Network Protocol and Communications

Network Protocol and Communications
Summary
Conclusion
Lab Installing Wireshark
Wireshark is a software protocol
analyzer, or "packet sniffer"
application, used for network
troubleshooting, analysis,
software and protocol
development, and education.
Wireshark is used throughout the
course to demonstrate network
concepts. In this lab, you will
download and install Wireshark.
Lab Using Wireshark to View
Network Traffic
In this lab, you will use Wireshark
to capture and analyze traffic.
Class Activity Guaranteed to
Work!
You have just completed the
Chapter 3 content regarding
network protocols and
standards.
Assuming you resolved the
beginning of this chapter’s
modeling activity, how would
you compare the following steps
taken to design a
communications system to the
networking models used for
communications?
Establishing a language to
communicate
Dividing the message into small
steps, delivered a little at a time,
to facilitate understanding of the
problem
Checking to see if the data has
been delivered fully and correctly
Timing needed to ensure quality
data communication and delivery
Data Transfer in the Network
Message Segmentation
In theory, a single
communication, such as a music
video or an email message, could
be sent across a network from a
source to a destination as one
massive, uninterrupted stream of
bits. If messages were actually
transmitted in this manner, it
would mean that no other device
would be able to send or receive
messages on the same network
while this data transfer was in
progress. These large streams of
data would result in significant
delays. Further, if a link in the
interconnected network
infrastructure failed during the
transmission, the complete
message would be lost and have
to be retransmitted in full.
Data Encapsulation
Encapsulation Example
When sending messages on a
network, the encapsulation
process works from top to
bottom. At each layer, the upper
layer information is considered
data within the encapsulated
protocol. For example, the TCP
segment is considered data
within the IP packet.
Click Play in the figure to see the
encapsulation process as a web
server sends a web page to a web
client.
Deencapsulation
This process is reversed at the receiving
host, and is known as deencapsulation.
Deencapsulation is the process used by a
receiving device to remove one or more of
the protocol headers. The data is
deencapsulated as it moves up the stack
toward the enduser application.
Click Play in the figure to see the
deencapsulation process.
Standard Organizations
Open Standards
Open Standards
Open standards encourage
interoperability, competition,
and innovation. They also
guarantee that no single
company’s product can
monopolize the market, or have
an unfair advantage over its
competition.
A good example of this is when
purchasing a wireless router for
the home. There are many
different choices available from a
variety of vendors, all of which
incorporate standard protocols
such as IPv4, DHCP, 802.3
(Ethernet), and 802.11 (Wireless
LAN).
Internet Standards
Internet Standards
Standards organizations are
usually vendorneutral,
nonprofit institutions
established to develop and
promote the concept of open
standards. Various organizations
have different responsibilities for
promoting and creating
standards for the TCP/IP
protocol.
Electronics and Communications
Standard Organizations
Other standard organizations
have responsibilities for
promoting and creating the
electronic and communication
standards used to deliver the IP
packets as electronic signals over
a wired or wireless medium
Lab Researching Networking
Standards
Reference Model
The Benefits of Using a Layered
Model
The Benefits of Using a Layered
Model
The benefits to using a layered
model to describe network
protocols and operations include:
Assisting in protocol design
because protocols that operate
at a specific layer have defined
information that they act upon
and a defined interface to the
layers above and below.
Fostering competition because
products from different vendors
can work together.
Preventing technology or
capability changes in one layer
from affecting other layers above
and below.
Providing a common language to
describe networking functions
and capabilities.
The OSI Reference Model
The TCP/IP Protocol Model
OSI Model and TCP/IP Model
Comparison
Reference Models
Activity Identify Layers and
Functions
Packet Tracer Investigating the
TCP/IP and OSI Models in Action
OSI Model and TCP/IP Model
Comparison
The protocols that make up the
TCP/IP protocol suite can also be
described in terms of the OSI
reference model. In the OSI
model, the network access layer
and the application layer of the
TCP/IP model are further divided
to describe discrete functions
that must occur at these layers.
The TCP/IP Protocol Model
The TCP/IP protocol model for
internetwork communications
was created in the early 1970s
and is sometimes referred to as
the Internet model. As shown in
the figure, it defines four
categories of functions that must
occur for communications to be
successful. The architecture of the
TCP/IP protocol suite follows the
structure of this model. Because
of this, the Internet model is
commonly referred to as the
TCP/IP model.
The OSI Reference Model
The OSI model provides an
extensive list of functions and
services that can occur at each
layer. It also describes the
interaction of each layer with the
layers directly above and below.
The TCP/IP protocols discussed
in this course are structured
around both the OSI and TCP/IP
models. Click each layer of the
OSI model to view the details.
Network Protocols and
Standards
Protocols
Rules that Govern
Communications
Salah satu cara terbaik untuk
memvisualisasikan bagaimana
protokol dalam sebuah suite
berinteraksi adalah dengan
melihat interaksi sebagai
tumpukan. Tumpukan protokol
menunjukkan bagaimana
masingmasing protokol dalam
sebuah suite diimplementasikan.
Network Protocols
Network Protocols Pada tingkat
manusia, beberapa peraturan
komunikasi bersifat formal dan
yang lainnya hanya dipahami
berdasarkan kebiasaan dan
praktik. Agar perangkat berhasil
berkomunikasi, suite protokol
jaringan harus menjelaskan
persyaratan dan interaksi yang
tepat. Protokol jaringan
mendefinisikan format umum
dan serangkaian aturan untuk
bertukar pesan antar perangkat.
Beberapa protokol jaringan yang
umum adalah Hypertext Transfer
Protocol (HTTP), Transmission
Control Protocol (TCP), dan
Internet Protocol (IP).
Protocol Interaction
Komunikasi antara web server
dan web client adalah contoh
interaksi antara beberapa
protokol. Protokol yang
ditunjukkan pada gambar
tersebut meliputi:
HTTP adalah protokol aplikasi
yang mengatur cara server web
dan klien web berinteraksi. HTTP
mendefinisikan konten dan
format permintaan dan
tanggapan yang dipertukarkan
antara klien dan server. Baik
klien dan perangkat lunak server
web menerapkan HTTP sebagai
bagian dari aplikasi. HTTP
bergantung pada protokol lain
untuk mengatur bagaimana
pesan dikirim antara klien dan
server.
IP bertanggung jawab untuk
mengambil segmen yang
diformat dari TCP,
mengenkapsulasi mereka ke
dalam paket, menugaskan
mereka alamat yang sesuai, dan
mengantarkannya ke host
tujuan.
Ethernet adalah protokol akses
jaringan yang menjelaskan dua
fungsi utama: komunikasi
melalui link data dan transmisi
fisik data pada media jaringan.
Protokol akses jaringan
bertanggung jawab untuk
mengambil paket dari IP dan
memformatnya agar dikirim
melalui media.
TCP adalah protokol transport
yang mengelola percakapan
individual. TCP membagi pesan
HTTP menjadi beberapa bagian
kecil, disebut segmen.
Rules Of Communications
The Rules
Message encoding adalah Salah
satu langkah pertama untuk
mengirim pesan adalah
pengkodean. Encoding adalah
proses mengubah informasi
menjadi bentuk lain yang dapat
diterima, untuk transmisi.
Decoding membalik proses ini
untuk menafsirkan informasi.
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