6 Dec
2004
6 Dec
'04
11:56 a.m.
On Tue, 7 Dec 04 01:03:17 GMT, Michael Sokolov <msokolov(a)ivan.harhan.org> wrote:
If you needed to connect the DMF32 sync port to a
Cisco router, why didn't
you implement Cisco HDLC on the VAX side instead? (As I've done in 2000
in 4.3BSD-Quasijarus0b on a DSV11.) I'm sure you know the frame format:
<flag> <addr> 00 <Ethertype> packet <FCS-16> <flag>
addr is 0F for unicast or 8F for multicast/broadcast*.
It's the simplest and IMO the best framing format for IP over a sync line,
I've used it on T1s (well, fractional T1 since DSV11 is limited to 256 kbps),
and it comes from Cisco.
Hmm... an interesting idea... I have these COMBOARDs, see... and they
have a 68000 processor on board, and either a COM5025 or a Z8530
serial chip. I seriously doubt that the processor could keep the line
fed much faster than 128kbps or 256kbps (99% of our customers needed
9600 - 56/64k), at least it has a DMA interface on the VAX side.
The boards have between 128K and 2MB of DRAM, plus 16K - 128K of ROM
(and are designed to get their application into RAM from a file on the
VAX)... I think there's
everything there except the app to make them into HDLC IP conduits...
I might have to fiddle with that a bit when I get back. I'd been
thinking of a way to make these guys talk IDE or SCSI... to at least
have _some_ practical use for them.
-ethan