category 8 connectivity challenges
TRANSCRIPT
Category 8 Connectivity Challenges
Ing. Davide Badiali, RCDD
Technical Manager COMMSCOPE
Athens, 10 October 2014
Category 8 Connectivity Challenges ABSTRACT
The development of the Category 8 cabling specifications is well underway, with an aggressive timetable for completion. As with previous-generation twisted-pair cabling specifications, achieving the standard-specified performance levels presents an extreme challenge for connecting-hardware developers. This presentation offers a look at the current status of the Category 8 spec along its development timeline, paying specific attention to current developments with the plug/jack interface.
From 1987 to present…
IEEE 802.3bq 40GBASE-T Update
40GBASE-T Task Force builds on the development of Cat 8 – An iterative cycle, IEEE 802.3 working closely with TIA & ISO
Cabling community evaluates feasibility
Agreed new cabling
specifications 40GBASE-T
implementers evaluate new
channel models
40GBASE-T implementers analyze impact
on PHYs
40GBASE-T implementers
request cabling
features
Where does 40GBT fit
40GBASE-T is well suited to cover connections within the row
Distance served by CR4 • Within the rack • Neighboring racks
Distance served by NGBASE-T • Within the rack • Neighboring racks,
stranded ports • End of row
Server Drivers for Interconnect
Server I/O capability – LAN on Motherboard (LOM) driving 10GE today
– PCIe slots support 4x10GE today, enabling the transition to 40G
– Initial adoption of 10GE was in a NIC, moving to LOM
– 40GE will start on the NIC, move to LOM
– Four RJ45’s fit on a Peripheral Component Interconnect Express (PCIe) Low Profile card
Switch Drivers for Interconnect
At the switch – 48 ports is a traditional density in 1 Rack Unit (RU)
– Top of Rack (ToR) topology benefits from higher 40GE port density than offered by Quad (4/channel) Small Form-factor Pluggable (QSFP) • QSFP size drives 32 port density plus uplinks, 1.28Tb/s
• RJ45 size connector permits 2Tb/s plus uplinks
– End of Row switches add distance as an enabler • 48 port 1RU density possible w/ RJ45 size connector
• Rows can go up to 24 racks, distances well in excess of passive Direct Attach Copper
Attributes
40GBASE-T provides capabilities not otherwise available in the portfolio
NextGenBASE-T 40GBASE-CR4
BackwardsCompatibility/Autonegotiation
Autonegwillbeintegral,compatiblewith10GBASE-T&1000BASE-T
BreakoutcaninterfacewithSFP+orSFP,noAutonegotiation
Latency 640nsec 480nsecDensityin1RU 2Tb+,48portsplusuplinks(enabled
byRJ45size)1.28Tb+,32portsplusuplinks
(assumingQSFP)Cabling 4twistedpair 8pair,twinaxCostfactors Noactiveelements,assumetwisted
pair,widelysourcedCategory8cabling
QSFPendpointwithfinitecostandassemblycomplexity,some
vendorsrestrictsourcingReach CandoEndofRowandwithin-rack,
upto30m7m,thencanuseactivecable
Integration Compatiblewithsiliconintegration,LAN-on-Motherboard
RequiresQSFPcage
Timeframe: 2015-2016
40GBASE-T requires 2 GHz Specifications
IEEE 802.3bq analysis has shown physical layer power is conserved by using high-bandwidth cabling
– Independent of crosstalk reductions, ~1600 MHz signaling bandwidth will be needed
– Category 8 cabling is adequately specified to 2GHz bandwidth
40GBASE-T has Chosen a PHY Baseline
• Baseline specification chosen in March 2014
– 4X speedup of 10GBASE-T (3.2 Gbaud, 128-DSQ w/ LDPC coding)
– Full crosstalk and echo cancellation
• Minor enhancements to 10GBASE-T signaling approved
– Lessons learned on 10GBASE-T, including added protection from impulse noise, simplified power back off
• Power targets at 1.5 to 2X 10GBASE-T
– Wider bandwidth, improved cabling helps PHY designers save power and cost
• Backwards compatible to 10GBASE-T, 1000BASE-T through RJ-45 interface and IEEE 802.3 Auto Negotiation
• Physical layer performs well on Cat8 30m channel
– > 6dB MORE margin than 10GBASE-T at this stage of standardization
• Well-defined technology basis from 10GBASE-T will aid time to standard and products
IEEE 802.3bq objectives
• Define a link segment based upon copper media specified by ISO/IEC JTC1/SC25/WG3 and TIA TR42.7 meeting the following characteristics: – 4-pair, balanced twisted-pair copper cabling – up to 2 connectors – up to at least 30 m
• Define a single 40 Gb/s physical layer supporting operation on the link segment
• Legacy Ethernet requirements (auto-neg, EMC, BER, duplex)
Standard Structured Cabling Topology
EQ
Equipment cord
Q EQ
Horizontal cable (90 m max)
Channel (100 m max)
C
Work area cord
Telecommunications Room (TR)
Patch cord
Work Area
TO
CP
• The 100 m derived after many surveys and analysis to cover over 90% of the possible configurations in commercial buildings. • The 100 m reach was a stretch for 10GBASE-T and as a result of this decision, the complexity and power of this application became very challenging: this is one reason for the slow and delayed introduction of 10GBASE-T equipment many years after the 10GBASE-T standard was ratified.
Category 8 two connection Channel
Switch Equipment
cord Server
Horizontal cable
Channel (30m max)
C
Equipment cord
End of Row Cabinet or Rack
EO
Server Cabinet or Rack
For design we can break down this 30 m length into:
- 20 m of horizontal cable the length of 20 cabinets
- 3 m drop at the two ends from overhead to the cabinets
- 2 m cords at each end to connect to from patch panels to server ports
Direct Attach Channels
• IEEE 802.3 40GBASE-T does include the option of direct attach channels to cover the case of TOR distribution.
•Note that this type of distribution is not structured cabling and not as flexible and generic as EOR cabling. • Consequently TIA has limited the length of direct attach channels to 10 m
- “Cable lengths for point-to-point cabling between equipment in the Equipment Distribution Area (EDA) should be no greater than 10 m (33 ft) and should be between equipment in adjacent racks or cabinets in the same row. This point-to-point cabling should be routed in cable management or accessible pathways, and not interfere with fixed cabling.”
Switch Server
Direct attach Channel (10 m max)
C
Server Rack or Cabinet
Top of Rack or Cabinet
NGBase-T Standards and Timeline
2012 2013 2014
SG Meeting (01/22 – Contribution of
CommScope Cat-8 Channel
View presentation:
http://www.ieee802.org/3/NGBASET/public
/jan13/Larsen_01a_0113_NGBT.pdf
ISO WG3 Meeting (09/12)
Technical Report - Class 1 & 2
2nd SG Meeting (11/12) - Joint
Contribution with Belden, ETL and Fluke
Networks on Cat-8 FTP solution
1st SG Meeting (9/12) – Presented
contribution containing draft TIA
specs for NG Cabling
CFI NGBASE-T (07/12)
TIA TR42 Meeting (10/12)
NG Cabling is named Category 8
4th SG Meeting (03/20) – Established
Task Force to develop 802.3bq
TIA TR42.7
Interim Meeting (12/12) for Cat-8 Cabling
Standard Development Std Dev.
TIA TR42 Meeting (02/13)
Propose CAT 8 as name
ISO WG3 Meeting (03/13)
Propose CAT 8 as name
TIA-568-C.2-1 Category 8 parameters
Category 8 specifications include improved requirements up to 2 GHz for:
• Insertion Loss
• Return Loss
• NEXT and PSNEXT
• ACRF and PSACRF
• Alien cross-talk parameters, balance parameters, and coupling attenuation
• Propagation Delay and Delay skew
TIA TR42.7 update from San Diego meeting June 9, 2014 week
• Category 8 mock ballot comments were resolved including: – Permanent link Return Loss plateau was improved from 6
dB to 8 dB up to 2 GHz – Pair to pair unbalance in support of 4-pair PoE was set to
7% for the channel and 5% for the cable – A task group was established to study direct attached
channels – There was no consensus to add Class II requirements at
this time – The use of Category 8 cabling was extended to be used in
the backbone in addition to horizontal cabling – 22 AWG is allowed within the Category 8 umbrella
ISO TR 11801-99-1 channels for 40 G
Specifies two new channel classes of up to 30 meter length with two connections characterized up to 1600 MHz (2000 MHz und.dev.) in support of 40 G applications:
• Class I based on Category 8.1 specifications (F/UTP construction)
• Class II based on Category 8.2 specifications (Pairs in Metal Foil (PiMF) construction) – Class I specifies the IEC 60603-7-81
2 GHz RJ-45 connector
– Class II will likely use one of 3 connector types: o IEC 61076-104-2000 8 pin 2 GHz Connector (Tera)
o IEC 61076-110 -2000 8 pin 2 GHz Connector (ARJ45)
o IEC 60603-7-82-2000 12 pin 2 GHz Connector (ARJ45)
Recent changes to ISO TR 11801-99-1 cabling guidelines
• Class I is harmonized with TIA Category 8 specifications – Class I and Class II are also coming closer in most specifications
with differences in: • Channel IL (Class I slightly higher due to connector IL)
• Channel TCL and ELTCTL (Class I is tighter)
• Channel NEXT, PSNEXT, delay Skew (Class II is tighter)
• Qualification of existing Category 6A and 7A cabling to support 40GBASE-T was downgraded to a description up to 1600 MHz and moved to an informative annex
• ISO/IEC TR 11801-99-1 was approved for publication in May 2014 and should be available soon
Category 8 field tester channel test
• Field testing is a key aspect for customers to verify the installation and be assured they are getting the performance they paid for.
• Measurement standards for Category 8 are in progress in TIA and IEC committees.
• Tester vendors have responded quickly to the opportunity and the challenge of making accurate testers that measure out to 2 GHz.
Channel is 30 m with 2 connections
Cable setup:
• 26 meters Cat8 cable spool
• 2 connections (RJ45)
• 2 x 2 meters Cat8 test cords
Field tester uses bare wire channel adapters
Bare wire adapters are used for Network analyzer measurements to conform to the definition of a “30 m channel”.
The goal is to compare the measurements of the field tester with the network analyzer measurements
Category 8 RJ-45 Mated connection
The plug and jack are being standardized in IEC 60603-7-81 and will both be backward compatible to previous versions of the standard.
Channel Insertion Loss using Network Analyzer & Field Tester
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7,8
1,2
4,5
3,6
Limit(dB)
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Limit(dB)
1,2
3,6
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Using Network Analyzer Using Field Tester
IL is the loss of signal energy in dB on the y-axis shown as a function of frequency up to 2 GHz on the x-axis >>> Good correlation between NA and FT <<<
Channel Return Loss using Network Analyzer & Field Tester
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Limit
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Limit(dB)1,2
3,6
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7,8
1,2
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4,5
Using Network Analyzer Using Field Tester
RL is the ratio of the reflected energy to the launched signal energy in dB on the y-axis shown as a function of frequency up to 2 GHz on the x-axis >>> Good correlation between NA and FT <<<
Channel NEXT using Network Analyzer & Field Tester
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Limit(dB)1,2-3,6
1,2-4,5
1,2-7,8
3,6-4,5
3,6-7,8
4,5-7,8
1,2-3,6
1,2-4,5
1,2-7,8
Using Network Analyzer Using Field Tester
NEXT loss is the ratio of noise from one pair to another pair at the near end in dB on the y-axis shown as a function of frequency up to 2 GHz on the x-axis. >>> Good correlation between NA and FT <<<
Channel ACRF using Network Analyzer & Field Tester
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Channel ACRF Using NA Channel ACRF Using FT
ACRF (Attenuation to Crosstalk Ratio, Far-end) is noise coupling from one pair to another pair at the far end in dB on the y-axis shown as a function of frequency up to 2 GHz on the x-axis >>> Good correlation between NA and FT <<<
In Summary
• IEEE 40GBASE-T has reduced channel length to 30 m and 2 connections to allow 40 Gb/s application speeds sufficient to cover EOR topology in data centers
• Feasibility, interoperability, and backward compatibility (using the RJ45) of Category 8 channel and component specifications has been demonstrated by multiple vendors
• Category 8 will provide higher density, lower cost, easy installation, simple administration (MACs), and proven reliability of structured cabling for increased “uptime”
RJ45 supports 10BASE-T to 40GBASE-T
Ing. Davide Badiali, RCDD
Technical Manager Italy, Greece & Cyprus
Via Archimede 22/24, 20864 Agrate Brianza (MB) Italy
T: +390396054687
M: +393483013063
www.commscope.com