Re: [libpcap] New DLT value Request - Wattstopper DLM (#401)

[Steve Karg <skarg () users sourceforge net>]

Hello Guy,

> > > > The Family/Address/IR field contains 3-bits of family code, 2-bits of
> > > > address mode, 2-bits of IR (infrared) routing, and 1-bit unused.
> > > > The 8 Legrand NITOO families are 000=CAD Filaire, 001=TopDog, 010=CAD RF,
> > > > 011=CAD PLC, 100=CAD IR, 101=DLM, 111=escape, and 111=DLM Bootloader).
> > > > This document only describes the DLM family.
> > >
> > > Are the fields following the Family/Address/IR field dependent on the family code?  Or can the rest of the packet, 
> > > with the possible exception of the opcode and payload, be parsed the same way regardless of the family code?
> >
> > Yes, the fields following the Family code are dependent on the Family code.
>
> I.e., following the Family/Address/IR field, other families might not have the Sequence ID, Source and Destination 
> MAC addresses, Opcode, and Payload Length followed by Payload?

Yes, that is correct.

> Is the checksum family-code independent or might packets with other family codes not have it (or calculate the 
> checksum differently)?

I presume the checksum is family-code dependent (although by luck it
might not be).

> What I meant was that you said "The 8 Legrand NITOO families are ..." - is this a protocol used only by Legrand, so 
> that those are the only family codes used, or are there other vendors who might have their own set of families and 
> family codes, different from the Legrand ones?

This protocol is only used by Legrand and their subsidiary companies
(i.e. WattStopper), as far as I know.

> > The LRC does not cover the Dongle Code or Packet Delay or Preamble.
>
> I.e., it checksums packet data starting at the Family/Address/IR field and continuing through the end of the Payload 
> field?

Yes, that is correct.

Best Regards,

Steve
-- 
http://steve.kargs.net/
_______________________________________________
tcpdump-workers mailing list
tcpdump-workers () lists tcpdump org
https://lists.sandelman.ca/mailman/listinfo/tcpdump-workers