ad7i (07/06/82)
Date: 25 June 82
To: All Packeteers
From: Hank Magnuski
I am about 95% through testing new versions of the LIP/TIP and KA6M/R
software which does away with hardwired ID codes. The strategy is an
expansion of the AMRAD suggestion to put the callsign at the front of each
packet. Each packet will have a header of the following form:
FLAG ADDR CTL FMCALL TOCALL ID0 ID1 Infofield FCS FLAG
Where
ADDR Assigned always to some fixed value. I'm using FE.
CTL All current values unchanged plus the addition of
Repeater connection reject packet
Station connection reject packet
Broadcast packet
FMCALL 7 bytes of callsign of the originator
TOCALL 7 bytes of callsign of the desination
ID0, ID1 Two bytes to indicate the protocol being used at the next
higher level, level 3.
Info Usual information field
The rules for operation are very simple:
A link-level packet going from A to B will have CALLA and CALLB
in the header, with no exceptions. This applies to the repeater
as well, which keeps a table of how to redirect packets.
All packets transmitted by the repeater have its call in the
FMCALL field.
I will have more details later, but I feel that this format solves most
of the problems which have been aired recently, and solves problems
which are currently restricting our growth. I'm open to midcourse
corrections, but they better come before we get all our EPROMs burned!
The strategy allows multiple repeaters on the same frequency in an RF
domain, it allows direct point-to-point contacts, and allows AMSAT to
use PHASE IIIB without any person coordinating the addressing codes.
I will put LIPM04.ASM and TIPM04.ASM on this medium when I feel they are
adequately tested.
See you when I get back from my vacation (July 12th).
73, Hank