PAM Programming Manual

Link-Level Interfaces
PAM Programming Manual—142482
3-10
Formatting an Aggregate SDU and an SDU Header
(Ethernet)
The Ethernet Port^Type supports only the UI SDUType. The LLC1 Port^Type
supports all three SDUTypes.
For C programs replace the caret (^) with an underscore ( _ ).
P^F^Flag (INT)
Optional input that allows applications to set or reset the poll/final bit. The poll (P)
bit is used in command PDUs to solicit a response from the addressed peer. The
final (F) bit is used in response PDUs to indicate that the PDU is a response to a
solicitation (poll). True sets the bit. False resets the bit. The default value is false.
Rsp^Flag (INT)
An optional input that designates whether a particular PDU is a command (false) or
a response (true). The default value is false (command).
Foreign^Addr^ptr (STRING .EXT)
Required input that points to a buffer holding the destination service access point
(DSAP) of the peer entity to which this particular SDU is to be sent.
SDU^User^Data^Offset^B (INT .EXT)
Conditional output returns the byte offset from the beginning of the aggregate SDU
buffer where the application should begin placing data associated with an outbound
SDU. If the SDU^User^Data^Size^B parameter is passed and is nonzero, then this
parameter must be passed; otherwise it is not required.
SDU^User^Data^Size^B (INT)
Optional input that declares how many bytes of user data the application wants to
put in the user data portion of the SDU. If no user data is to be added to the SDU,
then this parameter does not need to be included.
Service^Class (INT)
PAM does not support Service^Class. PAM ignores this field.
The syntax for C programs is
short ZL2S_FRMT_AGGR_SDU_N_SDU_HDR_
( char *Ag_SDU_Buff_Ptr
,short Ag_SDU_Buff_Size_B
,short L2S_Type
,short L2S_SDU_Type
,short P_F_Flag
,short Resp_Flag
,char *Foreign_Adr_Ptr
,short *SDU_User_Data_Offset_B
,short SDU_User_Data_Size_B
,short Service_Class)