ECEN5553 Telecom Systems Dr. George Scheets Week 6 Read [11a] "The Unpublicized Sea Change in the Internet" [11b] "MPLS VPN: The Network of Choice" [11c] "MPLS Will Succumb to Internet Economics" [12a] "Do You Know Your Cyberthreats?" [12b] "Stuxnet,

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ECEN5553 Telecom SystemsDr. George ScheetsWeek
6Read 11a "The Unpublicized Sea Change in the
Internet"11b "MPLS VPN The Network of
Choice"11c "MPLS Will Succumb to Internet
Economics"12a "Do You Know Your
Cyberthreats?"12b "Stuxnet, the Real Start of
Cyber Warfare?"12c "2011's Biggest Security
Snafus"12d "Does a Cyber-9/11 Loom?"
Outline (12 October, Lecture 22) DL no later
than 19 October Exam 2 (2 November
Live) Async DL no later than 9 November
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OutlinesReceiveddue 12 October (live)By 19
October (DL)
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3
Ex) Commodity InternetCorporate Internet
Connectivity
From\To OKC DET NYC ISP
OKC - 144 76 60
DET 88 - 28 50
NYC 112 34 - 40
ISP 110 100 90 -
310/280 I/O _at_ OKC ? 640 Kbps 194/186 I/O _at_ NYC ?
448 Kbps 278/166 I/O _at_ DET ? 576 Kbps
4
Ex) IP with QoS Corporate Commodity Internet
Connectivity
Detroit
576 Kbps
MPLS VC, OKC - Detroit
Internet Service Provider Network
OKC
768 Kbps
448 Kbps
MPLS VC, NYC - OKC
NYC
From/To OKC DET NYC ISP
OKC - 144 76 60
DET 88 - 28 50
NYC 112 34 - 40
ISP 110 100 90 -
Detroit NYC No change. OKC Port Speed must be
bumped to relay Detroit ? NYC corporate traffic.
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Leased Line at OKC ? ISP

• Outbound
• OKC?Det 144
• OKC?NYC 76
• OKC?ISP 60
• Det ?NYC 28
• NYC ? Det 34

• Inbound
• Det?OKC 88
• Det?NYC 28
• NYC?OKC 112
• NYC?Det 34
• ISP ? OKC 110

From/To OKC DET NYC ISP
OKC - 144 76 60
DET 88 - 28 50
NYC 112 34 - 40
ISP 110 100 90 -
Total Outbound 342 Kbps Total Inbound 372
Kbps Leased Line Size gt 744 Kbps Leased Line
768 Kbps minimum.
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Carrier Leased Line Network
Trunks
Byte Aware
Leased Line
Cross-Connect
Carrier reserves BW from pool for our use. Ex)
For a 384 Kbps connection, Cross-Connects assign
6 byte sized TDM time slots 8000 times/second
688000 384 Kbps.
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Internet Service Provider Backbone
Trunks
Packet Aware
Leased Line
Router
ISP Routers assign BW for our use on Random, as
needed basis via StatMux Packet Switching.
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Internet Service Provider Network
PC
Trunks
Leased Line
Router
Corporate customers might attach via Edge Router
Leased Lines.
WS
9
Internet Service Provider Backbone
Leased Line
Router
Internet Cloud Trunks use StatMux Packet
Switching
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Internet (Inside the Cloud)

• Example

Internet Router
100 Mbps Trunk
?? 1.54 Mbps Connections P(Access Line is
Active) 10
How many access lines can this switch support?
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Internet (Inside the Cloud)

• Infinite Buffers
• "OK" so long as Average Offered Input Rate lt
  Output Line Speed

Internet Router
100 Mbps Trunk
?? 1.54 Mbps Connections P(Access Line is
Active) 10
How many access lines can this switch
support? 100 Mbps/154 Kbps 649 (theoretically)
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Internet (Inside the Cloud)

• Negligible Buffers
• OK so long as Instantaneous Offered Input Rate
  lt Output Line Speed

Internet Router
100 Mbps Trunk
?? 1.54 Mbps Connections P(Access Line is
Active) 10
How many access lines can this switch
support? With 404 users, 99.99 sure Input Rate lt
Line Speed
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Bounds on Packet Switch Carrying Capacity
100 Mbps Trunk, 1.54 Mbps Inputs with 154
Kbps average loads

• Lower Upper90 553 64999
  485 64999.9 439 64999.99
  404 649

Instantaneous Input lt Line Speed
Where switch could operate
Where switch probably operates
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WAN Connectivity Options

• Leased Line
• Cross Connects are byte aware
• Circuit Switched
• Resources dedicated to customer use for duration
  of connection
• Connection Set-Up Procedure
• Coordinates byte time slot assignments between
  switches
• Bytes are assigned at 1/8000th second intervals
  (TDM)
• Switch then repetitively moves input bytes to
  designated output byte time slots
• Pricing a function of connection size distance

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Carrier Leased Line Network
PC
Trunks
Byte Aware
Leased Line
Cross-Connect
Corporate customers might attach via Edge Router
Leased Lines.
WS
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Leased Lines (Inside the Cloud)

• OK so long as Sum of Input Line Speeds
  lt Output Line Speeds

Leased Line Cross-Connect
100 Mbps Trunk
?? 1.54 Mbps Connections P(Access Line is
Active) 10
How many access lines can this switch
support? 64
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Leased Lines (TDM)
Leased Line Cross-Connect

• TDM time slots are moved from input to output
• TDM switch is not "packet aware"
• Time slots are allocated whether or not there is
  any traffic on them

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Circuit Switched connections waste bandwidth for
bursty traffic.
traffic NYC to OKC
1.54 Mbps Line Speed
146 Kbps Average
time
Idle Time gtgt Active Time
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Given 100 Mbps of Bandwidth...

• 64 1.54 Mbps Circuit Switched TDM Customers
  with 154 Kbps average load 100
  availability
• 404 - 649 1.54 Mbps Packet Switched StatMux
  Customers with 154 Kbps average load
  99.99 availability

64 x 154 Kbps 9.856 Mbps
404 x 154 Kbps 62.22 Mbps
More Bursty Data Traffic can be moved with the
Packet Switched StatMux network.
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Switched Network Carrying Capacities
Carrying Capacity
Packet Switch StatMux
Circuit Switch TDM
0 Bursty
100 Bursty 100 Fixed Rate
0 Fixed Rate
Offered Load
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Network Cost...

• Can be spread over 64 Leased Line customers
• Can be spread over 404 Internet customers
• The Internet Is a Packet Switched StatMux
  network Largely hauling bursty data
  traffic Effectively hauling bursty data traffic
  Inexpensive (compared to a Leased Line)

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Internet Performance
This type of plot valid for all real world full
duplex statistically multiplexed
switches Ethernet, Internet, Frame Relay
Number of dropped packets
Average Delay for delivered packets
0
100
Trunk Offered Load
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Internet Performance Effect of priorities
Average Delay for low priority packets Average
Delay for all delivered packets Average Delay
for high priority packets
0
100
Trunk Offered Load
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Internet Performance Effect of priorities
Number of low priority drops Number of dropped
packets Number of high priority drops
0
100
Trunk Offered Load
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Internet Backbone Engineering

• Option A)Deploy best effort RoutersRapidly
  Deploy Trunk BandwidthKeep Trunks Lightly Loaded
• Delays will be small
• Dropped packets will be few
• Quality fine for all traffic

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Backbone Engineering Option A
Number of dropped packets
Average Delay for delivered packets
0
100
Keep Trunks Lightly Loaded
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Internet Backbone Engineering

• Option B)Deploy more complex QoS
  enabled Routers Deploy fewer, more heavily
  loaded Trunks Give preferential treatment to
  interactive Voice/Video
• Option A seems to be preferred today

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Backbone Engineering Option B High Priority
delay at 50 Load Delay for all
traffic at 20 Load
Average Delay for low priority packets Average
Delay for all delivered packets Average Delay
for high priority packets
0
70
Heavier Trunk Load
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Internet Traffic Growth
Source August 2007 Network World
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Frame Relay

• ANSI Standard covering OSI Layer 2
• Accessed by Routers
• Derived from X.25 Protocol Dumps almost all
  error checking Requires fiber on the long haul
• Uses Virtual Circuits (PVCs) VC differs from
  Datagram Long Term Connection Requires Carrier
  intervention to change

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Frame Relay

• 1st Commercial Deployment 1990
• WilTel ? Worldcom? bankrupt ? Verizon
• Cheaper alternative to Leased Lines
• Faster alternative to X.25
• Internet a small network in 1990
• Academia
• Military
• Some commercial traffic
• See CUCKOO'S EGG to get a flavor

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Frame Relay

• 7 Application
• 6 Presentation
• 5 Session TCP
• 4 Transport TCP
• 3 Network IP
• 2 Data Link Frame Relay
• 1 Physical

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Wide Area Connectivity Options

• Frame Relay Network
• Switches are frame aware
• Virtual Circuit is assigned trunk BW via StatMux
• BW required based more so on average input rates
• Routing through system determined in advance
• Pricing a function of Port Speed, CIR, and maybe
  distance

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Frame Relay

• Committed Information Rate (CIR) Is a Quality of
  Service Guarantee "Guaranteed" minimum
  Bandwidth Should be set gt average traffic
  during appropriate peak period
• Port Connection Speed a.k.a. Port Speed or Burst
  Speed Bandwidth you can burst to
  provided network capacity exists. Set Bit
  Rate of Access Line

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Frame Relay Packet Format
Header includes 10 bit Data Link Connection
Identifier (DLCI) - Locally Unique (FR
ports)Trailer includes 2 byte CRC Sequence that
only checks Header I/O decisions based on FR
address look-up table.
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Frame Relay Backbone
Trunks
Frame Aware
Leased Line
FR Switch
Frame Relay Cloud Full Duplex Trunks use
StatMux Packet Switching
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Ex) Frame RelayCorporate Connectivity
Detroit
PVC, OKC - Detroit
Carrier Frame Relay Network
OKC (Hub)
PVC, NYC - OKC
NYC
Router
Local Carriers dedicate bandwidth to our use.
Carrier provides random Packet Switched StatMux
connectivity via PVCs.
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Ex) Frame Relay Corporate Connectivity
Detroit
384 Kbps
VC, OKC - Detroit
Carrier Frame Relay Network
OKC
576 Kbps
320 Kbps
VC, NYC - OKC
NYC
From/To OKC DET NYC
OKC - 144 76
DET 88 - 28
NYC 112 34 -
OKC Outbound 220 28 34 Kbps OKC Inbound 200
28 34 Kbps Leased Line Size gt 2282 564
Kbps Leased Line 576 Kbps minimum.
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Ex) IP with QoS Corporate Connectivity(Same as
Frame Relay)
Detroit
384 Kbps
MPLS VC, OKC - Detroit
Internet Service Provider Network
OKC
576 Kbps
320 Kbps
MPLS VC, NYC - OKC
NYC
From/To OKC DET NYC
OKC - 144 76
DET 88 - 28
NYC 112 34 -
OKC Outbound 220 28 34 Kbps OKC Inbound 200
28 34 Kbps Leased Line Size gt 2282 564
Kbps Leased Line 576 Kbps minimum.
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Ex) Frame RelayCorporate Internet Connectivity
Detroit
ISP
576 Kbps
Resized PVC, OKC - Detroit
640 Kbps
Carrier Frame Relay Network
OKC
Router
448 Kbps
960 Kbps
Resized PVC, NYC - OKC
NYC
From/To OKC DET NYC ISP
OKC - 144 76 60
DET 88 - 28 50
NYC 112 34 - 40
ISP 110 100 90 -
OKC FR Leased Line must handle NYC Det traffic
? Internet, OKC ? corporate, and Detroit/NYC
pass-thru traffic.
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Leased Line at OKC ? FR Net

• Outbound
• OKC?Det 144
• OKC?NYC 76
• Det?NYC 28
• NYC?Det 34
• ISP?Det 100
• ISP?NYC 90

• Inbound
• Det?OKC 88
• Det?NYC 28
• Det?ISP 50
• NYC?OKC 112
• NYC?Det 34
• NYC?ISP 40

From/To OKC DET NYC ISP
OKC - 144 76 60
DET 88 - 28 50
NYC 112 34 - 40
ISP 110 100 90 -
Total Outbound 472 Kbps Total Inbound 352
Kbps Leased Line Size gt 944 Kbps Leased Line
960 Kbps minimum.
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Frame Relay

• End-to-End DelayInternet Frame Relay gt
  equivalent sized Leased
  Line Network
• Cost TendencyInternet lt Frame Relay lt
  equivalent sized Leased
  Line Network

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300,000 Byte Data File

• 1460 Layer 7 Bytes per Ethernet Packet
• 205 full packets one with 700 Bytes
• 40 Bytes TCP IP
• 6 Bytes Frame Relay
• 2051506 1746 309,476 Bytes
• 2,475,808 bits / 1,536,000 bits/sec 1.612
  seconds
• Overhead 20646/309,476 3.06

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Worldwide Frame Relay Revenues
Declining.
10.5B 00
21B 04
12.7B 01
6.25B 98
8.00B 99
15.4B 02
16.7B 03
0.08B 93
3.87B 97
0.23B 94
0.65B 95
1.28B 96
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