PAM Programming Manual

Link-Level Interfaces
PAM Programming Manual—142482
3-21
Formatting Library for Token Ring Ports
Formatting Library for Token Ring Ports
This subsection describes the use of primitives in the L2TR Formatting Library for
token ring ports. The following topics are covered:
•
Primitives for Token Ring
•
Formatting an Aggregate SDU Header (Token Ring)
•
Formatting an Aggregate SDU and an SDU Header (Token Ring)
•
Getting an SDU (Token Ring)
•
Getting an SDU (Token Ring)
Primitives for Token Ring
The L2TR Formatting Library currently contains four primitives. The four primitives
described here are always passed an aggregate SDU buffer:
ZL2TR^Frmt^Aggr^SDU^Hdr^
Initializes an aggregate SDU buffer and formats an aggregate SDU header for an
outgoing aggregate SDU message. See Formatting an Aggregate SDU Header
(Token Ring) for a detailed description of this primitive.
ZL2TR^Frmt^Aggr^SDU^n^SDU^Hdr^
Initializes an aggregate SDU buffer, formats an aggregate SDU header, and formats
an initial individual SDU header for an outgoing aggregate SDU message in one
operation. The type of individual SDU header is dependent on the Port^Type in use
(LLC1), and the SDUType (UI, XID, or Test) being built. See Formatting an
Aggregate SDU and an SDU Header (Token Ring) for a detailed description of this
primitive.
ZL2TR^Frmt^SDU^Hdr^
Formats a header for an individual SDU in an aggregate SDU buffer. The type of
individual SDU header is dependent on the Port^Type in use (LLC1), and the
SDUType (UI, XID, or Test) being built. See Formatting an SDU Header (Token
Ring) for a detailed description of this primitive.
ZL2TR^Get^SDU^
Finds the first or next SDU in an inbound aggregate SDU buffer, interprets the SDU
header, points the application to the beginning of the user data portion of the SDU,
and tells the application how much user data there is. See Getting an SDU (Token
Ring) for a detailed description of this primitive.
The ZL2TR^Frmt^Aggr^SDU^Hdr^ primitive initializes an aggregate SDU buffer and
formats the aggregate SDU header. The ZL2TR^Frmt^Aggr^SDU^n^SDU^Hdr^
primitive initializes an aggregate SDU buffer, formats the aggregate SDU header, and
formats an initial individual SDU header. Subsequent SDU headers formatted with the