2008-ciena the shift to ethernet in the wan-wabik

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© Ciena Confidential and Proprietary

The Shift to Ethernet in the WAN

Jeff Wabik

VP, Data Architectures

11 Mar 2008



Ciena Corporate Overview

Philosophy: Create flexible, adaptable, manageable andassured service-selectable networks

Key offerings:

Optical, Ethernet and access networking platforms

Network and service management systems

Global network services and professional services

Founded 1992

HQ in Maryland USA

Cumulative globalmarket leader in longhaul DWDM andIntelligent OpticalSwitching

Over 250 Patents heldwith 100 pending.

Numerous R&D

centers worldwide.Service and supportacross the Americas,EMEA and Asia

Serving the world’slargest and most

advanced service

provider, government,

and enterprise networks

Dynamic wavelength routing

Service interworking

Circuit-to-packet migration

Advanced service-level management

Optical transport & switching

True Carrier Ethernet

OTN-based Networks

Intelligent optical control planeautomation

Programmable network interfaces

Core Competencies:

© Ciena Confidential and Proprietary 2




Outline

Intro and background – The Shift to Ethernet

Addressing Ethernet’s shortcomings -- building blocks for Ethernet

WAN architectures

Summary and Q&A




So what’s going on out there?Market Situation & Requirements

Service & Network Migrations to IP

Substantial increase in network demand from …

New Applications: Triple Play, Ethernet Business Services, Storage Extension, Fixed-

Mobile Convergence, etc ..

Video is the largest driver

Underlying Architectures?

Universal Language: Nearly all end-applications produce/receive “IP” packets

Universal Network: Nearly all LANs are Ethernet-based

Why Ethernet?

Commoditized: Low cost, readily available, universally recognized

Simplicity: Lower technology curve

Scalability and Flexibility of bandwidth (10..10000Mb/sec, plug ‘n’ play compatible)

But this is really about IP. . .

Supporting these IP services between arbitrary global endpoints is the requirement




So should we deploy IP networks?What networks are valid? What questions lead to a network type decision?

Scalability?Management?

Engineered? Connection-based?

Routing? Signaling?Simple?Cheap? Reliable?

Connectionless?Switching?

Bandwidth? Convergence?

Interoperable?

Is “All IP” the right answer?

In some places, IP is required... elsewhere, cost and simplicity goals drive curiosity..




The Migration to one NetworkSimple(r), Cheap(er) Ethernet

Legacy solution was a set of T1s to each customer

Supported by multiple, discrete networks

Not scalable, slow, wasteful

Inefficiencies and high cost

Established Direction is a single Ethernet pipe

Simplicity of a single connection

Scalability and performance of Ethernet

Economics of Ethernet and packets




Simplicity and Cost ReductionEthernet end-to-end

Traditional Telco Network

Copper

Copper

Voice Oriented Connectivity

Carrier Ethernet Network

E-Line and ELAN business services

Ethernet LAN Ethernet LANMetro Ethernet

Aggregation

Regional

Switch/Router

IP or Ethernet

Metro Ethernet

Aggregation

Copper

Local Loop

Routers CSU/DSUs RoutersCSU/DSUs

Copper Copper Copper

Local Loop

Ethernet LAN

ATM

Switch

ATM

Switch

MUX MUX

Telco Central Office

ATM Sonet/SDHATM

Ethernet LAN

Any media

Regional

Switch/Router

Internet

Any media Any media




Ethernet as “The new T1” (actually, the new TDM)

How’s that work?

Ethernet has amazing momentum based upon its price-points

But Ethernet isn’t ready to “replace” TDM just yet ..

“Desktop” connectionless Ethernet does not have strong (or any)

support for security, management, provisioning, resilience, …

These properties are present and robust in traditional TDM

Ethernet, The Next Generation: Connection Oriented Ethernet

Standards bodies are all aflutter defining and honing NG Ethernet

and corollary attributes




Outline

Intro and background – The Shift to Ethernet

Addressing Ethernet’s shortcomings -- building blocks for Ethernet

WAN architectures

Summary and Q&A




Addressing LAN Ethernet Shortcomings(The “several deadly sins” of Ethernet)

1. Scalability

Ethernet LANs designed for 100s or 1000s of stations/users, not 10Ks or “millions”

2. SecurityLAN Ethernet standards assume Ethernet switch ports are all part of the same “domain”, and thatflooding unknown traffic to “all ports” is the proper step. This is unsafe in service-provider networks.

3. OAM / Management

No standardized “service points” to check for “upness”; PM is less voluminous than optical domain.

4. Protection / Redundancy / Reliability

Fail-overs even with {M,R}STP/etc bounded in seconds; no 50 msec end-to-end restoration guarantees

Traditional Ethernet LAN switches not designed for five or 6 nines (99.9999%) carrier-class reliability

5. Traffic Management (QoS)

No standard definition/implementation of end-to-end QoS (even though 802.1P defined CoS bits/levels)

6. Infrastructure Variability

Lack of a consistent standards across transport layer in the WAN is a concern

An all-Ethernet network is not practical/possible;

Access (DSL?), Metro (OTN?), Core (MPLS?)




Scaling Ethernet

Challenges: Scaling Ethernet most often focuses on address spaces issues

VLANS:

By definition, only 4096 per domain.

Source/Destination (SA/DA):

Ethernet addresses are not summarized, hierarchical or “prefixed” like phone numbers inPSTN networks (Country Code-Area Code-Exchange) or addresses in IP networks (X.X.X.X)

Requires large forwarding tables in Ethernet switches with one table entry for each possiblestation

Making carrier switches impossible, expensive, difficult or all-of-the-above to design

Solutions: Tunneling & Encapsulation Methods

VLANS domain: Solved with Q-in-Q encapsulation or Ethernet pseudowires (EoM)

SA/DA domain: Solved with MAC-in-MAC encapsulation or similar abstraction

Each encapsulation has the benefit of making an Ethernet “circuit” (i.e. Connection Oriented) whentraffic engineering paths based on source/dest address




Scaling Ethernet: Q-in-Q Frame Format(Addressed in “Provider Bridges” IEEE 802.1ad)

Q-in-Q Frame

Basic Ethernet Frame

VLAN Frame

12 bits

S-VLAN IDCFI

3 bits

802.1p

The S-VLAN tag looks very

much like the C-VLAN tag:CFI = Canonical Frame

Indicator

• The Q-in-Q Frame adds 4 bytes to the Ethernet frame. The first two bytes are another Protocol Type

• SVLAN = Service Provider VLAN domain; CVLAN = Customer VLAN domain

• Still doesn’t scale sufficiently (same 4K VLAN addresses for the SP)




Scaling Ethernet: MAC-in-MAC Frame Format(Addressed in Provider Backbone Bridges (PBB) IEEE 802.1ah)

VLAN Frame

802.1ad

Q-in-Q

Prio/

DEVers Service Instance ! 24bits

The actual format and size of the fields has not

been finalized yet in the standard.

MAC-in-MAC provides sufficientlyBetter scaling, while reducing the

Requirements for SP switch forwarding

tables

802.1ah




Compare/Contrast COE Methods

PBB-TE/PBT T-MPLS VLAN XC

Origin IEEE Standards track, 802.1ah

and proprietary work

Derivative of IETF MPLS Simple IEEE802.1q switching

What is it? MAC-in-MAC encapsulation

provides addressing domain /

boundary for TE and security;

Enet switching.

20-bit MPLS tag added to

provides addressing domains

and boundaries for TE and

security. MPLS forwarding

Push one or more 802.1q

VLAN tag(s) provides addr

domain / boundary for TE and

security. 802.1q switching.

Pros Based on simple Ethernet,

hence presumed to be

inexpensive

Ahead of PBB in standards,

supports multiple services,

leverages existing MPLS.

Based on very simple

Ethernet, no standards to

evolve, very cheap.Cons Standards are slow.

Addition of management

and control planes may

dramatically increase cost.

No major technical hurdles.

Concerns over underlying

cost of MPLS solutions.

Insufficient address space

to provide necessary scale.

No real management or

control plane planned.

Standards

Process

Standards Underway,

expected 12-24 months.

Tough parts (TE, etc)

standard, others underway

Standardized basics,

defacto COE deployment

Fit Better fit for those who haveL2 religion or existing Enet.

Lower cost.

Better fit for those who haveL3 religion or existing MPLS

Good fit for small, simplenetworks, or those that are

virtually switched.




Securing Ethernet

Definition and Concerns

Securing Ethernet doesn’t (generally) mean “Encryption”, butrather keeping disparate customers’ packets separated

Solution

Various connection methods also help solve these security issues

Q-in-Q, MAC-in-MAC, T-MPLS, etc..

Customer Traffic

hits the node on

separate links

Traffic aggregated

on packet

boundaries on a

shared link

Need to make sure

Customer “A” never

sees Customer “B”

traffic

Customer A

Customer B

Customer A

Customer B

Network




Protection of Ethernet Transport

Protection can be provided for Carrier Ethernet at any or multiple layers. Examples:

Layer 0/1: Optical & TDM Protection mechanisms (OTN, SONET/SDH, etc)

Applicable at any transport network element

Very fast failure recovery/reconvergence times

Interfaces (< 50 msec) or mesh with shared protection bandwidth

Layer 1/2: Ethernet InterfaceProtection

Link Aggregation (802.3ad)

Layer 2+: Ethernet Network Protection

xSTP (Spanning Tree – Multiple Flavors)

Applied to any Ethernet domain in the logical topology, Reconvergence time <=1000 msec




Example Transporting/Protecting Ethernet:OTN – ITU G.709 Digital Wrapper

OTN (ITU G.709 / Digital Wrapper) is theoptical backbone network of the future today.

OTN maps all services into a common set of

wavelengths

Simplifying monitoring, deployment, sparing

and capacity management.

Extends the reach of optics/WDM with fewer

regenerators due to Forword Error Correction

(FEC)

Offers 50ms protection in ring topologies

Enhances Ethernet OAM capabilities

Enables error detection at the optical level




Importance of Ethernet OAM

Reduce Management Complexity

Simplify deployment of Ethernet outside of the LAN

Operational Efficiency

Minimize cost of downtime, avoid truck rolls and reduce Opex

Facilitate Network-independent Ethernet Service DeliveryBlameless handoff between multiple constituent networks belonging

to disparate organizations with different technologies

Monitor and Verify SLA performance

Accurate end-to-end service visibility

OAM expectations have been set by existing WAN solutions

Users want, “Manageability like TDM at the cost of Ethernet ”

Operations

Administration

Maintenance

&

Provisioning

Eth t L

For end-to-end



Ethernet Layer

Service OAM/Management

Is a service operational?

Where is it broken?

Who does it belong to?

Requires excellent visibility into the performance of Ethernet networks

Enable flow-through provisioning of services in network elements

Remotely configure customer equipment

Monitor the connectivity and performance of the service from customer premises to

customer premises

Detect and isolate network problems that impact the service

Enable customers monitor services end to end

Fast association of network events with specific customer service

Guaranteed & measurable SLAs

EoMPLS

EoSDH

EoWDM

EoCopper

EoPON

EoMPLS

EoSDH

EoWDM

EoCopper

EoPON

For end to end

Ethernet…

Required that

Ethernet

supports its

own OAMcapability

Dependency on

another layer’s

OAM is not an

option





Relevant Ethernet OAM Standards“Tools to Enable Better Service Management”

Performance

Management

Fault

Management

Link

Management

802.1ag

Connectivity

Fault

Management

MEF10

Ethernet

Services

Attributes

802.3

(ex. 802.3ah

EFM)

Protection

Switching

Configuration

Management

MEF16

Ethernet LMI

Y.1731

OAM functions and mechanisms

for Ethernet based networks

G.8031

Ethernet

Protection

Switching

Y.ethperf

MEF 17

Service OAM




IEEE 802.3 (Clause 57) – Adjacency OAMPreviously known as 802.3ah “Ethernet in the First Mile”

Consistent link layer OAM for Ethernet supporting Point-to-Pointcommunications between two adjacent devices

Typically used to monitor, test and troubleshoot access links betweenProvider (PE) and Customer (CE) devices

In band OAM PDUs

“Slow” protocol limited to 10

packets per second

OAM Discovery

Discover OAM capabilities onadjacent device

Link Performance Monitoring

Notification of error threshold

events

Remote Failure Indication

Inform a peer that the receive

path is down (like RDI)

Dying gasp, link fault & critical

event

Remote Loopback

Remotely configure adjacent

device into loopback mode for

link test




IEEE 802.1ag – Service OAMConnectivity Fault Management

End-to-end connectivity fault management per Ethernet connectionusing Ethernet frames that are agnostic to underlying infrastructure

Continuity Check (CC)

Periodically exchanged todetect loss of continuity or incorrect connections

“Heart beat” used as trigger for protection switching

Loopback (LB)

Verify bidirectional connectivityexists with another device withina specific domain

Used as an in-/out-of-service

diagnostic toolUnicast support only

Link Trace (LT)

Exchanged with other deviceswithin a domain to identifyadjacency relationships

Used to identify actual path,verify network configuration & toisolate faults

Remote Defect Indication (RDI)

Informs upstream device of downstream failure (e.g.interface failure)

Carried within CC messages




ITU-T Y.1731OAM functions and mechanisms for Ethernet based networks

Superset of functions identified in IEEE 802.1ag

Includes (CC-unicast version only, Loopback, Link Trace, Remote Defect Indication)

Additional “Experimental” and “Vendor Specific” OAM reserved

*Note: AIS is not defined in

802.1ag because of

inconsistency with Spanning

Tree Protocol (STP) and

multipoint limitations

Automatic Protection

Switch (APS) PDU is defined

(see G.8031 for details)

Alarm Indication Signal (AIS)*

Suppresses client alarms andeliminates alarm storms from asingle failure

Informs higher level clients thatserver layer has failed

Multicast Loopback

Multicast supported in additionto 802.1ag unicast

Performance Management

Packet Delay

Delay Variation

Packet Loss

Maintenance CommunicationsChannel (MCC)

For remote maintenance

Lock

Suppresses client alarms byindicating that service is notavailable due to maintenance

Allows clients to differentiatebetween defects and intentionalmaintenance

TestMeasures BER, throughput or frame sequence

In-service or out-of-service




ITU-T Y.ethperf Ethernet Frame Transfer and Availability Performance

Frame Transfer Delay (FTD)

Time required to transfer a

frame from its source to its

intended destination

Mean, Minimum, Median &

Delay Variation

Frame Error Ratio (FER)

Ratio of {total errored frames}

to {total successful frames +

errored frames}

Frame Loss Ratio (FLR)

Ratio of {total lost frames} to

{total transmitted frames}

Spurious Frame Rate

Number of spurious Ethernet

frames per service-second

Percent Ethernet Service

Availability (PEA)

% of total scheduled service

time that is available

Percent Ethernet Service

Unavailability (PEU)

% of total scheduled service

time that is unavailable

PEU = 100 – PEA

Parameters to specify and assess Ethernet connection performanceSpeed, accuracy, dependability and availability

Applicable to end-to-end, pt-pt and multi-point connections

Eth t Q lit f S i (Q S) & T ffi M t




Ethernet Quality of Service (QoS) & Traffic Management

Why?

Guarantee customer service levels

Optimize networkbandwidth utilization

Revenue Opportunity:

Offer differentiated or multiple class service

Limit network congestion

Manage packet-basedover-subscription

Different applicationshave different needs

How?

Classify customer flows (often different flows and

profiles per port)

Typically defined by combination of SA/DA and

other fields in headers

Examples: Ethernet VLAN P-bits, IP DSCP,

MPLS EXP bits

Applying a specific treatment to each class

Police (rate limit or drop) the inbound traffic

Queue and forward the traffic with a specifiedpriority

Perform accounting on the traffic

Mark as being eligible for congestion avoidance

Shape the traffic on output

Quality Ethernet: QoS System Flow



Quality Ethernet: QoS System Flow

PacketEnters

Packet

OK?

No

Yes

Queues

ClassifyAnd

ResolveHeader

ClassifyAnd

ResolveHeader

Policing/ShapingPolicing/Shaping Outbound PacketsScheduler

PacketProcessing

PacketProcessing

Billing

• Packets are ingressed andclassified based upon their headers

• Packets are ingressed andclassified based upon their headers

Packets from each defined queue are checked

by the scheduler for eligibility

• The best eligible packet, per queue definitions, is scheduledper the algorithm and delivered

• Scheduler counts the packets andsends counts to OSS systems

• “In profile” packets are en-queuedfor delivery; Others are dropped

• “In profile” packets are en-queuedfor delivery; Others are dropped

• Per policy, traffic is policed and

shaped

• Per policy, traffic is policed andshaped


Quality Ethernet:




Q y

Traffic Policing

Policing

Determines maximum percentage of offered traffic that ishanded to the network for delivery

In-profile traffic passed to the network for delivery

Offered

tonetwork

20 Mb/sec

250 Mb/sec

80 Mb/sec100 Mb/sec

100Mb/sec

1Gb/sec

100Mb/sec

100Mb/sec

P

O

L

IC

E

C

O

L

L

E

C

T

S

C

H

E

D

U

L

E

Infrastructure Variability




Infrastructure Variability

Addressed by enabling a standardized Ethernet across multiple infrastructures

Physical Layers Encapsulation Layers Forwarding Schemes OA&M

802.3z / ae

(1GbE/10GbE)

802.3ah

(Ethernet First Mile)

802.11* / 802.16

(Wireless/WiFi

Ethernet)

PDH (T1/E1 T3/E3)

DSL Q-in-Q (802.1q) 802.1d (Bridging)

802.1Q

(VLAN Switching)

802.1ag

(Connectivity Fault

Management)

ITU-T G.7041 (GFP, EOS)

ITU-T G.7042 (LCAS)

G.709 “Digital

Wrapper” (OTN)

MPLS/PWE

Encapsulation

(Various IETF)

802.1ad

(Provider Bridges)

802.3ah

(Ethernet First Mile)

802.1ah

(Backbone Provider

Bridges)

SNMP

IP/MPLS -> VPLS Y.1731 Service OAMMac-in-Mac

(PBT, PBB, etc)

Summary: Ethernet is “The New T1”




Summary: Ethernet is The New T1

What’s in your toolbox?




What s in your toolbox?



© Ciena Confidential and Proprietary

Questions?

Ciena Points of Contact for the R&E Marketplace

Jeff Verrant

Director, Research Initiatives

515-238-5685

[email protected]

http://www.ciena.com/

Jim Archuleta

Director, Government Solutions

410-981-7340

[email protected]

But is Ethernet a LAN or WAN Technology?



gy

It’s designed for the LAN, but .. Extending now to WAN. So, it’s both ..

and…its an interface, a networking and aggregation technology, a service, a

transport, an access mechanism, etc…

To achieve this, Ethernet must be carried on any transport type

Ethernet Ethernet

• IEEE 802.3 PHY

• Ethernet “mesh”

• PDH

• OTN• WDM

• SONET/SDH

• MPLS

• ATM

• IP• Carrier Pigeon (RFC 1149)

WAN

User A User B


2008-ciena the shift to ethernet in the wan-wabik

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