Cat.8 „The Relevance of the Test Plug“

Christian Schillab Fluke Networks Europe

Christian.Schillab@flukenetworks.com

AGENDA

• The “Bandwidth-Brakes” • The Test Interfaces • What RJ-45 Connector better then a phone plug • Testing of components in the lab • Comparing field test with lab results • Requirements for the Permanent-Link-Adapter • Status of standards for field tester

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„The RJ45 2GHz Test Plug: A prerequisite for relevant tests of 2 GHz Links as per Cat.8.1“

The “Bandwidth-Brakes”

• Distance …. Insertion Loss • Crosstalk … NEXT, FEXT, ACR, Alien Crosstalk, … • Reflections …. Return Loss • Mode Conversion (Common <-> Differential)… TCL, ELTCTL • … other

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AGENDA

• The “Bandwidth-Brakes” • The Test Interfaces • What makes a RJ-45 Connector better then a

phone plug • Testing of components in the lab • Comparing field test with lab results • Requirements for the Permanent-Link-Adapter • Status of standards for field tester

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Test Interfaces & Reference Planes

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Application

LINK

CHANNEL

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Cable 97%

1000MHz

Cable 42% Connector

58%

1000MHz

What Limits The Bandwidth more … Connectors or Cable ?

Example: 30m Link

• IL (Insertion Loss)

• NEXT (Near End Crosstalk)

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CHANNEL

Cable 56%

Connector 44%

500Mhz

Cable 69%

Connector 31%

100MHz

Cable 97%

100MHz

Cable 97%

500Mhz

AGENDA

• The “Bandwidth-Brakes” • The Test Interfaces • What makes a RJ-45 Connector better then a

phone plug • Testing of components in the lab • Comparing field test with lab results • Requirements for the Permanent-Link-Adapter • Status of standards for field tester

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What makes a Cat.5e, -.6, -.6A, .-8.1 Connector work ?

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Note: Above is shown for the most critical pair 3,6/4,5 at 100MHz

NEXT: 37dB …14mV

Cat.6, Cat.6A, Cat.8.1 …“Mated NEXT” > 54dB … < 1.9mV

Let‘s assume the plug is …

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Cat.6, Cat.6A, Cat.8.1 …“Mated NEXT” > 54 dB … < 1.9mV

… “worse” … “better”

The jack „under compensates“ because the plug is to “LOW”

The jack „over compensates“ because the plug is to “HIGH”

Plug / Jack NEXT Compensation at 2GHz is not trivial

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Cat.6/6A Cat.8.1

Good performance rquires that the plug and jack NEXT are in perfect balance.

AGENDA

• The “Bandwidth-Brakes” • The Test Interfaces • What makes a RJ-45 Connector better then a

phone plug • Testing of components in the lab • Comparing field test with lab results • Requirements for the Permanent-Link-Adapter • Status of standards for field tester

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Back in 2002: Many Plugs, Many Pyramids ….

Multiple plugs used to test jacks for Cat.6 compliance Included High, Low and Centered

Plugs Up to 12 plugs used Finding 3 meeting all requirements

would be like getting all right in a lottery

The jack had to demonstrate compliant “Mated Next” in all 12 cases

Low Center High

“New” in 2006: One Centered Plug & Mathematics

A single plug can be used to test for compliance in 14 cases A more stringent approach because it truly emulates high

an low plugs “Leaded” or PCB based test plugs may be used Most of the time a PCB based plug is preferred

… off the shelf …stable …convenient …proven in

“round robins”

AGENDA

• The “Bandwidth-Brakes” • The Test Interfaces • What makes a RJ-45 Connector better then a

phone plug • Testing of components in the lab • Comparing field test with lab results • Requirements for the Permanent-Link-Adapter • Status of standards for field tester

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CHANNEL

Comparing CHANNEL Results

• Least accurate due to remaining error when „eliminating“ the contribution of the connection Channel Adapter <-> Equipment Cord*

• Only relevant if the final cords are used and the orientation will not be changed * NOTE: The „eliminated“ connection is very much relevant for the peformance of the application

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BASE LINE Comparison

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Base Line Test Setup

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• Often used during the development phase to evaluate the to expected channel performance to verify mathematical models

• Not practical for field test: Fragile and destructive because the equipment cords need to be cut

• A field tester to lab equipment comparison hides the true channel / permanent link accuracy which relies on a perfect connector compensation / a centered plug

ComparingPermanent Link Results

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• The Test Plug dominates the results • The variation/non-compliance of the test plug is not included in

the comparison

Comparing PERMANENT LINK Results

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A combined Field & Lab Tester Concept for Cat.8.1….

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Test Plug “Centered Plug” Test Plug

Interface (proprietary)

Test Plug Adapter

Definition of the key elements

Cat.8.1 Combined Lab / Field – Test Concept

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Nur mit Artefakten und Adaptern für das proprietäre Test Plug Interface …. 1. … kann der Einfluss des Messaufbaus

eliminiert und charakterisiert werden 2. … kann der Test-Plug auf seine Eignung

(zentriert) geprüft werden

How simple was Cat.6A in comparison! Cat.8.1 Action photos from the lab

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AGENDA

• The “Bandwidth-Brakes” • The Test Interfaces • What makes a RJ-45 Connector better then a

phone plug • Testing of components in the lab • Comparing field test with lab results • Requirements for the Permanent-Link-Adapter • Status of standards for field tester

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Let Us Prevent The Wrong „Reverse Conclusion“!

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An Elephant is a grey animal A grey animal will always be an elephant ?

A Centered Test Plug is most typically PCB based

A PCB based Plug on a Patch Cord is not necessarily* centered

* Note: A PCB based plug allows the manufacture to tightly control the properties. He will most likely focus it in the upper third because in average it will provide the better results. His motivations are different from the maker of test plugs for test adapters.

Permanent Link Adapter for the „Heavy Duty Field Use“

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Test Plug “Centered Plug”

Test Plug Interface (proprietary)

Test Plug Adapter

Consumable

Permanent Link Adapter for the „Heavy Duty Field Use“ – Strain Relieve

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Return Loss should be 10+ dB better then PL limit

Permanent Link Adapter for the „Heavy Duty Field Use“ – Cable

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Credible or Not ?

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A vehible for Forest Work?

A plug and cord for Heavy Field Use ?

Requirements for Feld Testers

• ISO/IEC 61935-1 : Specification for the testing of balanced and coaxial information technology cabling – Part 1: Installed balanced cabling as specified in ISO/IEC 11801 and related standards

• ANSI/TIA-1152: Requirements for Field Test Instruments and Measurements for Balanced Twisted- Pair Cabling

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Cat. 5e 6 6A 7 7A 8.1 8.2

Level IIe III IIIe IV V VI VI (Cl.II)

+

AGENDA

• The “Bandwidth-Brakes” • The Test Interfaces • What makes a RJ-45 Connector better then a

phone plug • Testing of components in the lab • Comparing field test with lab results • Requirements for the Permanent-Link-Adapter • Status of standards for field tester

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Question #1: “In a Cat.6A project should I demand Level-IIIe or prefer Level-IV or better?”

Answer: Aboluetely NO ! Level IV/V is in this case without Relevance Afuture Level VI (für Class I) would be relevant.

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Level IIe III IIIe VI (Cl.I)

Level IV V VI (Cl.II)

Level IV V VI (Cl.II)

Cat. 5e 6 6A 7 7A 8.1 8.2

Qestion #2: “Does ANSI/TIA define a more accurate tester than ISO/IEC”

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When & How Are Field Tester Requirements Defined?

Feasible

Tester manufactures demonstrate based on experimental data and error models and simulations that certain performance parameters can be achieved.

Affordable & Practial

The resulting cost should stay within the typical pricing and the required handling should be practical

Sufficient

The “worst case” or “typically observed” uncertainty should be significantly less then the expected/demonstrated performance margin of a new category cabling system

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Mesurement Error Verus Typcial Performance Margin

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Tester Uncertainty

Tester Uncertainty

System B Margin

System A Margin

System B

System A

False FAIL !

Status Cat.8 : Field Tester Requirements

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• ISO/IEC 61935-1 : Specification for the testing of balanced and coaxial information technology cabling – Part 1: Installed balanced cabling as specified in ISO/IEC 11801 and related standards Working Draft

ANSI/TIA-1152: Requirements for Field Test Instruments and Measurements for Balanced Twisted- Pair Cabling DRAFT 4.0

Can we learn from History ? Cabling vs. Field Test Standards

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Kategorie 20

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Class-E / Cat.6

Class-F / Cat.7

Class-EA / Cat.6A

Class-FA / Cat.7A

Class I / Cat.8.1

Class II / Cat.8.2 ?

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Channel

Components

Field Test Standard

Yellow Testers

The standard turns „solid“

NEWS … Test of Cat.8 Components in Independent Laboratories

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Looking into the crystal ball …

Tech Forum „Verkabelung - Netze - Infrastruktur” 42

Tech Forum „Verkabelung - Netze - Infrastruktur”

Thank You ! for your kind attention

Questions ?

christian.schillab@flukenetworks.com