Subject: Re: Flow Control curve ball...

From: "Peter W. Gayek" <[email-masked]>
Date: Mon, 19 Dec 94 10:37:05 EST

Since at least Shannon and Pandian still feel strongly that we shouldn't
revert to an implied initial grant, I guess that is not an option.  I
like Paul's proposed compromise, so my vote is that we endorse it for
inclusion in the proposed CP version 1 document that Alan is anxious
to post.

Paul, if I understand this right, here are the instructions we should
give to Alan (please confirm):
 In section 8.2, the 2nd diagram:
 - Change "Y*" to "N" in the column "may have valid ..." on the row
   for "CANUREACH_cs"
 - Change "Y" to "Y*" in the column "may have valid ..." on the row
   for "ICANREACH_cs"
 - Change the *Note at the bottom to read "ICANREACH_cs cannot carry
   FCA, as there cannot be an outstanding FCI."

Ravi, I have added comments on the following text:

>Peter,
>
>With NetBIOS, the frames that flow between the time we get a Name
>Recognized and SABME are all UI Data frames. That are not locally
>acked and the end stations retry the frame. So these frames should
>also go "for free"!

I agree that these frames will normally flow as DATAFRAMEs and
therefore will not be paced.  I didn't think I said otherwise anywhere;
I was just worried about adding IFCMs in the case where an end-station
might be timing the interval between Name_Rec and Session_Init.

>
>Also, if I remember it correctly, the latest proposal was to start
>the link station NOT with the Name Recognized frame, but with the
>SABME that comes in after the NR frame. So we do not require the
>piggy-backing for this purpose.
>

I agree this is the normal case, but I don't think I have understood
the point you are making about piggy-backing.

>I have not yet really thought through Paul's proposal yet. So no
>comments on it yet.
>
>Thanks,
>Ravi Periasamy,
>[email-masked]
>

Peter Gayek
ibm corp.

---

From: Ravi Periasamy <[email-masked]>
Date: Mon, 19 Dec 94 15:02:46 EST

Peter,

I must have misunderstood you previous note.

You said:
:I checked with Gene Cox since he originated the piggy-backing idea,
:and one key concern was the number of frames that have to flow
:to get a circuit up and running, especially for NetBIOS.  I continue
:to feel that adding two IFCM frames to the bring-up flow would
:cause extra delay that should not be required.  Another approach

I thought it meant that the piggy backing idea was to solve the concern
about the number of frames that have to flow to get a circuit up and
running, especially for NetBIOS. Hence my two points about datagram
frames going "for free" and about piggy backing not a requirement for
this. (It may be required for some other reason, that I do not know of).

You are right about the IFCMs adding a delay to the session startup.

Ravi Periasamy,
[email-masked]

PS: Just when I thought I understood English .... :-)