FBB forwarding protocol

Fbb forwarding protocols can operate either in ASCII or binary compressed modes.

This page describes the three versions of this protocol. Each version is backwards compatible with the previous one. These versions are :

Source code is available. Click here.


Ascii Basic Protocol

This line must not to be followed by a F>.
If the other side has no message (after receiving an FF), it sends a line :

and disconnects.

Connects xxxxx
Connected to xxxxx

[FBB-5.11-FHM$]

Welcome, Jean-Paul. 

> 
[FBB-5.11-FHM$] (F6FBB has the F flag in the SID) 

FB P F6FBB FC1GHV.FFPC.FRA.EU FC1MVP 24657_F6FBB 1345 

FB P FC1CDC F6ABJ F6AXV 24643_F6FBB 5346 

FB B F6FBB FRA FBB 22_456_F6FBB 8548 

F> 
FS +-+ (accept the 1st and the 3rd)

Title 1st message

Text 1st message ...... 

^Z 

Title 3rd message 

Text 3rd message ...... 

^Z 
FB P FC1GHV F6FBB F6FBB 2734_FC1GHV 234 

FB B FC1GHV F6FBB FC1CDC 2745_FC1GHV 3524 

F> 
FS -- (Don't need them, and I send immediately the proposal)

FB P FC1CDC F6ABJ F6AXV 24754_F6FBB 345 

F> 
FS + (Accepts the message)

Title message 

Text message ...... 

^Z 
FF (no more message)

FB B F6FBB TEST FRA 24654_F6FBB 145 

F> 
FS + (Accepts the message) 

Title message 

Text message ...... 

^Z 
FF (still no message) 
FQ (No more message)

Disconnection
Disconnection of the link.

 

Binary Compressed Forward Version 0

Format of header for a binary compressed file (type FB) :

Binary Compressed Forward Version 1

 

[FBB-5.15-B1FHLM$].

The submission of a binary file will be in the form :

FB P FC1CDC F6ABJ F6AXV 24754_F6FBB 345

Format of header for a binary compressed file (type FB) :

<SOH> 1 byte = 01 hex 

Length of the header 1 byte = Length of the filename and offset, including the two <NUL> characters. 

Name of the file 1 to 80 ascii bytes 

<NUL> 1 byte = 00 hex 

Offset 1 to 6 ascii bytes 

<NUL> 1 byte = 00 hex 

French regulations require that the title of the message or the file name are transmitted in readable ascii and are not compressed.

The offset is also transmitted in ascii and specifies the offset at which the data should be inserted in the file (in case of a fragmented file). In the version 5.12, this parameter is not utilized and is always equal to zero.

A data block contains from one to 256 bytes. It begins by two bytes which specify the format.

Data block format :

<STX> 1 byte = 02 hex 

Size of data 1 byte = 00 to ff hex. if length is 256 bytes, the value is 00.

Data bytes 1 to 256 bytes

<EOT> 1 byte = 04 hex Checksum 1 byte = 00 to ff hex