Transcript PPT

Paper Delivery
I want a Hard Copy...
 ...but will be ‘happy’ to print it here
 If you submit Electronically...
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 Word
Perfect (V9.0 or earlier)
 Word (2000 or earlier)
 format for Cannon BJ-200ex
or another Cannon Bubble Jet
 You are still liable for ‘Detail’ errors
Homework
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Term Paper due 12 April
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Readings:
[16] “Reconstructing Transmission Networks
using ATM and DWDM”
[17] “Scaling Optical Data Networks with
Wavelength Routing”
[18] “New Juice for Analog Modems”
Signaling
In Channel Signaling:
Uses same resources for signaling &
traffic
(phone - Central Office)
 Out of Channel Signaling
a.k.a. Common Channel Signaling:
Uses separate resources for signaling &
traffic
(Central Office - Central Office)
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Signaling
is the ‘nervous system’ of the telephone
network
 Advantages of CCS vs. ICS
Signaling hardware reduced
Fraud reduced
Faster call set up
Centralized Switching Control
Intelligent Network Features
 Signaling System 7 (OSI Layers 1-7)
protocol used on CCS
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Odds & Ends
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PBX
Customer owned or leased voice switch
May have data capabilities
Smaller versions a.k.a. Hybrid Key Systems
Contains many useful features for businesses
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Centrex
Carrier offering which mimics PBX
functionality
Network Synchronization
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Public Network is broken up into Sync Regions
Each region is driven by a Master Clock which may
be sync’d to GPS
Selected tandems sync to Master Clock
CO’s sync to a tandem, PBX’s sync to a CO
Connections between regions are Plesiocronously
timed
Elastic Stores help smooth out timing differences
Slips will screw up data or video traffic & (maybe)
compressed voice
SONET
Optical Signal Standard OC-N (OSI Level 1)
 STS-1 Multiplexing format (OSI Level 2)
Uses byte interleaving
 Basic Building Block: 51.84 Mbps STS-1
 Extensive OA&M capabilities
 Designed to move traffic synchronously
(traffic bytes mapped to specific STS-1 bytes)
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SONET
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SONET Cross-Connects, ADM, OA&M
capabilities, & Ring Architectures allow rapid
fault recovery
Current technology requires optical-to-electrical
conversions at switches, hence STS protocol.
Typical Carrier TDM Backbone Speeds
2.5 Gbps OC-48
10 Gbps OC-192
OC-1, OC-3, OC-12 are common slower speeds
Note that ATM
has no Physical Layer...
7 Application
 6 Presentation
 5 Session
 4 Transport
 3 Network
 2 Data Link
 1 Physical
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TCP
TCP
IP
ATM
SONET fits the bill!
5 Session
 4 Transport
 3 Network
 2 Data Link
 1 Physical
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TCP
TCP
IP
ATM & SONET
SONET
LAN based ATM products frequently have SONET built in,
which usually suffices given the small distances involved.
WAN based ATM usually needs additional SONET hardware
due to a combination of long distances, high bit rates, mixed
traffic, and the OA&M requirements of carrier backbones.
SONET Ring
Physical Network
OSI Level 1 & 2
SONET ADMs
& Cross-Connects
Fiber Optic Cables
in the ground
ATM Backbone
Logical Network
OSI Level 2
Trunks may be over
TDM SONET based
Cross-Connects.
Carrier Backbone
ATM Switches
ATM Backbone riding over SONET
Private ATM ‘Edge’ Switch
Carrier Frame
Relay Switch
Carrier Backbone
ATM Switch
ISP Router
Carrier
Voice Switch
You gotta have SONET!
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Covers OSI Layer 1 (& Layer 2)
Just about every WAN protocol we’ve discussed does
not have a physical layer...
ATM, OSI Layer 2
 Frame Relay, OSI Layer 2
 Frame Relay over ATM
 Internet Protocol, OSI Layer 3, over Frame Relay over
ATM
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Exception! Last Mile Connectivity...
T1 & T3 Leased Lines, OSI Layer 1& 2
Traffic Growth
Data
Voice
time
Traffic Growth
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It’s becoming expensive to continually increase
SONET TDM rates
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OC-768 in the labs
Cheaper to multiplex slower speed TDM signals
onto the fiber
Take OC-48’s or OC-192’s...
 ...driving lasers tuned to different frequencies...
 ...shoot everything down one fiber.
Result = WDM (OSI Layer 1)
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f1
f2
f3
f4
OC-192
OC-192
OC-192
OC-192
FDM
Different channels use some of
the frequency all of the time.
frequency
f1
f2
f3
f4
OC-192
OC-192
OC-192
OC-192
WDM
FDM over fiber is called
Wavelength Division Multiplexing.
frequency
TDM
Zoom in on one laser frequency band,
and you’ll see SONET based TDM.
frequency band f1
1
2
3
4
WDM: 32 OC-48’s
#1 STS-48
Laser
@ f1
Detector
#1
#1 STS-48
#2 STS-48
Laser
@ f2
Detector #2 STS-48
#2
Fiber in the
ground
#32 STS-48
Laser
@ f32
Optical
Combiner
Optical
Splitter
Detector #32 STS-48
#32
Systems are also available that can map an arbitrary input
(doesn’t have to be SONET based) onto an optical wave.
WDM
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Typical Deployed system:
32 WDM OC-48 = 79.63 Gbps
16 WDM OC-192 = 159.25 Gbps
For Sale:
100+ WDM OC-48
In the labs:
1,000+ WDM OC-48
In the labs & seeing initial deployment
optical cross-connects
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These devices will likely chew into SONET market
share
ATM Backbone
Logical Network
OSI Level 2
OC-48 trunks may be
WDM based optical
Cross-Connects.
Carrier Backbone
ATM Switches