Navigating Complexity: The Role of Trusted Partners and VIAS3D in Dassault Sy...
OSI Model.pptx
1.
2. • OSI was developed by the International
Organization for Standardization (ISO)
and introduced in 1984.
• It is a layered architecture (consists of
seven layers).
• Each layer defines a set of functions
which takes part in data communication.
OSI Model
6. Application Layer
Application Layer is responsible for
providing an interface for the users to
interact with application services or
Networking Services .
Application Layer Protocol
------------------------------
HTTP, HTTPs, SNMP, Telnet, SSH,
SMTP, DNS, DHCP, POP3, FTP etc.
Application
Presentation
Session
Transport
Network
Data Link
Physical
Application
7. Common Protocol and Port No.
Service Port No.
FTP 20,21
SSH 22
TELNET 23
SMTP 25
DNS 53
DHCP/BOOTP 67/68
TFTP 69
HTTP 80
POP3 110
IMAP4 143
SNMP 161
BGP 179
LDAP 389
Service Port No.
LPR/LPD 515
SMTPs 465
MSN 863
IMAPs 993
POP3s 995
MS PPTP 1723
SIP 5060
Yahoo msgr 5050
VNC Server 5900+
Squid Proxy 3128
HTTPs 443
NTP 123
8. Application
21
80 25 67
53 69
Data flow from Application Layer
Data
Presentation
Session
Transport
Network
Data Link
Physical
9. Presentation Layer
Presentation Layer It is responsible for
defining a standard format to the data.
Encoding – Decoding
Ex: ASCII, EBCDIC (Text)
JPEG,GIF,TIFF (Graphics)
MIDI,WAV (Voice)
MPEG,DAT,AVI (Video)
Encryption – Decryption
Compression – Decompression
Application
Presentation
Session
Transport
Network
Data Link
Physical
Presentation
10. Data flow from Presentation Layer
Data
Data
Application
Presentation
Session
Transport
Network
Data Link
Physical
11. Session Layer
Session Layer
It is responsible for establishing,
maintaining and terminating the
sessions.
The Session layer is responsible
for setting up, managing and then
tearing down sessions between
Presentation layer entity
Examples :
Simplex, Half duplex, Full Duplex
Application
Presentation
Session
Transport
Network
Data Link
Physical
Session
12. Data flow from Session Layer
Data
Data
Data
Application
Presentation
Session
Transport
Network
Data Link
Physical
14. Transport Layer
Transport Layer
It provides data delivery
mechanism between the
applications in the network.
The major functions described at
the Transport Layer are..
• Identifying Service
• Segmentation
• Sequencing & Reassembling
• Error Correction
• Flow Control
• Window size
Application
Presentation
Session
Transport
Network
Data Link
Physical
Transport
15. Identifying a Service
• Identification of Services is done using Port
Numbers.
• Port is a logical communication Channel
Total No. Ports 0 – 65535
Well-known or Server Ports 1 – 1023
Registered Port 1024 - 49151
Client or Random Ports 49152 – 65535
16. • Transmission Control
Protocol
• Connection Oriented
• Supports Ack’s
• Reliable communication
• Slower data Transportation
• Eg: HTTP, FTP, SMTP
• User Datagram
Protocol
• Connection Less
• No support for Ack’s
• Unreliable communication
• Faster data Transportation
• Eg: SNMP, DHCP, TFTP
TCP UDP
• The protocols which takes care of Data
Transportation at Transport layer
are…TCP,UDP
Transport Layer Protocols
19. Sequencing & Reassembling
Hello! How are you ?
Hello! How Are You ?
Hello!
How are
you ?
A B
You Hello! How ? Are
Hello! How Are
You ?
you
Hello!
How ?
are
20. Sequencing & Reassembling
Hello! How are you ?
Hello!
1/5
How
2/5
Are
3/5
You
4/5
?
5/5
Hello!
How are
you ?
A B
Hello! How are you ?
Hello!
1/5
How
2/5
Are
3/5
You
4/5
?
5/5
Hello!
1/5
How
2/5
Are
3/5
You
4/5
?
5/5
Hello!
How are
you ?
24. Error Correction
Hello! How are you ?
Hello!
1/5
How
2/5
Are
3/5
You
4/5
?
5/5
Hello!
How are
you ? Hello!
1/5
Are
3/5
You
4/5
?
5/5
Hello!
1/5
Are
3/5
You
4/5
?
5/5
Segment Missing
Hello!
1/5
Are
3/5
You
4/5
?
5/5
How
2/5
How
2/5
Hello! How are you ? Hello!
How are
you ?
A B
25. Data flow from Transport Layer
Data
Data
Data
Data
TH
Segment
Application
Presentation
Session
Transport
Network
Data Link
Physical
26. Network Layer
Network Layer
It provides Logical addressing & Path
determination (Routing) in this layer.
The protocols that work in this layer are:
Routed Protocols:
IP, IPX, AppleTalk. Etc
Routed protocols used to carry user data
between hosts.
Routing Protocols:
RIP, EIGRP, OSPF. BGP, IS-IS Etc
Routing protocols performs Path
determination (Routing).
ICMP (ping) – Networking Utilites
Hardware:
PC, Router, IP Phone, L3 Switch
Application
Presentation
Session
Transport
Network
Data Link
Physical
Network
29. Data flow from Network Layer
Data
Data
Data
Segment
Segment
NH
Packet
Application
Presentation
Session
Transport
Network
Data Link
Physical
Devices that work at
Network Layer
are Router, Multilayer
switch etc..
30. Datalink Layer
Datalink Layer
It has 2 sub layers
• MAC (Media Access Control) It provides reliable
transit of data across a physical link.
It also provides ERROR DETECTION using CRC
(Cyclic Redundancy Check) and ordered delivery
of Frames.
Ex: Ethernet, Token ring…etc
• LLC (Logical Link Control)
It provides communication with Network layer.
Negotiates with Network Layer using SAP & SNAP
protocols
Application
Presentation
Session
Transport
Network
Data Link
Physical
Data Link
31. Error Detection – CRC Check
Hello!
How are
you ?
Packet
Packet
Source MAC
00-20-18-C0-07-71
Destination MAC
00-20-18-C0-07-72
00000
32434
22222
89696
55434
99323
43434
99434
46323
11114
33333
00000
32434
22222
89696
55434
99323
43434
99434
46323
11114
Error Detected
192.168.1.1
00-20-18-C0-07-71
192.168.1.2
00-20-18-C0-07-72
A B
PC-A
CRC No. 33333
PC-B
CRC No. 11114
Error Detected
For Error Correction
Contact Source Transport layer
32. Error Detection – CRC Check
Packet
Packet
Source MAC
00-20-18-C0-07-71
Destination MAC
00-20-18-C0-07-72
00000
32434
22222
89696
55434
99323
43434
99434
46323
11114
20202
00000
32434
22222
89696
55434
99323
43434
99434
46323
11114
20202
Source MAC
00-20-18-C0-07-71
Destination MAC
00-20-18-C0-07-72
Packet
Hello!
How are
you ?
192.168.1.1
00-20-18-C0-07-71
192.168.1.2
00-20-18-C0-07-72
A B
33. Data flow from Data Link Layer
Data
Data
Data
Segment
DH
Packet
DT
Application
Presentation
Session
Transport
Network
Data Link
Physical
Packet
Packet
Frame
Devices that work at
Data link layer are
Switch, Bridge etc..
34. Physical Layer
Physical Layer
It defines the electrical, Mechanical &
functional specifications for communication
between the Network devices.
The functions described at this layer are..
Encoding/decoding:
It is the process of converting the binary data
into signals based on the type of the media.
• Copper media : Electrical signals of different
voltages
• Fiber media : Light pulses of different
wavelengths
• Wireless media: Radio frequency waves
Application
Presentation
Session
Transport
Network
Data Link
Physical
Physical
35. Physical Transmission of data
Example:
Frame
Frame
1010101010101010
1010101010101010
Frame
Hello!
How are
you ?
A B
0101011010101010101010101
1010101101010101010101010
0101011010101010101010101
1010101101010101010101010
0101011010101010101010101
36. Data flow from Physical Layer
Data
Data
Data
Segment
Packet
Frame
Bits
Application
Presentation
Session
Transport
Network
Data Link
Physical
Devices that work at
physical layer are ..
Hub, Repeater.. Etc
37. Segment
Packet
Frame
A B
Packet
Data
Data
Data
Bits
Data
Segment
Data Encapsulation & De-capsulation
Packet
Data
Data
Data
Application
Presentation
Session
Transport
Network
Data Link
Physical
Application
Presentation
Session
Transport
Network
Data Link
Physical
Bits
DH DT
NH
TH
Segment
Packet
DT Packet
DH DT
DH
NH Segment NH
TH Data
TH
Frame Packet
