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IT 1303: Fundamentals of Computing Networking Prepared by Nguyen Xuan Phong

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Table of content

Content Page number

Table of content 2

Abstract 3

Introduction to Gigabit Ethernet 4

1. Background 52. Discussion 6

2.1 Feature 6

2.2 How does it work? 6

2.3 Advantages and Disadvantages 10

2.4 Introduction 10Gigabit Ethernet 11

3. Conclusion 13Introduction to Wireless Networks IEEE802.11 14

1. Background 152. Discussion 15

2.1 WLAN architecture 15

2.2 WEP 16

2.3 Create a WLAN 18

2.4 Advantage 19

3. Conclusion 19Reference 20

List of Figure

Figure1: Gigabit Ethernet Frame Format 4Figure 2: Stratix II GX Gigabit Ethernet MAC in a Control Plane

Application5

Figure 3: Nowadays, some mainborads integrate Gigabit Ethernet

gateway.9

Figure 4: The instruction of standard 802.3ae* 11

Figure 5: 10Gigabit Ethernet in Local Area Networks 12Figure 6: 10Gigabit Ethernet in Local Area Networks 12Figure 7: WLAN Overview. 15Figure 8: Peer to peer Overview 16Figure 9: WIFI network with access point 18Figure 10: WIFI network without access point 19


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Abstract

Nowadays, networking is an integral part of Information Technology. It

plays an essential role in transferring data or communicating among computers.

The demands of connecting, transferring, communicating data are more and more.

As the result, networking improves quickly and becomes one of the most

disputatious topics. There are many kinds of Network. This report will mention

two typical networks in present: Gigabit Ethernet and Wireless Network

IEEE802.11.


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1. Background:Ethernet was originally defined as a LAN technology to interconnect client

PCs at line rates of 10 Mbps through switches (also known as hubs). Over

the years, client line rates increased to 100 Mbps (Fast Ethe1net) and

switches supporting 1,000 Mbps (Gigabit Ethernet) line rates emerged to

interconnect multiple 10/100 Ethernet hubs. The near ubiquitous use of

Ethernet technologies in LANs has resulted in significant economies of

scale, driving down the component costs, including the switch devices.

Today, Gigabit Ethernet is a cost-effective technology when used to do the

following:

y Connect multiple devices to a local CPUy Interconnect multiple boards across a backplane for datay Control signaling between line cards and the host CPU within an

embedded system

y Figure 1 shows a typical 10-Gbps line card using a Stratix II GX FPGAfor backplane interconnect, including the Stratix II GX Gigabit Ethernet

MAC for control signaling to the host CPU.

Figure 2: Stratix II GX Gigabit Ethernet MAC in a Control Plane Application


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2. Discussion:2.1Feature:

Ethernet technology was built and standardized to do the function in data

link layer and physical layer. This technology supports providing

services point-to-point and some topologies such as ring, hub and spoke.

Gigabit Ethernet is improved step of Ethernet Technology, applied

popularly in LAN- Local Area Network in recent two decades. Not only

the feature of classic Ethernet Technology, but Gigabit Ethernet also

develops and adds more functions and new applications for satisfying the

demands of various kinds of services, speed transfer, material transfer

In present, Gigabit Ethernet protocols are standardized in typical IEEE

802.3z, 802.3ae, 802.1w. Gigabit Ethernet provides speed of transferring

about 100 Mbps, 1000 Mbps, or few thousands Mbps and support manytransferring physical material such as copper cable, fiber optic with half-

duplex or full-duplex.

Gigabit Ethernet also supports many kinds of service for connecting

point-to-point, point-to-multipoint, multi-point especially Ethernet

Line Service ( ELS ), Ethernet Relay Service ( ERS ), Ethernet

Multipoint Service ( EMS ). One of the most important applications,

which gathered all functions of others, is VLAN Virtual LAN. That

service allows companies, enterprises, groups to connect each other from

geographic distance becoming a common network.

2.2How does it work?2.2.1CAT 5 Cable:

Gigabit Ethernet allows transferring data with speed of 1000Mbps but

uses cable in CAT 5 UTP standard (Unshielded Twisted Pair). How is

the CAT 5 cable- which normally can transmit in 100Mbps - able totransmit in 1000 Mbps?

CAT 5 Ethernet Cable has 4 pairs, but according to standard 10BaseT

and 100BaseT there are only 2 pairs (4 wires). One pair is used for

transmitting data and the other one is used for multiplying data.


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Pin

Color

Function1

White with Green

+TD

2

Green

-TD

3

White with Orange

+RD

4Blue

Not Used

5

White with Blue

Not Used

6

Orange

-RD

7

White with Brown

Not Used

8

Brown

Not Used

Ethernet standard uses anti- electromagnetic interference technology.

If the two wires are parallel, the wire closet to the source of the noise gets

more interference than the noise further away. This results in an uneven loadand a damaged signal.


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2.2.2 Transmitting data:

According to 10BaseT standard, each Bit that computer wants to

transfer is the only transferred physical cipher. That means transferring 8

bits must have 8 levels of signal transferred in wire. If the speed is

10Mbps, the pulse frequency is 10MHz, because each pulse is a

transferred bit.

100BaseT uses encode called 8B/10B, which each group of 8 Bits is

encrypted into signal 10 Bits. Thus, the difference from 10BaseT is each

Bit does not present one signal in the wire. The pulse frequency is 125

MHz (10/8 * 100).

In short, the CAT 5 cable has pulse frequency 125MHz.

Gigabit Ethernet changes the encode signal? From each bit one signal in

10BaseT standard or 8 bit 10 signal in 100BaseT standard?

So, each signal in Gigabit Ethernet represents 2 bits. In other words,

change from using 2 levels of voltage which represent 0 and 1 to 4 levels

of voltage which represent 00, 01, 10 and 11.

Instead of using 4 wires in cable, Gigabit Ethernet uses all wires

(8wires). Most importantly, all wires use Bi-directional.

10BaseT and 100BaseT use different pairs to transmit data or multiply

data, however, in Gigabit Ethernet cable some pairs are used as both

transmitting data and multiplying data.

Gigabit Ethernet use CAT5 cable, and the pulse frequency is 125Mhz,

but it can transmit more data in the same time:

125 MHz x 2 bit /each signal (one pair) x 4 signals one time = 1000Mpbs

The technology to transmit data is called 4D-PAM5 ( Four Dimensional

Pulse Amplitude Modulation 5 ), it uses 5 levels of voltage ( the fifth

voltage is used for checking ).

Caution: Gigabit Ethernet dont have pulse frequency of 1000MHz but it

is 1000Mbps, it uses 125MHz like Fast Ethernet (100BaseT), it can reach

the speed of 1000Mbps because it transmits 2 Bits one time and uses 4pairs in cable. This following table will help you check:


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Pin

Color

Function1

White with Green

+BI_DA

2

Green

-BI_DA

3

White with Orange

+BI_DB

4

Blue

+BI_DC5

White with Blue

-BI_DC

6

Orange

-BI_DB

7

White with Brown

+BI_DD

8

Brown

-BI_DD

Figure 3: Nowadays, some mainborads integrate Gigabit Ethernet gateway.


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2.3Advantages and Disadvantages:2.3.1 Advantage:

Gigabit Ethernet has some advantages:- Gigabit Ethernet has the ability of suporting to transfer data in

high speed very well.

- CSMA/CD Ethernet allows tranferring data with wide

bandwith and large amount of data.

- Propotious in providing conecting services to custommers. No

require customers to change technology, upgrade Local Area

Network, interface connection.

- Almost data networks in companies, organizations are builtbase on Ethernet technology. It will reduce significant amount

of cost investment.

- Easy to extend and upgrade.

- Standized in group of IEEE.802.3. It makes easy to connect,

the adaptable connection is high among devices from many

manufactures.

- Easy to manage the network.

2.3.2 Disadvantge:Gigabit Ethernet also has some disadvantages:

-Cannot deliver specific bit rates or limit jitter to deliver

effective QoS (Quality of Service)

-Cannot prioritize traffic to deliver effective CoS (Class of

Service)

- Uses 802.1p and 802.1q to try and achieve QoS and CoS.

These technologies are still in development.

- RSVP protocol not well supported

- Not originally designed to support real-time voice or video

traffic

- Not a WAN solution


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2.4Introduction 10Gigabit Ethernet:2.4.1 10Gigabit Ethernet:

The 10 Gigabit Ethernet or 10GbE or 10 GigE standardwas first published in 2002 as IEEE Std 802.3ae-2002 and is

the fastest of the Ethernet standards. It defines a version of

Ethernet with a nominal data rate of 10 Gbit/s, ten times as fast

as Gigabit Ethernet.

Figure 4: The instruction of standard 802.3ae*

The 802.3ae-2002 and 802.3ak-2004 amendments have

been consolidated into the IEEE 802.3-2005 standard. The

other amendments will be consolidated into IEEE Std 802.3-

2008 which has not yet been published.

10 Gigabit Ethernet supports only full duplex links which can

be connected by switches. Half Duplex operation and

CSMA/CD (carrier sense multiple access with collision detect)

are not supported in 10GbE.

The IEEE 802.3ae* 2002 ( 10 Gigabit Ethernet standard)

is different in some respects from earlier Ethernet standards in

that it will only function over optical fiber, and only operates in

full-duplex mode (collision-detection protocols areunnecessary). Ethernet can now progress to 10 gigabits per

second while retaining its critical Ethernet properties, such as

the packet format, and the current capabilities are easily

transferable to the new standard.


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2.4.2 Application for 10Gigabit Ethernet:1) 10Gigabit Ethernet as a Fabric Interconnect

2) 10Gigabit Ethernet in Local Area Networks

Figure 5: 10Gigabit Ethernet in Local Area Networks

- 10Gigabit Ethernet in Metropolitan and Storage Applications

- 10Gigabit Ethernet in Wide Area Networks

Figure 6: 10Gigabit Ethernet in Wide Area Networks2.4.3 Summary:

The 10Gigabit Ethernet is a developed step in improving

Ethernet speed. In future cost of installment and alternativematerial might be decreased, it is time for 10Gigabit Ethernet to

become popular.


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3. Conclusiony Gigabit Ethernet retains simplicity and Manageability of Ethernet and Fast

Ethernet

y Easy to integrate with existing LAN equipmenty Increase in backbone over Fast Ethernet with a minimal support staffy Extra bandwidth helps deal with unplanned changes and additions to the

network

y A powerful backbone/server solutiony Works with your existing traffic management system


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Introduction

WIRELESS NETWORK IEEE 802.11

Wireless Networking is a new solution for model networks such as offices,

family house or large place that Ethernet cannot apply. Installing a Wireless

network is basically simpler than Ethernet (Wired Network). You can add more

PCs or other nodes into network easily.

In few recent years, we can see the improvement of telecom and information

technology. Demands of communicating information anytime, anywhere have

made the term Wireless appear recently. One of the strongest applications is

definitely telephone. Similarly, in network, IEEE802.11 did a revolution and

became a standard, to contribute the powerful improvement of Wireless technology

in few recent years. In this report, I will introduce some information about

Wireless Network IEEE802.11.


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1. Background:IEEE 802.11 is a Wireless Local Area Network (WLAN) standard

which specifies a radio interface and Layer 2 (Link Layer) protocol for data

communications in the 2.4 GHz spectrum. 802.11b supports up to 11 Mbps

of capacity, depending on what part of the world you are in, and has a rangeof up to a hundred meters or more in open spaces, but more like 50 Meters in

a practical office environment using off the shelf equipment.

IEEE802.11 specifies standards for connecting between wireless

client and a base station or among wireless clients. This standard, 802.11 is

developed by IEEE and published in 1997.

It consists: 802.11, 802.11a, 802.11b, 802.11b+ ( improved from 802.11b),

802.11g, 802.11h

2. Discussion:2.1 WLAN architecture:

WLANs consist of Access Points (APs) and Stations as shown in

Figure 6: WLAN Overview. The APs are the connection between the

wireless and fixed-line world. The Stations are devices with 802.11 radios

that access the network through the APs. APs contain configuration

information for Stations and generally also have the ability to manage users

in some form or another depending on the vendor.

Figure 7: WLAN Overview.


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An alternate form of WLAN architecture discussed throughout this

paper is a Peer-to-Peer LAN. This is a simpler architecture in which two

Stations form the network, with one of the Stations acting as a gateway for

the other(s) through a second network interface. The primary difference is

that this arrangement is generally simpler and possesses fewer features for

managing WLAN connections.

Figure 8: Peer to peer Overview

2.2WEP (Wireless Equivalent Privacy):WEP is the security element which has been bundled to 802.11 directly

and serves to provide confidentiality and authentication services to 802.11

networks. WEP uses a shared (symmetric) secret-key to encrypt data at the link-

layer (MAC layer) using differing sizes of keys, depending on the

manufacturer. The baseline security is 40 bit encryption using the RC4

algorithm. The 802.11 standard was amended in late 2000 to allow for the

support of 128 bit encryption keys a substantial improvement in the overall

strength of WEP. However, WEP was still found wanting.The primary design flaws that make WEP vulnerable were not addressed

by an increase in key size. There were two fundamental flaws found in WEP7

security: one was a flaw in the use of key scheduling and random number

generation that weakens the RC4 algorithm but not to the point of making

practical attacks feasible. The flaws were WEP handled the RC4 keys to be

used for encrypting the 802.11 payloads; specifically, there is a problem with


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the use of an Initialisation Vector (IV). The IV is concatenated to an RC4 key to

make up the actual key that WEP uses for converting cleartext to cyphertext

(sic. encoding). Unfortunately for WEP, this IV is also transmitted in the 802.11

payload in the clear along with the cyphertext for the purposes of rapid

decryption at the receiving end. The IV was a sequential number that repeated

more or less frequently, depending on the amount of traffic. This repeated IV

allowed crackers to compare different encrypted payloads for which part of

the key is known with enough sample data the full RC4 key is derived. Thus

an attempt to improve and simplify performance has damned WEP because of

the earlier findings around RC4. Combined, these 2 distinct flaws punched a

hole in WEP security. The nail in coffin of WEPs reputation was the release of

tools on the Internet in mid 2001 which ostensibly allowed any low-resource

script kiddie to successfully crack

WEP keys without any significant skills or equipment. Despite all the

forgoing, WEP serves a very useful function in hardening an 802.11 networkand should not be discounted completely, for the following reasons:

i. In order to crack WEP keys, you need to collect very specific types

of packets (special packets) from the data stream that occur very

infrequently. This means that you need a lot of traffic. Likely days, if not

weeks, worth of traffic on an average WLAN. For a determined attacker,

this is very possible. But this requires far more patience and resources

than a drive-by hacker possesses.

ii. Even with the right tools, such as WEP Crack, getting these tools to

run can be a trick all on there own and requires knowledge of UNIX. Again,

a barrier to entry for non- programmers, and non-UNIX hacker-wannabes.

WEP has also seen several (sometimes proprietary) improvements

introduced by certain vendors which also contribute to security. For instance, RSA

Security recently announced a product for 802.11 which will encrypt every packet

with a distinct key, rather than re-using the same key over and over. This product is

based on the 802.1X specification known as Fast Packet Keying which was

passed in June of 2001. This represents a quantum leap in security over the original

WEP keys. Users should be aware, however, that products like RSAs are not part

of the specification and will require that all users on the 802.11 network to utilisethe same RSA software to enjoy the enhanced security. Similarly, other vendors

have offered some alternative key management systems for WEP which have

properties similar to Fast Packet Keying that was introduced by the IEEE. Again,

these are proprietary solutions and will require all users to have the same vendor-

software on their systems. Indeed, WEP that is currently available in most

contemporary 802.11 systems is flawed.


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However, the level of knowledge and effort required to exploit these flaws in

not insignificant. Basically, all but the most dedicated intruders will be deterred.

Having said that, WEP should not be relied upon for corporate security. Corporate

spies can easily buy the necessary skills and can afford the time to break into

WLANs.

2.3Create a WLAN:WLAN is the choice for you if:

- You want to move anywhere in your house with your laptop

connecting to Internet and LAN.

- You dont want any more wires, move around in your house ( e

specially there are many devices in your house ).

To create a WLAN at home, generally we use a WIFI access point.

An access point considers as a Hub or switch like a Wired LAN - centralpoint - connect all nodes (Pocket PC, Laptop, Desktop) each other or

connect Wireless LAN with Wired LAN or connect to Internet.

Figure 9: WIFI network with access point


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However, a Wireless LAN that devices connect one another directly is called

Ad-hoc network.

Figure 10: WIFI network without access point

2.4Advantage:- Wireless network can replace Wired Network in case of Wired Network

costs expensive while it is not convenient to deploy. ( Ex: Wireless

Network in a high building ).- Wireless LAN can be used to create a temporary network. It is

significant with a short-time mission. (Ex: Network in meeting, seminar,

conference)

- In some respects, it is more aesthetic. Some buildings dont allow

installing wires. So Wireless Network is a suitable alternative choice.

3. Conclusion:The original version of the standard IEEE 802.11, released in 1997 and

clarified in 1999, specified two raw net bit rates of 1 or 2 megabits persecond (Mbit/s), plus forward error correction code, to be transmitted in

Industrial Scientific Medical frequency band at 2.4 GHz. Legacy 802.11 was

rapidly supplemented (and popularized) by 802.11b.

However, Wireless Network 802.11 is developing more and more.


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Reference

Gigabit Ethernet:

http://en.wikipedia.org/10_gigabit_ethernet/

http://www.quantrimang.com/inc_contents.asp?Cat_ID=8&news_id=1621

http://www.webopedia.com/TERM/G/Gigabit_Ethernet.html

http://www.altera.com/technology/high_speed/protocols/gb_ethernet/pro-

gb_ethernet.html

http://www.cisco.com/en/US/tech/tk389/tk214/tech_brief09186a0080091a8a.ht

ml

Wireless Networks IEEE802.11:

http://en.wikipedia.org/wiki/IEEE_802.11#Channels_and_international_compa

tibility

http://my.opera.com/vietrung/blog/show.dml/1738781

http://wimaxpro.org/forum/archive/index.php?t-379.html

http://www.soeco.com/forum/showthread.php?t=29

Hardening Wireless Network IEEE802.11 byTyson Macaulay

Ethernet and Wireless Network

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