G.8032 Ethernet Ring Protection Overview March, 2008 ITU-T Q9 SG 15

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2. Plan. G.8032 Recommendation IntroductionG.8032 Objectives and PrinciplesG.8032 ConceptsG.8032 Protection SwitchingG.8032 R-APS MessagesG.8032 Items Under Study. 3. ITU-T SG15/Q9 G.8032 Recommendation. G.8032 Recommendation assented February 2008This Recommendation characterizes the APS convention and assurance exchanging instruments for ETH layer ring topologies. Included are points of interest relating to br

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G.8032 Ethernet Ring Protection Overview March, 2008 ITU-T Q9 – SG 15

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Agenda G.8032 Recommendation Introduction G.8032 Objectives and Principles G.8032 Concepts G.8032 Protection Switching G.8032 R-APS Messages G.8032 Items Under Study

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ITU-T SG15/Q9 G.8032 Recommendation G.8032 Recommendation assented February 2008 This Recommendation characterizes the APS convention and insurance exchanging instruments for ETH layer ring topologies. Included are points of interest relating to crossed over ring insurance attributes, structures and the ring APS convention. G.8032 Recommendation Consent G.8032 Proposals and Contributions G.8032 Objective, Principles, and Requirements Setting G.8032 Converged Proposals G.8032 ERP Work Item Approved in ITU-T

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G.8032 Objectives and Principles Use of standard 802 MAC and OAM outlines around the ring. Utilizes standard 802.1Q (and revised Q spans), yet with xSTP incapacitated. Ring hubs underpins standard FDB MAC learning, sending, flush conduct and port blocking/unblocking systems. Forestalls circles inside the ring by blocking one of the connections (either a pre-decided connection or a fizzled interface). Checking of the ETH layer for disclosure and recognizable proof of Signal Failure (SF) conditions. Assurance and recuperation exchanging inside 50 ms for common rings. Add up to correspondence for the assurance component ought to expend a little rate of aggregate accessible data transmission.

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G.8032 Terms and Concepts Ring Protection Link (RPL) – Link assigned by system that is obstructed amid Idle state to forestall circle on Bridged ring RPL Owner – Node associated with RPL that pieces activity on RPL amid Idle state and unblocks amid Protected state Link Monitoring – Links of ring are observed utilizing standard ETH CC OAM messages (CFM) Signal Fail (SF) – Signal Fail is proclaimed when ETH trail flag fall flat condition is recognized No Request (NR) – No Request is announced when there are no extraordinary conditions (e.g., SF, and so on.) on the hub Ring APS (R-APS) Messages – Protocol messages characterized in Y.1731 and G.8032 Automatic Protection Switching (APS) Channel - all inclusive VLAN utilized solely for transmission of OAM messages including R-APS messages

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G.8032 Timers G.8032 determines the utilization of various clocks to keep away from race conditions and pointless exchanging operations WTR (Wait to Restore) Timer – Used by the RPL Owner to check that the ring has balanced out before hindering the RPL after SF Recovery Hold-off Timers – Used by hidden ETH layer to sift through discontinuous connection deficiencies Faults may be accounted for to the ring insurance instrument if this clock lapses

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Controlling the Protection Mechanism Protection exchanging activated by Detection/clearing of Signal Failure (SF) by ETH CC OAM Remote asks for over R-APS channel (Y.1731) Expiration of G.8032 clocks R-APS asks for control the correspondence and conditions of the ring hubs Two fundamental R-APS messages indicated - R-APS(SF) and R-APS(NR) RPL Owner may change the R-APS(NR) showing the RPL is blocked: R-APS(NR,RB) Ring hubs might be in one of two states Idle – ordinary operation, no connection/hub issues distinguished in ring Protecting – Protection exchanging essentially in the wake of distinguishing a flag blame

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2 6 1 3 5 4 ETH-CC ETH-CC ETH-CC ETH-CC ETH-CC ETH-CC 2 6 1 RPL 3 5 4 Ring Idle State Physical topology has all hubs associated in a ring ERP ensures absence of circle by obstructing the RPL (interface between 6 & 1 in figure) Logical topology has all hubs associated without a circle. Each connection is observed by its two nearby hubs utilizing ETH CC OAM messages Signal Failure as characterized in Y.1731, is trigger to ring security Loss of Continuity Server layer disappointment (e.g. Phy Link Down) ETH-CC ETH-CC RPL Owner RPL ETH-CC ETH-CC ETH-CC ETH-CC Physical topology Logical topology

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2 6 1 2 6 1 R-APS(SF) R-APS(SF) R-APS(SF) 3 5 4 3 5 4 R-APS(SF) 2 6 1 RPL 3 5 4 Protection Switching  Link Failure Link/hub disappointment is identified by the hubs neighboring the disappointment. The hubs neighboring the disappointment, hinder the fizzled connection and report this inability to the ring utilizing R-APS (SF) message R-APS (SF) message triggers RPL Owner unblocks the RPL All hubs perform FDB flushing Ring is in assurance express All hubs stay associated in the sensible topology. RPL Owner RPL Physical topology Logical topology

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R-APS(NR) R-APS(NR) R-APS(NR) R-APS(NR) R-APS(NR, RB) 2 6 1 RPL R-APS(NR, RB) 3 5 4 1 2 6 3 5 4 Protection Switching  Failure Recovery When the fizzled interface recoups, the activity is kept obstructed on the hubs adjoining the recuperated connect The hubs neighboring the recouped connect transmit R-APS(NR) message showing they have no nearby demand display When the RPL Owner gets R-APS(NR) message it Starts WTR clock Once WTR clock terminates, RPL Owner pieces RPL and transmits R-APS (NR, RB) message Nodes getting the message – play out a FDB Flush and unblock their already blocked ports Ring is currently come back to Idle state RPL Owner RPL Physical topology 2 6 1 3 5 4 Logical topology

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Defined by Y.1731 Defined by G.8032 Non-determined substance Signaling Channel Information ERP utilizes R-APS messages to oversee and organize the security exchanging R-APS characterized in Y.1731 - OAM basic fields are characterized in Y.1731. Adaptation – "00000" – for this rendition of Recommendation OpCode – characterized to be 40 in Y.1731 Flags – "00000000" – ought to be disregarded by ERP

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R-APS Specific Information Specific data (32octets) characterized by G.8032 Request/Status (4bits) – "1011" = SF | "0000" = NR | Other = Future Status – RB (1bit) – Set when RPL is blocked (utilized by RPL Owner in NR) Status – DNF (1bit) – Set when FDB Flush is a bit much (Future) NodeID (6octets) – MAC address of message source hub (Informational) Reserved1 (4bits) , Status Reserved (6bits) , Reserved2 (24octets) - Future advancement

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Items Under Study G.8032 is right now an underlying suggestion that will keep on being upgraded. The accompanying themes are under review for future forms of the suggestion: Interconnected rings situations: shared hub, shared connections RPL obstructed at both closures – design of the ring where both hubs associated with the RPL control the insurance system Support for Manual Switch – authoritative choice to shut down a connection and constrain a "recuperation" circumstance are fundamental for system upkeep Support for Signal Degrade situations – SD circumstances require extraordinary thought for any security component Non-revertive mode– Allows the system to stay in "recuperation" arrangement either until another flag disappointment or regulatory exchanging RPL Displacement – Displacement of the part of the RPL to another ring join adaptably in the typical (sit out of gear) condition top to bottom examination of various enhancements (e.g., FDB flushing) Etc.

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Thank You

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Backup

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Robustness: Source Steering Protection Failure 50ms Switch Times Connectivity: Unicast, MC and BC Data Transfers Unicast Flow Multicast Flow G.8032 Basic Functions

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ERP Functionality Decomposition Inputs – Local hub demands, ETH signals, R-APS messages, WTR Timer . Channels – Local Priority Logic, Validity Check, Guard Timer, Priority Logic – ensure that most astounding need message touches base for handling. ERP Processing – R-APS Request Processing – forms separated message as per State Machine with information of current state and RPL-Owner sign Outputs – Node capacities (FDB Flushing, Block/Unblock port), sending (or halting) R-APS messages

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State Machine Three hub states – Initialization – when first characterizing the ring An (Idle) – the "ordinary" condition of the ring hubs with RPL blocked and all hubs/ports working B (Protecting) – when assurance exchanging is in actuality, RPL unblocked, other (typically blame) connection is blocked. Distinctive information messages allocated need as shows up in the State Machine depiction. Need system to permit appropriate response to issues State Machine portrays the moves to be made by the hub reliant on current state and information message. Just message with most elevated need will go through the separating. Diverse activities incorporate – transmission of R-APS message, blocking/unblocking a port, flushing the FDB, exchanging current condition of hub, and beginning/ceasing clocks.

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State Machine FDB flushing will clear the greater part of the scholarly separating rules inside the hub. Current Recommendation incorporates essential advancement – just flushing once on blame revelation and once on recuperation. DNF status banner is for future definition

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Switching Triggers Detection/Clearing of SF (Signal Fail): SF: Loss of CCM, SF flag left behind from fundamental (sub)layer Switching is performed when hold-off clock lapses after recognition of SF. Administrator's ask for: Lockout, Forced switch, Manual switch, Clear (for future detail) Remote ask for: Switching ask for demonstrated in got R-APS data from the other hub.  Protection exchanging calculation depends on needs doled out to all triggers

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Ethernet Rings and the RPL Ethernet hubs associated in a ring topology. Every hub associated with two neighbors by means of connections (E & W ports) Deterministic system topology Avoid circles inside ring by hindering an assigned connection (RPL) Node dependable to control the blocking condition of RPL will be RPL proprietor RPL is unblocked amid insurance state and may return to obstructed amid recuperation RPL

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RPL Owner gets SF message and unblocks its end of RPL connection [row 3] Stable State – SF messages on the ring Further SF messages trigger no further activity [row10] Normal State Failure Occurs Nodes C and D recognize nearby Signal Fail

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