webinar ethernet basics part a v1.3
DESCRIPTION
TRANSCRIPT
1
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
3
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
5
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
7
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
8
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
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
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,..
10
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
14
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
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
User data
User data
User data
layer 2
header
layer 3
header
layer 4
header
layer 2
trailer
Bit stream
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,..
The Core element of a Layer 2 - Network: Switch
Ethernet Frame: Transport of IP-Packets through local networks
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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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Traffic Distribution
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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Traffic Distribution
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
1 byte 6 bytes 6 bytes 2 bytes 46 - 1500 bytes
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
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
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)?
30
The Network Layer: L3
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
User data
User data
User data
layer 2
header
layer 3
header
layer 4
header
layer 2
trailer
Bit stream
HTTP, FTP, HTTPS, SMTP, LDAP, NCP, SIP, H.323, RTP
TCP, UDP, SCTP, SPX,
Softphone, Email…
G.729, G.723, G.711,..
The Core element of a Layer 3 - Network: Router
Ethernet Frame: Transport of IP-Packets through local networks
IP Packet: To carry the TCP- UDP Packets through different Networks
31
7 bytes 4 bytes
Pream ble SFD FC SD estination Source D AT ALength /
type
1 byte 6 bytes 6 bytes 2 bytes 46 - 1500 bytes
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
32
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
L3: Internet Protocol version 4 - IPv4
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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
L3: Internet Protocol version 4 - IPv4
35
L3: Internet Protocol version 4 - IPv4
LAN WAN
DSL ModemWLAN-Router
Network Address translation NAT
WAN Port1 Public
IP AddressLAN PortCopper and WiFi
multiple Private IP Addresses
36
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
L3: Internet Protocol version 6 - IPv6
37LAN WAN
DSL ModemWLAN-Router
Faster due to a lower latency as NAT is not required anymore
L3: Internet Protocol version 6 - IPv6
38
Summary
Layer1
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
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?
39
The Transport Layer: L4
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
User data
User data
User data
layer 2
header
layer 3
header
layer 4
header
layer 2
trailer
Bit stream
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,..
Ethernet Frame: Transport of IP-Packets through local networks
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
42
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
Ethernet Frame: Transport of IP-Packets through local networks
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
43
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
Ethernet Frame: Transport of IP-Packets through local networks
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
44
Summary
Layer1
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
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
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 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