[Dave Piscitello <dave@xxxxxxxxxxx>]

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.

This was one of those "only standards bodies could devise" notions.

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.

So look to see if there's a null octet between 802.3 LLC/SAP and COTP.


At 01:19 PM 5/22/2003 -0700, Guy Harris wrote:
> If there's a standard Ethernet type or LLC SAP for COTP (not CLNP,
> *COTP*; 0xFE is a standard SAP for CLNP, and Ethereal *does* recognized
> that - as CLNP, *NOT* COTP), then let us know what it is.


----------
David M. Piscitello
Core Competence, Inc.
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