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ECEN5553 Telecom SystemsDr. George Scheets Week #5Read[7c] "How can the Internet have too many routes and not enough addresses?"[8a] "The Cognitive Net is Coming"[8b] "The Internet of Things"[9a] "Browse at your Own Risk"[9b] "The Data Brokers: Selling Your Personal Information"[10a] "Internet QoS: Pieces of the Puzzle"[10b] "Innovation on the Web Lives and Dies with Net Neutrality"Exam #1 Lecture 16, 24 September (Live) No later than 1 October (Remote DL)Outline 8 October 2014, Lecture 22 (Live) No later than 15 October (Remote DL)

exam 1 90 points
Exam #1 (90 points)
  • Friday, 24 September (Local)Remote Distant Learners, no later than 1 October
  • Work 3 of 4 pages
  • Closed Book & Notes
  • Calculators & phones are NOT allowed...Set up numerical problem for full credit
  • Most equations are provided (on 5th page)
  • Approximately 40% of upcoming exam will be lifted from the Fall 2013 Exam #1
  • Anything in the notes, on Power Point, or in reading assignments is fair game
on short answer or essay questions
On Short Answer or Essay Questions
  • Answer the Question!
  • Memory Dump in the space provided
    • Knowledgeable individual can write more
    • Grader will look for "Power Point bullets"
    • Same remarks as instructor\'s typically not required
  • To get "A" or "B", instructor needs to walk away with impression you could\'ve said more
    • Got space? Anything else pertinent to add?
    • It is NOT necessary to write small or fill up allotted space to get a good score!
    • Lost points? No comments? → Insufficient info provided
    • Rule of Thumb: "X" point question needs > "X" facts
the internet
The Internet
  • VAST collection of interconnected networks
  • Key Building Block:Routers running IP (Layer 3)
  • Router link speeds range up to 100 Gbps
  • Hierarchical Alpha-Numeric [email protected]
tracer ou t e to www cisco com
Traceroute to WWW.CISCO.COM
  • 4 Internal OSU-Stillwater routers
  • 3OneNet routers (all in OKC? Tulsa?)
  • 2 Qwest routersdal-edge-18.inet.qwest.net
  • 2 NTT routersae-19.r08.dllstx09.us.bb.gin.ntt.net
  • Akamai Technologies (Hosting Service)
  • (12:55 pm, 11Sept14, rtt = 9 msec, 11 routers)
tracer ou t e to www tulsa com
Traceroute to WWW.TULSA.COM
  • 4 Internal OSU-Stillwater routers
  • 3OneNet routers (Tulsa?)
  • 5 Cogent Communications routers
    • te4-4.1052.ccr01.tul01.atlas.cogentco.com
    • be2128.ccr21.den01.atlas.cogentco.com
    • be2126.ccr21.slc01.atlas.cogentco.com
  • 2 Ace Data Center routers (Hosting Service)
    • ve15.ar05.prov.acedc.net
  • End server (198.57.177.235) probably in Provo, Utah area
  • (1:20 pm, 11Sept14, rtt = 60 msec, 14 routers)
isp routes sometimes roundabout
ISP Routes Sometimes Roundabout

Launched 13 September 2014, 2 miles from OSU campus

  • 1 Scheets\' home router
  • 4 AT&T routers
    • adsl-70-233-159-254.dsl.okcyok.sbcglobal.net
    • ggr3.dlstx.ip.att.net
  • 4 Cogent Communications routers
    • Be2032.ccr22.dfw01.atlat.cogentco.com
    • te0-0-2-1.rcr12.okc01.atlas.cogentco.com
  • 3 ONENET routers
    • OKC?
  • 3 Oklahoma State routers
  • (12:30 pm, 11Sept14, rtt= 84 msec, 15 routers)
fall 2007 weird traceroute seen by student tulsa to osu stillwater
Fall 2007 Weird TraceRoute Seen by StudentTulsa to OSU Stillwater
  • Tracert launched from Tulsa, hitAtlantaWashington, D.C.IllinoisKansas CityTulsaOklahoma CityOSU Stillwater
internet service provider backbone
Internet Service Provider Backbone

Trunks

Access Line

Router

Switched Network, full duplex trunks.

Access lines attach to corporate routers &

routers of other ISP\'s.

osu backbone
OSU Backbone

Trunks

Access Line

Router

Access lines attach to Ethernet switches,

Onenet and other routers.

iso osi seven layer model
ISO OSI Seven Layer Model
  • Layer 7 Application
  • Layer 6 Presentation Windows API
  • Layer 5 SessionWindows TCP
  • Layer 4 Transport Windows TCP
  • Layer 3 NetworkWindows IP
  • Layer 2 Data Link PC NIC
  • Layer 1 Physical PC NIC
internet protocal v4 20 bytes
Internet Protocal v4 (20 Bytes)

4 Bytes

TOS

TTL

Source Address

Destination Address

802 3 ethernet packet format
802.3 Ethernet Packet Format

Bytes: 7 1 6 6 2

MAC

Destination

Address

MAC

Source

Address

20 20 6-1460 4

IPv4

TCP

Data + Padding

CRC

ipv4 header
IPv4 Header
  • Contains two addresses
    • 4B Source Address
    • 4B Destination Address
    • 4B = 32b = 4.295 G potential addresses
  • Example address
    • 10001011 01001110 01000010 11010011
  • Dotted Decimal Format simplifies
    • x.x.x.x
    • Treat each byte as Base2 number, write in Base10
    • Above number simplifies to 139.78.66.211
ip header
IP Header
  • Alpha-numeric name simplifies further
    • es302.ceat.okstate.edu
    • Domain Name Servers convert to numerical
  • All OSU Stillwater addresses are of form
    • 139.78.0.0 to 139.78.255.255
  • IP addresses & alpha-numeric names are effectively backwards
    • 139.78.66.211 mapped to es302.ceat.okstate.edu
ip vs ethernet addresses
IP vs Ethernet Addresses
  • Ethernet has a flat address space
    • Similar to Social Security Number
      • Adjacent #\'s nearby or on other side of globe?
    • Huge look up tables required to avoid flooding
      • Need 70.37 trillion entries
  • IP has a hierarchical address space
    • Packet delivery similar to Mail delivery
      • Adjacent IP addresses frequently nearby
    • Reduces size of look up tables
      • Don\'t need 4.295 billion entries
isp router overload
ISP Router Overload

Source:

1 October 2007

Network World

Fall 2011

Level3

BGP entries

375,550 IPv4

7,210 IPv6

Peak Traffic

8.0 Tbps IPv4

500 Mbps IPv6

isp router overload1
ISP Router Overload
  • Core BGP entries as of 19 August 2014
    • IPv4 about 520,400
    • IPv6 about 18,300
  • 2nd week of August
    • Caused some problems
    • Some routers had 512,000 entry limit

source:

bgp.potaroo.net

Network World , 13Aug2014, "Internet outages expected to abate as routers are modified, rebooted"

tcp header
TCP Header

4 Bytes

Source Port

Destination Port

Sequence Number

ACK Number

Window

Checksum

wireshark packet capture
Wireshark Packet Capture
  • This interaction starts with a click on a Firefox bookmark to a distance calculator. Firefox then triggers a query to an OSU Domain Name Server asking for the IPv4 address of www.indo.com. This is next followed by a TCP 3 way handshake to open logical connections, an HTTP request to download the distance calculator page, and the beginning of the file transfer.
iso osi seven layer model1
ISO OSI Seven Layer Model

MSS = 1460 B =

Size of Layer 6 & 7 info per packet

  • Layer 7 Application
  • Layer 6 Presentation Windows API
  • Layer 5 Session Windows TCP
  • Layer 4 Transport Windows TCP
  • Layer 3 Network Windows IP
  • Layer 2 Data Link PC NIC
  • Layer 1 Physical PC NIC

Ethernet

Payload = 1500 B

tcp window size layer 4 effects end to end throughput
TCP Window Size (Layer 4) Effects End-to-End Throughput
  • Suppose
    • Window Size (set by PC) = 64 KB
      • Microsoft Windows XP
    • Maximum Segment Size = 1 KB
    • Server can send < 64 unACK\'d packets

PC

Server

3,000 Km

throughput on 64 kbps line
Throughput on 64 Kbps Line

PC

Server

Packet #1

3,000 Km, 64 Kbps line

  • NPD = Prop Delay / Packet inject time
    • Prop Delay = distance / EM energy speed = 3,000,000 m / 200,000,000 m/sec = 0.015 seconds
    • Packet inject time = 8,376 bits / 64 Kbits/sec = 0.1309 seconds (7B PPP, 20B IPv4, 20B TCP)
    • NPD = 0.015 / 0.1309 = 0.1146
    • Front end of packet arrives at far side prior to back end being transmitted.
throughput on 64 kbps line1
Throughput on 64 Kbps Line

PC

Server

#1

Packet #2

#1 ACK

  • At this instant in time...
    • 2nd unACK\'d packet is being transmitted
    • ACK for #1 enroute back to server
      • TCP+IP+Layer 2 → 47 bytes if PPP
    • When ACK#1 arrives at server, only packet #2 is unacknowledged.
  • Will 64 packet unACK\'d limit be reached?
    • No. At most, 1 packet likely unACK\'d.

3,000 Km, 64 Kbps line

throughput on 45 mbps line
Throughput on 45 Mbps Line

PC

Server

#3

#2

#1

3,000 Km, 45 Mbps line

  • NPD = Prop Delay / Packet inject time
    • Prop Delay = distance / EM energy speed = 3,000,000 m / 200,000,000 m/sec = 0.015 seconds
    • Packet inject time = 8,376 bits / 45 Mbits/sec = 186.1 μseconds (PPP, IPv4, TCP overhead)
    • NPD = 0.015 / 0.0001861 = 80.60
    • 80.60 average sized packets will fit back-to-back on this line
throughput on 45 mbps line1
Throughput on 45 Mbps Line

PC

Server

Packets 1 - 64

  • At this instant in time, the Server...
    • Has transmitted 64 packets w/o ACK.
    • Has hit window limit. Halts.

3,000 Km, 45 Mbps line

throughput on 45 mbps line2
Throughput on 45 Mbps Line

PC

Server

Packets 2 - 64

#1

ACK#1

  • At this instant in time,
    • The PC has processed 1st packet & sent an ACK
    • The Server is still halted, waiting for ACK #1.
      • When ACK #1 arrives, server can then transmit one additional packet.
      • Other ACK’s arrive fast enough to allow back-to-back transmission of next group of 64 packets

3,000 Km, 45 Mbps line

can estimate throughput with a time line
Can Estimate Throughput with a Time Line

to = 0

t1

t2

t3

time

  • to: Leading edge of 1st packet injected
  • t1: Trailing edge of 64th packet injected
    • t1 = (64*1047B)(8b/B)/(45 Mb/sec) = 11.91 msec
  • t2: Leading edge of 1st packet hits far side
    • 15 msec (propagation delay)
    • If ACK injected right away...
  • t3: ...ACK arrives at server at t = 30 msec
  • Process Repeats...
can estimate throughput with a time line1
Can Estimate Throughput with a Time Line

to = 0

11.91

15.00

30.00

time (msec)

  • This system can transmit
    • 64(1,047) = 67,008 B = 536,064 bits
    • Every 30 msec (one round trip time)
    • Estimated throughput = 536,064/0.03 = 17.89 Mbps
  • Actual throughput a bit lower
    • 1st ACK not transmitted until packet #1 fully received...
      • ... and processed by PC
    • 65th packet not transmitted until ACK #1 fully received...
      • ... and processed by Server
can estimate throughput with a time line2
Can Estimate Throughput with a Time Line

to = 0

11.91

15.00

30.00

time (msec)

  • Need to be able to fill the pipe for 1 RTT
    • 30 msec in our example
    • 45 Mbps * .030 sec = 1.35 M b = 168,750 B = 168,750/1,047 = 161.2 packets
    • Window Size needs to be = 161.2 segments*1,000 bytes/segment = 161,200 B
  • Actually would need another segment or two to cover source & sink processing
tcp header1
TCP Header

4 Bytes

Source Port

Destination Port

Sequence Number

ACK Number

Window

Checksum

udp header 8 bytes
UDP Header (8 Bytes)

4 Bytes

Source Port

Destination Port

Checksum

For interactive real-time traffic, usually used

with Real Time Transport Protocol (12 bytes).

virtual circuits
Virtual Circuits
  • Routing decisions made once when circuit is set up
    • Concerned switches have internal Look-Up tables updated
  • All packets part of info transfer follow the same path
  • Allows option of setting aside switch resources (buffer space, bandwidth) for specific traffic flows
  • MPLS, Frame Relay, ATM, & Carrier Ethernet use VC’s
datagrams
Datagrams
  • IP uses Datagrams
  • Routing Tables updated independently of individual traffic flows
    • Routers continuously talking with each other
    • Packets may follow different paths
  • Routers get no advance warning of specific packet flows.
ip is connectionless
IP is Connectionless

20 20 up to 1,460

IP

TCP

Data + Padding

I/O decisions based on IP address & look-up table.

Tables updated independent of traffic, hence path

thru network may suddenly change.

TCP is connection oriented.

tcp udp and ip
TCP, UDP, and IP
  • 30+ year old Protocols Designed for dataOne Priority & “Best Effort” servicesNo QoS GuaranteesAvailable bandwidth depends on other users
  • TCP (Layer 4 & 5) provides reliable transfer
  • UDP (Layer 4 & 5) unreliable transfer
  • IP at Layer 3
  • Arbitrary Protocols at Layers 1 & 2
internet traffic 2008 2009 comparison
InternetTraffic2008 - 2009 Comparison

source: http://www.sandvine.coms

fixed access internet traffic profile
Fixed Access Internet Traffic Profile

2013

Source: www.sandvine.com/downloads/documents/Phenomena_2H_2012/ Sandvine_Global_Internet_Phenomena_Snapshot_2H_2012_NA_Fixed.pdf

& www.sandvine.com/downloads/general/global-internet-phenomena/2014/1h-2014-global-internet-phenomena-report.pdf

2012 mobile access internet traffic profile
2012 Mobile Access Internet Traffic Profile

http://www.sandvine.com/downloads/documents/Phenomena_2H_2012/

Sandvine_Global_Internet_Phenomena_Snapshot_2H_2012_NA_Mobile.pdf

2013 mobile access internet traffic profile
2013 Mobile Access Internet Traffic Profile

source: www.sandvine.com/downloads/general/global-internet-phenomena/2014/1h-2014-global-internet-phenomena-report.pdf

internet traffic growth
Internet Traffic Growth

source: "The Road to 100G Deployment", IEEE Communications Magazine, March 2010

internet traffic growth1
Internet Traffic Growth

source: www.cisco.com/c/en/us/solutions/collateral/service-provider/visual-networking-index-vni/VNI_Hyperconnectivity_WP.html

slide50
VoIP
  • PC to PC
  • Internet Phone to Internet Phone

Commodity

Internet

slide51
VoIP
  • PC to Wired Phone
  • Internet Phone to Wired Phone

Gateway

Commodity

Internet

Phone

System

voip wired phone to wired phone
VoIP (Wired Phone-to-Wired Phone)
  • Carrier prioritizes VoIP traffic (DiffServ)
  • Paths nailed down (MPLS)
  • Gateways control # of voice calls
  • Good Quality Possible with this configuration

Gateway

Gateway

Phone

System

Phone

System

"QoS Enabled"

Internet

traditional videoconferencing
Traditional Videoconferencing

384 Kbps fixed

rate output(video + audio)

Camera

Dedicated BandwidthNetwork:

Circuit Switched TDM

6 Bytes @ 8000 times/sec

*State Owned Fiber *ISDN

Codec

Audio

Video

Codec

2002 non traditional videoconferencing
2002 Non-Traditional Videoconferencing

384 Kbps fixed

rate output(video + audio)

Now > 784 Kbps

Packet Switched

StatMuxed

Prioritized

*State Owned Fiber

This is technique being

used in this class for

video to & from Tulsa &

Stillwater.

Camera

Codec

Audio

Video

Codec

internet video streaming
Internet Video Streaming

The Internet

Quality of

Received Stream

depends on:

(1) Size of your

pipe.

(2) Internet

congestion.

(3) Server congestion.

Disk Drive

PC

internet video streaming1
Internet Video Streaming

Disk Drive

Stillwater

Video Server

generates

packets.

Fairly steady generation if server not swamped.

Rate depends on pipe size.

internet video streaming2
Internet Video Streaming

Internet

Disk Drive

Video Server

Packets exit at an irregular rate.

Random delays.

Non-Dedicated Bandwidth(Packet Switched, Stat Muxing)

isp routes can be roundabout
ISP Routes can be Roundabout

Launched 30 January 2007, 2 miles from OSU campus

  • 1 Dr. Scheets\' home router
  • 6 SBC routers
    • adsl-70-233-191-254.dsl.okcyok.sbcglobal.net
    • ex2-p11-0.eqchil.sbcglobal.net
  • 7 Level3 routers
    • Te-3-2.Chicago1.Level3.net
    • kscymo2wcx010-pos9-0-oc48.wcg.net
    • tulsok6wcx2-pos11-0-oc48.wcg.net
  • 5 ONENET routers
    • at least 1 in Oklahoma City
  • 3 Oklahoma State routers

Using DiffServe, End-to-End

performance on

this 22 router path ...

isp routes can be roundabout1
ISP Routes can be Roundabout

Launched 5 September 2008, 2 miles from OSU campus

  • 1 Scheets\' home router
  • 4 SBC routers
    • adsl-70-233-191-254.dsl.okcyok.sbcglobal.net
    • bb1-g1-0-2.rcfril.sbcglobal.net
  • 1 Equinix router
  • 1 Transitrail router
    • onenet.chcgil01.transitrail.net
  • 3 ONENET routers
    • at least 1 in Oklahoma City
  • 4 Oklahoma State routers
  • rtt = 55 msec

...may be worse

than End-to-End

performance on

this 14 router path when not using DiffServ.

internet service provider network

LAN

LAN

Internet Service Provider Network

PC

Trunks

Leased Line

Router

Corporate sites using Internet as WAN.

Can pay ISP extra $$ →

Traffic between sites gets preferential treatment.

PC

interactive voice video over the commodity internet best effort no priorities
Interactive VOICE & VIDEO over the commodity INTERNET(Best Effort, No Priorities)
  • Is not ready for Prime Time
  • Delay & Quality problems difficult to solve under the current system...
  • ...although throwing Bandwidth at the problem will alleviate
  • Has a place for the user whose main concern is $$$$ or convenience
internet service provider network1

LAN

LAN

Internet Service Provider Network

PC

Trunks

Leased Line

Router

Routers operate at Layers 1-3.

PC’s operate at Layers 1-7.

Routers do not monitor opening of TCP

Logical Connections. RSVP would change this.

PC

multi protocol label switching
Multi-Protocol Label Switching
  • Enables Virtual Circuits
    • End-to-End Paths nailed down
    • Traffic Engineering Easier
    • Resource Reservation Easier
  • Seeing fairly widespread ISP deployment
internet qos
Internet QoS
  • Most every ISP is installing or testing one or more of following...
    • DiffServ
    • MPLS
    • Resource Reservation capability
    • Pricing structure to reflect different QoS

... but they are not yet widely deployed.

  • As a result, currently the Commodity Internet remains mostly
    • Best Effort, FIFO Routing
thinking of moving large amounts of high quality time sensitive traffic over the commodity internet
Thinking of moving large amountsof high quality, time sensitivetraffic over the Commodity Internet?

Check back in 2-3 years when...

  • Priorities Enabled (IPv6 and/or DiffServ)
  • Resources Guaranteed (Resource Reservation Protocol (RSVP) or equivalent is deployed)
  • Flat rate pricing is gone
the internet is
The Internet Is...
  • A superb information source
    • Sometimes difficult to separate wheat from chaff
    • IEEE Communications or Proceedings
      • Peer Reviewed
    • IEEE Spectrum
      • Reviewed by editor
    • Jane Doe\'s Web site
      • Reviewed by Jane Doe
  • A good marketing tool
the internet is a security nightmare
The Internet Is... a Security Nightmare
  • Any-to-Any connectivity is both strength and weakness
    • Tracert yields Router IP Addresses
    • Could Telnet or HTTP to many. Password?
  • Espionage
    • Read “The Cuckoo’s Egg” by Cliff Stoll
      • Former #1 on New York Times Best Seller
      • Recommended by Dr. Scheets’ Mom
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