© Ciena Confidential and Proprietary 1 Carrier Ethernet Technology and Standards Update Presented by: Rick Gregory Senior Systems Consulting Engineer May

© Ciena Confidential and Proprietary

1

Carrier Ethernet Technology and Standards Update

Presented by:

Rick Gregory

Senior Systems Consulting Engineer

May 25,2011


2

Carrier Ethernet: Evolution, Defined


3

1973 Metcalfe & Boggs of Xerox PARC invented ALOHA packet-based network access protocol over a wired shared medium

3 Mb/s operation

1982 “The Ethernet Blue Book” Digital, Intel, Xerox (DIX) 10Mb/s operation based on the Xerox PARC concepts

1985 IEEE 802.3 Carrier Sense Multiple Access w/ Collision Detection (CSMA/CD) Formal standards definition, based on “Blue Book”

1999 Gigabit Ethernet standards ratified for use over copper twisted pair; vendorsalso implement fiber optic versions; 1000Base-T

IEEE 802.3ab

2000’s Fiber standards ratified for single and multimode fiber; speeds evolve to 10, 40 and (eventually) 100Gbps

Ethernet Evolution Timeline1970s to today


4

Ethernet Evolution EventsEffect: Carrier Ethernet becomes Leading Transport Technology

Events Effects

International standardizationEthernet is the first global network

access technology

Unrivaled success in enterprise

Access, metro, and wide-area

applications

Large number of component and

equipment manufacturers

Lowest cost per megabit; < 8¢ per

megabit for triple-speed NIC

Mature, transparent layer 2

technologySimple plug-and-play installation

Ethernet over any media…any service over Ethernet


5

Basic Ethernet Bridging (IEEE 802.1D)

A switch builds forwarding table by LEARNING where each station is (relative to

itself) by watching the SA of packets it receives.

A switch builds forwarding table by LEARNING where each station is (relative to

itself) by watching the SA of packets it receives.

Four Important Concepts/Operations (upon switch receipt of a packet):

1. LEARNING: The Source MAC Address (SA) and port number, if not known

2. FORWARDING: Looking up Destination Address (DA) in table and sending to correct port

3. FILTERING: Discarding packets if destination port = receiving port

4. FLOODING: Sending to all other ports if DA is unknown, multicast or broadcast

Address PortABCDEF

122333

Forwarding Table

Unknown DestinationMulticast

Broadcast

Unknown DestinationMulticast

Broadcast


6

Ethernet’s Evolution

10 Mbps, then 100M

Half Duplex

Yes (CSMA/CD)

Entire LAN

None

Bus

Coax

Less Than 30%Due to Collisions

Limited by CSMA/CDPropagation Time

1 Gbps, 10G, 40G, 100G

Full Duplex

No Collisions (Full Duplex)

VLAN Controlled

802.1p

E-LAN, E-Tree, E-Line(Access, Trunks)

UTP, Optical (Access, Trunks)

Approaching 100%

Limited Only byMedia Characteristics

Originally Now

Bandwidth

Transmission

Collisions

Broadcast Domain

Prioritization

Topology

Cabling

Utilization

Distance


7

Standards: Current, Forthcoming, and Direction


8

Scaling Ethernet…beyond 802.1ad (Q-in-Q)

Preferred: “Large” number of customers Reality: One MAC domain for customer and Provider results in large forwarding table size

48-bit MAC address (no ‘prefixing’ as in IP address) Every network switch needs to learn Destination Address (DA) of customer switches

Preferred: Customer Isolation/Transparency Reality: One L2 broadcast domain for customer and provider

Broadcast storms in one customer’s network can affect other customers and provider as well

Preferred: Million+ service instances Reality: Limited VLAN space, i.e., only 4095 (i.e., 212-1)

802.1ad (Q-in-Q) suggested 16million+ instances but forwarding only to same S-tag (4095!)

Preferred: Deterministic behavior for services Reality: “p” bit for priority but no bandwidth guarantee & arbitrary forwarding/backup paths

Data plane dependent on address table, vlan partition, spanning tree, bandwidth contention


9

Ethernet Transport at Layer 2 & 2.5: Approaches to COE VLAN and Stacked VLAN (Q-in-Q) Cross-Connects

Explicit forwarding paths using VLAN based classification. Tunneling via VLAN tag encapsulations and translations. Defined in IEEE 802.1Q and IEEE 802.1ad specifications. Standards completed.

Provider Backbone Bridging (PBB-TE) and Provider Backbone Bridging (PBB)

Explicitly forwarding paths using MAC + VLAN tag. Tunneling via MAC-in-MAC encapsulations. Defined in IEEE 802.1Qay and IEEE 802.1ah specifications. Standards completed.

E-SPRing

Shared Ethernet Ring Topology based Protocol mechanism that delivers sub-50ms in IEEE 802.1Q and IEEE 802.1ad (Q-inQ) Ethernet Networks. Defined in ITU G.8032 specification. Standards completed.

MPLS & VPLS/H-VPLS

Widely deployed in the core, less so in the metro / access. Uses pseudo wire emulation edge-to-edge (PWE3) for Ethernet and multi-service tunneling over IP/MPLS. Can be point-to-point or multi-point (VPLS). Defined in IETF RFC 4364 (formerly 2547bis) and Dry Martini (IETF RFC 2026). Standards completed.

Provider Link State Bridging (PLSB)

Adds a SPB (Shortest Path Bridging) using IS-IS for loop suppression to make Ethernet fit for a distributed mesh and point to multi-point routing system. PBB-TE/PBB along with PLSB can operate side-by-side in the same network infrastructure. PLSB is optimized for Any to Any E-LAN and Point to Multi-Point E-Tree Network Topology Service delivery. Defined in IEEE 802.1aq specification. Standards to be completed. Target completion approximately 2H 2011.

MPLS-TP

Formerly know as T-MPLS (defined by ITU-T). New working group formed in IETF now called MPLS-TP. Transport-centric version of MPLS for carrying Ethernet services based on PWE3 and LSP constructs. Defined in IETF RFC 5654. Standard to be completed. Target completion approximately 1H 2012.


10

What’s Next in Carrier Ethernet ?

802.1ah PBB

802.1ag Fault Management

Y.1731Performance Management

802.1Qay PBB-TE

802.1aq PLSB

Ethernet has steadily evolved to address more robust networking infrastructures

Scalable, Secure Dataplane

Service and Infrastructure CFM Diagnostics

Proactive Performance Management

Traffic Engineered Ethernet Tunnels

Robust L2 Control Plane

G.8032 Ethernet Shared Ring Resiliency


11

CESD Technology and MechanismsOAM And QOS

Ethernet Service Monitoring

March 2010


12

Predictable ResilienceCreate a stable network, that remains stable as it scales

Ciena is the leader in Connection-oriented Ethernet (COE) and provides a range of carrier-class resiliency schemes (RSTP, MPLS, PBB-TE)

COE tunnels (PBB-TE, MPLS-TP (future)) are connection-oriented and traffic engineered

Provides deterministic performance for predicable SLAs

Better resiliency & stability of provider networks

802.1Q/ad domains protected using 802.1w RSTP with 50 ms restoration

PBB-TE domain supporting sub-50 ms protection (via 802.1ag Connectivity

Check Messages)

Design


13

Granular Bandwidth ControlControlled & measurable for predictable QoS

Specific service identification with rich

L1-L2 classification

Segmented bandwidth via a hierarchy of

“virtual ports”

Flexible priority resolution for CoS mapping

Traffic profiles and traffic management at

all levels in the hierarchy

Specify CIR/CBS, EIR/EBS, Color Aware profiles

Allows efficient service upgrades

80/200

30/100

50/100

MAC SA A

Logical Port(e.g. all the client ports of a Business)

Sub-Port(e.g. Dept VLAN range)

Flow Interface (e.g. Combo of TCP/UDP port, IP DSCP, MAC, etc.)

TCP port 80

Voice VLAN

MAC DA B

L2VPN

20/55

10/40

20/0

10/100

20/100

IP SA 192.168.1.23DENY

CIR/EIR

Design

Enhance revenue with Service StratificationEnhance revenue with Service Stratification


14

IETF RFC 5357 TWAMPTwo-Way Active Measurement ProtocolIETF RFC 5357 TWAMPTwo-Way Active Measurement Protocol

ITU-T Y.1731 Ethernet OAMITU-T Y.1731 Ethernet OAM

IEEE 802.1ag CFMConnectivity Fault ManagementIEEE 802.1ag CFMConnectivity Fault Management

IEEE 802.3ah EFMPhysical LinkIEEE 802.3ah EFMPhysical Link

Layer 2 SLA Monitoring & Metrics: Delay, Jitter, Frame Loss

Comprehensive OAMReduce the cost to run the network and keep services profitable

Complete standards-based Operations, Administration, and Maintenance

(OAM) offering provides visibility, manageability, and controls Proactive SLA assurance, rapid fault isolation and minimized downtime

Includes L2 and L3 based performance measurement capability as a way to differentiate services

Enhanced troubleshooting, rapid network discovery

Service Heartbeats, End-to-End & Hop-by-Hop fault detection

Layer 3 SLA Monitoring & Metrics: Delay, JitterLayer 3 SLA Monitoring & Metrics: Delay, Jitter

Operate


15

Technology Options for Packet Transport

Routing, i.e., forward IP packets IP -over- {IPsec, GRE -over-} MPLS IP -over- {IPsec, GRE -over-} IP MPLS -over- L2TPv3 -over- IP Ethernet -over- L2TPv3 -over- IP

Bridging, i.e., forward Ethernet frames based on MAC DA Ethernet -over- Ethernet: PBB Ethernet -over- MPLS: VPWS & VPLS

Switching, i.e., forward of Ethernet frames based on tunnel label Ethernet -over- Ethernet: PBB-TE Ethernet -over- MPLS-TP

Goal: cost-effective, high-performance transport

IP

MPLS (L3)

PBB-TE

MPLS (L2)

MPLS-TP

PBB

Packet transportSubscriber

Management

“Application” “Service”

Management

IP/MPLSService Edge

& Core

Metro access & aggregation


16

Mechanisms to Build the Carrier Grade Enterprise Ethernet Network

• IEEE 802.1Qay Ethernet Tunneling

• Deterministic Service Delivery

• QoS & Traffic Engineering

• Resiliency & Restoration

• Connectivity / Service Checks

• ITU Y.1731 Performance Metrics

• Complete Fault Management

• 802.1ag

• IEEE 802.1ah PBB

(MAC in MAC)

• Secure Customer Separation

• Service/Tunnel Hierarchy

• Reduced Network State

PBB-TE PBB-TE PBB-TE PBB-TE Ethernet Ethernet OAM OAM

Ethernet Ethernet OAM OAM

PBBPBBPBBPBB


17

Performance Monitoringand

Connectivity Fault Management


18

Maturing Ethernet OAM into a Transport Technology

CCM Continuity CheckLBM/LRM LoopbackLTM/LTR Link TraceAIS Alarm Indication SignalRDI Remote Defect IndicationLCK Locked SignalTST Test SignalMCC Maintenance Comms. ChannelVSM/EXM Vendor/Experimental OAM

Performance Management FunctionsFLR Frame Loss RatioFD Frame DelayFDV Frame Delay Variation

Fault Management Functions Y.1731

802.1ag

DiscoveryLink MonitoringRemote Failure DetectRate LimitingRemote Loopback

802.3ah (2005) Link Management Functions

E LMI StatusE-LMI VLAN mappingE-LMI BW AdmissionMEF-ENNIRemote Loopback

MEF UNI and LMI

Y.1731 802.1ag

Traffic Engineering for deterministic bandwidth utilization

Network planning: Bandwidth resources & traffic placement

Performance monitoring & statistics collection

Fault sectionalization & propagation mechanisms

Trace & loopback facilities

Local Link Management

Control plane for automated end-to-end provisioning and resiliency

True Ethernet transport must maintain important functions from the TDM Transport Environment

IEEE 802.1Qay for PBB-TE – Connection Oriented Ethernet

IEEE 802.3ah EFM defines link level diagnostics and OAM

ITU Y.1731 “OAM functions and mechanisms for Ethernet based networks”

IEEE 802.1ag “Connectivity Fault Management”, a subset of Y.1731

MEF10 and Y.1731 describe Packet PM

MEF16 describes Ethernet-Local Management Interface (LMI)

ITU G.8031 “Ethernet Protection Switching”

draft-fedyk-gmpls-ethernet-PBB-TE-01.txt for Control Plane

A Partial List of Completed and Evolving Standards


19

PBB / PBB-TE management 802.1ag Properties

802.1ag has the concept of maintenance levels (hierarchy). This means

that OAM activity at one level can be transparent at a different level.

802.1ag has clear address and level information in every frame. When

one looks at an 802.1ag frame, one knows exactly

Where it originated from (SA MAC)

Where is it going (DA MAC)

Which maintenance level is it

What action/functionality does this frame represent.

Design Inherently address the OAM aspects for MP2MP connectivity

(e.g. VLANs)


20

The New Ethernet OAM

Continuity Check (Fault)Multicast/unidirectional heartbeat

Loopback – (MEP/MIP Fault Connectivity)Unicast bi-directional request/response

Traceroute (MEP/MIP Link Trace - Isolation)

Trace nodes in path to a specified target

DiscoveryService (e.g. all PEs supporting common service instance)Network (e.g. all devices common to a domain)

Performance MonitoringFrame DelayFrame Delay VariationFrame Loss

EdgeSwitch

EdgeSwitch

TransitSwitch

Adapt Adapt

NNILink

NNILink

UNILink

UNILink

Link OAM

Trunk OAM

Service OAM (SID)

customer demarcs

Link OAM Link OAM

Trunk

802.1ag

802.1ag

Service

Standards-based IEEE 802.1ag and ITU Y.1731802.1ag Maintenance levels/hierarchy

Conceptually:-monitor the trunk or the service… or both

Built-in and on-switch

MEP MEPMIP

Maintenance End Point = MEPMaintenance Intermediate Point = MIP


21

Carrier Ethernet Technology and Standards Update

PBB/PBB-TE/E-SPRing G.8032/PLSB and

MPLS/VPLS/HVPLS/MPLS-TP

Presented by:

Rick Gregory

Senior Systems Consulting Engineer

May 25,2011


22

Provider Backbone Bridging (PBB)

IEEE 802.1ah


23

Provider Backbone Bridge Introduction

IEEE 802.1ah is the Provider Backbone Bridge standard

Also known as Mac In Mac (MiM) encapsulation

PBB solves several of today’s Ethernet challenges

Service Scalability – up to 16 millions VPNs

Customer Segregation – Overlapping VLANs supported

MAC Explosion – Customer MAC addresses only learned at edge

Security – Customer BPDUs are transparently switchedSADA

Payload

S-VC-VID

B-SAB-DAB-VID

802.1ahProvider BackboneBridges

I-SID


24

Ethernet Frames…Before and After

DASA

Payload

DASA

Payload

VID

DASA

Payload

S-VID

C-VID

DASA

Payload

802.1basic

802.1Qtagged VLAN

SA = Source MAC addressDA = Destination MAC addressVID = VLAN IDC-VID = Customer VIDS-VID = Service VIDI-SID = Service IDB-VID = Backbone VIDB-DA = Backbone DAB-SA = Backbone SA

I-SID

Ethertype Ethertype

Ethertype

Ethertype

Ethertype

Ethertype

S-VID

C-VID

Ethertype

Ethertype

Ethertype

B-DAB-SA

B-VIDEthertype

Ethertype

802.1adQinQ

Provider Bridge

802.1ahMACinMAC

PBB

Pre-existing (unchanged)

New (backbone)


25

802.1ah PBB Encapsulation Header as used by PBB-TE

Backbone Destination MAC

address

Backbone Source MAC

address

PCP

DEI

RE

S1

RE

S2I-SID

Service Ethertype 0x88C8

B-TAGTunnel

Ethertype 0x88A8

I-TAGB-SA MACB-DA MAC

B-VID PCP

DEI

Field Size Value

Backbone-DA 6 bytes Tunnel destination MAC address. This must be a Unicast address only. Multicast MAC addresses are not allowed to be specified for this field.

Backbone-SA 6 bytes Tunnel source MAC address used to identify this node in the network.

B-TAG Ether-type 2 bytes 0x88A8 (default)

B-VID 12 bits Tunnel VID (802.1Q compliant).

B-TAG DEI 1 bit Drop Eligibility Indicator: 1=Drop eligible, 0=Not drop eligible

B-TAG PCP 3 bits Tunnel Priority Code Point (0-7)

I-SID 24 bits Service identifier (1 – 16 million)

I-TAG Ether-type 2 bytes 0x88C8 (default)

RES1 2 bits Don’t care

RES2 2 bits Don’t care

I-TAG DEI 1 bit Drop Eligibility Indicator: 1=Drop eligible, 0=Not drop eligible

I-TAG PCP 3 bits Service Priority Code Point (0-7)

DA

SA

58 Bit Tunnel Address


26

PBB: Solving Current Ethernet Challenges

Ethernet Challenges:

Service Scalability

Customer Segregation

MAC explosions, Broadcast Storms

Learning, Forwarding, Flooding Control

Overlapping V-LANs supported

Up to 16 million service instances using 24 bit

service ID ISID

Customer MAC is completely separate from

Backbone MAC

Stops MAC Explosions and Broadcast Storms at MAC-in-MAC Demarcation Point

Architected to build E-LAN, E-Tree and E-Line services


27

Provider Backbone BridgingWith Traffic Engineering

(PBB-TE)IEEE 802.1Qay


28

PBB-TE (IEEE 802.1Qay)

MPLS ServicesMPLS Services(RFC 2547 VPN, PWs etc.)(RFC 2547 VPN, PWs etc.)

Ethernet ServicesEthernet Services(EVPL, ELAN, ELINE, Multicast)(EVPL, ELAN, ELINE, Multicast)

> Keep existing Ethernet, MPLS…FR/ATM…ANY & ALL services

> Capitalize on Ethernet as transport for significant savings

> Existing network-friendly solution!

PBB-TEPBB-TE


29

P2P traffic engineered trunks based on existing Ethernet forwarding principles Reuses existing Ethernet forwarding plane

Simple L2 networking technology Tunnels can be engineered for diversity, resiliency or load spreading 50 ms recovery with fast IEEE 802.1ag CFM OAM

Ethernet Metro

Traffic engineered PBB-TE trunks

E-LINE

PBB

E-LINE

PBB

PBB-TE


30

PBB-TE Solving Current Ethernet Challenges

Ethernet Challenges:

Customer Segregation

Traffic engineering

Spanning Tree challenges: Stranded bandwidth Poor convergence

MAC explosions

Security

Full segregation in P2P model

End to End TE With QoS & 50 ms recovery

Disable STP No blocked links Fast 802.1ag convergence

MAC Explosions Eliminated

Backbone MAC is Completely

Different Than Customer MAC


31

Provider Link State Bridging (PLSB)

IEEE 802.1aq


32

Introducing….PLSB

PBB-TE is a trivial change to the Ethernet dataplane that has huge Benefits

Explicit enforcement of configured operation

Ability to have non STP based VLANs

Similarly PLSB requires a further trivial change with huge Benefits

Adding loop suppression to make Ethernet fit for a distributed routing system

PBB-TE, PLSB and existing Ethernet control protocols can operate side-by-

side in the same network infrastructure

Consequence of ability to virtualize many network behaviors on a common Ethernet base….


33

PLSB Approach

If Ethernet is going to be there….use it!

Take advantage of Ethernet’s more capable data plane

Virtual partitions (VLANS), scalable multicast, comprehensive OAM

PLSB uses a Single (1) Link State Control Plane protocol – IS-IS

IS-IS topology and service info (B-MAC and I-SID information)

Integrate service discovery into the control plane

PLSB nodes use link state information to construct unicast and per service (or I-SID) multicast connectivity

Combines well-known networking protocol with well-known data plane to build an efficient service infrastructure


34

VPLS Operation

Signal PWEsN2 manual session creation

Required for Auto-DiscoverySeparate RR topologies (to help scale)

Eases burden of statically managing VSI PWE’s

Base LDPs: build LSP tunnels

Redundant to IGP (same paths)

Base IGP: TopologyRequired for network topology knowledge

Physical LinksLink layer headers striped off, label

lookup per node

IGP (IS-IS or OSPF)

LDP or RSVP-TE

E-LDP

SONET, SDH, Ethernet, etc…

BGP-AD

Tu

nn

el

LS

P P

roto

co

lsV

PN

Pro

toc

ols

Typical VPLS Implementation:

VPLS CONTROL PLANE


35

PLSB Operation

PLSB (IS-IS)

Ethernet

One IGP for Topology & Discovery

-One protocol now provides - Auto-discovery- Fast fault detection- Network healing - Shortest path bridging- Intra-AS only Link State Protocol- Dijkstra's algorithm for best path- No VSI awareness required at Edge- Once Standardized Ciena could deploy- Own I.P. from MEN acquisition- Target IEEE 802.1aq Ratification 2H 2011

Physical Links: - Link layer headers reused as a label lookup through every node

Tu

nn

el +

VP

N P

roto

cols

PLSB Implementation:

Minimizing control plane = Minimized complexity = Reduced cost


36

PPB/PBB-TE and PLSB Delivers

CESD

E-LANAny to Any

E-TREEPoint to Multi-Point

E-LINEPoint to Point

CESD

CESD

Characteristics:PLSB – 200-500ms resiliencyPBB-TE – 50ms resiliencyOptimized per service multicastFeature Rich OAMSLA and Service MonitoringLatency MonitoringNo Spanning Tree Protocol

Value:Simplest Operations ModelLess Overhead and Network LayeringMost Cost Effective EquipmentEfficient Restoration


37

Ethernet Shared Ring(E-SPRing)ITU G.8032


38

G.8032 Objectives and Principles

Use of standard 802 MAC and OAM frames around the ring. Uses standard 802.1Q (and amended Q bridges), but with xSTP disabled.

Ring nodes supports standard FDB MAC learning, forwarding, flush behaviour and port blocking/unblocking mechanisms.

Prevents loops within the ring by blocking one of the links (either a pre-determined link or a failed link).

Monitoring of the ETH layer for discovery and identification of Signal Failure (SF) conditions.

Protection and recovery switching within 50 ms for typical rings.

Total communication for the protection mechanism should consume a very small percentage of total available bandwidth.


39

ITU G.8032 Ethernet Ringsa.k.a. E-SPRing (Ethernet Shared Protection Rings)

Deterministic 50ms Protection

Switching

Fault

E-Line, E-LAN, E-Tree

Full service compatibility

Grow ring diameter, nodes,

bandwidth

E-SPRing Values• Efficient connectivity (P2P, multipoint, multicast)• Rapid service restoration (<50 msecs)• Server layer technology agnostic (runs over Ethernet, OTN, SONET/SDH, etc…)• Client layer technology agnostic (802.1 (Q, PB, PBB, PBB-TE), IP/MPLS, L3VPN, etc…)• Fully Standardized (ITU-T SG15/Q9 G.8032)• Scales to a large number of nodes and high bandwidth links (GE, 10G, 40G, 100G)

Multi-Layer Aggregation with

Dual Homing

SubRing

SubRing

SubRing

MajorRing


40

CONTROL PLANE

FORWARDING PLANE

MANAGEMENT PLANE

NETWORKINGCiena PORTFOLIO

SCALABLE

STANDARDIZEDSTANDARDIZED

The Ciena G.8032 SolutionThe Ciena G.8032 Solution

CONTROL PLANE• Sub-50ms protection for E-LINE,

E-TREE, and E-LAN services• Guarantees loop freeness with

prevention of frame duplication and reorder service delivery

FORWARDING PLANE• Utilizes existing IEEE defined

Bridging and IEEE 802.3 MAC• Supports IEEE 802.1Q, 802.1ad,

and 802.1ah

MANAGEMENT PLANE• Ciena G.8032 solution MIB• Generic Information Model• Supports Ethernet OAM (802.1ag,

Y.1731) fault and performance management

• Operator commands (e.g., manual/force switch, DNR, etc.)

NETWORKING• Dedicated rings• Ring interconnect via shared node

and dual node• Dual-homed support to provider

network technologies (e.g., PB, PBB, PBB-TE, MPLS, etc.)

Ciena PORTFOLIO• Carrier Ethernet: 318x, 3190,

3911, 3916, 3920, 3930, 3931, 3940, 3960, 5140, 5150

• Transport: OME 6500, OM 5K, OME 6110/6130/6150

SCALABLE• Physical/server layer agnostic• Supports heterogeneous rings• Leverages Ethernet BW, cost, and

time-to-market curve (1GbE10GbE40GbE100GbE)

STANDARDIZED• ITU-T Q9/15 G.8032 (ERP)• IEEE 802.3 MAC• IEEE 802.1Q, 802.1ad, 802.1ah• Ethernet OAM IEEE 8021.ag• Ethernet OAM ITU-T Y.1731

STANDARDIZED• ITU-T Q9/15 G.8032 (ERP)• IEEE 802.3 MAC• IEEE 802.1Q, 802.1ad, 802.1ah• Ethernet OAM IEEE 8021.ag• Ethernet OAM ITU-T Y.1731


41

Example G.8032 Network ApplicationsWireless BackhaulWireless Backhaul

Business Services - AccessBusiness Services - Access

Business Services – Private BuildBusiness Services – Private Build

Business Services – DSL Business Services – DSL AggregationAggregation

CO

Metro Packet TransportMetro Packet Transport

N x T1/E1s

Ethernet

DataData

VoicVoicee

BSC

RNC

Metro/CollectorMetro/CollectorG.8032G.8032

Metro/CollectorMetro/CollectorG.8032G.8032

AccessAccessG.8032G.8032

Metro Packet Metro Packet TransportTransport

Other Core TechnologyOther Core TechnologyDataData

VoicVoicee

BSC

RNC


HQMetro Packet Metro Packet

TransportTransport

Metro/ Metro/ CollectorCollectorG.8032G.8032

Metro/ Metro/ CollectorCollectorG.8032G.8032


Metro Packet Metro Packet TransportTransport

Other Core TechnologyOther Core Technology

DataData

PSTNPSTN

HQ

DataData

PSTNPSTN

PBXEthernet

T1/E1s

Branch Office #1

PBX

Ethernet

T1/E1s

Branch Office #2

PBX

Ethernet

T1/E1s

Branch Office #3

PBX

Ethernet

T1/E1s

PBX

T1/E1s

Ethernet

Branch Office #1

PBX

Ethernet

T1/E1s

Branch Office #2

Branch Office #3

HQ

StandaloneStandaloneG.8032G.8032

DataData

PSTNPSTN

Ethernet

StandaloneStandaloneG.8032G.8032

LAG

MetroCore

Ethernet

EthernetEthernet


42

General G.8032 Concepts


43

Channel Block Function

A B

C

DE

F

Blocking Port

What is a Channel Block?

A Channel block can be an ingress/egress rule

placed on a G.8032 node port

The Channel block rule specifies that any traffic

with a VID received over this port within a given

VID space should be discarded

NOTE: The Channel block function prevents

traffic from being forwarded by the G.8032 node,

however, it does not prevent traffic from being

received by Higher Layer Entities (e.g., G.8032

Engine) on that node

Each G.8032 ringlet needs at least a single

channel block installed


44

Ringlet 2

Ringlet 1

What is a Ringlet (a.k.a. Virtual Ring)?

A Ringlet is a group of traffic flows over the

ring that share a common provisioned channel

block

NOTE: It is assumed that each traffic flow has a

VLAN associated with it

The traffic flows within a Ringlet is composed

of

A single ringlet control VID (R-APS VID)

A set of traffic VIDs

A group of traffic flows over the ring can be

identified by a set of VIDs

Multiple Ringlets on a given Ring can not have

overlapping VID space


45

R-APS messages

a) Normal configuration b) Ring span failure occurs

c) LOS detectedd) Port blocking appliede) APS message issued

f) R-APS causes forwarding database flushg) Ring block removed

1

43

2A B

C

DE

F

A B

C

DE

F

A B

C

DE

F

A B

C

DE

F

R-APS messages

A

G.8032 E-SPRing Failure/Restoration

Please view in animation mode


46

AA

EE DD

CC

BB

FF

14.Normal configuration

Rec

ove

ry E

ven

tsR

eco

very

Eve

nts

V

VIII

VI

AA

EE DD

CC

BB

FF R-APS(NR,RB)

11. When WTR expires, RPL block installed, Tx R-APS(NR,RB)12. Nodes flush FDB when Rx R-APS(NR,RB)13. Nodes remove port block when Rx R-APS(NR,RB)

VII

AA

EE DD

CC

BB

FF

10.When RPL owner Rx R-APS(NR), it starts WTR timer.

WTR

R-APS(NR)

8. Ring span recovery detected9. Tx R-APS(NR) and start Guard Timer

AA

EE DD

CC

BB

FF

Guard TimerGuard Timer

R-APS(NR)


47

G.8032 Product Specifications


48

G.8032 E-Spring Interconnectionsa

dc

b

Dual HomingDual Homing

e

Phase 1Standalone Ring

Phase 2Dual-Homed Ring

E-SPRing E-SPRing1 E-SPRing2

Phase 1Standalone Rings, LAG interconnect

Phase 2Dual-Homed

Rings (Major and Minor rings)

E-SPRing2E-SPRing1

E-SPRing

E-SPRing1 E-SPRing2

Phase 1If each ring is

different Virtual Switch


49

GG

EE JJ

II

HH

FFAA

CC DD

EE

FF

BB Sub-Sub-RingletRinglet

Major-Major-RingletRinglet

GG

EE JJ

II

HH

FFAA

CC DD

EE

FF

BB Sub-Sub-RingletRinglet

Major-Major-RingletRinglet

Data Path example Control Path example

Phase 2 AvailabilityDual-Homed Rings (Major and Minor rings) are not supported in SAOS 6.8Chaining Rings and R-APS Protocol

There can be only one R-APS session running for a given VID Group on a ring span.

Major-Ringlets and Sub-Ringlets are used to chain rings.

On a Sub-Ringlet, the provisioned block for the data path is at the RPL owner (or on each side of a link fault), and the control path ALWAYS has its blocks where the Sub-Ringlet is open.


50

G.8032 Terms and Concepts Ring Protection Link (RPL) – Link designated by mechanism that is blocked during

Idle state to prevent loop on Bridged ring

RPL Owner – Node connected to RPL that blocks traffic on RPL during Idle state

and unblocks during Protected state

Link Monitoring – Links of ring are monitored using standard ETH CC OAM

messages (CFM)

Signal Fail (SF) – Signal Fail is declared when ETH trail signal fail condition is

detected

No Request (NR) – No Request is declared when there are no outstanding

conditions (e.g., SF, etc.) on the node

Ring APS (R-APS) Messages – Protocol messages defined in Y.1731 and G.8032

Automatic Protection Switching (APS) Channel - Ring-wide VLAN used exclusively

for transmission of OAM messages including R-APS messages


51

A. Physical topology has all nodes

connected in a ring

B. ERP guarantees lack of loop by blocking

the RPL (link between 6 & 1 in figure)

C. Logical topology has all nodes

connected without a loop.

D. Each link is monitored by its two

adjacent nodes using ETH CC OAM

messages

E. Signal Failure as defined in Y.1731, is

trigger to ring protection

Loss of Continuity

Server layer failure (e.g. Phy Link Down)

RPL Owner

RPL

ETH-CC

ETH-CC

ETH-CC

ETH-CC

ETH-CC

ETH-CC

ETH-CC

ETH-CC

ET

H-C

C

ET

H-C

C

ET

H-C

C

ET

H-C

C

Physical topology

Logical topology

12 6

43 5

RPL

12 6

43 5

Ring Idle State


52

Protection Switching Link Failure

A. Link/node failure is detected by

the nodes adjacent to the failure.

B. The nodes adjacent to the failure,

block the failed link and report

this failure to the ring using R-

APS (SF) message

C. R-APS (SF) message triggers

RPL Owner unblocks the RPL

All nodes perform FDB flushing

D. Ring is in protection state

E. All nodes remain connected in

the logical topology.

Physical topology

Logical topology

12 6

43 5

RPL12 6

43 5

RPL

12 6

43 5

12 6

43 5

RPL Owner

RPL

R-APS(SF) R-APS(SF)

R-APS(SF)

R-A

PS

(SF

)


53

Protection Switching Failure Recovery

A. When the failed link recovers, the traffic is kept blocked on the nodes adjacent to the recovered link

B. The nodes adjacent to the recovered link transmit R-APS(NR) message indicating they have no local request present

C. When the RPL Owner receives R-APS(NR) message it Starts WTR timer

D. Once WTR timer expires, RPL Owner blocks RPL and transmits R-APS (NR, RB) message

E. Nodes receiving the message – perform a FDB Flush and unblock their previously blocked ports

F. Ring is now returned to Idle state

RPL Owner

RPL

R-APS(NR) R-APS(NR)

R-APS(NR)

R-A

PS

(NR

)

R-APS(NR, RB)

R-A

PS

(NR

, RB

)

Physical topology

Logical topology

12 6

43 5

RPL

12 6

43 5

12 6

43 5

RPL

12 6

43 5


54

Multi Protocol Label Switching

(Layer 3 IETF RFC 4364 / aka 2547bis)(Layer 2 IETF RFC 2026 / Dry Martini)(Layer 2 IETF RFC 5654 / MPLS-TP)

(MPLS/VPLS or PBB/PBB-TE)


55

Ethernet Access – Network Choices

Legacy Ethernet (No MEF compliance)

Carrier Class Ethernet (MEF compliance)

1. Connection-less Ethernet 802.1Q or 802.1ad or 802.1ah: VLANs

2. Connection Oriented Ethernet 802.1Qay (PBB-TE): VLANs MPLS-TP: Traffic Engineered PWs over LSP

3. IP control plane based IP or MPLS VPNs IP VPN: Ethernet over L2TPv3 over IP MPLS VPN: Ethernet PW or VLAN over LSP


56

MPLS vs. Ethernet– Data Plane (+OAM)

MPLS metro network

L3 (IP/MPLS): terminate Ethernet & forward IP frames over IP PW in MPLS LSP over Ethernet port

L2 (VPLS/VPWS, MPLS-TP): forward Ethernet frames over Ethernet PW in MPLS LSP over Ethernet port

Multiple, varied data planes: IP, PW, LSP, Ethernet

complex hw/sw interactions resulting in higher cost1

complex OAM

MPLS-TP LSP OAM yet to be defined

Ethernet (PBB-TE) metro network

L2: forward Ethernet frames over Ethernet EVCs over Ethernet port

Fewer data planes and OAM levels – Ethernet Service and Network/Link

Simpler hw/sw for >40% lower cost2

IP awareness for dataplane behavior but no need for OAM at IP layer

Less complex OAM using 802.1ag and Y.1731 for Ethernet service and network/tunnel layers

Ethernet (PB, PBB) can enable Pt-Mpt and Mpt-Mpt, in addition to Pt-Pt

Data PlaneService

Network

Complex

IP, EthernetPWLSP

Ethernet


Management


Management

IP/MPLSService Edge

& Core


Simpler

IP, EthernetVLAN (EVC)

Ethernet

1 Reid, Willis, Hawkins, Bilton (BT), IEEE Communications Magazine, Sep 20082 (40-60% less) McKinsey & Co., Jan 2008; (40% less) CIMI Corp, Jul 2008


57

MPLS vs. Ethernet– Control Plane (+OAM)

MPLS metro network

Complex link-by-link label swapping – inherent source of unreliability1

Complex L3 control plane for PW/LSP signaling/routing (& PW stitching at core edge)

PW/LSP labels: LDP or BGP

LSP setup: RSVP-TE (signaling), OSPF-TE (routing)

MPLS-TP can avoid L3 control plane; use complex NMS-based link-by-link LSP config instead

Complex protocol couplings resulting in processing complexity and higher opex3

Ethernet (PBB-TE) metro network

Complete, global Ethernet header

BEB’s SA/DA+BVID for tunnel

No label switched path setup needed

E2E visibility, connectivity verification

Simpler L2 control plane for discovery only

No distributed routing/signaling needed

Metro hub-&-spoke (vs. core mesh) affords explicit failure mode config4

<=9 such modes in large metro

12% lower opex (future: up to 44%)4

Simpler OAM: reliable & lower opex1,3

3 Seery, Dunphy, Ovum-RHK, Dec 20064 CIMI Corp., Netwatcher newsletter, Jul 2008

Ethernet provides just enough control & data plane functionality to meet all service needs while containing cost and complexity


Management


Management

IP/MPLSService Edge

& Core



58

PBB/PBB-TE or VPLS/MPLS?

Light Reading webinar: PBB-TE’s Winning Wayshttp://www.lightreading.com/webinar_archive.asp?doc_id=28511

Light Reading webinar: Building Converged Services Infrastructurehttp://www.lightreading.com/webinar_archive.asp?doc_id=28415

Light Reading webinar: Building Converged Services Infrastructurehttp://www.lightreading.com/webinar_archive.asp?doc_id=28415

PBB-TE perceived to offer cost advantages

CO-Ethernet is one option

Ethernet is the new paradigm

Deterministic Transport

with OAM&P

Caution: Unscientific poll results


59

EVC (PW)EVC Q-in-Q or PBB-TE Tunnel

EVC (PW)MPLS LSP

PB/PBB/PBB-TE and MPLS Tunnel Inter-working

Ingress and egress virtual interfaces provide greatest flexibility and interoperability

with existing and emerging technologies

Dual-tag push/pop/swap enables multi-protocol interworking (e.g., PBB-TE, MPLS)

Standard IEEE and popular Cisco-proprietary protocol handling enable robust L2VPNs

Q-in-Q or

PBB/PBB-TE

MPLS H-VPLS

or PBB/TEMEF UNI

Access / Aggregation Metro Core

Q-in-Q or PBB-TE TunnelEVC

Q-in-Q or PBB-TE TunnelEVC

Seamless interworking between PB (Q-in-Q), PBB/PBB-TE and MPLS simplifies the handoff between domains

Dual tag push/pop/swap

IEEE and Cisco proprietary L2 control frame tunneling


60

PBB-TE provides cost-effective robust packet transport, but why not combine that with IP/Ethernet service intelligence on one node?

i.e. IP Routing isn’t deterministic, but it has useful service

layer functions – multicast, differentiated services treatment

Why not use IP/MPLS nodes? IP for services

Multicast

L3 Prioritization

MPLS for services

VPLS: Mpt-Mpt

VPWS: Pt-Pt

MPLS-TP for transport

Pt-Pt

Because Carrier Ethernet Switches are >40% lower cost than IP/MPLS Carrier Ethernet Switch/Routers

(40-60% less) McKinsey & Co., Jan 2008(40% less) CIMI Corp, July 2008

Need a Carrier Ethernet Switch that combines “IP/service-aware” switching while retaining carrier-grade packet transport qualities!


61

Ethernet data planeFunctions PBB-TE / PBB MPLS-TP

Ethernet Aggregation

Native Ethernet (E-o-E) with less overhead. Scalability with 24-bit I-Sid

Same as MPLS.

Need PW & tunnel headers (E-o-PW/LSP-o-E).

Can nest aggregation layers. May help with scaling

Forwarding labels

Unique end-to-end: DA+B-Vid

Scales as # of endpoints (nodes) + service classes, if any.

Same as MPLS.

(tunnel) labels can be per hop or end-to-end

May scale as # of links + service classes, if any. Need coordination across links along a path

Transparency & Isolation

Separate MAC address space (provider/Backbone vs. customer)

MAC learning can be enabled for PBB-TE’s B-vid space

Transparent transport for Ethernet clients

No MAC learning defined but possible

Topology ELINE (Point-Point): Yes

ETREE (Point- Multipoint): Yes

ELAN (Multipoint): Yes

ELINE (Point-Point): : Yes

ETREE (Point- Multipoint): : Yes

ELAN (Multipoint): Needs either Pt-Mpt or full mesh of Pt-Pt LSP tunnels. May use VPLS model but need complex MPLS control plane & also requires either Pt-Mpt or full mesh of Pt-Pt PW’s.

Layering, Partitioning, Hierarchy

Simple: Backbone MAC address space w.r.t. Customer MAC address space

Complex: additional PW/LSP layers. Nested tunnels can introduce OAM/provisioning complexity

Peering MEF’s ENNI and CoS IA are work in progress for service level. IEEE already provides interface and link models

Work in progress. Peering with MPLS network may mean complex MPLS control plane. Also, need PW signaling end-to-end.

“other” services

Adjunct platforms where needed to achieve ATM/FR IW. Possible to use PWs if necessary

PW capability along with protocol zoo for ATM/FR IW


62

Ethernet Management planePBB-TE / PBB MPLS-TP

OAM Reuse 802.1ag/Y1731.

(a) CCM needs to use unicast DA (allowed by

802.1ag and already defined in Y.1731). Also, MIPs

need to intercept if DA is of MIP.

(b) LBM/LBR in most cases, will use same VID in

forward and reverse direction and so no issues.

(c) LTM/LTR is possible if MIPs can intercept/ignore

frames as needed. New TLV with MIP DA to be

defined

Use 802.1ag/Y.1731 for Ethernet EVC

PW/LSP is work in progress

End-to-End

visibility

I-Sid for service (EVC)

DA+B-vid for tunnel

PW/LSP is work in progress

MEG levels Less oam levels: Ethernet customer flow, Ethernet

EVC, operator and transport / link

More oam levels: Ethernet customer flow, Ethernet

EVC, LSP tunnel(s), operator and transport / link

Protection End-to-end (1+1, m:n), IEEE Link Aggregation

G.8031/G.8032

Transport network like using APS for 1+1/m:n

PW and LSP level, span/segment/end-to-end

may use fast re-route if control plane present


63

MPLS Protocols (net-net)

MPLS Requires

IGP+TE

RSVP-TE

FRR

BFD

PWE3 control plane

VPLS control plane

H-VPLS/ MS-PW for scalability

MPLS forwarding plane upgrades

MPLS control plane server cards

MPLS Provides:

Virtually unlimited service scalability

Eliminates MAC table explosions

50 ms resiliency

OAM

Traffic Engineering

Bandwidth guarantees

Increased OPEX

Increased CAPEX

Requires RSVP-TE + FRR everywhere

OAM relies on the control plane

Limited performance monitoring

Requires DS-TE for multiple bandwidth pools

PBB-TE eliminates these protocols


64

PBB/PBB-TE Protocols (net-net) Carrier Ethernet Service Delivery Provides:

Virtually unlimited service scalability

Eliminates MAC table explosions

50 ms resiliency

Service OAM

Traffic Engineering

Bandwidth guarantees

Carrier Ethernet Delivers:

Provider Backbone Bridging

Provider Backbone Bridging with TE

IEEE 802.1ag, ITU Y.1731

Standardized Ethernet forwarding and OAM

No changes to the hardware No huge learning curve Still just forwarding Ethernet Enterprise demands Simplicity

Sub 50 ms recovery with PBB-TE

Deterministic and scalable in-band OAM

Standardized performance monitoring

PBB-TE provides traffic engineering and bandwidth guarantees


65

Positioning Carrier Ethernetto Enterprise Customer


66

Packet Access ComparisonKey aspects Connectionless

Ethernet

IP VPNs MPLS MPLS-TP

(Work In Progress)

PBB/PBB-TE

Interoperability - Ethernet

MEF Ethernet UNI/ENNIMEF Ethernet Services

Interoperability - other

MPLS NNIATM/FR/TDM/MPLS UNI

Transparency

Address & control protocols

Scalability

Network & Services(Pt-Pt & MPt)

Reliability

50-100msec protectionDisjoint Working/Protect

paths

Manageability

Fault sectionalizationService & Network OAM/PM

Deterministic Perf/QoS

Guaranteed rate,

latency/jitter/loss

Low CapEx and OpEx

Need IWF, dry Martini

L3

TBD

L2

FRR

1+1

Need IWF, dry Martini

Connection Oriented Ethernet

Need IWF (L2TP, GRE)

Need IWF (L2TP, GRE)

TBD


67

Positioning Carrier Ethernet to EnterpriseVPLS/H-VPLS/MPLS

1. Multiple VPN & Tunneling Control Plane Protocols

2. Optimized for Large Carrier Customers with MPLS backbone and IP/MPLS knowledgeable and

trained Engineering Staff

3. Requires Extensive Engineering

4. 2 to 3 9s SLAs Ethernet Service Delivery

5. Second/s to Sub-second Restoration (R-STP/FRR)

6. Q-in-Q Stacked VLANs 4096 maximum

7. High priced MPLS HW and SW based Routers

8. Requires strong L3/IP/MPLS Knowledge/Config

9. Locked into a Vendor’s MPLS Products/Solution

10. Desire to fill unused capacity

11. Higher % sales of L3VPN

12. Solving core not aggregation

13. Desire protocols to provision

14. Techs trained for L3/IP config

15. Difficult to deploy @ customer

1. Field techs not trained

2. Higher $$$ CPE

3. More complex configuration

PBB/PBB-TE/E-SPRing1. PBB-TE/PBB/E-SPRing Forwarding Plane Only

2. Optimized for Enterprise Customers looking to minimize OPEX and

CAPEX spend (low cost plug & play Network)

3. CCIE type skills Not Required (+ Ethernet and SONET knowledgeable

Engineers Get it !)

4. Need to Lease Fiber (Typically unless you already own)

5. High Reliability, Resiliency, Scalability, and Simplicity

6. 4 to 5 9s SLAs Ethernet Service Delivery

7. Sub 50ms Protection Switching / Restoration (IEEE 802.1ag)

8. Ethernet is the single End to End Protocol Language Spoken

9. Excellent OAM (Y.1731 and 802.1ag) – Jitter/Latency

10. Stop MAC/VLAN explosions and Broadcast Storms (Separate MAC Tables

– Customer LAN & Backbone)

11. Minimizes MAC Learning and Distribution/Forwarding (True MAC learning

Demarcation between LAN and MAN/WAN)

12. 16 Million VPNs (IEEE 802.1ah Mac-in-Mac), PBB only

13. Low CAPEX and OPEX Economics

14. SONET Like Skill sets to Configure and Manage Network

15. Ethernet Open Standards – 3rd Party Vendor Interop benefits

16. Transport over GE Microwave


68

Carrier Ethernet Service DeliverySummary

Increased Simplicity with universally acknowledgeable Ethernet MAC

• Ethernet MAC is the single End to End Protocol Language (No Multi-Protocol Translation, Ethernet only)

Improved Reliability with IEEE 802.1ag

• Sub 50ms Protection Switching / Restoration (IEEE 802.1ag Network Continuity Message that is tunable)

QoS (Quality of Service) without Control Plane Complexity with IEEE 802.1Qay PBB-TE

• Traffic engineered tunnels with B-MAC’s B-VID pcp (p-bit) Classification Prioritization

Superior OAM with IEEE 802.1ag and ITU Y.1731

• Monitor Performance End to End (Varying Delay-Jitter/Delay-Latency/Loss) in and out of Network at Layer 2

• Loop Back Message / Link Trace Message (SONET like) Loopback troubleshoot testing on Ethernet

Enhanced Network Control applying IEEE 802.1ah MACinMAC Backbone

• Stop MAC/VLAN explosions and Broadcast Storms

• Minimize MAC Learning and MAC Distribution (Separate MAC Demarc between LAN and MAN/WAN)

Massive Scalability with IEEE 802.1ah MACinMAC Backbone Frames

• 24 bit ISID delivers 16 Million VPNs (IEEE 802.1ah Mac-in-Mac)

• Only learns and forwards based on Backbone MAC Addresses (LAN MAC learning stays in the LAN)

Lower OPEX and CAPEX plus Open Standards inter-operability benefits

• Lower OPEX, SONET and/or Ethernet Engineering Skill sets/experience to Configure and Manage Network

• Lower CAPEX, Open to inter-operate with “any” 3rd Party Ethernet Products, Ethernet Price Points

Key Message to Customer

• Ethernet Switch Where You Can

• IP/MPLS Route Where You Must


69

Carrier Ethernet Service Delivery Value Proposition

1. Scalable Eliminate control plane restrictions Deployable on Optical and Broadband NEs

2. Operationally Sound, Easier to Troubleshoot Better OAM tools: 802.1ag vs. VCCV/LSP-PING Fewer Moving Parts: No IGP, MPLS signaling etc. Consistent Operations Model with PMO Easier transition of workforce Consistent use of Metro OSS systems

3. Number # 1 with 20% Market Share in the Layer 2 CEAD Ethernet over Fiber Market, “Light Reading July 14, 2010 www.lightreading.com/document.asp?doc_id=194390

4. SLA / Performance Measurement Built In Simplified Network Layering Ethernet is the faceplate and network layer

5. Lower CAPEX Ethernet based infrastructure that rides Ethernet cost curves


70

Thank you !

(Q & A)


71

G.8032 Terms and Concepts

Ring Protection Link (RPL) – Link designated by mechanism that is blocked

during Idle state to prevent loop on Bridged ring

RPL Owner – Node connected to RPL that blocks traffic on RPL during Idle state

and unblocks during Protected state

Link Monitoring – Links of ring are monitored using standard ETH CC OAM

messages (CFM)

Signal Fail (SF) – Signal Fail is declared when ETH trail signal fail condition is

detected

No Request (NR) – No Request is declared when there are no outstanding

conditions (e.g., SF, etc.) on the node

Ring APS (R-APS) Messages – Protocol messages defined in Y.1731 and G.8032

Automatic Protection Switching (APS) Channel - Ring-wide VLAN used exclusively

for transmission of OAM messages including R-APS messages


72

G.8032 Timers

G.8032 specifies the use of different timers to avoid

race conditions and unnecessary switching

operations

WTR (Wait to Restore) Timer – Used by the RPL Owner to verify that the ring has stabilized before blocking the RPL after SF Recovery

Hold-off Timers – Used by underlying ETH layer to filter out intermittent link faults

Faults will only be reported to the ring protection mechanism if this timer expires


73

Controlling the Protection Mechanism

Protection switching triggered by

Detection/clearing of Signal Failure (SF) by ETH CC OAM

Remote requests over R-APS channel (Y.1731)

Expiration of G.8032 timers

R-APS requests control the communication and states of the ring nodes

Two basic R-APS messages specified - R-APS(SF) and R-APS(NR)

RPL Owner may modify the R-APS(NR) indicating the RPL is blocked: R-APS(NR,RB)

Ring nodes may be in one of two states

Idle – normal operation, no link/node faults detected in ring

Protecting – Protection switching in effect after identifying a signal fault


74

Signaling Channel Information

ERP uses R-APS messages to manage and coordinate the protection

switching

R-APS defined in Y.1731 - OAM common fields are defined in Y.1731.

Version – ‘00000’ – for this version of Recommendation

OpCode – defined to be 40 in Y.1731

Flags – ‘00000000’ – should be ignored by ERP

1 2 3 4

8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 1

1 MEL Version (0) OpCode (R-APS = 40) Flags (0) TLV Offset (32)

5 R-APS Specific Information (32 octets)

.. …

37 [optional TLV starts here; otherwise End TLV]

last End TLV (0)

Defined by Y.1731 Defined by G.8032 Non-specified content


75

R-APS Specific Information

Specific information (32octets) defined by G.8032

Request/Status(4bits) – ‘1011’ = SF | ’0000’ = NR | Other = Future

Status – RB (1bit) – Set when RPL is blocked (used by RPL Owner in NR)

Status – DNF (1bit) – Set when FDB Flush is not necessary (Future)

NodeID (6octets) – MAC address of message source node (Informational)

Reserved1(4bits), Status Reserved(6bits), Reserved2(24octets) - Future development

1 2 3 4

8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 1

Request /State Reserved 1 Status Node ID (6 octets)

RB

DNF

Status Reserved

(Node ID)

Reserved 2 (24 octets)


76

Items Under Study

G.8032 is currently an initial recommendation that will continue to be enhanced. The following topics are under study for future versions of the recommendation:a) RPL blocked at both ends – configuration of the ring where both nodes

Interconnected rings scenarios: shared node, shared links

b) connected to the RPL control the protection mechanism

c) Support for Manual Switch – administrative decision to close down a link and force a “recovery” situation are necessary for network maintenance

d) Support for Signal Degrade scenarios – SD situations need special consideration for any protection mechanism

e) Non-revertive mode– Allows the network to remain in “recovery” configuration either until a new signal failure or administrative switching

f) RPL Displacement – Displacement of the role of the RPL to another ring link flexibly in the normal (idle) condition

g) In-depth analysis of different optimizations (e.g., FDB flushing)

h) Etc.

Documents

© Ciena Confidential and Proprietary 1 Carrier Ethernet Technology and Standards Update Presented by: Rick Gregory Senior Systems Consulting Engineer May