I've done some more investigation. The protocol is an ICL (a brand now
subsumed into Fujitsu) protocol called OSLAN (try a Google search on OSLAN
protocol). OSLAN is, as Dave was describing, TP4 over 802.3; I don't know
about the null CLNP stuff.
OSLAN is in widespread use in the UK - wherever there is an ICL mainframe.
This tends to be government organisations or organisations with a government
legacy, like ourselves.
I've attached a capture of some sample activity.
The capture starts with four connections disconnecting, then the four
reconnecting, then a test message down the connection, then all four
connections closing again.
We'd love to have this working in Ethereal.
Many thanks,
Matthew
-----Original Message-----
From: Guy Harris [mailto:guy@xxxxxxxxxx]
Sent: 22 May 2003 23:11
To: Dave Piscitello
Cc: CNS - Matthew Bradley; 'ethereal-usersetherealcom'
Subject: Re: [Ethereal-users] ISO8073 OSI COTP over Ethernet
On Thu, May 22, 2003 at 05:25:07PM -0400, Dave Piscitello wrote:
> I worked on the IEEE and ISO committees that created the LLC/SNAP
> headache/header, nearly 20 years ago, and no standard I know specifies
this.
>
> I have this fuzzy recollection of a "version" of CLNP called "null", where
> there's no CLNP header, only the single, initial protocol identifier with
a
> value of zero.
Yes, there is - it's the "inactive subset" of CLNP.
> If every host you ever wanted to have communicate is connected to an 802.3
> network, you could in theory use MAC addressing and framing(the network
> layer in this situation doesn't provide any added function), then
> encapsulate TP4 in a null CLNP (one octet of zero), and then indicate it's
> CLNP in the LLC SAP value Guy mentions, in the 802.3 frame.
We already handle the inactive subset of CLNP, and dissect the stuff
after the inactive subset as COTP, so that's presumably not what he's
seeing on his network.
CNS
4 Brunel Way, Fareham, PO15 5TX
Switchboard : +44 (0)1489 589922 Fax : +44 (0)1489 554100
Help Desk : +44 (0)1489 581234
http://www.cnsonline.net/
Reg. no. 2084279 England
*************************************************************
All views or opinions expressed herein are solely
those of the author and do not necessarily represent those
of Community Network Services Ltd who do not accept
liability for any action taken in reliance on the contents
of this message (other than where the company has a legal
or regulatory obligation to do so) or for the consequences
of any computer viruses which may have been transmitted
by this E-Mail
The E-Mail and any files transmitted with it, are confidential
and intended solely for the use of the individual or entity to
whom they are addressed. If you have received this message
in error please notify the sender and delete the message
immediately or alternatively email postmaster@xxxxxxxxxxxxx
***************************************************************
Attachment:
sample-oslan2.pcap
Description: Binary data