webinar ethernet basics part a v1.3

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Welcome to the Webinar Training courses

2

AGENDAEthernet Webinar Courses

1. Ethernet Intro Part A

2. Ethernet Intro Part B

3. Carrier Ethernet Intro

4. Carrier Ethernet Test

5. New GbE Testers Intro

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AGENDAEthernet Webinar Courses

1. Ethernet Intro Part A

2. Ethernet Intro Part B

3. Carrier Ethernet Intro

4. Carrier Ethernet Test

5. New GbE Testers Intro

4

Agenda

Introduction Ethernet

IEEE 802.3

ISO/OSI Reference Model

Layer 1 - The physical layer Ports Power over Ethernet PoE Duplex Autonegotiation

Layer 2 - The Data Link Layer Traffic Distribution Ethernet Frame IEEE 802.3 MAC Adress

Layer 3 - The network layer Internet Protocol IP IPv4 IPv6 Addresstypes

Layer 4 - The Transport Layer UDP TCP

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History of Data Networks

1973 Robert Metcalfe deploys Ethernet (3Mb/s) for the company XEROX

1979 Metcalfe founded 3com (Computers, Communication and Compatibility) and convinced DEC, Intel and Xerox (DIX Consortium)

1980 Ethernet - DIX v1.0 (10Mb/s)

1982 Ethernet - DIX v2.0

1983 IEEE 802.3 - Ethernet 10Mb/s

1995 IEEE 802.3u - Fast Ethernet 100 Mb/s

1998 IEEE 802.3z - Gigabit Ethernet 1000 Mb/s

2002 IEEE 802.3ae - 10 Gigabit Ethernet

6

IEEE 802.3

International Association of Electrical Engineering and computer science Engineers

Since 1963

Forms committees on standardization of technology, hardware and software

400000 Members worldwide

Design standards for Data Transmission within the Project number 802 (deducted from February 1980 )

The wrokgroup No. 3 is taking care about Ethernet

Networks can now carry Data due to a common standard

► Transmission standard IEEE 802.3

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ISO

due to different applications the type of data carried is varying

it is very imprtant to standardize the way of communication through the Data Networks

all stations across the world must be able to communicate to each other

This will then be the basis for the Internet as well

all systems must be open and interconnectable

Therefore the ISO created a model how the interaction can work

International Standards Organization

ISO / OSI

The Open System Interconnection Model

This is comparable with a book containing 7 chapters.

The 7-Layers-Reference-Model

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The ISO/OSI 7-Layer Reference Model

7

6

5

4

3

2

1

Application

Presentation

Session

Tansport

Network

Data Link

Physical

Network process to application

Data Representation, encryption and decryption, convert user dependent data into machine dependent data

Interhost communication, managing sessions between applications

End-to-end connections, reliability and flow control

Path determination and logical addressing

Physical addressing

Media, signal and binary transmission

Ethernet Frame: Transport of IP-Packets through local networks

Session Packets: To carry the digital User Data (between the Applications)

TCP/UDP-Packets: To carry the Session Packets (between the Devices) IP Packet: To carry the TCP- UDP Packets through different Networks

Analogue Signal

Digital Signal

Bit stream

User data

User data

User data

layer 2

header

layer 3

header

layer 4

header

layer 2

trailer

User datalayer 5

header

9

The physical Layer: L1

7

6

5

4

3

2

1

Application

Presentation

Session

Tansport

Network

Data Link

Physical






Physical addressing


User data

User data

User data

layer 2

header

layer 3

header

layer 4

header

layer 2

trailer

Bit stream

Ethernet

HTTP, FTP, HTTPS, SMTP, LDAP, NCP, SIP, H.323, RTP

TCP, UDP, SCTP, SPX,

ICMP, IGMP, IP, IPX

Softphone, Email…

G.729, G.723, G.711,..

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Ports

Copper RJ-45

8 PINs Pin assignment (Fast) Ethernet: 1+2 Transmit (Tx)

3+6 Receive (Rx)

Pin assignment Gigabit Ethernet: all 8 Pins

Two Port types: MDI (Medium Dependent Interface) 1-2 Tx / 3-6 Rx

MDI-X (crossover) 1-2 Rx / 3-6 Tx

Ethernet Pinout RJ45

1 2 3 4 5 6 7 8

10-Base T Tx+ Tx- Rx+ Rx-

100-Base T Tx+ Tx- Rx+ Rx-

1000-Base T D1+ D1- D2+ D3+ D3- D2- D4+ D4-

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Ports

Optical - SFP

Small Form-Factor Pluggable

Having Tx & Rx two ports with LC Connectors

Rate from 100Mb/s to 10Gb/s.

1000 Base SX (850 nm, Multimode)Multimode SFPs can reach a distance of 500 m. A LED is enough to couple the light into the broader core of a Multimode Fiber. They are therefore much cheaper and only seen in LANs

1000 Base LX (1310 nm, Singlemode)Singlemode SFPs can reach a distance up to 40 km. They are using Laser-Diodes which are required to couple the light into the thin core of a singlemode Fiber. They are therefore expensive and mostly used for long distance in WANs

Other type of SFPs1000 Base ZX (1550nm, Singlemode) for up to 70 km. 1000 Base BX10 (1490nm Tx, 1310nm Rx) or Bi-Di SFP for up to 10Km over a single fiber. SFP+ supports up to 10Gb/s at 850nm MM or 1310nm SM.

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Ports

Optical - Connectors

LC: Lucent Connector is the most common optical connector dueto its small form factor. It therefore displaced the SC connector as the standard in the LAN. MM and SM

SC: In 2002 the Subscriber Connector diplaced the ST-Connector as the standard in the LAN. Easier to use as and requires less space as ST.

ST: The Straight Tip connector is still very common in the LAN. It is mainly used in Multimode. Secure connection due to a bajonet mechnaism.

FC: Due to its robustness the Fiber Connector is still very common in WAN. Mainly SM

E2000: A mechanical Laser Protection flap is automaitcally closing to protect the Fiber. Mainly used for Singlemode in MAN and WAN Networks

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Power over Ethernet PoE

PoE

Defined by the standard IEEE 802.1af

Enddevices are feeded via the Data Cable and doesn't need an external power supply anymore

Typically used for IP-Phones, Cameras and Wireless access points

Reduction of Installation costs

Devices are feeded by a PoE-Switch, a PoE Patch Panel or a supsequently installed PoE-Injector

Typical Values: 48V at a maximum consumption of 15 Watts

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Power over Ethernet PoE

PoE+ / PoE PLUS

The standard IEEE 802.1at defines a higher powerconsumption up to 25 Watts.

PoE / PoE+ power range

Depending on the type of devices there are typical power ranges

These Ranges are defined by 5 PoE-Classes as follows

Class Available Power in Watt

0 0.44–12.96

1 0.44–3.84

2 3.84–6.49

3 6.49–12.95

4 (Poe+) 12.95-25.50 (only 802.3at)

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Port Properties

Halfduplex HD

The port can only work unidirectional at a time meaning either transmit data (Tx) or receive data (RX)

The port never can send and receive Data at the same time

A typical Halfduplex device is a Hub.

A typical Example for halfduplex: Phonecall - one person is listening while the other person is talking

Fullduplex FD

Ports are working bidirectional

Rx and Tx can be done simultaneusly

Typical Fullduplexdevice: Switch

Example:Videoconferencing - your picture is transmitted while you are receiving the picture of others

.

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Port Properties

Halfduplex Halfduplex

Halfduplex Fullduplex

Fullduplex Fullduplex

CollisionCollision

Correct Transmission

Correct Transmission

Errors and CollisionsLoss of Data

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Port Properties

Autonegotiation / Autoneg

Is taking place after the link establishment

A handshake to determine the best way of transmission between two Interfaces

Automoatic detection if Transmission can be done on Fullduplex or must be done on Halfduplex

It follows the simple Principle: Question A: Can you work on fullduplex

Answer B: Yes, I can

Commitment: OK, let's then do fullduplex

It is absolutely necessary, that both interfaces have enabled Autoneg!

.

Fullduplex Fullduplex

Autoneg ONAutoneg ONCan you do Fullduplex?

Yes, I can

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Port Properties

Autonegotiation / Autoneg

Missing Autoneg Configurations will cause Network errors

Both stations need to set to Autoneg ON

Otherwise the questioning Interface is going back to halfduplex once the answer is missing

It follows a the simple Priciple: Question A: Can you work on fullduplex

Answer B: No Answer due to Autoneg is set to OFF

Interface A: is going to Halfduplex while B is set to 100 Mb/s - FD!

Gigbabit is always on Fullduplex!

.

Halfduplex Fullduplex

Autoneg OFFFixed to 100 Mb/s - FD

Autoneg ONCan you do Fullduplex?

No Answer

CollisionCollision

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Port Properties

Tester Switch

Auto Auto

1000 FD Auto

1000 FD 1000 FD

100 FD 1000 FD

100 FD Auto

Auto 100 FD

100 FD 100 FD

100 HD Auto

10 HD Auto

10 HD 100 HD

Auto 100 HD

Auto 10 HD

ResultTester ResultSwitch

1000 FD 1000 FD

1000 FD 1000 FD

1000 FD 1000 FD

no link no link

100 FD 100 FD

100 HD 100 FD

100 FD 100 FD

100 HD 100 HD

10 HD 10 HD

no link no link

100 HD 100 HD

10 HD 10 HD

Practice Autoneg

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Summary

We have choosen now the right cable

We decided to choose the right connector

We decided if we need PoE or not

We configured our Ports correctly.

due to a working Autoneg Scenario the Link is now established without any issue

► Let's start to transmit Data

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The Data Link Layer: L2

7

6

5

4

3

2

1

Application

Presentation

Session

Tansport

Network

Data Link

Physical






Physical addressing


User data

User data

User data

layer 2

header

layer 3

header

layer 4

header

layer 2

trailer

Bit stream



ICMP, IGMP, IP, IPX

Softphone, Email…

G.729, G.723, G.711,..

The Core element of a Layer 2 - Network: Switch


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Traffic Distribution

HUB

Node B

Node D

Node C

Node A

How can we send Data from A to Station B in that Local Area Network (LAN) ?

A Hub can help here as it is spreading the traffic into every span

Disadvantage: Every network element will receive the Traffic which is causing a high load in the LAN

Hubs can only work in Halfduplex mode and are internally causing network errors and collisions

CollisionsCollisions

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SWITCH

Node B

Node D

Node C

Node A

How can we send Data from A to Station B in that Local Area Network (LAN) ?

A Switch is the perfect solution

Advantage: Only the target element will receive the Traffic - the network load is drastically reduced

A switch is a Fullduplexdevice - no errors or collisions anymore

Addressing is required

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As we heard now that addressing is required this is the first time where we have to think about the structrue of our Data

Somebody did that already for us: IEEE

Within their Transmission standard they defined how the Data Structure must look like.

They created a model and gave it the simple name: Frame

► IEEE 802.3 Ethernet Frame

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Ethernet Frame (IEEE 802.3)

The principal design of the Ethernet Frame

Data Structure: Thousands of alligned Bits

7 bytes 4 bytes

Preamble SFD FCSDestination Source DATALength /

type

1 byte 6 bytes 6 bytes 2 bytes 46 - 1500 bytes

Definitions of frame size

Smallest Ethernet Frame: 64 Byte biggest Ethernet Frame: 1518 Bytes Special Form: VLAN Frame 1522 bytes Special Form VLAN (Q-in-Q) Frame: 1526 Bytes Jumboframes up to 10000 Bytes

Frame size

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Ethernet Frame (IEEE 802.3)

Data Structure: Thousands of alligned Bits

7 bytes 4 bytes

Preamble SFD FCSDestination Source DATALength /

type


Preamble: required to get every single packet synchronized

SFD: Start Frame Delimiter indicates the beginning of the relevant data

Destination: Contains the Destination Address (MAC)

Source: Contains the source Address (MAC)

Lenght: Indicates the Lenght of the Ethernet Frame

Type: Indicates the type of packets which are coming from higher Layers

DATA: Contains the User Data / Packets of the higher Layers

FCS: Frame Check Sequency determines incorrect transmission due to faults

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MAC Address

Every Device is having a unique Hardware-Address

Every Medium can then be accessed in a controlled way

It is therefore called Media Access Control MAC

It's hexadecimal and looks like that: 00:16:06:88:01:6F

The first part is the Vendor Code

00:16:06:xx:xx:xx = Ideal Industries

Due to the MAC Addresses the Switches are now

able to determine where the Frame needs to got to within

the local network

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MAC Address

Ethernet Frames are on Layer 2 and can therefore only be transmitted

locally. They can not be transmitted in foreign networks!!

Sender

Anwendung / Prüfmuster

IP - Layer 3

Ethernet - Layer 2

Physikal. - Layer 1

IP - Layer 3

L 2

L1

Router

L 2

L 1L 1 L 1

Ethernet - Layer 2

SwitchL3

L3L2 L3L2 L3L2

LAN WAN

Layer 3

Layer 2

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Summary

Layer1






Layer 2

The data structure is framed by IEEE 802.3 can can be trasmitted locally

► What's to do if we need to leave the local network (Internet)?

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The Network Layer: L3

7

6

5

4

3

2

1

Application

Presentation

Session

Tansport

Network

Data Link

Physical






Physical addressing


User data

User data

User data

layer 2

header

layer 3

header

layer 4

header

layer 2

trailer

Bit stream



Softphone, Email…

G.729, G.723, G.711,..

The Core element of a Layer 3 - Network: Router


IP Packet: To carry the TCP- UDP Packets through different Networks

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7 bytes 4 bytes

Pream ble SFD FC SD estination Source D AT ALength /

type


E thernet F ram e

IP

Header

TCP, UDP, ICMP Daten

L3: Intenet Protocol IP

As Ethernet Frames are not transmitted by Routers another Packet Type is used in Layer 3

IP Packet

The IP Packed is embedded within a Ethernet Frame

The IP header contains a new Address format

IP-Packet

Ethernet Frame

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Since the early 80s the Internet Protocol has already been defined in its fourth Version

► IPv4

The plan was, that every device should have it's unique IP-Address that the devices can communicate worldwide

32 bit are reserved in the header for an IPv4 Address, meaning 4.294.967.296 Addresses are available

In the Local Networks there is no need of unique addresses. e.g. we can use 192.168.1.1 in Chigaco locally as well as locally in London as long as those networks are not linked to each other.

Two Adress types are therefore defined: Private IP Addresses

Public IP Addresses

L3: Internet Protocol version 4 - IPv4

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Format: four blocks written in decimal: e.g. 192.168.0.1

Written in binary numbers: 11000000.10101000.00000000.00000001

Private IPs can not be routed through the internet. They can only be used locally

Public IPs are basically the remaining ones e.g. 212.67.56.187

the Public IPs are owned by the service providers.

Every user gets one Public IP Adress assigned with the contract.

Addressrange Number of hosts Netclass

10.0.0.0–10.255.255.255 224 = 16.777.216 Class A: 1 private Network

172.16.0.0–172.31.255.255 220 = 1.048.576 Class B: 16 private Networks

192.168.0.0–192.168.255.255 216 = 65.536 Class C: 256 private Networks


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IP Packets are routed on Layer 3

Since the traffic is now routed on Layer 3 the communication can work worldwide

Sender

Anwendung / Prüfmuster

IP - Layer 3

Ethernet - Layer 2

Physikal. - Layer 1

IP - Layer 3

L 2

L1

Router

L 2

L 1L 1 L 1

Ethernet - Layer 2

SwitchL3

L3L2 L3L2 L3L2

LAN WAN

Layer 3

Layer 2

L3

L3L2


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LAN WAN

DSL ModemWLAN-Router

Network Address translation NAT

WAN Port1 Public

IP AddressLAN PortCopper and WiFi

multiple Private IP Addresses

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Since the early 90s it turned out that the reccources of IPv4 addresses are coming to its end

► IPv6

128 bit are reserved in the header for an IPv6 Address, meaning 3,4 × 1038 Addresses are available. 3,400,000,000,000,000,000,000,000,000,000,000,000,000

every device can now get a unique IP Address which is written hexadecimal

Example 2001:0db8:0000:08d3:0000:8a2e:0070:7344

If one block consists of purely zeros then it can be replaced by a single zero: 2001:db8:0:8d3:0:8a2e:70:7344 is therefore the same address as mentioned above

If there are continous blocks of zeroes, they can be left out completely:2001:0db8:0:0:0:0:1428:57ab is the same as 2001:db8::1428:57ab


37LAN WAN

DSL ModemWLAN-Router

Faster due to a lower latency as NAT is not required anymore


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Summary

Layer1






Layer 2

The data structure is framed by IEEE 802.3 can can be trasmitted locally

Layer 3

Within the Ethernet frame there are now IP Packets why we now can leave the local network because IP

Packets can be routed between different networks

. ► What if some packets are lost during the transmission. Does it make sense to retransmit them?

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The Transport Layer: L4

7

6

5

4

3

2

1

Application

Presentation

Session

Tansport

Network

Data Link

Physical






Physical addressing


User data

User data

User data

layer 2

header

layer 3

header

layer 4

header

layer 2

trailer

Bit stream



ICMP, IGMP, IP, IPX

Softphone, Email…

G.729, G.723, G.711,..


40

L4: Transport

The Transport layer is basically to ensure that everything is transmitted completely

But Some applications are allowing to loose some data

Realtime Applications such as Video or VoIP

lost data doesn't need to be delivered subsequently. E.g. Video streaming. When you see a pixel error then it doesn't make sense to deliver the missing information later on. We don't need it to understand the core message.

Data Transfer

Missing informations are making the files looking like corrupted. The Data is not usable anymore

Lost informations must be delivered subsequently E.g. backup of a laptop: such files are containig very important informations to recover the system. If the file is not complete then the restore cannot be done.

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L4: Transport

The protocols of the Transport layer are furthermore responsible that the arrived data is directed to

the right application

The Transport Packets are therefore using Addresses again. No address to find a station (Like IP

or MAC).

These addresses are now used to find the right applications within the device.

These addresses are now called Ports

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L4: UDP

When Realtime Transmission doesn't require and end-to-end error correction, then

The User Datagram Protocol (UDP) is only addressing the data to the application

UDP doesn't do an end-to-end error correction

UDP is the Transport Protocol for Realtime Transmission

UDP could be used for: Video, IPTV, CCTV, VoIP

Bit stream

User data

User data

User data

layer 2

header

layer 3

header

layer 4

header

layer 2

trailer


RTP: Realtime Transport Porotocol (between the Applications)

UDP-Packets To carry the Session Packets (between the Devices) No Error Correction IP Packet: To carry the UDP Packets through different Networks

Analogue Speech

Digital Speech Signal

User datalayer 5

header

Example VoIP Call

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L4: TCP

For DATA Tranmission an end-to-end error correction is essential.

The Transmission Control Protocol (TCP) is detecting if some informations are missing.

Every single Packet gets its own number (TCP Sequence Number) from the Sender.

A missing number can then be dected via TCP at the destination device

The destination is chasing the sender to retransmit the missing packet.

PCs are basically transmitting DATA and therefore using TCP

That's why most users are talking from TCP/IP (TCP over IP)

User data

User data

User data

layer 2

header

layer 3

header

layer 4

header

layer 2

trailer

Bit stream


SMTP: Simple Mesage Transfer Protocol (between the Applications)

TCP-Packets To carry the Session Packets (between the Devices) With Error Correction IP Packet: To carry the UDP Packets through different Networks

Typing email on a keyboard

Convert into digital

User datalayer 5

header

Example Email

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Summary

Layer1






Layer 2

The data structure is framed by IEEE 802.3 can be trasmitted locally

Layer 3

Within the Ethernet frame there are now IP Packets why we now can leave the local network because

IP Packets can be routed between different networks

Layer 4

The assurance of end to end connection and flow control of specific application is made via sessions.

45

The ISO/OSI 7-Layer Reference Model

7

6

5

4

3

2

1

Application

Presentation

Session

Tansport

Network

Data Link

Physical






Physical addressing



Session Packets: To carry the digital User Data (between the Applications)

TCP/UDP-Packets: To carry the Session Packets (between the Devices)

IP Packet: To carry the TCP- UDP Packets through different Networks

Analogue Signal

Digital Signal

Bit stream

User datalayer 3

header

User datalayer 2

header

layer 2

trailer

User datalayer 5

header

User datalayer 4

header

46

Questions and Answers

47

Thanks for attending Ethernet series webinar

training courses

Module I

Ethernet Introduction Part A

webinar ethernet basics part a v1.3

Technology

ethernet networks

ethernet 10mbs1995 ieee

carrier ethernet intro4

carrier ethernet test5

z gigabit ethernet

u fast ethernet

tx rx

10mbs1982 ethernet dix