PAM Programming Manual

Link-Level Interfaces
PAM Programming Manual—142482
3-30
Additional Header for Token Ring
Additional Header for Token Ring
PAM supports an SDU header that cannot be formatted using the primitives from the
formatting library. This header is used to send LLC2 frames over token ring on LLC1
ports.
The format for this SDU header is as follows:
The fields of SDU header for LLC1 MAC frames are defined as follows:
z8025-SDU-Hdr
The 802.5 header is as follows:
zSDU-Size
The number of bytes of buffer space required for this SDU.
z8025-MAC-Frame
The 802.5 MAC frame is as follows:
def zL2TR-DDL-8025-SDU.
02 z8025-SDU-Hdr type ZL2TR-DDL-8025-SDU-HDR.
02 z8025-MAC-Frame type ZL2TR-DDL-8025-MAC-FRAME.
end.
def zL2TR-DDL-8025-SDU-Hdr.
02 zSDU-Size type ZSPI-DDL-INT.
end.
def zL2TR-DDL-8025-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-DDL-BYTE
occurs 6 times.
02 Route type ZSPI-DDL-BYTE
occurs 18 times.
02 DSAP type ZSPI-DDL-BYTE.
02 SSAP type ZSPI-DDL-BYTE.
02 LLC-unnum type ZL2TR-DDL-LLC-UNNUM.
02 LLC-num type ZL2TR-DDL-LLC-NUM
redefines LLC-unnum.
end.
def zL2TR-DDL-LLC-Unnum.
02 zctrl type ZSPI-DDL-BYTE.
02 zdata type ZSPI-DDL-BYTE.
end.
def zL2TR-DDL-LLC-Num.
02 zCtrl1 type ZSPI-DDL-BYTE.
02 zCtrl2 type ZSPI-DDL-BYTE.
end.