802.17c Protected Inter-Ring Connection

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802.17cProtected Inter-Ring Connection

• Rafi Ram - Corrigent Systems
• March 2007

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PIRC Sublayer in MAC Block Diagram
3
Network Diagram

• Stations A B are protection group on the
  primary ring
• Station A is the 0 member and station B is the
  1 member
• Stations C D are protection group on the
  secondary ring
• Station C is the 0 member and station D is the
  1 member

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PIRC Sublayer Logicon the Path MAC ? Client

• if (bit 40 of the RPR DA is set) then
• if (PG state is both active) then
• if ((hash modulo result) ! (member type))
  then
• discard frame
• else
• if ((MAC is on secondary ring) and (RPR
  SA is the mate MAC addr))
• discard frame
• else
• forward frame
• else
• if (PG state is self down or
  hold-off) then
• discard frame
• else
• forward frame
• else
• forward frame

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PIRC Sublayer Logic as State Table
Row Condition Action
1 RPR DA40 is 0 Forward
2 PG state is mate down Forward
3 PG state is self down Discard
4 PG state is hold-off Discard
5 This MAC is on primary ring Forward
6 RPR SA is equal to mate MAC address Discard
7 - Forward