RE: [RPRWG] SendA, SendB, SendC
Anoop,
I'm not enough of a token ring expert to answer your questions about how and
why 802.5 works the way it does. Maybe our esteemed vice chair can answer
your question about how and why 802.5's treatment of priorities is different
from 802.17's usage of service classes.
As for what happens if a client chooses to ignore the signals, the client's
frames may not be accepted by the MAC. The send signals are a friendly way
of informing the client that it has exceeded the relevant shaper. If it
tries to send a packet with a Service Class value of X while the sendX
signal is not asserted, the MA_UNITDATA.request will be refused.
jl
-----Original Message-----
From: Anoop Ghanwani [mailto:anoop@xxxxxxxxxxxxxx]
Sent: Wednesday, June 19, 2002 1:30 PM
To: 'John Lemon'; Anoop Ghanwani; 'stds-802-17@xxxxxxxx'
Subject: RE: [RPRWG] SendA, SendB, SendC
John,
802.5 MACs have several priorities and the client
can request a specific priority for its transmission.
Why is 802.17 any different?
If the client can ignore the signals, why do we
need to have them? In other words, what happens
different if the client ignores them versus
uses them.
-Anoop
> -----Original Message-----
> From: John Lemon [mailto:JLemon@xxxxxxxxxxxx]
> Sent: Wednesday, June 19, 2002 1:33 PM
> To: 'Anoop Ghanwani'; 'stds-802-17@xxxxxxxx'
> Subject: RE: [RPRWG] SendA, SendB, SendC
>
>
> Anoop,
>
> We need 3 such signals because we have 3 separate service
> classes. Other 802
> MACs do not have distinct service classes. A client is free
> to ignore the
> signals if does not want to use them or does not know how to use them.
>
> jl
>
> -----Original Message-----
> From: Anoop Ghanwani [mailto:anoop@xxxxxxxxxxxxxx]
> Sent: Wednesday, June 19, 2002 11:35 AM
> To: 'stds-802-17@xxxxxxxx'
> Subject: [RPRWG] SendA, SendB, SendC
>
>
>
>
> Why does 802.17 need SendA, SendB, SendC signals
> going from the MAC to the client? Other 802 MACs
> do not have a similar primitive even though they
> have to get the client to wait in order to get
> access to the medium (e.g., in token ring LANs, a
> station must wait until a free token arrives).
>
> Can anyone shed some light on this?
>
> -Anoop
> --
> Anoop Ghanwani - Lantern Communications - 408-521-6707
>