Re: [802.3_MAINT] summary of MAC interface issues
You might want to take a look at the original slides from the telecon,
which are here: http://www.ieee802.org/3/maint/email/msg00017.html .
Also the telecon notes are at
As you can see from the notes and ensuing discussion, the MAC interface
for an extra primitive (aka "3 arrow") was talked about in the adhoc -
however it was not regarded as viable for reasons including some that
you list - as well as compatibility with 802.1. The approaches
considered til now include:
a) creating a precise definition of MA_DATA.Request() interaction with
b) writing some text that explains that the MAC client is expected to
somehow ensure that it doesn't invoke the MA_DATA.Request() for the
subsequent frame too soon.
You seem to lean to option b), correct?
- Jeff Mandin
MAC interface Maintenance adhoc chair
[mailto:owner-stds-802-3-maint@xxxxxxxx] On Behalf Of Brad Booth
Sent: Tuesday, August 12, 2008 7:19 PM
Subject: Re: [802.3_MAINT] summary of MAC interface issues
Thanks for providing the slides. I was unable to attend the meeting in
Denver, so the slides are helpful in getting up to speed on this.
Here's some feedback on the problems you highlight in slide 2:
1) I don't understand how this is a problem. From what I can see, the
existing state machine and function call look fine. As a matter of
fact, I believe the changes being proposed would break the existing
standard. The goal of the state machine is to queue up incoming data
for the TransmitFrame function. Waiting for the TransmitFrame function
to complete before waiting for the next frame would be assuming that no
other MA_DATA.requests are received. If the upper layer protocol is
transmitting MA_DATA.requests faster than the frames are being
transmitted, then an implementer must be prepared to buffer those frames
until the TransmitFrame function can perform the requested operation.
The TransmitFrame function is not an instantaneous action, but rather a
2) The MA_DATA.request can be generated instantaneously after the
current MA_DATA.request is completed. You are correct that the MAC
Client is unaware of the status of the request. If, and that's a big
if, the 802.3 WG felt that an indication of the status of the request
was required, then the MAC and the MAC Client would need to exchange a
unique identify for each frame to track the status of that frame. This
would be required due to the fact that in problem #1, the interaction
between 4.2.8 and the TransmitFrame function results in a queue;
therefore, the status response to the MA_DATA.request may be delayed
relative to the original request.
[mailto:owner-stds-802-3-maint@xxxxxxxx] On Behalf Of Glen Kramer
Sent: Monday, August 11, 2008 5:56 PM
Subject: [802.3_MAINT] summary of MAC interface issues
In the attached slides, I tried to summarize the MAC interface issues
that were discussed in Denver and on the reflector, as well as outline
various options to resolve them. I could not join the conference call,
so if some other options were discussed, please let me know and I'll add
I am looking forward to everyone's feedback.