PAM Programming Manual

Link-Level Interfaces
PAM Programming Manual—142482
3-3
Port Type Identifiers (Ethernet Only)
•
An exchange identification (XID) or Test PDU is received that is destined for
the LLC1 port’s protocol type.
•
SETMODE sets a port’s data forward count (DFC) and data forward time
(DFT) parameters. SETMODEs are queued with WRITEs on the WRITE
queue. PAM supports the following SETMODE functions:
•
#18 (SM^THRESHOLD) sets the current values for the DFC and DFT
parameters to user specified values. When activated, the DFC is set to
parameter 1 and the DFT to parameter 2.
•
#28 (SM^INIT) sets the current DFC and DFT parameters to the default
values defined by an ADD PORT or ALTER PORT command or to the
values set by any previous SETMODE call SM^THRESHOLD(#18).
•
FILE_CLOSE_ or CLOSE causes a file-system disconnect. All requests associated
with the corresponding open are canceled.
•
FILE_GETINOFBYNAME_ and DEVICEINFO return the frame size of the port.
The frame size is the physical-recordlen parameter of DEVICEINFO. The
frame size is the maximum SDU data size of any SDU in the aggregate SDU buffer
used in calls to the L2S Formatting Library procedures ZL2S^FRMT^SDU^HDR^
and ZL2S^FRMT^AGGR^SDU^N^HDR^, the L2TR Formatting Library
procedures ZL2TR^FRMT^SDU^HDR^ and
ZL2TR^FRMT^AGGR^SDU^N^HDR^, in parameter
SDU^USER^DATA^SIZE^B. An Aggregate SDU buffer containing an SDU with
SDU^USER^DATA^SIZE^B greater than physical-recordlength will not
be delivered. The application WRITE will complete with error FEBADCOUNT.
Port Type Identifiers (Ethernet Only)
The ZPAM^Val^Port^Type identifier is a required input parameter for all primitives in
the L2S Formatting Library. It is used to determine how the fields of the SDUs are to be
formatted and interpreted. The two valid port type identifiers defined for level-2 services
(L2S) are
•
ZPAM^Val^Port^Type^LLC1 (IEEE 802.2 Link Level Control, Type 1). The IEEE
802.2 Logical Link Control, Type 1 (LLC1) LAN access interface provides
unacknowledged, connectionless logical link control support for both Ethernet
(IEEE 802.3) drivers at the physical level. (ZPAM^Val^Port^Type^LLC1 has the
same value as ZLAM^Val^Port^Type^LLC1 for backwards compatibility with
TLAM applications.)
•
ZPAM^Val^Port^Type^Enet (DIX Ethernet format, not IEEE 802.3 Ethernet). The
Ethernet LAN access interface provides direct access to the Ethernet driver at the
physical level, providing interoperability for LANs that use DIX Ethernet packets.
(ZPAM^Val^Port^Type^Enet has the same value as ZLAM^Val^Port^Type^Enet for
backwards compatibility with TLAM applications.)
Note. For new applications, use FILE_GETINFOBYNAME_. DEFICEINFO is supported
for compatibility with previous software.