IEEE Std 802.17 Resilient Packet Ring (RPR)

1. IEEE Std 802.17Resilient Packet Ring (RPR)

2. IEEE Std 802.17 Resilient Packet RingOverview RPRStation • Dual counter-rotating ringlets • Concurrent transmissionBandwidth reuse • Three traffic classes • Real Time, GIRLow Delay/Jitter, CIR+EIR • Best Effort • Fairness • Reuse of unused bandwidth • Weighted allocation to EIR, best effort • Plug-and-play • Automatic topology discovery • Robustness • Sub 50 ms fault detection & restoration • Fault tolerant • No single point of failure RPRStation RPRStation Normaloperation RPRStation

3. EastPHY ringlet0 WestPHY ringlet1 MAC RPRStation RPRStation PHY PHY PHY PHY RS RS RS RS MACDatapath MACDatapath MACDatapath MACDatapath MAC MAC RS RS RS RS RPRStation PHY PHY PHY PHY RPRStation Key: MAC MAC – Medium access controllerPHY – Physical layer entityRS – Reconciliation sublayer IEEE Std 802.17 Phys • PHY Independence • Agnostic to which PHY used • RS defined for SONET/SDH and • 1 and 10 Gbps Ethernet PHYs • PHY • Must be same speed on all links • Media can be different • West PHY • Receiving on ringlet0 Transmitting on ringlet1 • East PHY • Transmitting on ringlet0 • Receiving on ringlet1

4. Real SLAs • BW allocations restored upon demand • Class based prioritization allows restoration within delay and jitter requirements for SLAs • Allows full utilization and hard SLAswithout reserving BW • FR/ATM-derived classes of service

5. w w w S16 Mb/s S26 Mb/s S36 Mb/s S16 Mb/s S26 Mb/s S36 Mb/s S16 Mb/s S26 Mb/s S36 Mb/s equalweightedshapers unequalweightedshapers 2w 2w 6w 0 Mb/s 2 Mb/s 3.3 Mb/s 4 Mb/s 10 Mb/savailablecapacity 2 Mb/s 3.3 Mb/s 6 Mb/s 6 Mb/s 3.3 Mb/s Unfairness Equal Fairness Weighted Fairness Fairness

6. IEEE Std 802.17 protection mechanismsNormal operation RPRStation RPRStation RPRStation Normaloperation RPRStation - Sub 50ms fault restoration - Two paths available between any two nodes

7. IEEE Std 802.17 protection mechanismsSteering RPRStation RPRStation RPRStation FailureSteering x Directs frame on opposing ringlet that still has connectivity RPRStation

8. IEEE Std 802.17 protection mechanismsWrapping (optional) RPRStation RPRStation RPRStation FailureWrapping x RPRStation Transmits frame on opposing ringlet in order to route around the fault

9. IEEE Std 802.17 Frame formats Extended frame format Basic frame format 1 1 ttl ttl 1 1 baseControl baseControl header header 6 da 6 da 6 6 sa sa ttlBase ttlBase 1 1 Size (Octets) extendedControl extendedControl 1 1 Size (Octets) 2 2 hec hec payload 6 daExtended protcolType 2 6 saExtended serviceDataUnit payload n trailer protcolType 2 4 fcs serviceDataUnit n Key: da – Destination address ttl – Time to live sa – Source address fcs – Frame check sequence trailer 4 fcs

10. IEEE Std 802.17 Datapath sublayer MAC service interface Fairness algorithm,OAM, Protection,Topology Control MAC control sublayer Ringletselection Type check Control packets – OAM,Topology, protection Transmit framesyield to transitframes MAC datapath sublayer Receive frames Transmit frames MAC Address match – Receive, stripMulticast – Copy, transitExpired TTL - stripElse - Transit Spatial reuse – Ingress framesuse timeslots previously usedby egress frames Transit bufferSingle queue orDual queue Frame HeaderChecker Frame HeaderChecker Ringlet0 datapath Ringlet1 datapath PHY service interface

11. IEEE 802.17 Standards • IEEE 802.17-2004TM Resilient packet ring (RPR) access method and physical layer specifications • IEEE 802.17a-2004: Bridging of IEEE Std 802.17 • IEEE 802.17b-2007: Spatially Aware Sublayer • IEEE 802.17c-2010: Protected Inter-Ring Connection All available through Get IEEE 802 http://standards.ieee.org/getieee802/802.17.html