Re: [RE] Stream identification at the MAC SAP
Title: Re: [RE] Stream identification at the MAC SAP
See comments below...
Just an opinion, but ...
- None of the higher layer services running on
ethernet/802(anything)/IP have any idea what to do with isochronous data ...
so it is not surprising that there are no service parameters that deal with
this.
[Bill Shvodian] I don't think that is quite true. RSVP can be
used to reserve bandwidth for a stream. From rfc 2205: "An
RSVP session is defined by the triple: (DestAddress, ProtocolId [,
DstPort])." This information could be used to identify an isochronous
strream.
- At the guts of ResE, I expect we will need a unique
EtherType to indicate an isochronous packet, just like you do for MAC control
frames.
[Bill Shvodian] Identifying it as isochronous is one thing.
Identifying which stream is another. You may have two video
streams and multiple audio streams between two nodes, but since the
reservations and treatment may be different depending on the type of
stream.
- I expect there will have to be a NEW service interface
for isochronous data (yet another reason for this to be done in 802.3). This
might look just like the existing MA-UNITDATA.request, except with scheduling
parameter(s).
[Bill Shvodian] I agree. I just wish that 802.2 had
agreed to make the change so that ALL 802 standards would use the
same defined parameters, rather than having one for RE, one for 802.11e,
one for 802.15.3, etc, etc.
On
11/10/04 3:33 PM, "Shvodian William-r63101" <bill.shvodian@FREESCALE.COM>
wrote:
I have a general question on the MAC-SAP interface for RE.
All 802 standards are required to support the 802.2 interface. The
802.2 interface does not provide a way of identifying an isochronous stream to
the MAC at the MAC SAP. When 802.2 was up for reconfirmation last year I
suggested that they add a stream identification parameter that could be used
for protocols that provide isochronous services like 802.15.3 or now 802.3 RE.
802.2 rejected the comment.
Has anyone given a thought to how streams would be identified at
the MAC-SAP? Would there be optional parameters added beyond those
provided by the 802.2 interface? The current parameters from 802.3 are
listed here:
MA-UNITDATA request
(
source_address,
destination_address,
routing_information,
data,
priority,
service_class
)
and from 802.3:
MA_DATA.request
(
destination_address,
source_address,
m_sdu,
service_class
)
Thanks.
Bill
--
Michael D. Johas Teener
-- http://public.xdi.org/=Michael.Johas.Teener
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