Maintenance Adhoc Overview

Jeff MandinPMC-SierraJuly 2008

July 2008 802.3 Maintenance Adhoc 2

Background

1. 802.3-2005 describes two different interfaces to the MAC:

a) MA_DATA.Request/Indication in Clause 2- This is the ISO/IEC/802.1 interface

b) TransmitFrame()/ReceiveFrame() in Clause 4

2. In 802.3as it was determined that this “longstanding discrepancy” between the interface definitions should be remedied

- “Service to humanity”

- MAC Control sublayer no longer an “optional” sublayer inside the MAC but instead a MAC client

- State diagram added to reconcile MA_DATA.Request with TransmitFrame()

- MAC Control Clauses (31, 31B, 64) were modified to use the Clause 2 “service interface primitives” instead of the TransmitFrame()/ReceiveFrame() “functions”

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802.3-2005: MAC Control sublayer is part of MAC

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802.3ay D2.3: MAC Control sublayer no longer part of MAC

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State diagram from Clause 4 (802.3ay D2.2)

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An instance of impact on MAC Control that wasn’t recognized (Maint #1196)

1. There are cases where the TransmitFrame() function cannot simply be replaced by the MA_DATA.Request() primitive

- TransmitFrame() has “duration” ie. it does not complete until all supplied bits are transferred to the PHY

2. Clause 64 (Multipoint MAC Control) specifies the “Control Multiplexer” – which transmits frames to the MAC with extra gap time after IPG to enable the PHY to include FEC parity

3. In 802.3-2005, the Control Multiplexer relies on the duration of TransmitFrame() as part of its calculations of gap time

- When TransmitFrame() is replaced by MA_Data.Request(), this calculation needs to be modified

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MPCP Control Multiplexer

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Questions for the adhoc

1. Are there other instances in the MAC Control clauses (or elsewhere) that were affected by the MAC interface change?

- eg. Is the PAUSE operation transmit state diagram in figure 31B-1 in need of modification?

2. Is there a need to reevaluate the MAC interface changes affecting MAC Control?

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Backup

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PAUSE Operation Transmit State Diagram (Figure 31B-1)

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OAM Multiplexer State Diagram (Figure 57-7)