Scenario of Communicating
• You are all on different computers that are
connected to the internet and you want to
send messages or data to each other.
• Every application, generally, has a way to
send or receive information, data, etc. to
someone else on the Internet.
…Scenario of Communicating
• I send a message that gets translated into the
language of each layer of the protocol software
that must be traversed in order to tell the
hardware to send the message out over the
cables or wireless.
• The hardware speaks in “1’s” and “0’s” and each
bit has special coded significance, some bits
being commands and others being data.
• I have no desire to speak one’s and zero’s.
What is a protocol
• Set of rules that governs the communications
between computers on a network.
• These rules include guidelines that regulate the
following characteristics of a network:
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access method,
allowed physical topologies,
types of cabling, and
speed of data transfer
The TCP/IP Layering Model
TCP/IP Relationship to ISO/OSI
Reference Model
more details
TCP/IP & Other Protocols vs
Original ISO/OSI 7-Layer Model
7
Application
HTTP, SMTP, SNMP, FTP, Telnet,
scp, NFS, RTSP
6
Presentation
XML, XDR, ASN.1, SMB, AFP
5
Session
TLS, SSH, ISO 8327 / CCITT
X.225, RPC, NetBIOS, ASP
4
Transport
TCP, UDP, RTP, SCTP, SPX, ATP
3
Network
IP, ICMP, IGMP, X.25, CLNP, ARP,
RARP, OSPF, RIP, IPX, DDP
2
Data Link
1
Physical
Ethernet, Token ring, PPP, HDLC,
Frame relay, ISDN, ATM
electricity, radio, laser
Network Protocol Game
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Each student participant assumes
a different role in the protocol
layer.
One student starts as user and
passes the message on to a
student acting as the application
layer.
Each student identifies what layer
he/she is and what has to be done
to pass it on to the next level.
When the message gets to the
physical level, the player
representing the physical level
identifies what has to be done to
the message and by what medium
the message is going to travel
over the network and where it is
going next and what the final
destination is.
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The message then travels either to a
computer that relays the message
on or to the final destination. This
will be determined by the instructor
or the student.
When the message gets to the
player representing the final
destination, the process starts in
reverse starting at the physical layer
and going to the application layer
and finally the receiving user.
Each player will start with 10 points
and depending on whether he
correctly executes his task, will
receive a plus point or a negative
point.
This game will be used throughout
the semester and varied in detail
depending on what is being taught.
TCP/IP Layer Responsibilities
Stacking Protocol Layers
4. Application Layer
3. Transport Layer
2. Internet Layer
1. Network Access Layer