User guide

2: Freeway Client-Server Protocol
DC 900-1303C 35
2.3.2 Freeway Header Format
The Freeway header immediately follows the TSI header. All TSI Data packets must
contain a Freeway header; these packets include Freeway control packets (Open Session
and Close Session) and Freeway data packets (ICP protocol data).
The Freeway header contains 44 bytes and must be in network byte order (big-endian).
The fields in the Freeway header are as follows:
Reserved (8 bytes)
This field is a reserved area for use by the Freeway server only.
Shared Header Size (2 bytes)
This field indicates the size of the actual header from the Type field to the
Reserved field, inclusive. Normally, this field contains 12 (decimal). However,
Freeway server code is subject to change.
Private Header Size (2 bytes)
This field indicates the size of the second reserved area in the header (called
“Private” in the above Freeway Header diagram). Normally, this field contains 20
(decimal). However, Freeway server code is subject to change.
Freeway Header
Reserved 8 bytes
Shared Header Size 2 bytes
Private Header Size 2 bytes
Type 2 bytes
Command 2 bytes
Status 2 bytes
Client Session ID 2 bytes
Freeway Session ID 2 bytes
Reserved 2 bytes
Private 20 bytes