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مشاهدة النسخة كاملة : Revision Questions For Semester 1 (1/3) - Data Communications and Networks 1


Hassan Al-Ibrahim
10-11-2004, 03:51 PM
Salam,

I wanted to start this thing to get the ajer for whomever come after me ;)

These are the answers for the Revision Questions For Semester 1 - Data Communications and Networks 1 B263

Anyway with the Help of Mubarak Al-Marri and Jassir Al-Dossri we came up with these answers and we are still working with the rest of the questions.

1 – Describe:
a - Protocol: A protcol is set of rules that govern the operation of functional unites to achieve communication
b - Peer-to-peer communication: The kind of communication found in a system using layered protocols. Each software or hardware component can be considered to communicate only with its peer in the same layer via the connection provided by the lower layers.

c - Service access point:A conceptual location at which one OSI layer can request the service of another OSI layer.

d - Encapsulation: Data portions of an information unit at a given OSI layer potentially can contatin header, trailers and data from all higher layers



2 - By means of a block diagram, explain the ISO OSI reference model


http://images.google.com/images?q=tbn:N-5JsRHo7JQJ:http://www.cse.dmu.ac.uk/~cfi/Networks/ProtocolsAndArchitectures/ISO7LayerModel.gif (http://www.cse.dmu.ac.uk/~cfi/Networks/ProtocolsAndArchitectures/ISO7LayerModel.gif)




3 – What is the role of the physical layer in the ISO model?

The role of the physical layer: defines the electrical, mechanical, procedural and functional specifications for activating, maintaining, deactivating the physical link between communicating network systems.

4 – What is the role of the data link layer in the ISO model?

The role of data link layer: provide a reliable transit of data across a physical network link. It also provides mechanisms for retransmitting damaged or lost frames.

5 – What is the role of the network layer in the ISO model

The role of network layer: provides routing and related functions that enable multiple data links to be combined into an internetwork (interconnection of networks).

6 – What is the role of the transport layer in the ISO model

The role of transport layer: the network layer for the transfer of information between end systems across a given communication network.

7 – Describe and compare LANs, MANs, WANs.

a – LAN: A local computer network for communication between computers; especially a network connecting computers and word processors and other electronic office equipment to create a communication system between offices.

b – MAN: (MAN) A data network intended to serve an area the size of a large city. Such networks are being implemented by innovative techniques, such as running optical fibre through subway tunnels. A popular example of a MAN is Switched Multimegabit Data Service.

c – WAN: a computer network that spans a wider area than does a local area network.

8 through 10 not avilable :)

11 – What is an internet? What is the internet? What is an intranet?

Internet:

refers to the global information system that --

is logically linked together by a globally unique address space based on the Internet Protocol (IP) or its subsequent extensions/follow-ons;

is able to support communications using the Transmission Control Protocol/Internet Protocol (TCP/IP) suite or its subsequent extensions/follow-ons, and/or other IP-compatible protocols; and

provides, uses or makes accessible, either publicly or privately, high level services layered on the communications and related infrastructure described herein.

The Internet:

The Internet is a global communications network consisting of thousands of networks typically interconnected by fiber optic cabling. It had two parent networks whose joining began the ongoing evolution.

- U. S. Military (Tactical communication in the event of telephone downtime during wartime)

- Academics (Shared information between researchers)

Intranet:

A restricted computer network; a private network created using World Wide Web software

12 - 15 not avilable yet

Saif Al-Kuwari
10-11-2004, 04:19 PM
I see my suggestion is wokring well :)
Thank you Hassan

Mohamed Al-Naimi
10-11-2004, 04:32 PM
.. yn6eek al3afya 3eenee ..

.. ma 3ndek shweat notes (Architecture) .. :p

.. looOOOOool ..

.. allah ywafgkom en sha allah ..

.. Mubark ..

.. anqel yallah ..

.. mn gdk 3ndk classmate cool :cool: ..

yours,
Mohamed Al-Naimi

Mubarak Al-Marri
10-11-2004, 06:30 PM
مشكور اخوي حسن


تصدق للحين ما درست :confused:


الله يعين شكل الاسئله صعبه :eek:



الله يوفق الحميع

Hassan Al-Ibrahim
11-11-2004, 04:33 AM
10 - first part ..

Connection-Oriented Protocols

Most network protocols have connection-oriented services. These protocols ensure a reliable connection across the network. They can handle errors on their own, independently of any higher level protocols or applications.

The Internet’s TCP/IP protocol provides this capability with the transmission control protocol (TCP). In Novell’s IPX/SPX protocol, the sequenced packet exchange (SPX) protocol provides connection-oriented services.

Mubarak Al-Marri
11-11-2004, 05:18 AM
هذة اخر تطورات الاجوبه للمادة communications

1 – Describe:

a - Protocol: A protocol is set of rules that govern the operation of functional unites to achieve communication
b - Peer-to-peer communication: The kind of communication found in a system using layered protocols. Each software or hardware component can be considered to communicate only with its peer in the same layer via the connection provided by the lower layers.

c - Service access point: A conceptual location at which one OSI layer can request the service of another OSI layer.

d - Encapsulation: Data portions of an information unit at a given OSI layer potentially can contain header, trailers and data from all higher layers



2 - By means of a block diagram, explain the ISO OSI reference model







3 – What is the role of the physical layer in the ISO model?

The role of the physical layer: defines the electrical, mechanical, procedural and functional specifications for activating, maintaining, deactivating the physical link between communicating network systems.

4 – What is the role of the data link layer in the ISO model?

The role of data link layer: provide a reliable transit of data across a physical network link. It also provides mechanisms for retransmitting damaged or lost frames.

5 – What is the role of the network layer in the ISO model

The role of network layer: provides routing and related functions that enable multiple data links to be combined into an internetwork (interconnection of networks).

6 – What is the role of the transport layer in the ISO model

The role of transport layer: the network layer for the transfer of information between end systems across a given communication network.





7 – Describe and compare LANs, MANs, and WANs.

Describe:
a – LAN: A local computer network for communication between computers, especially a network connecting computers and word processors and other electronic office equipment.

b – MAN: (MAN) a data network intended to serve an area the size of a large city. A popular example is Switched Multimegabit Data Service.

c – WAN: is a data communication network that covers a relatively broad area.

Compare:

LANs MANs WANs

*Size 0-5 1-100 KM >100 KM

*No of Nodes 1-200 up to 500 10,000s

*Data rate 1GBPS 1-200MBPS 100KBPS

-9 -3 -6 -3 -6 *BER <10 10 to 10 10 to 10


*Deluges Up to 100 ms 100 ms > 0.5 S


* LIMK
AGGS Bridges Gateways Routers


*Routing
Complexity None simple complex

8- Compare datagram and virtual-circuit-switched connection in packet switching networks?

In the datagram each packet is treated independently of all others.

In the virtual circuit a pre-planned approach is established before any packets are sent.

9 – Whit is the impact of packet size on the transmission time in packet-switched networks?

Reducing the packet size tends to decrease the transmission time up to certain point.

10 - Give two example applications for which connection-oriented service is appropriate. Now give two examples for which connectionless service is best.

Most network protocols have connection-oriented services. These protocols ensure a reliable connection across the network. They can handle errors on their own, independently of any higher level protocols or applications.

The Internet’s TCP/IP protocol provides this capability with the transmission control protocol (TCP). In Novell’s IPX/SPX protocol, the sequenced packet exchange (SPX) protocol provides connection-oriented services.

Connectionless is used in bridges and routers.


11 – What is an internet? What is the internet? What is an intranet?

Internet:

refers to the global information system that --

is logically linked together by a globally unique address space based on the Internet.

is able to support communications using the Transmission Control Protocol/Internet Protocol (TCP/IP).

Provides uses or makes accessible, either publicly or privately.

The Internet:

The Internet is a global communications network consisting of thousands of networks. It had two parent networks whose joining began the ongoing evolution.

- U. S. Military (Tactical communication in the event of telephone downtime during wartime)

- Academics (Shared information between researchers).

Intranet:

A restricted computer network, private network created using World Wide Web software

Hassan Al-Ibrahim
11-11-2004, 03:13 PM
1 – Describe:


a - Protocol: A protocol is set of rules that govern the operation of functional unites to achieve communication.


b - Peer-to-peer communication: The kind of communication found in a system using layered protocols. Each software or hardware component can be considered to communicate only with its peer in the same layer via the connection provided by the lower layers.


c - Service access point: A conceptual location at which one OSI layer can request the service of another OSI layer.


d - Encapsulation: Data portions of an information unit at a given OSI layer potentially can contain header, trailers and data from all higher layers



2 - By means of a block diagram, explain the ISO OSI reference model


http://images.google.com/images?q=tbn:N-5JsRHo7JQJ:http://www.cse.dmu.ac.uk/~cfi/Networks/ProtocolsAndArchitectures/ISO7LayerModel.gif (http://www.cse.dmu.ac.uk/~cfi/Networks/ProtocolsAndArchitectures/ISO7LayerModel.gif)


3 – What is the role of the physical layer in the ISO model?


The role of the physical layer: defines the electrical, mechanical, procedural and functional specifications for activating, maintaining, deactivating the physical link between communicating network systems.


4 – What is the role of the data link layer in the ISO model?


The role of data link layer: provide a reliable transit of data across a physical network link. It also provides mechanisms for retransmitting damaged or lost frames.


5 – What is the role of the network layer in the ISO model?


The role of network layer: provides routing and related functions that enable multiple data links to be combined into an internetwork (interconnection of networks).


6 – What is the role of the transport layer in the ISO model?

The role of transport layer: transfer of information between end systems across a given communication network.

Hassan Al-Ibrahim
11-11-2004, 03:15 PM
7 – Describe and compare LANs, MANs, and WANs.

Describe:


a – LAN: (Local Area Network) A local computer network for communication between computers, especially a network connecting computers and word processors and other electronic office equipment.

b – MAN: (Metropolitan Area Network) A data network intended to serve an area the size of a large city.


c – WAN: (Wide Area Network) is a data communication network that covers a relatively broad area.



Comparison:

http://www.qataries.net/test.jpg



8- Compare datagram and virtual-circuit-switched connection in packet switching networks?

In the datagram each packet is treated independently of all others. Similar to the connectionless where there is no error and correction.

In the virtual circuit a pre-planned approach is established before any packets are sent.Similar to connection-oriented where there is error and correction.

OR



A connection-oriented network service which is implemented on top of a network which may be either connection-oriented or connectionless (packet switching).


9 – Whit is the impact of packet size on the transmission time in packet-switched networks?

Reducing the packet size tends to decrease the transmission time up to certain point.

10 - Give two example applications for which connection-oriented service is appropriate. Now give two examples for which connectionless service is best.

Connection-Oriented is where information is delivered with ability to error and correction.

Examples: FTP, the TCP in the TCP/IP protocol, and SPX in Novell’s IPX/SPX protocol.



Connection-less is where there is no error and correction; and information is being delivered in packets.

Examples: bridges and routers, and web casting.


11 – What is an internet? What is the internet? What is an intranet?

An internet:

An internet is a multi network (LAN, WAN, MAN) connected by routers and bridges.

The Internet:

a computer network consisting of a worldwide network of computer networks that use the TCP/IP network protocols to facilitate data transmission and exchange


Intranet:

A restricted computer network, private network created using World Wide Web software.

Saoud Al-Emadi
16-11-2004, 02:45 PM
y3tyek alf 3afeyah a'7oy 7asan o ja3alah allah fe mezan 7sanatek