OutlinesReceived

due13 March 2000

OutlinesReceived

due13 March 2000 18%

HomeworkHomework Review for Midterm (1 March 2000)Review for Midterm (1 March 2000) Research PaperResearch Paper ReadingsReadings

[5] “Virtual Private Networks”[5] “Virtual Private Networks”[6] “Internet QoS: A Big Picture”[6] “Internet QoS: A Big Picture”[7] “IP Routers: New Tool for Gigabit[7] “IP Routers: New Tool for Gigabit

Networking”Networking”[8] “Corporate-Class Internet? Don’t[8] “Corporate-Class Internet? Don’t

Count on It!”Count on It!”

BridgeBridge Operates at OSI Layers 1 & 2Operates at OSI Layers 1 & 2

Follows MACFollows MAC Uses MAC addresses to switch packetsUses MAC addresses to switch packets May be capable of minor protocol conversionsMay be capable of minor protocol conversions If properly placed will improve performanceIf properly placed will improve performance

Filters unneccesary trafficFilters unneccesary traffic Improves EfficiencyImproves Efficiency Increases average Bandwidth to each end user Increases average Bandwidth to each end user Tends to increase delay Tends to increase delay acrossacross the bridge the bridge

RouterRouter

Operates at OSI Layers 1, 2, & 3Operates at OSI Layers 1, 2, & 3

capable of making complex routing decisionscapable of making complex routing decisions‘peers into’ packets‘peers into’ packets

Very useful on Large Networks with Very useful on Large Networks with multiple end-to-end pathsmultiple end-to-end paths

Switched HubSwitched Hub

ASK VENDOR!!!ASK VENDOR!!! May be a multi-port bridgeMay be a multi-port bridge May route (OSI Layer 3) first packet of a May route (OSI Layer 3) first packet of a

flow (OSI Layer 5), bridge (OSI Layer 2) flow (OSI Layer 5), bridge (OSI Layer 2) remainder remainder

The InternetThe Internet VASTVAST collection of interconnected collection of interconnected

networks networks Key Building Block:Key Building Block:

Routers running IPv4 (Layer 3)Routers running IPv4 (Layer 3) Router link speeds range from 56 Kbps to Router link speeds range from 56 Kbps to

2.5 Gbps2.5 Gbps Hierarchical AddressingHierarchical Addressing

username@machine.institution.domainusername@machine.institution.domain

ISO OSI Seven Layer ModelISO OSI Seven Layer Model

Layer 7 ApplicationLayer 7 Application NetscapeNetscape Layer 6 PresentationLayer 6 Presentation Win95 (API) Win95 (API) Layer 5 Session Layer 5 Session Win95 (TCP)Win95 (TCP) Layer 4 TransportLayer 4 Transport Win95 (TCP)Win95 (TCP) Layer 3 Network Layer 3 Network Win95 (IP)Win95 (IP) Layer 2 Data LinkLayer 2 Data Link 3Com NIC3Com NIC Layer 1 Physical Layer 1 Physical 3Com NIC3Com NIC

Internet Service Provider BackboneInternet Service Provider Backbone

ISP ‘Cloud’ Trunks use StatMux & Packet Switching

Router

TrunksLeased Line

11Feb00 Traceroute to WWW.CISCO.COM11Feb00 Traceroute to WWW.CISCO.COM 3 Internal OSU routers 3 Internal OSU routers 2 OneNet routers2 OneNet routers

border3-border3-okc-oc3atmokc-oc3atm.onenet.net .onenet.net 4 SBC routers4 SBC routers

edge1-fa0-0-0.edge1-fa0-0-0.okcyokokcyok.swbell.net.swbell.net 2 Williams routers2 Williams routers

williams1-oc3-gr1. williams1-oc3-gr1.dal2dal2.dbn.net.dbn.net 7 BBNPlanet routers7 BBNPlanet routers

p1-0.p1-0.lsancalsanca1-br1.bbnplanet.net1-br1.bbnplanet.net p7-3.p7-3.paloaltopaloalto-nbr2.bbnplanet.net\-nbr2.bbnplanet.net\

2 Cisco routers2 Cisco routers

11Feb00 Traceroute to LABRATS.COM11Feb00 Traceroute to LABRATS.COM

3 Internal OSU routers3 Internal OSU routers 2 OneNet routers2 OneNet routers

OKCOKC 7 Williams Routers7 Williams Routers

OKCOKC DallasDallas TulsaTulsa

1 Labrat Router1 Labrat Router

Virtual CircuitsVirtual Circuits Routing decisions made Routing decisions made onceonce when when

circuit is set upcircuit is set up All packets part of info transfer followAll packets part of info transfer follow

the same path the same path Frame Relay & ATM use VirtualFrame Relay & ATM use Virtual

Circuits Circuits

Allows switch resources (buffer space, bandwidth) Allows switch resources (buffer space, bandwidth) to be set aside for specific traffic flowsto be set aside for specific traffic flows

DatagramsDatagrams

Routing decisions are made “on the fly”Routing decisions are made “on the fly”multiple times multiple times

(every time a packet hits a Router) (every time a packet hits a Router) Packets may follow different pathsPackets may follow different paths IP uses DatagramsIP uses Datagrams

Routers get no ‘advance warning’ of Routers get no ‘advance warning’ of packet flows.packet flows.

What works* on the Internet?What works* on the Internet? Non Real Time Data ServicesNon Real Time Data Services

EMailEMailUsenetUsenetFaxFax

Interactive Data Based ServicesInteractive Data Based ServicesFile Transfer ProtocolFile Transfer ProtocolTelnetTelnetWorld Wide WebWorld Wide Web

Excellent

Good

*Provided you’re not trying to sip bandwidth through a straw.

What works* on the Internet?What works* on the Internet?

Interactive Data Based ServicesInteractive Data Based ServicesWhite BoardingWhite BoardingApplication SharingApplication Sharing

Non-Interactive One-Way AudioNon-Interactive One-Way Audio Interactive Two-Way AudioInteractive Two-Way Audio One way motion videoOne way motion video Interactive motion VideoInteractive motion Video

Fair

Poor

*Provided you’re not trying to sip bandwidth through a straw.

TCP, UDP, and IPTCP, UDP, and IP 20 year old Protocols 20 year old Protocols

Designed for dataDesigned for dataOne Priority & “Best Effort” servicesOne Priority & “Best Effort” servicesNo QoS GuaranteesNo QoS GuaranteesAvailable bandwidth depends on otherAvailable bandwidth depends on other users users

TCP (Layer 4 & 5) provides reliable transferTCP (Layer 4 & 5) provides reliable transfer UDP (Layer 4 & 5) provides unreliable UDP (Layer 4 & 5) provides unreliable

transfertransfer

Interactive Telephony over the INTERNET

Interactive Telephony over the INTERNET

““... is a toy until delay and voice-quality ... is a toy until delay and voice-quality problems are overcome”problems are overcome”

Network World, 19 August 1996Network World, 19 August 1996

Interactive VOICE & VIDEO over the INTERNET

Interactive VOICE & VIDEO over the INTERNET

Is not ready for Prime TimeIs not ready for Prime Time Delay & Quality problems Delay & Quality problems not likely to be solved not likely to be solved under the under the

current system...current system... ...although throwing Bandwidth at the problem will ...although throwing Bandwidth at the problem will

alleviatealleviate Has a place for the user whose main concern is $$$$ or Has a place for the user whose main concern is $$$$ or

convenienceconvenience

Thinking of moving time sensitive traffic over the Internet?

Check back in 2-3 years when...

Thinking of moving time sensitive traffic over the Internet?

Check back in 2-3 years when...

Priorities Enabled (IPv6 and/or DiffServ)Priorities Enabled (IPv6 and/or DiffServ) Resources Guaranteed Resources Guaranteed

(Resource Reservation Protocol (RSVP) or (Resource Reservation Protocol (RSVP) or equivalent is deployed)equivalent is deployed)

Flat rate pricing is goneFlat rate pricing is gone

Pros of Using the InternetPros of Using the Internet

Any-to-Any ConnectivityAny-to-Any Connectivity It’s Inexpensive (save $$$$)It’s Inexpensive (save $$$$) Tons of valuable information availableTons of valuable information available Excellent marketing/sales toolExcellent marketing/sales tool

Cons of Using the InternetCons of Using the Internet Any-to-Any Connectivity Any-to-Any Connectivity

puts all attached machines at riskputs all attached machines at risk

Slightly higher risk of Theft of TrafficSlightly higher risk of Theft of Traffic Tons of Worthless Information Available Tons of Worthless Information Available No QoS guarantees or Guaranteed BandwidthNo QoS guarantees or Guaranteed Bandwidth

May have trouble rapidly moving large filesMay have trouble rapidly moving large filesMay have trouble reliably moving timeMay have trouble reliably moving time

sensitive trafficsensitive traffic

WARNING: SECURITY HAZARD!

Worldwide ISP RevenuesWorldwide ISP Revenues

$1.3

5B ‘9

5$2

.40B

‘96

$5.2

8B ‘9

7$8

.42B

‘98

$12.

10B ‘9

9

$0.1

9B ‘9

4

Source:Data Communications

Internet PerformanceInternet Performance

0% 100%Trunk Offered Load

Probability of dropped packets

Average Delay fordelivered packets

Backbone EngineeringBackbone Engineering

Option A)Option A)Deploy ‘best effort’ RoutersDeploy ‘best effort’ RoutersRapidly Deploy Trunk BandwidthRapidly Deploy Trunk BandwidthKeep Trunks Lightly LoadedKeep Trunks Lightly Loaded Delays will be smallDelays will be small Dropped packets will be fewDropped packets will be few Quality fine for Interactive Voice/VideoQuality fine for Interactive Voice/Video

Backbone EngineeringBackbone Engineering

Option B)Option B)Deploy more expensive QoS enabledDeploy more expensive QoS enabled

Routers Routers Deploy fewer, more heavily loadedDeploy fewer, more heavily loaded

Trunks Trunks Give preferential treatment to Give preferential treatment to

Voice/VideoVoice/Video

Which is less expensive in the long run?Which is less expensive in the long run?

Connectionless vs. Connection Oriented

Connectionless vs. Connection Oriented

ConnectionlessConnectionless* Packet delivery may be out of order * Packet delivery may be out of order * Packet delivery NOT guaranteed* Packet delivery NOT guaranteed* Packets may be mangled* Packets may be mangled* End User’s responsibility to fix any* End User’s responsibility to fix any problems problems

Connection OrientedConnection Oriented* Packet delivery in order* Packet delivery in order* Packet delivery usually guaranteed* Packet delivery usually guaranteed