PAM Programming Manual

Link-Level Interfaces
PAM Programming Manual—142482
3-18
Additional Library Headers for Ethernet
Additional Library Headers for Ethernet
PAM supports two SDU headers for Ethernet applications that cannot be formatted using
the primitives from the formatting library. These headers send LLC2 frames over LLC1
ports enabled for LLC2 (for example, LLC2ENABLED set using the SCF ADD PORT
command).
Header for LLC1 MAC Frames
The Ethernet SDU header format for LLC1 MAC frames is defined as follows
The fields of SDU header for LLC1 MAC frames are defined as follows:
zSDU-Size
The number of bytes of buffer space required for this SDU.
zDest-MAC-Addr
The destination MAC address.
zSrc-MAC-Addr
The source MAC address.
zLength
The length of the frame as defined in the 802.3 Ethernet standard.
zDSAP
The destination service access point (DSAP) address.
zSSAP
The source service access point (SSAP) address.
zCtrl
This is the one-byte LLC control field defined for LLC1 frames.
def ZL2S-DDL-LLC1-SDU-Hdr.
02 zSDU-Size type ZSPI-DDL-INT.
02 zDest-MAC-Addr type ZSPI-DDL-BYTE
occurs 6 times.
02 zSrc-MAC-Addr type ZSPI-DDL-BYTE
occurs 6 times.
02 zLength type ZSPI-DDL-INT.
02 zDSAP type ZSPI-DDL-BYTE.
02 zSSAP type ZSPI-DDL-BYTE.
02 zCtrl type ZSPI-DDL-BYTE.
02 zSDU-data type ZSPI-DDL-BYTE.
end.