1. What is Communication
People have many ways to communicate:
– Verbal/ non Verbal
– Face to face/ over the telephone
– Handwritten Letter
– Chatting
Requires Common Rules
2. The rules of communications are Protocol.
Some of the protocols required for
communication to occur include:
- Sender & receiver
- Method of communicating (face to face, phone,
letter, photo and so on)
- Language and Grammar
- Speed & Timing of delivery
- Confirmation / Acknowledgement requirements
3. Element of Network
1. Rules / Agreement ( PROTOCOL): Rules
or agreement govern how the messages are
sent, directed, received and interpreted.
2. Message: The messages or unit of information
travel from one device to another.
3. Medium: a means of interconnecting devices,
a medium can transport the messages from one
device to another.
4. Device: devices on the network exchange
messages with each other
4. Early networks had varying standards and as
a result could not communicate easily wit
each other.
People use many technologies and devices
that they do not understand.
Computer networks are similar.
Two people communicating on end devices
in different networks can do so only if many
complex processes are succesfully
completed.
5. Message
Message:
The messages or unit of information travel
from one device to another.
Message is a generic term that encompasses
web pages, email, instant messages,
telephone calls & other form of
communication.
The message must be one that the network
can carry.
6. The messages must be supported in software
at the end device.
It does not matter whether the message is:
text, voice, or video because all form are
converted into bits, binary-coded digital signals,
to be carried over a wirelles , copper, or fiber
optic connection.
The digital signal can change with the media, but
the original message content will remain intact.
7. Medium
Medium that physically carries the message
can change several times between the
sender & receiver.
Network connections can be wired or
wirelless.
8. In wired connections the medium is either
copper with electrical signals or optical fiber
with light signals.
The copper medium includes cables :
twisted pair telephone wire, coaxial cable, or
Category 5 unshielded twisted pair (UTP)
Optical fibers, thin strands of glass or plastic
that carry light signals
10. In wirelles connection the medium is:
Earth's atmosphere / space, and the
signals are microwave.
Wireless media can include the home
wireless connection between a wireless
router & computer with wireless network
card, the terrestrial wireless connection
between 2 ground stations, or the
communication between devices on earth &
sattelite
11. Devices
Many devices : switch and router, work to see
the message is properly directed from the
source (originating device) to the
destination device.
At the destination network there can be more
switches, cable or wireless router that will
deliver the instant message to the receiver.
12. Rules
As communication process happen, tens of
thousands of process can happen in a
single second.
To work properly, the network process must
be controlled. Rules govern every step of
the process, from the way cables are
designed to the way digital signals are sent.
These rules are called Protocols
13. Rules
Most common:
TCP Transmission Control Protocol
IP Internet Protocol
Service Protocol / Rule
WWW Hyper Text Transfer
Protocol
Email SMTP and POP
Instant Message XMPP & OSCAR
Ip Telephony SIP
15. Fault Tolerance
Fault tolerance:
Sistem harus tetap berjalan meskipun
beberapa komponen mengalami
kegagalan.
Key Factor: -Redundancy:
Duplikasi peralatan & media
18. Scalable Network Architecture
Scalable network mampu untuk tumbuh
tanpa adanya perubahan fundamental pada
inti /core.
Contoh:
Internet is a collection of many private and public
network interconnected by routers.
19. Quality of Service (QoS)
Menunjukkan performance level dari service
yang ditawarkan melalui network.
Eg:
Live Video or Voice dapat memerlukan lbh
banyak resource drpd email.
Because many techs are converged onto 1
platform, the separation of types of services
on that platform can allow higher priority for
one service over another.
20. Menyediakan QoS
Qos :
Mengacu kpd mekanisme yang mengatur
congested network traffic.
Congestion is caused when the demand on
network resource exceeds the available
capacity.
Network bandwidth is the measure of the
data-carrying capacity of the network.
With Qos, the manager can manage the
priority.
21. Network Security
Menjadi esential ketika publik hrs mempunyai
rasa aman ketika mengakses internet.
Contoh:
Melakukan financial transaction.- Untuk
personal information memerlukan privasi
melalui:
- Encripted messages.
- Security devices to control network access.
22. Providing Network Security
1. Securing the Network Infrastructure
means: protecting the devices from outside
contact
Contoh: -locking computer room door,
password protection.
2. Securing the Network Content means:
protection of data stored on network
devices & the protection of packets carryind
data into or out of the network.
24. Ensuring Confidentiality
Data privacy is maintained by allowing only
the intended and authorized recipient-
individual, proces, or device to read the
data.
Biasanya: User Authentication,
-Menggunakan password yang susah
ditebak.
-Mengganti password secara berkala.
25. Maintaining Communication
Integrity
Data integrity means:
Menjamin bhw informasi tidak di Alter dalam
pentransmisiannya dari origin ke destinasi.
Informasi dikorupsi secara sengaja atau tak
sengaja sblm sampai tujuan.
Source Integrity:
Adalah jaminan bahwa identitas sender sdh
divalidasi. User or device fakes the identity
& supply inccorect information to recipient.
26. Ensuring Availability
Meyakinkan bahwa resource tersedia kepada
authorized user / pemakai.
Contoh:
Serangan virus komputer, Denial of Service
(DoS) dpt membuat network menjadi Down.
Tools:
-AntiVirus SoftWare
-Firewall: analyze traffic enterring and exiting
a network.
