slide 0 Testing Patch Cords Why Bother ? Christian Schillab Product Manager Media Test Fluke Networks Europe

I N F R A S T R U C T U R E S U P E R V I S I O N slide Tx PAIR Defect at long distance may not be detected Rx PAIR NEXT and Distance of “Defect” Attenuation 100 Ω

I N F R A S T R U C T U R E S U P E R V I S I O N slide 2 PATCH CORD Cross- connect Panel HORIZONTAL CABLE TO PATCH CORD WORKSTATION TELECOMMUNICATIONS ROOM WORK AREA Testing the “Channel” CP * * Consolidation Point (Optional)

I N F R A S T R U C T U R E S U P E R V I S I O N slide 3 TESTER PATCH CABLE HORIZONTAL CABLE TO TESTER PATCH CABLE WORK AREA Testing the “Permanent Link” CP * * Consolidation Point (Optional) Test results do not include contributions by the tester patch cables

I N F R A S T R U C T U R E S U P E R V I S I O N slide 4 A detailed look at the Permanent Link Does NOT include Tester Adapter Cords Permanent Link Consolidation Point (optional) Telecommunication RoomWork Area Patch PanelT O

I N F R A S T R U C T U R E S U P E R V I S I O N slide 5 Significant for NEXT, much less for Return Loss! with the patch panel jack with the telecom. outlet End of permanent link Beginning of permanent link The PL test model renders worst case test ! NEXT Variability: in connections Variability from the patch cord plug mating

I N F R A S T R U C T U R E S U P E R V I S I O N slide 6 The balancing act for connector NEXT 37 dB ± 0.6 dB 37 dB ± ? dB If the plug and jack like each other they can achieve a “Mated NEXT” of > 54 dB Point of observation >54 dB Jack Plug NOTE: Large dB value = GOOD Small dB value = POOR

I N F R A S T R U C T U R E S U P E R V I S I O N slide 7 Cat.6 Plug range per TIA-568B.2-1 Cat.5e Cat.5 Limit cat Mhz) 100 MHz (Pair 1-3) for 4 Cat.6 Systems Kat.6 Jack + Plulg NEXT Performance of different Plug & Jack combinations Kat.6 Jack + Plug Class E Jack + Plug A “Compliant” Plug is within the allowed range Courtesy: NEXANS A „Centered“ Plug occupies only a small part of the allowed range

I N F R A S T R U C T U R E S U P E R V I S I O N slide 8 Problem – Solution Field test paradigm: –Test permanent link model –If pass, add “compliant” patch cords to complete end-to-end channel connection –This channel is compliant without re-certifying with a Channel test Key issue: –Do you know whether your patch cords comply with the standard? Compliant Link +Compliant Patch Cord =Compliant Channel

I N F R A S T R U C T U R E S U P E R V I S I O N slide 9 Patch Cord Performance is very Important to the Channel Most important is the mated NEXT performance of the plugs at the end of the patch cord –IEEE considers “armored” patch cords to meet Alien Cross talk requirements for 10GBE (at least this was said last autumn) Major impact on RL of the channel Proximity to the transmitter Conclusion: Test must include full evaluation of both of these parameters

I N F R A S T R U C T U R E S U P E R V I S I O N slide 10 Common Excuses I „My Cat.6 permanent link has such a great margin. It will make up for a poor patch cord“ –Not true, if the „sweet spot“ of the jack is in the wrong place. –Example: Jack covers compliant as well as a very high plug, but the patch cord uses a „low“ plug. –Often PC cable is used to „pull down to good plugs“. Works for short but is fatal on long lengths

I N F R A S T R U C T U R E S U P E R V I S I O N slide 11 Common Excuses II „My Cat.6 PL has such a great margin. Even with a poor Cat.5e Patch Cord I get Cat.5e“ –Not true, if the „sweep spot“ of the jack is in the wrong place. –Example: Jack covers compliant as well as a very high plug, but the patch cord is „low“.

I N F R A S T R U C T U R E S U P E R V I S I O N slide 12 Common Excuses III „If I add a non compliant Cat.6 cord to a Cat.5E link I‘ll get at least a Cat.5e Channel“ –Not true ! if the cord is on the very high end. –Example: shielded cord with a „very good“ (very high) but non compliant plug

I N F R A S T R U C T U R E S U P E R V I S I O N slide 13 Standards Define Patch Cord Test TIA/EIA-568-B.2-1 –Paragraph : NEXT Loss NEXT Loss of near-end connection Worst-case addition of the NEXT Loss of the remote connection compensated for the round trip attenuation of the cable Plus NEXT of patch cord cable Plus an allowance for reflected FEXT (=0.5 dB) –NEXT Loss test limits of patch cords is length- dependent Very similar to latest draft of IEC

I N F R A S T R U C T U R E S U P E R V I S I O N slide 14 PATCH CABLE PATCH PANEL HORIZONTAL CABLE WALL JACK PATCH CABLE TELECOMMUNICATIONS ROOM WORK AREA Testing the Channel CP * * Consolidation Point (Optional) The channel excludes the end-connection

I N F R A S T R U C T U R E S U P E R V I S I O N slide 15 Can I test Patch Cords like a Channel ? Channel test excludes the end connector Limit line assumes –Up to 90 m of horizontal cable –Up to 10 m of patch cord –Up to four (4) connecting points In the knowledgebase is a detailed article on the issue End of Channel

I N F R A S T R U C T U R E S U P E R V I S I O N slide 16 Can I test a patch cord in a channel model with a „golden link“ ? Common practice in the past Was o.k. for proprietary systems –Also here one of the two connectors is excluded (would require a second test –Exceptionally performing or proprietary (non-centered) Jack would compensate for non compliant patch cords –Exceptional performing horizontal cable (NEXT & RL) would „hide“ under performing cords

I N F R A S T R U C T U R E S U P E R V I S I O N slide 17 Any Questions? Thank You for Your Attention ! Christian Schillab Product Manager Media Test Fluke Networks Europe