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Re: [RE] Stream identification at the MAC SAP

Title: Objectives summary for a paper ...
The base definition for the MAC service interface is from ISO/IEC 15802-1 rather than IEEE 802. The most current definition of the IEEE 802.3 MAC service interface is in IEEE 802.3ae where it was updated to better align it to that. Clause 2.3.1.5 in IEEE 802.3ae explains the mapping from the primitives in ISO/IEC 15802-1 and IEEE 802.1D for bridges to the IEEE 802.3 primitives since 802.3 doesn't have a use for some of the generic parameters.
 
IEEE 802.3 allows LLC as a MAC client but it does not require it to be used. Use of the type field to identify the MAC Client is far more common in actual implementations. LLC didn't provide enough bits to identify protocols above it with fixed assignments - SNAP protocol remedies that by adding a way to include a type field, but that is a waste of bits when we can directly support the Type field in IEEE 802.3. There is no active working group and no chair for IEEE 802.2 at present. Protocols that IEEE 802.1 is doing such as VLAN tags and MAC security use type field and as they add bytes that increase MAC frame size beyond the lengths allowed in the length field (802.3 has a length field when LLC is used but when type is used that field holds the type) they would be difficult to accomodate in 802.3 with an LLC client.
 
Therefore, it seems highly unlikely that we would add new capabilities to LLC. It was reaffirmed because it is necessary for IEEE 802.5 which was being reaffirmed.
 
Regards,
Pat
-----Original Message-----
From: owner-stds-802-3-re@IEEE.ORG [mailto:owner-stds-802-3-re@IEEE.ORG]On Behalf Of Shvodian William-r63101
Sent: Wednesday, 10 November, 2004 3:37 PM
To: STDS-802-3-RE@LISTSERV.IEEE.ORG
Subject: Re: [RE] Stream identification at the MAC SAP

Sorry about the type: The first list of parameters is from 802.2.
 
Bill

From: owner-stds-802-3-re@IEEE.ORG [mailto:owner-stds-802-3-re@IEEE.ORG] On Behalf Of Shvodian William-r63101
Sent: Wednesday, November 10, 2004 6:33 PM
To: STDS-802-3-RE@listserv.ieee.org
Subject: [RE] Stream identification at the MAC SAP

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