Subject: Elimination of UI on SDLC

From: "Ray Bird" <[email-masked]>
Date: Tue, 15 Aug 95 10:15:45 EDT

As it turns out, the only product that has implemented SDLC so far
is NCP and they do not support UI frames.  So, in order to run
with NCP, you cannot use UI frames on SDLC.

Given this fact and the fact that SDLC is clearly not a high-speed
link of the future (the kind HPR was designed to take advantage of)
I propose that the HPR architecture be changed to say
that SDLC always be run in ERP mode (i.e., with no UI frames as is
is currently implemented).  If a requirement
to use UI frames on SDLC arises in the future, it can be added to
the architecture along with details such as how to manage the UI
frames, operational differences between point-to-point and multidrop, etc.

Ray

---

From: Dave Finnie <[email-masked]>
Date: Wed, 16 Aug 1995 08:41:17 +1000

Ray,

> with NCP, you cannot use UI frames on SDLC.

I'm sorry, NCP is not the only SDLC product. Do you mean only IBM SDLC
product ?

I don't understand why it is necessary to preclude SDLC from using UI,
although I agree it is not a strategic direction for APPN/HPR. Surely
if NCP (or anything else) knows that it does not support datagrams on
the underlying DLC, it can simply indicate ERP mode in XID ? Am I
missing something here ?

Dave