Transcript DATA COMMUNICATIONS SMU Course #: EE 8301

SMU Course #: EE 8301
NTU Course #: ST 750-N
“Live” Class Call-In Line: (214)768-3068
Tape Problems: [email protected]
DATA COMMUNICATIONS
Session #28 -- Dr. Baker
December 3, 1998
1
www.caida.ord
2
Dennis Heimann
District Sales Manager
AMP Incorporated
3
The Cabling Apple Cart Turns Over
Presented By:
Dennis Heimann, RCDD
District Sales Manager
4
Tony Beam, RCDD
Director of Global Systems Marketing
Gigabit 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!
5
Cabling, LAN Technologies & Standards
Chicken & Egg Story
LAN
Standards
• ATM Forum
• IEEE 802.3
LAN
Technologies
Cabling Trends
• Power Sum
• E-DIN 44312-5 Category 6
• Levels Program
• 622 Mbps ATM
Cabling
Standards
• Gigabit Ethernet
• Enhanced Cat 5
• Cat 6/Class E
• Cat 7/Class F
6
LAN Technologies
Data Rate and Signal Bandwidth
Network
7
Cable Full
Pairs Duplex
Line
Code
Min. Signal Coding Cabling
Bandwidth Levels Category
10 Base-T
2
No
Manch
-ester
10 MHz
2
3
100VGAnyLAN
4
No
NRZ
12.5 MHz
2
3
100 Base-Tx
2
No
MLT-3
32.5 MHz
3
5
155 Mb/s
ATM
2
Yes
NRZ
77.5 MHz
2
5
1000 Base-T
4
Yes
TX/T2
62.5 MHz
5
5?
Gigabit 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
25m
802.3z physical layer
8
1000BASE-T
Cat 5 UTP
Xcvr with DSP
100m
802.3ab
physical layer
Gigabit 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
9
Cabling
Evolving Horizontal Cabling Platforms
1.2 Gbps ATM ?
Bandwidth
MHz
Data Rate
Mb/s
1000BASE-T
1000
1000
155 Mb/s ATM
100
100BASE-Tx
10BASE-T
10
16 Mb/s
Token Ring
10
4 Mb/s
Token Ring
1
10
CAT3
1984
1988
?
CAT4
1992
100
CAT5
1996
CAT X
2000
1
Cabling
The Performance Decision
Margin
Cat 5/Class D
Enhanced
Level 5
Cat 5+
Cat 6/Class E
62.5 µm
Level 6
Level 7
Cat 7/Class F
Headroom!
50 µm
Singlemode
Aggregate Bandwidth
Filtering through the Premises Cabling
Revolution.
11
Current 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
12
Performance Characteristics
Pair-to-Pair Systems (Review)
• Key Performance Parameters
 Near End Crosstalk (NEXT)
 Attenuation
 Attenuation to Crosstalk Ratio (ACR)
XCVR
Pair 2
NIC
13
XCVR
Pair 1
HUB
Performance Characteristics
Attenuation to Crosstalk (Loss) Ratio
NIC
Coupled NEXT Noise
HUB
Transmitter
Receiver
Receiver
Transmitter
Attenuated
Signal
Transmitted
Signal
ACR
Attenuated Signal
14
NEXT Noise
Channel ACR
Minimum for Cat 5
45
40
NEXT Limit
35
30
25
3.1
Minimum ACR
dB
20
15
10
Attenuation Limit
5
0
0
20
40
60
Frequency MHz
15
80
100
But Wait, There’s More
TIA has two draft addenda out for ballot now • SP-4194
• SP-4195
 Proposed TSB to 568-A
 Proposed Addendum No. 5
to 568-A
 Additional Transmission
Performance Specifications
 Additional Transmission
for 100 Ohm 4-Pair Category
Performance
5 Cabling
Specifications for 4-Pair
100 Ohm Enhanced
 Informative not required
Category 5 Cabling
 Requirements
16
SP-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.”
17
Two-connector Topologies?
Other Topologies. . .
(i.e. with cross-connect and/or transition point)
18
SP-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.”
19
So 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.
20
Designed 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 spec’d higher than Cat 5
•Power Sum ELFEXT
•Spec’d in Addendum 4 (Cat 5)
•Don’t use 25-pair
•Don’t use crossconnect or transition point
21
Performance Specifications
4 Pair Systems
• Additional Performance Parameters
 Power Sum NEXT
 Power Sum ELFEXT
 Return Loss
 Skew
Pair 1
Pair 2
100
or
1000
Mb/s
Pair 3
100
or
1000
Mb/s
Pair 4
NIC
22
HUB
4 Pair Systems
1000BASE-T Noise Sources
250 Mb/s Full Duplex
PS NEXT
PS FEXT
1000
Mb/s
1000
Mb/s
Return Loss
NIC
•
•
•
•
23
EMI
NEXT - Cancelable by DSP
Return Loss
FEXT - Non-Cancelable by DSP
EMI - Non-cancelable by DSP
HUB
Cabling Standards
ANSI/TIA/EIA-568-A Draft Addendums
Informative not requirements
Additional Transmission
Performance Specifications
for 100 Ohm 4-Pair Category
5 Cabling
• ELFEXT
• Return Loss
Minimum recommendation for
new installations
Additional Transmission
Performance Specifications
for 100 Ohm 4-Pair
Enhanced Category 5
Cabling
24
• PS NEXT
• Return Loss
• ELFEXT
Current Industry Definition
Enhanced Category 5
Link and Channel Performance Specifications*
Attenuation
P-P NEXT
PS NEXT
ELFEXT
PS ELFEXT
ACR
PS ACR
RETURN LOSS
CHANNEL (dB)
100 Mhz
24
30
27
19
16
6**
3**
10.1
LINK (dB)
100 Mhz
21.6
32
29.3
21
18
10.4**
7.7**
12.1
*Draft figures only and subject to change
**Values are calculated and not a requirement of the Standard
25
Current Industry Definition
Category 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
26
Current Industry Definition
Category 6/Class E
Link and Channel Performance Specifications*
Attenuation
P-P NEXT
PS NEXT
ELFEXT
PS ELFEXT
ACR
PS ACR
RETURN LOSS
CC CHANNEL (dB)
100 Mhz 200 Mhz
21.6
31.8
39.9
34.8
37.1
31.9
23.2
17.2
20.2
14.2
18.3
3.0
15.4
0.0
12.0
9.0
IC CHANNEL (dB)
100 Mhz 200 Mhz
21.6
31.8
41.8
36.9
39.3
34.3
25.2
19.2
22.2
16.2
20.2
5.1
17.7
2.5
12.0
9.0
*Draft figures only and subject to change
27
LINK (dB)
100 Mhz 200 Mhz
18.6
27.3
41.8
36.9
39.3
34.3
25.2
19.2
22.2
16.2
23.2
9.6
20.7
7.0
14.1
12.0
ACR
for Category 5 , 5+ , 6 Channel
80
Cat 5 ACR 3.1dB min..
70
Cat 5+ ACR 6 dB min. (prop.)
NEXT Loss
60
Cat 6 ACR 18.3 db min. (prop.)
dB
50
40
30
20
10
0
0
50
Attenuation
Cat 5
28
100
150
Frequency MHz
Cat 5+
Cat 6
200
UTP System
Installed Channel Cost Comparison
Installed Cost
Materials and Labor*
Cat 6
127%
Enhanced
100%
Cat 5
92%
* Estimated labor by BICSI
08
29
Current Industry Definition
Category 7/Class F
• Industry Specification:
 Originally defined by E DIN 44312-5, Class E (Germany’s 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.
30
Shielded 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
STP or PiMF
 STP or STP-A = 150W IBM Cabling System
 PiMF = 100W “Pairs in Metal Foil” cables
 Individual pairs shielded to improve NEXT performance
 Overall shield used to improve EMC performance
31
Backbone 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
32
Cabling
Evolving Backbone Cabling Platforms
Bandwidth
MHz•km
Data Rate
Mb/s
10,000
SM
??
SW
500
LW
160
SW
SW
LW
1000 Base-F
1.2 Gbps ATM
FDDI
622 ATM
155ATM
Fast
Ethernet
2.5 Gbps
ATM
?
33
1986
1988
1994
100
10
10BASE-F
1984
1,000
1997
2000
Gigabit Ethernet
Optical Fibre Physical Layer Interfaces
Media Access Control (MAC)
full duplex and/or half duplex
Gigabit Media Independent Interface
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
802.3z physical layer
34
1000BASE-T Copper PHY
encoder/decoder
802.3ab
physical layer
What Has Changed
Since 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
35
The “Facts”
On 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.
36
Status of Standards
Now is the time to move forward and make a change
• Gigabit Ethernet:
62.5 µm
50 µm
Single-mode
Short
Wavelenght
Long
Wavelenght
220
550
----
550
550
5,000
• 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
37
50 µm Cable
Support 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
38
Optical Backbones
Distributed Network Architecture
TC
Max 500 m (fibre)
Max 90 m
TC
Equipment Room
Server
TC = Telecommunications Closet
39
User Requirements in Mbps
Intra-building Optical Backbones
Sizing for Performance
Switched
1000
1000.0
Switched
100
100.0
Switched
10
10.0
Shared
100
Shared
10
1, 2 or 5
Segments
1.0
0.5
62.5/125
0.2
Parallel 50 Links
50/125
0.1
Single mode
0
0
Based on 100 Users/closet
and 500m cable length
40
10
100
FDDI
100BaseF
155 ATM
1000
1000BaseF
1.2Gbps ATM
10,000
2.5 Gbps ATM
Backbone Requirements in Mbps
100,000
Next Gen Apps.
Optical Cabling
Centralized Network Architecture
TC?
Max 300 m total (fibre)
Interconnect or splice
Pull Through
Equipment Room
Server
TC = Telecommunications Closet
41
CNA Optical Cabling
Sizing for Performance
User Data Rate in Mbps
Switched
1000
Switched
100Base F
Switched
10
Shared
100
Shared
10
1, 2 or 5
Segments
1000.0
100.0
10.0
1.0
0.5
62.5/125
0.2
0.1
50/125
0
0
0.5
Shared 10Base F
Independent of # of users
Based on 300 meters cable length
42
1.0
10
Switched
10Base F
CNA Data Rate in Mbps
100
Switched
100Base F
1,000
Switched
1000BaseF
Next-Generation Optical
Connectors (Jacks)
Small-Form Factor
43
The Next Standard 2-Fiber System
Commercially Available Fiber Cable
To Hub
On board
Commercially
Available Fiber
Cable
44
Size Does Matter!
• Duplex Plug-Adapter-Plug Interface.
• Specialized cut-outs
• Depth to cable transition = 1.95”
• Surface Mounted interface
568SC
MT-RJ Plug / Jack
• Drop-In replacement for existing
8-position modular connectors
• Depth to cable transition = .926”
• Fits INTO J-Box
45
Small Form Factor Connectors
Solves the Electronics Issue
46
Issues 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
47
CONCLUSION
Cabling Sub-System Trends
Horizontal Cabling Typically Category 5
but quickly changing to
Enhanced Category 5
as minimum requirement
Inter-building Backbone Typically multimode fiber
but should include some
single mode fiber for longer distances
48
Intra-building Backbone Typically 62.5/125
multimode fiber but
50/125 fiber is
recommended for
greater bandwidth
Thank you
49
End of Session #28
EE 8301 ST750-N
Dr. Baker
E-Mail Address: [email protected]
Videotape Problems: [email protected]
50