large scale interconnects wide area network wan3488

7/27/2019 Large Scale Interconnects Wide Area Network Wan3488

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Large Scale

Interconnects

Wide Area Network (WAN)


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Agenda

LAN/WAN Introductions

Real-World Example

Wireless WANs WAN Potential


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Bus Network with Backbone Interconnections Between Different Network Types

Token Ring Network Topology Self-healing Ring TopologyTwo rings

Star Network Topology

Network Topology


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FDDI

Developed by the American National Standards Institute (ANSI) standardscommittee in the mid-1980s - at a time when high-speed engineering workstationswere beginning to tax the bandwidth of existing LANs based on Ethernet and TokenRing - the Fibre Distributed Data Interface (FDDI) specifies a 100 Mbit/s token-passing, dual-ring LAN using fibre-optic cable.

Token RingIn 1984, IBM introduced the 4 Mbit/s Token Ring network. Instead of the normal

plug and socket arrangement of male and female gendered connectors, the IBMdata connector (IDC) was a sort of hermaphrodite, designed to mate with itself.

Although the IBM Cabling System is to this day regarded as a very high qualityand robust data communication media, its large size and cost - coupled with thefact that with only 4 cores it was less versatile than 8-core UTP - saw Token Ringcontinue fall behind Ethernet in the popularity stakes. It remains IBM's primary

LAN technology however and the compatible and almost identical IEEE 802.5specification continues to shadow IBM's Token Ring development.


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EthernetEthernet was developed in the mid 1970's by the Xerox Corporation, and in

1979 Digital Equipment Corporation DEC) and Intel joined forces with Xerox tostandardise the system. The Institute of Electrical and Electronic Engineers(IEEE) released the official Ethernet standard in 1983 called the IEEE 802.3after the name of the working group responsible for its development, and in1985 version 2 (IEEE 802.3a) was released. This second version is commonlyknown as "Thin Ethernet" or 10Base2, in this case the maximum length is

185m even though the "2" suggest that it should be 200m.

Fast EthernetFast Ethernet was officially adopted in the summer of 1995, two years after agroup of leading network companies had formed the Fast Ethernet Alliance to

develop the standard. Operating at ten times the speed of regular 10Base-TEthernet, Fast Ethernet - also known as 100BaseT - retains the sameCSMA/CD protocol and Category 5 cabling support as its predecessor higherbandwidth and introduces new features such as full-duplex operation and auto-negotiation.


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Client-ServerClient-server networking architectures became popular in the late 1980s andearly 1990s as many applications were migrated from centralisedminicomputers and mainframes to networks of personal computers. Thedesign of applications for a distributed computing environment required thatthey effectively be divided into two parts: client (front end) and server (back

end). The network architecture on which they were implemented mirrored thisclient-server model, with a user's PC (the client) typically acting as therequesting machine and a more powerful server machine - to which it wasconnected via either a LAN or a WAN - acting as the supplying machine.


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Ethernet LANFDDI: Fiber Distributed Data Interface

100 Mbps


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Peer-to-peerIn a Peer-to-peer networking architecture each computer (workstation) hasequivalent capabilities and responsibilities. There is no server, and computers

simply connect with each other in a workgroup to share files, printers, andInternet access. It is practical for workgroups of a dozen or less computers,making it common in many SOHO environments, where each PC acts as anindependent workstation that stores data on its own hard drive but which canshare it with all other PCs on the network.

P2P computingBy early 2000 a revolution was underway in an entirely new form of peer-to-peer computing. Sparked by the phenomenal success of a number of highlypublicised applications, "P2P computing" - as it is commonly referred to -heralded a new computing model for the Internet age and had achievedconsiderable traction with mainstream computer users and members of the

PC industry in a very short space of time.

The Napster MP3 music file sharing application went live in September1999, and attracted more than 20 million users by mid-2000


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Gigabit EthernetThe next step in Ethernet's evolution was driven by the Gigabit EthernetAlliance, formed in 1996. The ratification of associated Gigabit Ethernetstandards was completed in the summer of 1999, specifying a physical layerthat uses a mixture of proven technologies from the original EthernetSpecification and the ANSI X3T11 Fibre Channel Specification:

Use of the same variable-length (64- to 1514-byte packets) IEEE 802.3 frameformat found in Ethernet and Fast Ethernet is key to the ease with which existinglower-speed Ethernet devices can be connected to Gigabit Ethernet devices,using LAN switches or routers to adapt one physical line speed to the other.


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FDDI- Fibre DistributedData Interface specifiesa 100 Mbit/s token-passing, dual-ring LANusing fibre-optic cable.

Network Topology

Self Healing Net Dual Ring


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WAN Introductions


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WANIntroductions

LAN (local area network) - Network that linkscomputers, printers and other devices locatedin an office, a building or even a campus

WAN (wide area network) - System thatextends for greater distances and is used to

connect LANs together.


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Interconnections

To link LANs into a WAN

DSL - Speeds up to a very fast 1.54 Mbps

T1- A digital transmission link with a total signalingspeed of 1.544 Mbps

T3 - Comprised of 28 T1 lines - 45 Mbps

OC1 - 51.85 Mbps

OC3 - 155.52 Mbps

Frame Relay - A telecommunication service

designed for cost-efficient data transmission forintermittent traffic between LANs and between end-points in a WAN


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Key Components of a WAN I

Access Router-the gateway

devices connectedto LANs

WAN connections- the actualconnectivitybetween sites


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Key Components of a WAN II

DSL (Digital Subscriber Line)

1.54 Mbps

To delivers reliable, high-speed

office-to-office connectivity over

traditional copper wires

Affordable to most small businesses

Security - Prevent any unauthorized people fromaccessing communications between sites


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Real-World Example


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WAN (Real-World Example)

Large architecture firm 4 offices

Portland, Seattle, Los Angeles, Washington DC

Reasons for implementing a WAN Share Internet connection

Access email

Transfer files

Foster the sense of one firm but four offices


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The Past

Frame Relay

Past to 2002

Hub-and-spoke topology

Portland was hub 64 Kbps, 128 Kbps, 256 Kbps to other offices

Issues Expensive

Inflexible Requires routers which needed maintenance

No way to manage

Difficult to troubleshoot


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The PastFrame Relay

Portland

768K

Local

Telco

768K

Frame Relay

Non-Meshed

Los AngelesSeattle Washington D.C.

LocalTelco

256K

LocalTelco

T1

LocalTelco

384K

Internet

256K

256K

256K

384K

T1

T1

T1


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The Recent Past

Leased Lines

2002 to 2003

Time Division Multiplexed Leased Lines

50% cost savings over Frame Relay Increased speed to 1.544Mbp for all offices

Issues Still hub-and-spoke

No more flexibility, just higher speeds and lower costs


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The Recent PastLeased Line

Portland

T1 (Leased Line)T1 (Internet) Local

Telco

T1(Inter

net)

Los Angeles

Seattle

Washington D.C.

Local

Telco

Local

TelcoT1 (leased line)

T1 (Leased Line)

T1 (Internet)Local

Telco

Internet

T1(Internet)

T1 (Internet)

T1(Internet)

Telco

T1 (Leased Line)

T1 (Internet)

T1

(Inte

rnet)

T1(Lea

sedLine)

T1 (Leased Line)T1 (Leased Line)

T1(L

easedL

ine)


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The Present and Future

MPLS Multi-Protocol Label Switching 2003 to Future Fully meshed - 3 Mbps Layer 2 label switching

A label is added to the packet

Benefits QOS Quality of Service Complete control end-to-end No IP routing so pre-defined path, no hops Extend Ethernet No routers More secure Cost savings Converged network (voice, data, video)


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The Present

9Mbps

3Mpbs

3Mbps

3Mbps

Public Internet

Public Switched

Telephone

Network

Local / Long Distance

Videoconferencing

Portland

Seattle

Los Angeles

D.C.

Wide Area Network

Provider

Partially converged MPLS Network

Local

Telco(PacBell)

Local

Telco

(Verizon)

Local

Telco

(Qwest)

isdnbackup

isdnbackup

isdn

backu

p

isdnback

up


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The Future

10/100

10/100

10/100

10/100

backup

backup

backu

p

backup

Public Internet

Public SwitchedTelephone

Network

Local / Long Distance

Videoconferencing

Portland

Seattle

Los Angeles

D.C.

Wide Area Network

Provider

Fully converged MPLS Network (voice/

video/data)

backup

b

acku

p

backup

Metro

Ethernet

Metro

EthernetMetro

Ethernet

Metro

Ethernet


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Why not use a VPN?

Issues Quality, flexibility, management and ease of

use when compared to a private WAN

Internet is stable but not a priority in downtime Vendors cannot guarantee Service LevelAgreements (SLAs)

Requires advanced knowledge of IP Security

(IPSec) Required special routers with VPN

accelerators


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WAN enhancement

Riverbed Steelhead appliance Reduces the latency of the WAN

Latency is the reason why you dont get your full bandwidth For example, 1.544 Mbps is actually 900 Kbps

TCP/IP has inherent limitations

Reduces 87% of protocol overhead and unnecessary round-trips. Increasing bandwidth by 2.6 times

Uses special data sequencing to cache data and only sendacross changes

Transaction prediction

Examples Users in DC connecting to Portland like LAN Backup warm servers across the WAN and replicate the changes

http://www.riverbed.com/
http://www.riverbed.com/http://www.riverbed.com/


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Wireless WANs


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Enabling Mobile Users

Mobile Users and Wireless Technology: The Beginning Started with proprietary wireless technologies Applied to Automated Data Collection years before 802.11a/b/g 802.11b is still most common in industry Small, hand-held wireless computing allow workers to work

throughout an entire plant or warehouse, collecting and receivingdata real-time Referred to as Wireless Local Area Networking (WLAN)

Wide Area Applications of Wireless Technology

IP Tunneling Wireless Hops Wireless Wide Area Networking (WWAN)


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IP Tunneling:

Roaming Across Networks

What if users want to work wirelessly across multiplesites? Could use DHCP and have wireless infrastructure installed at

each site IP Tunneling can provide static IP addressing and session

persistence Generally uses privately owned networks


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IP Tunneling:

Roaming Across Networks

What is IP Tunneling? IP Tunneling uses encapsulation to carry entire original packets

across a router using IP The outer IP and other header information is then stripped and

the original packet is provided on the wired network Mobile IP is a similar method, defined by TCP/IP Most implementations require a client and/or server to manage Our solution uses encapsulation and spanning tree to extend the

wireless network across routers Allows roaming across subnets seamlessly


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IP Tunneling Example


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Wireless Hops:

Extending Wired Networks

Wireless Hops can connect and extend networks Alternative to wired options for connecting buildings that are

100s of feet or even miles apart

Saves trouble and expense Usually 802.11bs range is a few hundred feet, but vendors use

high power directional antennas to extend significantly Must have LOS (Line of Sight)


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Wireless Hops Example


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Wireless WANs

Butwhat if users need to work across a much

wider geographic area such as a whole city,or even several states???


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Wireless Wide Area Networks:

Helping bring your favorite stuff to a store near you!

A well-known customer


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Wireless WANs

Some WWAN Fun Facts This technology allows route drivers to receive and transmit real-

time data wherever they are (Earlier solutions involved batcheddata, sent by modem)

Latest networks are shared use, packets-as-needed rather thancircuit-based, making them cheaper

Several providersmust match standard and provider Must subscribe to providers service Some interfaces use SIM cards for activation, just like mobile

phones Basically a cellular technology used for mobile phones as well

Limited bandwidths, speed depending on technology andnumber of channels used

Similar to modem speeds: 14.4 Kbps to 114 Kbps Some newer technologies promising 384 Kbps (EDGE)


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Wireless WANs

Some Service Types Code-Division Multiple Access (CDMA) Uses multiplexing,

which allows numerous signals to occupy a single transmissionchannel

General Packet Radio Services (GPRS) Packet-basedusedto provide data to phone and laptops

Global System for Mobile communication (GMS) Most widelyused worldwide and is the de facto standard in Europe

Enhanced Data GSM Environment (EDGE) Newer fasterservice available since around 2001


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Wireless WANs

WWAN Enables Mobile Users to: Download the days deliveries and orders Enter new orders Track inventory a store has on hand Capture signatures

Print receipts Run reports Close out day

Other Customers Include:

UPS DHL Blue Dart (Fedex) Camera based device allowed real estate agents and appraisers

to collect property photos


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Local and Wide Area

Wireless


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WAN Potential


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Upgrade Fast WAN, More Storage

SEC upgrades infrastructure

Increased traffic in imaging and opticalcharacter-recognition files

System will handle 30 to 50 terabytes ofdata in first year

2 high-speed 45-Mbps pipes at everyoffice


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Cisco, 3Com fire up new WAN routers

Cisco faces more competition than ever

Complete refresh of enterprise WANaccess routers for 2004

Addresses security concerns/obsolescent technology

will combine VoIP, VPN, firewall and

intrusion-detection system (IDS) support


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Start-up crams more data onto WAN

Orbit boosts throughput on WAN connections 10times over TCP

TCP can lead to throttled-back connections,

Orbit uses a feedback mechanism to use fullnetwork connection

Sold in pairs with one at each end of a WAN link

Pricing ranges from $12,000 for T-I throughputto $50,000 for 200M bit/sec throughput


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VoIP for Global Companies

Potential saving of 95%, VoIP averages 2cents per minute

International long distance rates average53 cents per minute

International teleconferencing ratesaverage 20-35 cents per minute

Three year window of opportunity


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How some rural communities are installing

high-speed Internet connections

Cable franchises are not interested in wiringrural areas for broadband

70 small communities are bridging the digital

divide on their own Kutztown PA, spent $5 million to bring residents

cable TV, telephone and Internet service

Fiber-optic lines connect the entire town to theinternet; costs is less than half that of privatecarriers


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Thank You

large scale interconnects wide area network wan3488

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