The 40Gbps Twisted-PairThe 40Gbps Twisted-Pair Ethernet Ecosystem

Valerie Maguire, The Siemon CompanyDavid Hess, Nexans/Berk-Tek

Agendag

• Valerie Maguire, SiemonValerie Maguire, Siemon– Why > 10Gbps over twisted-pair?– 40Gbps approaches– Modeling cabling capability– TIA Next Generation Cabling

• David Hess, Nexans– IEEE 802.3 Standards development– Category 7A media overview– Performance

Ethernet progression– Ethernet progression

What’s driving 40Gbps Ethernet?g p

• Data centers and server clusters– Storage rates are doubling every year– Server virtualization– Short term need (in 3 – 5 years)

• Local area networks (LAN’s)Vid ( d d i )– Video (on-demand, gaming, etc.)

– High performance computing– Long term need (in 5 – 10 years)– Long term need (in 5 – 10 years)

• Now is the time to start planning for 40Gbps Ethernet over balanced40Gbps Ethernet over balanced twisted-pair cabling!

Why a twisted-pair solution?y p

• Unique advantages of BASE-TUnique advantages of BASE T– Supports auto-negotiation– Server and switch upgrades may

be performed independently

• Supports multiple generations of network equipment

• Ease of supporting MAC work• Cost effective deployment• Support of PoE

Twisted-pair is extremely popular!p y p p

Total ports shipped

Twisted pair

shipped

Twisted-pair represents 90% of all ports shipped

What is the PHY?

• PHY = The Physical Layer 7 - Application Layer

• First and lowest layer in the seven-layer OSI model of

pp y

6 - Presentation Layerseven layer OSI model of computer networking

• Provides the electrical

5 - Session Layer

4 - Transport Later• Provides the electrical, mechanical, and procedural interface to the channel

3 - Network Layer

2 Data Link Layerinterface to the channel• Defines how bits are

t itt d

2 - Data Link Layer

1 - Physical Layer

transmitted

Predicted 40Gig PHY objectivesg j

• Eliminate or reduce cancellation• Maintain no AXT cancellation• Reduce:

– PHY complexity– Line driver power – Reduce the number of chokes and

transformers– Latency– Latency

• Less power consumption results in reduced cooling needsin reduced cooling needs

Media considerations

• Physical characteristics affect PHY power consumption, complexity, and latency

• Some choices to make:– Highest performing or most

widely installed category ofwidely installed category of cabling?

– Traditional 4-connector, 100 meter channel topology or a topology specifically targeted for the data centerfor the data center environment?

First order capacity analysisp y y

• Shannon Capacity variables:• Shannon Capacity variables:C = capacity (bits/sec)B b d idth (h t )B = bandwidth (hertz)S = signal power (watts)N = noise power (watts)

• Does not:– Address latency– Guarantee a realizable PHY design

Developing a capacity analysisp g p y y

• Shannon Capacity is unique to modeling assumptions such as:– Channel configurationg– Symbol rate (Msym/sec)– Power (dBm)( )– Background noise (dBm/Hz)– PSNEXT PSFEXT PSANEXTPSNEXT, PSFEXT, PSANEXT,

PSAFEXT, and echo, cancellation– Alien crosstalk environmentAlien crosstalk environment

10GBASE-T Shannon Capacityp y

C = 16 Gbps at 412 MHz

Key 10GBASE-T assumptionsy p

Channel: 100m 4 connectorChannel: 100m, 4-connectorSymbol rate: 800 Msym/sec

Power: 5 dBmBackground noise: -155 dBm/Hz

PSNEXT cancellation: 40 dBPSFEXT cancellation: 25 dBPSFEXT cancellation: 25 dB

Echo cancellation: 55 dB

The 40GBASE-T ecosystemy

• 40GBASE-T ecosystem assumptions– Channel configuration may vary– Target capacity = 4 x 16 Gbps = 64 Gbpsg p y p p– Assume similar encoding complexity– Symbol rate = 4 x 10GBASE-T = 3,200 Msym/secSymbol rate 4 x 10GBASE T 3,200 Msym/sec– Power (same as 10GASE-T)– Background noise (-150 dBm/Hz)Background noise ( 150 dBm/Hz)– PSNEXT, PSFEXT, PSANEXT, PSAFEXT, and echo,

cancellation (same as 10GASE-T)cancellation (same as 10GASE T)– Alien crosstalk environment

100m 40GBASE-T Shannon Capacityp y

Category 7A C = 19 Gbps

Category 6ACategory 6A C = 5.5 Gbps

Not enough capacity?g p y

• Strategies– Increase cancellation

(not desired)

5 meters (stranded)

5 meters (stranded)

– Decrease insertion loss by reducing

(stranded)

TBD meters

channel length– Investigate reducing

h b f (solid)the number of connectorsI b d idth– Increase bandwidth

40m 40GBASE-T Shannon Capacityp y

Category 7A C = 64 Gbps at

1,600 MHzCategory 6A C = 12 GbpsC 12 Gbps

Data center length distributiong

Data center length histogramg g

Data center topology summaryp gy y

• 37% of channels are less than37% of channels are less than 30 meters in length

• 55% of channels are less than 40 meters in length

• 72% of channels are less than 50 meters in length

• 85% of channels are less than 60 meters in length

• Channels in the data center typically contain 2-connectors

50m 40GBASE-T Shannon Capacityp y

Measured Category 7A

Channel

Category 7A Limit

50m 40GBASE-T Shannon Capacityp y

Measured Measured Category 6A

F/UTPCategory 7A

Channel

Measured Category 6A

UTPCategory 7A

Limit

Bandwidth versus lengthg

2- versus 4-connector gainsg

TIA Next Generation Cablingg

• ANSI/TIA-568-C.2-1: “Specifications for 100Ω Next Generation Cabling”

• 4 Task Groups Established– Cable Task Group– Connector Task Group– Applications Space Task Group

Capacit Task Gro p– Capacity Task Group

• No objectives established yet

• Target publication: 2013

Next Generation Cabling study itemsg y

• Capacity analysisCapacity analysis

• Data center topology

B d idth• Bandwidth

• Transmission performance

• TIA-1183, “Measurement Methods and Test Fixtures for Balun-less Measurements of Balanced Components and Systems”Systems

Ethernet over Twisted-Pair beyond 10GBASE-T

OVERVIEW• Ethernet over TP background, outlook• Ethernet over TP technology, what’s nextEthernet over TP technology, what s next• Standards developments, looking forward

Ethernet Ecosystem, Media Types• The Ethernet Ecosystem

– Data-rate range: 10Mb/s to 100Gb/sData rate range: 10Mb/s to 100Gb/s– Reach range: 1m to >10km

• Media types– Backplane (BP)– Twinax (TX)– Twisted-Pair (TP)– Coax (CX)– Multimode Optical Fiber (MMOF)– Single-Mode Optical Fiber (SMOF)

• Media types independently updated for each new data-rate• Each media type optimum for one reach-magnitude

Ethernet Ecosystem, Data-Rate and Reach

1000000

Ethernet Media Types

10000

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/s BP

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0 1 1 10 100 1000 10000 100000

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Note, includes point-to-point up to 10kmSource David Law chairman IEEE 802 3 2010

0.1 1 10 100 1000 10000 100000

Reach, Meters

Source, David Law, chairman, IEEE 802.3, 2010

Ethernet over Twisted-Pair (EoTP) Development

• Primary application, LAN Horizontal, 100m reachD t t f LAN t d f ll d M ' L– Data-rates for LAN, trend followed Moore's Law

– Next EoTP, considered 100G over 100m

• Secondary application Datacenter Interconnection• Secondary application, Datacenter Interconnection– 1Gb/s EoTP currently widely used– 10Gb/s EoTP expected for similar use10Gb/s EoTP expected for similar use– Data-rates for Datacenter Interconnection, following

slower trend – Next EoTP for Datacenter, under consideration, 40Gb/s

EoTP Development over Time

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Twisted-pair Ethernet

10GBASE-T

“40GBASE-T”“100GBASE-T”

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1.001985 1990 1995 2000 2005 2010 2015 2020

EoTP PHY Implementations

10BASE-T 100BASE-TX 1000BASE-T 10GBASE-T POTENTIAL10BASE T 100BASE TX 1000BASE T 10GBASE T 40GBASE-T

Rate 10 Mb/s 100 Mb/s 1 Gb/s 10 Gb/s 40 Gb/s

Bandwidth 20 MHz 31.25 MHz 62.5 MHz 413 MHz 1000(+) MHz

Efficiency (4pr) 0.5 b/s/Hz 3.2 b/s/Hz 16 b/s/Hz 24.2 b/s/Hz TBD(4pr)

Pairs 2 2 4 4 4

Category “CAT 3” CAT 5 CAT 5e/CAT 6 CAT 6A CAT 7ACategory CAT 3 CAT 5 CAT 5e/CAT 6 CAT 6A CAT 7A

TP Cabling Categories

CAT 3 CAT 5/CAT 5e CAT 6 CAT 6A CAT 7A

Bandwidth 16 MHz 100 MHz 250 MHz 500 MHz 1000 MHz

Critical Parameter NEXT

Return Loss, Improved Crosstalk

Balance, Improved Crosstalk

Alien Crosstalk Shielding

100MHz, 100m Attenuation 33 dB* 24 dB 22 dB 21 dB 20 dB

100MHz, 100m 20 dB* 27 dB 37 dB 37 dB 62 dBNEXT loss 20 dB* 27 dB 37 dB 37 dB 62 dB

*Extrapolated

TP Cabling Performance

0

100m Cable ACR

Ch l

-40

-20

C7A IL

Channel Capacity:

-80

-60dB

C7A PSNEXT

C6A IL

C6A PSNEXT

C6 IL

C6 PSNEXT

•Primarily determined by Frequency

-120

-100

1 10 100 1000

C6 PSNEXT

C5e IL

C5e PSNEXT

•Primarily limited by Attenuation

1 10 100 1000

Frequency (MHz)

CAT7A TP Cabling Specifics

• LOW LOSS– Reduced Attenuation

(Insertion Loss)– Reduced ReflectionsReduced Reflections

(Return Loss)

• SHIELDING– Reduced Internal Crosstalk– Reduced External Noise

CAT7A TP Cabling Advantages

• MORE SIGNAL– Superior Dielectric:

higher speed, lower loss– Compact Design: largerCompact Design: larger

conductor, lower loss

• LESS NOISE– Pair Shields: less twists,

less reflections, less skew– Core Shield: practically

l l lkeliminates Alien Crosstalk

IEC CAT7A TP Cabling Standards

International, Generic Cabling Standards:• Channel and Components, Projects completed• Channel Test, Project in Feasibility Stage

IEC ISO/IECChannel IS 11801 “Class FA”C tComponent:-Cable-Connector-Cord

IEC 61156-5, -6 “CAT7A”IEC 60603-7 Series “1GHz”IEC 61935-2 “CAT7A”

Channel Test IEC 61935-1 “Level IV-E”

TIA Next Generation TP Cabling Standards

Generic Cabling Standards:• Channel & Components Project in Preliminary Stage Task• Channel & Components, Project in Preliminary Stage, Task

Groups• Current areas of study

– Measurements: to 1000MHz, to 2000MHz– CAT 7A Cabling standards, specifications under consideration

CAT6A Next Generation TPChannel and Components

TIA-568C.2 Next Gen TP Task Groupp

Channel Test TIA-1152 Future Project

EoTP Next StepsIEEE 802 LAN/MAN Standards Committee (LMSC)

IEEE 802 3 Eth t W ki G P j t PIEEE 802.3 Ethernet Working Group, Project Process

Stage IEEE 802.3 group Milestone

P li i C ll f i (CFI) St d G lPreliminary Call-for-interest (CFI) Study Group approval

Investigation Study Group Project Authorization Request (PAR), 5Criteria and Objectives approval

Development

Task Force

Approval to start Working Group ballot

ApprovalWorking Group Ballot complete

Sponsor Ballot complete

Ratification Standards Board approval

EoTP Next Steps

• IEEE 802.3 Ethernet Working Group• IEEE 802.3 HSoTP IG:

Higher Speed over Twisted-Pair Interest Group– Consensus building, before Call-for-interest (CFI)– Considering technical viability– Considering timing

Ethernet over Twisted-Pair beyond 10GBASE-T

• Ethernet data rate and Cabling capacity• Ethernet data-rate and Cabling capacity increasing togetherI f i f 40GBASE T• Interest forming for 40GBASE-T

• Category 7A shielded cabling standard, benchmark under consideration for next generation EoTP