shielded systems for 10g on copper - bicsi · pdf filetransmission performance specifications...
TRANSCRIPT
Agenda
IEEE/ISO/TIA StandardsTransmission BasicsShielded vs. Unshielded Electrical PerformanceInstallation and Structure Issues
What is 10 Gigabit Ethernet
The latest standard from the IEEE for an Ethernet protocolIt represents a 10 fold increase over existing Ethernet protocols It represents a data rate of 10,000,000,000 bits per secondThe channel performance requirements for this standard drive the performance parameters for cabling specifications to support it.
Ethernet Adoption
Source: Dell Oro 2006
020406080
100120140160180
Mill
ions
of P
orts
1997 1999 2001 2003 2005 2007 2009
Year
Ethernet Adoption - history & projections
100MbpsTotal GigTotal 10Gig
Clearing Up the Mystery
IEEE 10GBaseT – vs. -– EIA/TIA-568-B.2.10 Augmented Category 6– ISO/IEC 11801:2002 Class EA
EIA/TIA – vs. – ISO/IECWhat the EIA/TIA and ISO/IEC standards say about Unshielded Media – vs. – Shielded Media
TIA/EIA Cat 6A vs. ISO Class EA
Two Standards – TIA/EIA Cat 6A vs. ISO Class EA
Characteristics ISO Class EA TIA Cat6APSNEXT Loss 24.8dB 23.2dBNEXT Loss 27.9dB 26.1dBPSANEXT Loss 49.5dB 49.5dBReturn Loss 8.0dB 6.0dBInsertion Loss 49.3dB 49.3dB
Extrapolated Test Limits for NEXT and PSNEXT to 500Mhz
Yes No
The ISO Class EA System has– More stringent Return Loss– More stringent NEXT– More stringent PSNEXT
IEEE Standards and Applications
Reference Source – The Ethernet Alliance
IEEE Standard
Date Standard Released
Description Designation Data Rate Media Distance Limitation Common Applications
802.3ab 1999 Gigabit Ethernet over UTP 1000Base-T 1000Mb/s Category 5 Cable 100 meters Desktop Computing802.3z 1998 Gigabit Ethernet over Fiber 1000Base-SX 1000Mb/s 220-550 meters Enterprise Backbone
1000Base-LX 5 Kilometers WAN,MAN802.3an 2006 10Gigabit Ethernet over copper 10GBase-T 10Gb/s Category 6A Cable 100 meters Data center, R & D, Computing
Category 6 Cable 37 - 55 meters High Resolution VideoAdvanced Desktop Computing
802.3ae 2002 10 Gigabit Ethernet over Fiber 10GBase-SR/SW 10Gb/s Singlemode fiber 300 meters Data center & Enterprise Backbone10GBase-LR/LW 10Gb/s Singlemode fiber 10 Kilometers WAN,MAN10GBase-ER/EW 10Gb/s Singlemode fiber 40 Kilometers WAN,MAN10GBase-LX-4 10Gb/s Multimode fiber 300 meters Data center & Enterprise Backbone10GBase-LX-4 10Gb/s Singlemode fiber 10 Kilometers WAN,MAN
802.3ak 2004 10 Gigabit Ethernet over short range copper 10GBase - CX4 10Gb/s screened 4 pair cable 15 meters Data center links
International Standards – Copper Cabling
Cabling StandardsEIA/TIA ISO/IEC CENELEC
Category 5 EIA/TIA-568 A - Category 5 11801:1995 Class D EN50173-1:1995 Class DCategory 5e EIA/TIA-568-B.2 - Category 5e 11801:2002 Class D EN50173-1:2002 Class DCategory 6 EIA/TIA-568-B.2 - Category 6 11801:2002 Class E EN50173-1:2002 Class EAugmented Category 6 EIA/TIA-568-B.2.10 Augmented Category 6 11801:2002 Class EA EN50173-2:200x Class EA
Standards for 10G Ethernet over Copper
International Standards for 10GBase-T Status
ISO/IEC 11801 A1.1 Channel specificationsThe International Standard organization approved the category 6A Channel specification for 10GBASE-T in February 2009
ISO/IEC 11801 A1.2 Component specifications Expected October 2009
EIA/TIA-568-B.2-10 Transmission performance specifications for 100 Ohm Augmented Category 6 Cabling
The American Telecommunications Industry Association (TIA) published the full standard in April 2008
EIA/TIA and ISO/IEC
Unshielded Media: – Acceptable copper cabling media for EIA/TIA-568-
B.2.10 Augmented Category 6– Acceptable copper cabling media for ISO/IEC
11801:2002 Class EA
Shielded Media– Acceptable copper cabling media for EIA/TIA-568-
B.2.10 Augmented Category 6– Acceptable copper cabling media for ISO/IEC
11801:2002 Class EA
Copper Cabling for 10 Gigabit
10GBase-T (802.3an) requirements– Each of the 4 pairs supports a data rate of
2500 MB/s bi-directionally & simultaneously– Star topology
IEEE 802.3an Unshielded vs. Shielded
Which media type does 802.3an suggest– It does not care– It cares that the minimum transmission channel
characteristics are available over CAT6 UTP, CAT6 FTP, CAT6A UTP or CAT6A FTP.
The big problem with 10GBase-T is dealing with an external noise source generated by….transmission over surrounding cables in a bundle of cables. This is known as Alien Crosstalk (AXT).
Alien Crosstalk
10GBase-T Public Enemy #1 is AXTAlien crosstalk is unwanted coupling of signals between adjacent cablesAlien crosstalk cannot be cancelled by Digital Signal Processing (DSP)Alien crosstalk can only be mitigated only with a shield or space separation
Category 6A Unshielded Cable
Strategies – Space between cables– Variable AWG & twist
schemes– Core to jacket
separators, fluted jackets, air injected plastics and non-round shape
Category 6A UTP cables can be as large as .9mm (.35”) OD– Larger cable diameter
provide better AXT but creates issues for routings & pathways Gap A > Gap B
A
B
CAT6A
CAT6
Category 6A Shielded Cable
Specifically designed for 10G performanceANEXT of 15dB headroom or higher Shields significantly reduces EMI including ANEXTSmaller cable OD (7mm vs. 9mm)
Interoperability between Unshielded Horizontal Cables
On July 2007 JEITA (Japan Electronics and Information Technology Industries Association) submitted to TIA TR 42.7 a short report (TR42.7-2007-07-076) showing that 3 different CAT 6A U/UTP cables bundled together failed the TIA ANEXT limits.
These cables comply to the TIA ANEXT limits when bundled to identical (=same vendor) cables, but when 3 different cables (= made by different vendors, having different constructions) were bundled together, two of them failed miserably.
The Shielded Advantage
Superior, most effective design for eliminating Alien Crosstalk NoiseThe most simple design for eliminating Alien Crosstalk NoiseThe most mechanically robust designMost able to survive installation stresses100% shield barrier throughout the entire cabling channel
Cat 6A – Pathways & Routing
Cable diameter increasedCable weight increaseIncreased bend radii considerationsIncreased cabling space requirements for ducts, trays, racks, raceway, and cable managementMore space needed in Equipment room and Telecommunications roomIt may be harder to install Category 6A into existing buildings which were not designed with this in mind
Cable Bundle Comparison
Cable Nom. OD ~ 9mm Cable Nom. OD ~ 7mm Cable Nom. OD ~6 mm Cable Nom. OD ~5mm
Cables Cat6a U/UTP Cat6A F/UTP Cat6 U/UTP Cat5e U/UTP
Approx. Diameter (mm) 48 cables Bundle 65mm 55mm 45mm 40mm
Approx. Weight (g) 48 cables bundle 500mm long 1750g 1300g 1050g 750g
Quick comparison of Category Cabling Systems
Cabling Relative Price Tested PathwaysType Bandwidth 24 x 4 inches
No of CablesCategory 5e 100% 100 MHz 1400Category 6 135 - 150% 250MHz 1000
Category 6A 165-180% 500MHz 700
Source: Ethernet Alliance
This is a major issue!
Cat 6A Unshielded Installation
Increased installation time to lay containment, lay cabling & terminate connecting hardwareCannot mix Cat6 or Cat5e UTP cables with Cat6A UTP cables due to AXT– Options:
• New containment system• Clear existing containment system
– Not an issue for Cat6A shielded systems
Field Testing Cat 6A Unshielded
Increased time required for field testing – Not addressed in standards but a major concern for
Cat6A UTP systems– Costly and time consuming sample based testing
• 3 – 10 min per victim pair• Cat 6 testing on Level 3 tester less 20 sec per
link– Not an issue for Cat6A shielded systems
Shielded Cabling Solution for 10GbEMolex’s PowerCat 6A Shielded System is specifically designed to support 10GBASE-T applications. – Minimizes alien crosstalk– Improved insertion loss performance– 15dB ANEXT headroom or higher– Superior electromagnetic interference (EMI) protection– No interoperability problems
Superior installation and testing to UTP systemsLeast impact on existing structureMeets the requirements of both the ratified TIA and draft ISO 10GBASE-T standardsCovered by Molex 25 year product and application assurance warranty