CPCS Design
	===========

SAP_CPCS Interface
------------------
This is the stack SAP interface between an AAL CPCS provider and an AAL CPCS
user.  The stack commands defined for this interface are modeled after the 
AAL3/4 and AAL5 protocol specification primitives CPCS-xxx.  See the protocol 
specification documents referenced below for full descriptions of the CPCS 
interface.


o The following stack commands are sent from a CPCS user to the CPCS provider:

Stack Command:	CPCS_INIT
Description:	Initialize a SAP instance.  This should be the first stack
		command issued across the SAP instance after the service stack 
		has been successfully instantiated.
Argument 1:	Not used.
Argument 2:	Not used.


Stack Command:	CPCS_TERM
Description:	Terminate a SAP instance.  This must be the last stack command
		issued across the SAP instance.  The stack instance will be
		deleted upon completion of this command.
Argument 1:	Not used.
Argument 2:	Not used.


Stack Command:	CPCS_UNITDATA_INV
Description:	Request that an SDU be sent to the remote AAL user.
Argument 1:	Pointer to an mbuf chain containing the user SDU.
		(struct mbuf *)
Argument 2:	Not used.


Stack Command:	CPCS_UABORT_INV
Description:	Not supported.
Argument 1:	N/A
Argument 2:	N/A


o The following stack commands are sent from the CPCS provider to a CPCS user:

Stack Command:	CPCS_UNITDATA_SIG
Description:	Indication that an SDU has been received from the remote AAL 
		user.
Argument 1:	Pointer to an mbuf chain containing the peer's SDU.
		(struct mbuf *)
Argument 2:	Not used.


Stack Command:	CPCS_UABORT_SIG
Description:	Not supported.
Argument 1:	N/A
Argument 2:	N/A


Stack Command:	CPCS_PABORT_SIG
Description:	Not supported.
Argument 1:	N/A
Argument 2:	N/A



Protocol Specifications
-----------------------
See I.363.



Implementation Limitations
--------------------------
o The CPCS-LP, CPCS-CI and CPCS-UU parameters are not supported.

o The Streaming Mode service is not supported.

o The Abort service is not supported.


	@(#) $Id: cpcs.design,v 1.1.1.1 1996/12/04 20:48:14 mks Exp $