Maintenance Adhoc Overview

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Maintenance Adhoc Overview

• Jeff Mandin
• PMC-Sierra
• July 2008

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Background

• 802.3-2005 describes two different interfaces to
  the MAC
• MA_DATA.Request/Indication in Clause 2
• This is the ISO/IEC/802.1 interface
• TransmitFrame()/ReceiveFrame() in Clause 4
• 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()/Receive
  Frame() 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 wasnt
recognized (Maint 1196)

• 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
• 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
• 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

• 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?
• 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)