The Evolution of Multi Array Connectivity (aka MT/MPO/MTP) Robert A. Reid Sr. Product Development Manager.

The Evolution of Multi Array Connectivity(aka MT/MPO/MTP)

Robert A. ReidSr. Product Development Manager

• Historical Perspective - MT Technology

• The MPO & MTP Connector System

• MPO Standards

• Plug/Play Ethernet & Fibre Channel Structured Cabling Components

• MPO Performance Issues/Cleanliness

• Future MPO Designs

• Migration to 40/100G & beyond 32G Fibre Channel

• Field testing w/ MPO

Agenda

• In the 1980’s, NTT in Japan began to build a fiber optics based communication infrastructure. • Fusion splicing high fiber count cables was too disruptive. • Pre-terminated MT ferrule ribbon cables enabled installers to

have a quick and reliable means to mechanically splice multiple fibers in communication infrastructures.

• In the 1990’s NTT-AT developed the MPO (Multifiber-Push-On) type connector to replace the original mechanical spring clamp/index matching gel method to mate MT ferrule connections (below right).

MT Ferrule TechnologyHistorical Perspective

• Rectangular Shape with Guide Pin Holes• Monolithic, high precision, molded component (2f - 72f)• Highly (60-80%) glass filled engineering polymer (typically Polyphenylene Sulfide)

– Large amount of glass filler improves thermal stability relative to glass. Compare with typical single fiber ferrules which are ceramic or zirconia.

Glass Filled Polymer

Optical Fiber

1985: SM MT Ferrule technology established by NTT Laboratories. (Thermosetting Epoxy Material)1988: NTT releases Thermoset MT technology into commercial subscriber lines. Widely used in Japan as a pre-engineered mechanical splice for outside plant applications.

MT Ferrule Origins

Multi-Fiber ConnectorsThe MT Ferrule Design Details

Optical performance is based on:• Fiber Alignment (axial & angular based on ferrule & guide pin)

– True Position of fiber-holes in the ferrule relative to alignment pin holes – Tolerance of the alignment pins– Diameter tolerance of fiber holes and alignment pin holes

• Fiber Tip Contact (endface geometry + connector spring force)• Fiber Tip Cleanliness & Quality

Connector Component Quality

Endface Quality

The fiber alignment is independent of the adapter!

+ +Fiber Tip Quality

Multi-Fiber ConnectorsMT Ferrule Technology

The MPO connector family is defined by two existing standards. Internationally the MPO is defined by IEC-61754-7. In North America the MPO is defined by TIA-604-5 (also called FOCIS 5).

The MTP® brand multi-fiber connector is the trademarked name for US Conec’s MPO connector. The MTP® connector is fully compliant with both FOCIS 5 and IEC-61754-7. The MTP® connector is fully intermateable with any FOCIS 5 or IEC-61754-7 compliant MPO connector

MTP® Connector or MPO - What is the Difference?MTP® Brand Connector = High Performance MPO

MPO Mechanical InterfaceKey Standards

82 mm2:

82 mm2/Fiber

82 mm2:

12F: 7.9 mm2/Fiber24F: 4.0 mm2/Fiber72F: 1.3 mm2/Fiber

> 63X Density w/72F Ferrules

Why Multi-Fiber?: DENSITYSC vs. MPO Cable Connector Footprint

Adapter / Coupler

Female Plug w/ Guide Pin Bores

Male Plug w/ Guide Pins

Flat or 8 deg APC endface

Protruded Fiber Tips ~1-3 microns typical

While various MT ferrule based

connectors have been on the market for many years, the

MPO push-pull connector format is the most common

MPO Connector OverviewGendered and Polarized

MTP ConnectorsComponent Parts

MTP ‘Ferrule’

Boot

Crimp Ring

Inner Housing

Spring

Outer Housing

Ferrule

Female Retainer (No Pins)

Male Retainer (Pins)

Dust Cap

• Patented ferrule floating mechanism for improved mechanical loading performance

• Patented elliptical guide pin shape for minimal debris generation when compared to chamfered pins

• Enhanced spring centering for consistent performance and protection of the fiber array

• Oval spring designs accommodate multi-ribbon, higher fiber count applications

• Removable housing (some skill required) for gender changes, reworks, interferometer scans, etc.

• It is fully intermateable with any FOCIS 5 or IEC-61754-7 compliant MPO connector

MTP® Connector OverviewTechnical Advantages over Standards-based MPO

Plug designation

The complete designation for a FOCIS 5 connector plug is:

FOCIS 5P-n-k-a-c-t

where:

P designates that it is the plug

n is the number of fibers

k defines the keying configuration

a is the angle of contact

c designates alignment pins or holes

t alignment pin/hole diameter

Number of Fibers

Eight values have defined for the number of fibers

4, 6, 8, 10, 12, 16, 20 & 24

FOCIS-5 ConnectorsWhat Does the Standard Say About MTP/MPO?

Plug Keying

Single keying option for FOCIS 5 plugs has been defined, k = 1.

Contact Angle

Angle between the plane of contact between mating fibers and a plane perpendicular to the optical axis of the plug.

a = 0, designates an angle of 0°

a = 8, designates an angle of 8°

Connector Gender

c = 1, Interface that contains alignment pins

c = 2, Interface that contains alignment holes

Alignment pin/hole Diameter

t = 1 Tight Tolerance for SM fiber applications

t = 2 Standard Tolerance for MM fiber applications

FOCIS-5 ConnectorsWhat Does the Standard Say About MTP/MPO?

MTP Connector SystemDefinition of “Fiber 1”

White Mark indicating fiber #1Fiber 1

Fiber 12

Adapter Keyway

MTP Connector SystemSinglemode Variant

• Singlemode MTP connectors are polished at a nominal eight (8) degrees with respect to the connector key

• Return Loss from the angled interface is maximized (>55dB)

• Assures that the normal Key Up/Key-Down adapter sleeve aligns the angled surfaces to compliment each other

• Precludes the use of Key Up/Key Up adapters for the single application (unless two different connector polishing orientations are made – not in the FOCIS document for SM)

Push-On Housing

Ribbon CableKey (Up)

Adapter

Ferrule

Latch

Angled Polish(singlemode)

a=8

Flat Polish(multimode)

a=0

Key (Down)

Adapter designation

Designation for a FOCIS 5 connector adapter is:

FOCIS 5A-k-m

where:

A designates that it is the adapter

k defines the keying configuration

m defines the mounting configuration

Adapter Keying Options

Two options are defined for the adapter keying configuration:

k = 1 - standard keying configuration for FOCIS 5 adapters

k = 2 - alternative keying configuration

MTP AdaptersTwo Different MTP/MPO Adapters

MTP AdaptersTwo Different MTP/MPO Adapters

Type-A Array Adapters (k=1)

• Type-A adapters mate two array connectors with the connector keys opposed (key-up to key-down)

• Designated as FOCIS 5A-1-0 (ANSI/TIA/EIA-604-5C)

Type-B Array Adapters (k=2)

• Type-B adapters mate two array connectors with the connector keys aligned (key-up to key-up)

• Designated as FOCIS 5A-2-0 (ANSI/TIA/EIA-604-5C)

• Type-B adapters are identified (by color/labeling) to distinguish from Type-A adapters

Keys are on same side

Keys are on opposing sides

MPO Variants4 Through 72 Fiber Connectors

Lateral Offset results when the centerlines of two fibers are not perfectly aligned.

LO is typically the single largest contributor to insertion loss.

• A 2 micron axial misalignment on 50 micron multimode fiber would result in an 8% reduction in the overlapping area and a similar reduction (loss) of coupled power.

• However 2 microns of axial misalignment on 9 micron singlemode fiber results in approximately a 36% reduction of the overlapping area and coupled power.

Fiber Connector TheoryLateral Offset

True Position Factors0.699 -

0.701mm

125-128µm250µm• Guide Pin Hole Center• Fiber Hole Pitch• Guide Pin Hole Position• Fiber Hole Diameter• Guide pin Hole Diameter• Fiber Hole Position

Fiber Connector TheoryMolding and Alignment Technology

Monte-Carlo Simulation w/Target EF Launch

-100

0

100

200

300

400

500

600

700

800

900

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

IL (dB)

Fre

qu

en

cy

LLMC

SM

MM

Connector Loss distribution is a one-sided Rayleigh Distribution

MTP Connector PerformanceMated Connector Loss

• Connector spring force• Fiber tip shape• Fiber tip height variation• Ferrule surface shape and angular orientation relative to guide pin bores• Best fit fiber tip line angles relative to guide pin bores• Ferrule material properties• Guide pin material properties• Pin to hole friction

MTP Connector AttributesKey Metrics which impact fiber tip physical contact

Part 1 - General & Guidance

Part 2 - Axial and Angular Offsets

Part 3 - MT Ferrule Dimensional Limits

61755-3-31 - PPS ferrule in development

61755-3-32 - Thermoset ferrule in development

PAS 61755-3-31

PPS publicly available specification defines key metrics: RX, RY, GX, GY, Fiber protrusion/undercut, Max height difference all fibers, Max adjacent fiber height differential

PAS 61755-3-32

Thermoset publicly available specification (identical to PPS PAS)

IEC 61755-3-X series documents have two primary elements:

1. Attributes which pertain to fiber core alignment

2. Attributes which pertain to fiber tip physical contact

MT Optical InterfaceKey Standard - IEC 61755

Polishing Techniques“Special” end-face morphology created to support the >20dB component RL requirement for IEEE 802.3.ae & ANSI-FC-PI-x

Uniform Height

MTP Connector PerformancePhysical Contact & RL Assurance

fiber

Pro

trus

ion

in m

icro

ns

7616 MTP ends

Fiber

Panduit Spec. = 4 microns max. above MTP ferrule surface

MTP Connector PerformanceHeight Processing Capability for Panduit CR

MT Optical InterfaceStandard MTP Ferrules

1

2

4

vs. 0.127mm +/-.001

vs. 0.700mm +/-.001

vs. 0.6970mm to 0.7010mm

3 Not shown on print – ‘Elite’ fiber hole true position from pin alignment datum is reduced from 0.003 mm to 0.0015 mm

MT Optical Interface‘Elite’ MTP Ferrules - - Performance ‘Enhancing’ Dimensions

Benchmark Simple link (2 cassette) testing comparing distribution of permanent link loss for standard MTP Cassettes to those built with US Conec ‘Elite’ MTP ferrules

Headroom gain >0.1dB per cassette (per mated MTP) and overall loss variation reduced significantly

‘Elite’ ferrules are available commercially to all Plug & Play suppliers

2 Cassette Link with std. fiber & std. MTP ferrules

2 Cassette Link with std. fiber & ‘Elite’ MTP ferrules

Performance BenchmarkingStd. vs. ‘Elite’ MTP Ferrules Deployed in Channels

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Contamination of the connector end face

Poor polishing of the ferrule

Mistakes in attaching labels to the cable

Damage to the optical connector

Damage to ferrule end face

Defective splicing

Macrobend loss from poor routing

Cable Installer Network Owner

• The chart above is a summary of a study from NTT-Advanced Technology that polled network owner and cable installers on the sources of network failures

• 98% of cable installers and 80% of network owners answered “Yes” to having contamination be the root cause of a network failure.

MPO Performance MaintenanceImpact of Contamination

MPO Performance MaintenanceSignal Degradation on MT Ferrules

Initial Clean Endface

Contaminated Endface

Mated 5 times dirty then cleaned results in severe permanent damage

• Debris generated from normal wear in mating and de-mating

• Dry wall dust• Saw dust• Residues from end caps

(outgassing)• Skin oil• Suntan lotion• Alcohol residue• Water residue• Vegetable oil• Hand lotion• Dryer lint• Saltwater residue• Graphite

MPO Performance MaintenanceLasting Effects of Contamination

Measurement Region Multi Fiber Connectors

Zone Diameter for Single Mode Diameter for Multimode

A: Core 0 µm to 25 µm 0 µm to 65 µm

B: Cladding 25 µm to 115 µm 65 µm to 115 µm

Notes:• All data above assumes a 125μm

cladding diameter.• Multimode core zone diameter is set at

65μm to accommodate all common core sizes in a practical manner.

• A defect is defined as existing entirely within the inner-most zone which it touches.

• Criteria must be applied to all fibres in the array for functionality of any fibres in the array

Zone A

Zone B

MPO Performance MaintenanceIEC 61300-3-35 Measurement Regions

This workflow chart comes from Cisco Systems Document 51834 titled “Inspection and Cleaning Procedures for fiber Optic Connections”

Cisco Systems advocates starting with dry cleaning. If the contamination is not removed after the second cleaning cycle, a wet-dry solution is called for.

MPO Performance MaintenanceBest Practice: Cisco Systems

Cleaning CassettesRelatively mature cleaning technology using a reel of specialty fabricExamples include: OPTIPOP, CLETOP, etc.

Sticks & SwabsSwabs may are beneficial for cleaning connector end faces installed in adapters - Examples include: Sticks, swabs, etc.

SolventsSolvents provide a chemical action to clean fiber optic connector end faces.Examples include: Water, alcohol, HFE, etc.

Compressed GasCompressed gasses provide a mechanical action for removing particulate contamination - Examples include: Canned air, CO2 snow, N, air compressors

Mechanical Cleaning ToolsRelatively new technology that advances a cleaning cloth across the end face in a controlled fashion - Examples include: IBC™ Brand Cleaning tools

MPO Performance MaintenanceBest Practice: Cisco Systems

1. Fiber Count Trend: Higher density ferrules reduce connector component cost and processing cost per fiber

2. MPO Port Trend: Ganged high fiber count ferrule connectors can reduce link cost and further increase density

3. Application Trend: Performance specific components and termination methods designed specifically for link application requirements

12f 24f 48f 72f

Cable OD: 3.0mm

Cable OD: 3.8mm

Cable OD: 5.5 mm

Cable OD: 7.5 mm

Multi-Fiber Connectivity Technology Evolution

• Same outer footprint as traditional MT• Compatible with MTP® connectors and other MT based

connector platforms• Connectors are backwards compatible to use traditional

ferrules for low-loss applications• Lower mating force required ~2.5N vs. 10-20N• Rows up 16F wide (~500 micron alignment posts, increased

pitch)• Row count up to 4F

Future MT TechnologyMT Lensed Ferrules

Epoxy windows

Fiber Lead-in areaPrecision micro holes

Optical Stop Plane

50 micron recess for lens array

• Collimating lenses• Micro-holes for precision alignment • Traditional pins or hermaphroditic, molded guide post• 36 Fiber, 3 x 12; 700 micron alignment posts (4.6mm pitch)

• 2 rows on 500 micron pitch (traditional 24F footprint)• 1 x 12 single row in center• Molded post & hole alignment

• TBD x 16 (up to 4 rows); 550 micron alignment posts (5.2mm pitch)• Future higher fiber counts TBD

Future MT TechnologyMT Lensed Ferrules

40 and 100 Gigabit Ethernet will initially be niche applications Fiber solutions are just starting to be commercialized using Multimode media for intermediate reach

Source: Dell’Oro January, 2011

PROJECTED GROWTH RATE ESTIMATED PORT SHIPMENTS CONNECTOR

APPLICATION 2012 2013 2014 2015 2012 2013 2014 2015 MDI SCS

SAN 1Gb to 32Gb Fibre Channel (FC)

19% 22% 25% 27% 7.67M 9.36M 11.7M 14.86MLC

ONLYLC & MPO

LAN 10Gb ETHERNET

49% 45% 40% 37% 6.59M 9.55M 13.37M 18.31MLC

ONLYLC & MPO

LAN 40Gb/100Gb ETHERNET

-1200

%162%

118% 5K 65K 170K 675KMPO ONLY

MPO ONLY

Source: Gartner December, 2011

1-32Gb Fibre Channel & 40/100Gb Ethernet Market Evolution

Impact on Cabling InfrastructureFrom Serial Duplex to Parallel

0 to 40000m: 40G Ultra-long reach over single-mode fiber40GBASE-ER4

Call-For-Interest (March 2013 Plenary) – 400G Ethernet

0 to 106m: 100G over OM4, Parallel multimode fiber (850nm) 100GBASE-SR44x25G QSFP+ with MPO

0 to 500m: 100G Over single-mode fiber (1310nm window)4 PMD Options under consideration: - Parallel Optics – 100GBASE-PSM4 - Duplex fiber pair: - Wavelength Division Multiplexing – WDM - Discrete Multi-Tone – DMT - Pulse Amplitude Modulation – PAMn

Parallel Optics Fiber

Single-mode Duplex Fiber Pair

0 to 20m: 100G Ultra-short reach, Un-retimed parallel optics 100GBASE-UR4

Lower power "SR-lite” 100GBASE-SR4 and 100GBASE-UR4 to be interoperable

4x25G QSFP+ with MPO

Retimed Module – CDR in module for optical transmitter

? (TBD)

- In support of Metro Area Networks- Extended reach option to 40GBASE-LR4- Same CWDM wavelengths, 20km and 40km options

Interest to standardize 1Terabit PMDNo proposals to date? (TBD)

4x25G QSFP+ with MPO

Ongoing IEEE 802.3 Higher Speed EffortsStandardization - March 2015

Panduit Confidential Information - not for Distribution

Chassis-Based40/100G

Landscape

Extreme Black Diamond 88K

6 port 40G QSFP

Cisco Nexus 7000 M2-Series

6 port 40G QSFP2 port 100G CFP (SM)

Huawei CE12812

96 port 100G CFP288 port 40G QSFP

Arista 7508

“40/100G Ready”

HP 12500

“40/100G Ready”

Panduit Confidential Information - not for Distribution

Modular (TOR)40G Landscape

Dell/Force 10 S4810

4 QSFP+ uplinks

Arista 7050S-64

4 QSFP+ uplinks

IBM Rack Switch G8264

4 QSFP+ uplinks

Cisco 3064

4 QSFP+ uplinks

HP 5900

4 QSFP+ uplinks

Extreme Summit X650

4 QSFP+ uplinks

Huawei Cloud Engine 68K

4 QSFP+ uplinks

Gnodal GS4008

8 QSFP+ uplinks

• Data Centers architected on basis of 100m (minimum) channels

• Designers value structured cabling model– Flexibility

– Troubleshooting

– Modularity

• Use of Structured Cabling System (SCS) strongly recommended– Many designers prefer flexibility offered by any to any cross connect

(Centralized Patching Location)

• SCS provides protected solution serving current requirements as well as allowing for easy expansion

• 10G systems meant to be “future-proofed” for 40/100G must be carefully designed not to exceed power budgets

MPO-Based 40/100G CablingDesigning with Link Power Budgets

12 pack of duplex 10G LC adapters

MPO Fiber Cassette24 Fiber 10 Gig LC Implementation

• Cassettes are used in bay to bay, long and short reach applications

• These elements are considered part of the Permanent Link

• All Cassettes have c=1 MTP connectors (male, pins)

• Depending on wiring configuration, cassettes may deploy k=1 or k=2 MTP adapters (Key-up/Key-down or Key-up/Key-up)

• 2 different wiring methods for these are specified in the standards (‘A’ & ‘B’)

Pulling “Sock” (protects connectivity during installation)

Pulling “Eye”MTP multi-fiber array connectors broken out from cable

MPO Assemblies/TrunksWiring Definitions per TIA-568-C.3 sec 5.2.2.3

Break-out legs supplied as flat ribbon multi-fiber units with wiring per TIA-568-C.3 sec 5.2.2.3

MPO Harness/HydraWhat is it?

Hydra n. Greek Mythology - The many-headed monster that was slain by Hercules

• Strengthened (or un-strengthened - 900 micron) breakout assembly of an MTP connector that fans to individual ‘traditional’ connectors (SC, LC, MT-RJ)

• Facilitates Routing of trunking assemblies directly to the rack and interconnect to SAN directors or switches via MTP (FAP solution with MTP feedthrough)

• Hydra assemblies by default have c=1 MTPs (male, pins); Key Up/Key Down by default

• Considered as a Specialized patchcord (not part of Perm. Link)

10G Links

40/100G Links

TIA 568C.0 Single Row Parallel Transmission with array cables Method ‘B’

Fiber PolarityParallel Transmission Example - 40GBASE-SR4

Fiber PolarityProposed Multi-Row Parallel Examples (currently not standardized) - 100GBASE-SR10

Channel Insertion Loss (CIL) = 1.9dB

= 1.5dB (connectors) + 0.4dB (fiber)

Power Budget(8.3dB)

100 meter Channel

Source: IEEE

MPO-Based 40/100G Cabling40GBASE-SR4/100GBASE-SR10 Channel Budget

• Trade-off between SCS ‘wants’ and IEEE requirements

100 meter OM3 channel with two 0.75dB (Max.) connectors (1.5dB connector insertion loss total)

0.100.200.300.400.500.600.700.800.901.001.101.201.301.401.501.60

100 110 120 130 140 150 160 170 180 190 200

Tota

l Con

nect

or L

oss

(dB)

Maximum Reach (m)

OM3OM4

150 meter OM4 channel with two 0.50dB (Max.) connectors (1.0dB connector insertion loss total)

“Engineered Link”

Source: Panduit extrapolation from IEEE model

MPO-Based 40/100G CablingLink Power Budgeting for Cabling

Panduit Confidential Information - not for Distribution

SM

Gender Change

Polarity Change

Universal MPO ConnectorGender and Polarity Change in the Field

Panduit Confidential Information - not for Distribution

40GBASE-SR4 & 100GBASE-SR10 Cabling

Cross ConnectPatch Cord

MTP Trunk or FlatRibbon

MTP Trunk or FlatRibbon

MTP PatchCords

MTP Patch Cords

MTP PanelMTP Panel MTP Panel MTP Panel

These links will need to be tested and qualified as permanent infrastructure

• MTP-based Light Source - Power Meter (LSPM) does not exist to test and warrant/certify parallel optics cable plant

• Customers deploying parallel optics cable plant to “future proof” their network infrastructure and who desire (or require) LSPM testing are using single fiber connector test units with reference grade harnesses (LC/SC to MPO breakouts)

• Test support infrastructure needs to evolve for field testing parallel optics as the market for parallel optics structured cabling matures

Testing MPO/MTP Cable PlantNeed for Recertification

Fluke MultiFiber Pro - released

Panduit has been engaged with Fluke on the development of this tester for over two years (first of it’s kind in the industry) - Fluke tested ‘Alpha’ version of tester (code name Gorgon) at Panduit customer (Cisco) in Texas

Performs unidirectional testing (first window - 850nm), polarity, and mis-wire checking

Tester is set up to primarily validate legacy, migrated cable plant with female trunks

Testing MPO/MTP Cable PlantNeed for Recertification

SM

(Female/Female Cord)

F

Questions?