PAM Programming Manual

Link-Level Interfaces
PAM Programming Manual—142482
3-27
Formatting an SDU Header (Token Ring)
LLC1 SDU Header Format
The LLC1 SDU header formatted by this L2TR primitive is defined as follows:
The field of the LLC1 SDU header is defined as follows:
zSDU-Size
The number of bytes of buffer space required for this SDU.
The fields of the LLC1 mac^frame are defined as follows:
ac
Access control.
fc
Function control.
Dest-mac
The destination MAC address.
Src-mac
The source MAC address.
Route
Routing information.
DSAP
The destination service access point (DSAP) address:
def ZL2TR-DDL-LLC1-SDU-Hdr.
02 zSDU-Size type ZSPI-DDL-INT.
end.
def ZL2TR-DDL-LLC1-mac-frame.
02 ac type ZSPI-DDL-BYTE.
02 fc type ZSPI-DDL-BYTE.
02 Dest-MAC type ZSPI-DDL-BYTE
occurs 6 times.
02 Src-MAC type ZSPI-DDLBYTE
occurs 6 times.
02 Route type ZSPI-DDL-BYTE
occurs 18 times.
02 DSAP type ZSPI-DDL-BYTE.
02 SSAP type ZSPI-DDL-BYTE.
O2 LLC-Ctrl type ZSPI-DDL-BYTE.
O2 SDU-data type ZSPI-DDL-BYTE.
end.