Title: SMU Course : EE 8301 NTU Course : ST 750-N
1SMU Course EE 8301NTU Course ST 750-N
Live Class Call-In Line (214)768-3068 Tape
Problems vthelp_at_seas.smu.edu
DATA COMMUNICATIONS
Session 28 -- Dr. Baker
December 3, 1998
2www.caida.ord
3Dennis Heimann District Sales Manager AMP
Incorporated
4The Cabling Apple Cart Turns Over
Presented By Dennis Heimann, RCDD District
Sales Manager
Tony Beam, RCDD Director of Global Systems
Marketing
5Gigabit Data Rates Market Trends/Drivers
- Demands on LANs are increasing
- Users desire latest technology
- Increasingly complex applications require more
memory - PC processing power doubling every 1.5 - 2 years
- Client/server computing increased to share
applications - End result is network stress
- Cabling should be part of the solution,
- not part of the problem!
6Cabling, LAN Technologies Standards Chicken
Egg Story
7LAN Technologies Data Rate and Signal Bandwidth
8Gigabit Ethernet Copper Physical Layer Interfaces
Media Access Control (MAC) full duplex and/or
half duplex
Gigabit Media Independent Interface
1000BASE-T Copper PHY encoder/decoder
1000BASE-X 8B/10B encoding/ decoding
1000BASE-CX Shielded Balanced Copper Xcvr
1000BASE-T Cat 5 UTP Xcvr
with DSP
100m
25m
802.3ab physical layer
802.3z physical layer
9Gigabit Ethernet On Copper Physical Layer
- Objective is for eventual GE deployment to
desktop on existing Category 5 cabling (US
penetration 72) - Simultaneously transmit and receive at 250Mb/s on
all four pairs. - 5-Level PAM (Pulse Amplitude Modulation) and
pulse shaping so spectrum is same as 100BASE-TX - Requires higher SNR (signal to noise) for given
BER than 100BASE-TX because of multi-level
signaling - Digital Signal Processing (DSP) is used to cancel
some of the noise - Due to DSP a 1000BASE-T Xcvr may have the
complexity of a 486 processor and initially cost
5 times more than a 100BASE-TX Xcvr
10CablingEvolving Horizontal Cabling Platforms
Data Rate
Bandwidth
Mb/s
MHz
1000
155 Mb/s ATM
100
100BASE-Tx
16 Mb/s Token Ring
10BASE-T
10
4 Mb/s Token Ring
CAT4
CAT5
CAT3
1
2000
1996
1992
1988
1984
11CablingThe Performance Decision
Cat 5/Class D
Characterized to 350 MHz
Able to transmit 622 Mbps to the workstation
able to transmit 1000 Mbps to the workstation
Aggregate Bandwidth
- Filtering through the Premises Cabling
Revolution.
12Current Industry Definition Category 5/Class D
- Original industry performance spec for CAT 5
- TIA/EIA-568-A, Category 5
- ISO/IEC 11801, Class D
- CENELEC EN 50173, Class D
- AS/NZS 3080 1996, Class D
- Specifies requirements for pair-to-pair
performance - Considered Bare Bones technology
- Recently amended to include Skew addendum
13Performance CharacteristicsPair-to-Pair Systems
(Review)
- Key Performance Parameters
- Near End Crosstalk (NEXT)
- Attenuation
- Attenuation to Crosstalk Ratio (ACR)
14Performance Characteristics Attenuation to
Crosstalk (Loss) Ratio
Coupled NEXT Noise
NIC
HUB
Receiver
Transmitter
Receiver
Transmitter
Attenuated Signal
Transmitted Signal
ACR
Attenuated Signal
NEXT Noise
15Channel ACR Minimum for Cat 5
45
40
NEXT Limit
35
30
3.1
25
Minimum ACR
20
dB
15
10
Attenuation Limit
5
0
0
20
40
60
80
100
Frequency MHz
16But Wait, Theres More
TIA has two draft addenda out for ballot now -
- SP-4194
- Proposed TSB to 568-A
- Additional Transmission Performance
Specifications for 100 Ohm 4-Pair Category 5
Cabling - Informative not required
- SP-4195
- Proposed Addendum No. 5 to 568-A
- Additional Transmission Performance
Specifications for 4-Pair 100 Ohm Enhanced
Category 5 Cabling - Requirements
17SP-4194 - Additional Cat 5 Specifications
The development of certain high-speed
applications has brought to the attention of the
TIA the need for additional transmission
requirements such as return loss and far end
crosstalk (FEXT). These parameters are needed by
system designers for applications that utilize
all four pairs in the cable for full duplex
transmission. Although these are new
specifications, the existing worst-case,
two-connector topologies compliant with
TIA/EIA-568-A are expected to meet these
requirements. Other topologies are supported as
long as they meet the ELFEXT and Return Loss
requirements of this document.
18Two-connector Topologies?
Other Topologies. . . (i.e. with cross-connect
and/or transition point)
19SP-4195 - Enhanced Cat 5
The development of certain high-speed
applications has brought to the attention of the
TIA the need for additional transmission
requirements such as multi-disturber NEXT, return
loss and multi-disturber far end crosstalk
(FEXT). These parameters are needed by system
designers for applications that utilize all four
pairs in the cable for simultaneous
bi-directional transmission. Addendum 5 for
category 5e cabling provides higher performance
over a minimally compliant category 5 channel and
recognizes advances in cabling technology.
20So What Do the Giga-guys Say?
IEEE Draft P802.3ab/D2.0 Physical layer
specification for 1000 Mb/s operation on four
pairs of Category 5 or better balanced
twisted pair cable (1000BASE-T)
40.8 Link Segment Characteristics 1000BASE-T uses
a duplex transmission system. Four full duplex
channels are required to transport data between
two PMDs. Each duplex channel supports an
effective data rate of 250 Mbps in each direction
simultaneously. The term link segment used in
this clause refers to four duplex channels and
the term duplex channel will be used to refer a
single channel with full duplex capability.
Specifications for a link segment applies equally
to each for the four duplex channels. 1000BASE-T
is designed to operate over a 4-pair Category 5
cabling system.
21Designed to Operate Over Cat 5, BUT. . .
ANNEX 40A Additional Cabling Design Guidelines
Although the 1 Gb/s specification described in
Clause 40 was designed to operate over 4-pair
Category 5 cabling systems as specified in
ANSI/TIA/EIA-568-A and ISO/IEC 11801, there are
additional steps that may be taken by network
designers that will provide additional operating
margins and ensure the objective BER of 10-10 is
achieved.
- Power Sum NEXT
- Defined but not specd higher than Cat 5
- Power Sum ELFEXT
- Specd in Addendum 4 (Cat 5)
- Dont use 25-pair
- Dont use crossconnect or transition point
22Performance Specifications4 Pair Systems
- Additional Performance Parameters
- Power Sum NEXT
- Power Sum ELFEXT
- Return Loss
- Skew
234 Pair Systems1000BASE-T Noise Sources
250 Mb/s Full Duplex
1000 Mb/s
1000 Mb/s
HUB
NIC
- EMI - Non-cancelable by DSP
- FEXT - Non-Cancelable by DSP
24Cabling StandardsANSI/TIA/EIA-568-A Draft
Addendums
- PS NEXT
- Return Loss
- ELFEXT
25Current Industry Definition Enhanced Category 5
Link and Channel Performance Specifications
Draft figures only and subject to
change Values are calculated and not a
requirement of the Standard
26Current Industry DefinitionCategory 6/Class E
- Industry Specification
- Originally a European de facto standard to be
fully compliant with EN 50173 and show a positive
ACR at 300 MHz - Recently proposed by ISO/IEC 11801-A as Category
6/ Class E specifying positive channel
performance to 200 MHz. - Purpose
- ISO released these channel performance
specifications to IEEE and the ATM forum to
assist them in new network equipment development - Necessary to future proof premises cabling
systems that will utilize high bandwidth leading
edge applications over the life of the cabling
system. - Allows customer a choice of high performance
unshielded or shielded cabling
27Current Industry Definition Category 6/Class E
Link and Channel Performance Specifications
Draft figures only and subject to change
28ACR for Category 5 , 5 , 6 Channel
Cat 5 ACR 3.1dB min..
NEXT Loss
Cat 5 ACR 6 dB min. (prop.)
Cat 6 ACR 18.3 db min. (prop.)
Attenuation
Frequency MHz
Cat 6
Cat 5
Cat 5
29UTP System Installed Channel Cost Comparison
Installed Cost
Materials and Labor
Cat 6 Enhanced Cat 5
127 100 92
Estimated labor by BICSI
08
30Current Industry DefinitionCategory 7/Class F
- Industry Specification
- Originally defined by E DIN 44312-5, Class E
(Germanys effort to establish a next generation
Copper performance category) - Recently proposed for ISO/IEC 11801-A Category
7/Class F specifying positive system channel
performance to 600 MHz. - IEEE has suggested characterization up to 750
MHz. - Purpose
- Originally designed to support 622 Mbps ATM on
two pairs using simple NRZ encoding - A shielded cabling solution that future proofs
premises cabling systems and assures sheath
sharing capabilities for the higher speed
applications.
31Shielded Cable Types
FTP or S-FTP
- FTP Overall foil shield
- S-FTP Overall foil shield plus an additional
braid - 100W, CAT3/4/5/6
- Shield used to improve EMC performance
32Backbone Requirements Effects of Evolving
Networking Traffic Flow
- Centralized server farms vs. departmental servers
- Centralized control of data vs. hard drive
- Databases
- Images
- Presentations and documents
- Intranet, Extranet and Internet
- Evolving network PCs
- Old rule - 80 local, 20 backbone traffic
- New rule - 20 local, 80 backbone traffic
- Shared to switched - now backbone can be the
bottleneck
33Cabling Evolving Backbone Cabling Platforms
Data Rate
Bandwidth
Mb/s
MHzkm
10,000
SM
1,000
500
100
160
10
1984
2000
1997
1994
1988
1986
34Gigabit Ethernet Optical Fibre Physical Layer
Interfaces
Media Access Control (MAC) full duplex and/or
half duplex
Gigabit Media Independent Interface
1000BASE-T Copper PHY encoder/decoder
1000BASE-X 8B/10B encoding/ decoding
1000BASE-LX LWL Xcvr
1000BASE-SX SWL Xcvr
SMF-5km 50um-550m 62.5um-550m
50um-550m 62.5um-220m
802.3ab physical layer
802.3z physical layer
35What Has ChangedSince 62.5 micron was
Standardized?
- Data rate requirements exceeds capabilities of
LEDs - Numerical aperture no longer critical
- LED output power and align improves
- Connector alignment and polishing improves
- Shortwavelength VSCELs are introduced and are the
future for high-speed applications - Fibre Channel
- 622 Mbps ATM
- 1 Gbps Ethernet/1.2 Gbps ATM
- SM Lasers and connector still not
cost-competitive - Gigabit VSCEL 1/3rd the price of LW laser
- Should equate to 1000 plus premium to the
customer
36The FactsOn Next-Generation Optical Fiber
Systems
- Combining laser sources with multimode fiber is a
relatively new concept in the LAN market. - The installed base of fiber is optimized for use
with LEDs - Most combinations of laser sources and multimode
fiber produce superior performance. - Some combinations of multimode fiber and laser
sources produce poorer than expected performance. - Examples of poor performance have been verified
with 62.5um fiber and single mode lasers. - No examples of poor performance of 50 um fiber
have been found. - 50um fiber cable typically 10 to 15 less
expensive.
37Status of StandardsNow is the time to move
forward and make a change
- Gigabit Ethernet
- TR-41.8 (TIA 568 Cabling Standard)
- 50 um fiber recommend by FOTG for inclusion in
next revision of TIA-568 - AMP expects adoption with next revision
- JTC1SC25WG3 (ISO/IEC 11801 Cabling Standard)
- 50 um fiber included in standard
- 50um fiber specifications exists to insure
interoperability
3850 µm CableSupport for Existing Standards
- Maximum power penalty with LEDs - 4.6dB
- Long Wavelength LED Applications
- FDDI, Fast Ethernet, and 155 Mbps ATM
- Power budget supports full 2 km distance
- Short Wavelength LED Applications
- 10Mbps Ethernet and 4/16 Mbps TR
- Specifications do not support full 2 km distance
- However three leading suppliers of transceivers
exceed power specifications - Testing indicates support for 2 km distance
- Uses the same electronics and connectors
39Optical BackbonesDistributed Network Architecture
TC
TC
Equipment Room
Server
TC Telecommunications Closet
40Intra-building Optical Backbones Sizing for
Performance
Bandwidth growth
User Requirements in Mbps
Based on 100 Users/closet and 500m cable length
Backbone Requirements in Mbps
41Optical Cabling Centralized Network Architecture
TC?
Pull Through
TC Telecommunications Closet
42CNA Optical Cabling Sizing for Performance
1000.0
100.0
10.0
User Data Rate in Mbps
Bandwidth growth
1.0
10
100
1,000
Independent of of users Based on 300 meters
cable length
CNA Data Rate in Mbps
43Next-Generation Optical Connectors (Jacks)
568SC
ST
Small-Form Factor
LC
MT-RJ
VF
44The Next Standard 2-Fiber System
On board
Commercially Available Fiber Cable
45Size Does Matter!
- Duplex Plug-Adapter-Plug Interface.
- Specialized cut-outs
- Depth to cable transition 1.95
- Surface Mounted interface
- Drop-In replacement for existing
- 8-position modular connectors
- Depth to cable transition .926
- Fits INTO J-Box
46Small Form Factor ConnectorsSolves the
Electronics Issue
47Issues to be Considered in Selection Process
- Intermateability Specifications (TIA FOCIS)
- Meet or exceed draft TIA connector performance
specifications - Strength of true supporters
- Connector manufacturers
- Transciever manufacturers
- LAN Electronic manufacturers
- Innovation balanced by realiability
- Ease of termination - labor cost reduction
48CONCLUSIONCabling Sub-System Trends
49Thank you
50End of Session 28 EE 8301 ST750-NDr. Baker
E-Mail Address hbaker_at_seas.smu.edu Videotape
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