NPL-000001 Public Packet Services Technical Interface 
Specifications, Issue 1, December 1985.  Ameritech TR-NPL-000003 Technical 
Interface Specifications for Asynchronous Service, Issue 2, May 1988.  
Ameritech TR-NPL-000007 Digital Service Interface Specifications, Type 1, 
Issue B, December 1988.  Ameritech TR-NPL-000016 Technical Interface 
Specifications for X.75 Service, Issue 2, May 1988.  
Bell Atlantic TR 72211 Interface Specification For The Bell Atlantic Public 
Data Network, November 1987.
BellSouth TR-73515 PulseLink(R) X.75 Interface Specification, July 1987. 
BellSouth TR-73516 PulseLink(R) Physical Interface Specification, Issue B, 
December 1988.
NYNEX NTR-74252 Infopath(sm) Packet Switching Service Asynchronous Interface
Specification, Issue 2, January 1988.
Pacific Bell PUB L-780060-PB Public Packet Switching (PPS) - Technical 
Interface Specification, Issue 1, August 1989.
Southwestern Bell Telephone Technical Publication TP 76800, MicroLink II 
X.25/X.75 Reference, Issue 2, January 1990.  Southwestern Bell Telephone 
Technical Publication TP 76810, MicroLink II Asynchronous Reference, Issue 2,
January 1990.
U S WEST USWTR 77359 DIGIPAC(sm) Packet Switching Interface Specifications, 
April 1988.

MicroLink II is a registered service mark of Southwestern Bell Telephone.
PulseLink is a registered trademark of BellSouth.
DIGIPAC is a service mark of U S WEST.
