1. _______ is the protocol suite for the current Internet.
A) TCP/IP
B) NCP
C) UNIX
D) ACM
2. _______ are special-interest groups that quickly test, evaluate, and standardize new technologies.
A) Forums
B) Regulatory agencies
C) Standards organizations
D) All of the above
3. This was the first network.
A) CSNET
B) NSFNET
C) ANSNET
D) ARPANET
4. Why was the OSI model developed?
A) manufacturers disliked the TCP/IP protocol suite
B) the rate of data transfer was increasing exponentially
C) standards were needed to allow any two systems to communicate
D) none of the above
5. The _______ model shows how the network functions of a computer ought to be organized.
A) CCITT
B) OSI
C) ISO
D) ANSI
6. The physical layer is concerned with the movement of _______ over the physical medium.
A) programs
B) dialogs
C) protocols
D) bits
7. The OSI model consists of _______ layers.
A) three
B) five
C) seven
D) eight
8. In the OSI model, as a data packet moves from the lower to the upper layers, headers are _______.
A) added
B) removed
C) rearranged
D) modified
9. The physical layer is concerned with the movement of _______ over the physical medium.
A) programs
B) dialogs
C) protocols
D) bits
10. In the OSI model, when data is transmitted from device A to device B, the header from Aís layer 5 is read by Bís _______ layer.
A) physical
B) transport
C) session
D) presentation
11. In the OSI model, which layer functions as a liaison between user support layers and network support layers?
A) network layer
B) physical layer
C) transport layer
D) session layer
12 . In the OSI model, what is the main function of the transport layer?
A) node-to-node delivery
B) process-to-process message delivery
C) synchronization
D) updating and maintenance of routing tables
13. In the OSI model, encryption and decryption are functions of the ________ layer.
A) transport
B) session
C) presentation
D) application
14. In the OSI model, which of the following is an application layer service?
A) network virtual terminal
B) file transfer, access, and management
C) mail service
D) all of the above
15. When a host on network A sends a message to a host on network B, which address does the router look at?
A) port
B) logical
C) physical
D) none of the above
16. To deliver a message to the correct application program running on a host, the _______ address must be consulted.
A) port
B) IP
C) physical
D) none of the above
17. IPv6 has _______ -bit addresses.
A) 32
B) 64
C) 128
D) variable
18. The ______ layer is responsible for moving frames from one hop (node) to the next.
A) physical
B) data link
C) transport
D) none of the above
19. The ______ layer adds a header to the packet coming from the upper layer that includes the logical addresses of the sender and receiver.
A) physical
B) data link
C) network
D) none of the above
20. The_________ layer is responsible for the delivery of a message from one process to another.
A) physical
B) transport
C) network
D) none of the above
21. The Internetworking Protocol (IP) is a ________ protocol.
A) reliable
B) connection-oriented
C) both a and b
D) none of the above
22. _______ is a process-to-process protocol that adds only port addresses, checksum error control, and length information to the data from the upper layer.
A) TCP
B) UDP
C) IP
D) none of the above
23. __________ provides full transport layer services to applications.
A) TCP
B) UDP
C) ARP
D) none of the above
24. The ________ address, also known as the link address, is the address of a node as defined by its LAN or WAN.
A) port
B) physical
C) logical
D) none of the above
25. Ethernet uses a ______ physical address that is imprinted on the network interface card (NIC).
A) 32-bit
B) 64-bit
C) 6-byte
D) none of the above
26. Which of the following can be an Ethernet physical address?
A) 01:02:01:2C:4B
B) 07:01:02:01:2C:4B:2C
C) 07:01:02:01:2C:4B
D) none of the above
27. A port address in TCP/IP is ______ bits long.
A) 32
B) 48
C) 16
D) none of the above
28. An IPV4 address is ______ bits long.
A) 32
B) 48
C) 16
D) none of the above
28. An IP address is a ______ address .
A) logical
B) physical
C) imaginary
D) none of the above
29. MAC address is a ______ address embedded in.
A) switches
B) network card
C) router
D) none of the above
30. IP address and mac address is resolved with ______ protocal.
A) TCP/IP
B) UDP
C) ARP
D) none of the above
Friday, May 4, 2012
Thursday, April 26, 2012
Data Representation in OSI 7 Layer model
Study how each layer sees data and the role each layer plays in data communication process
Packet framing
A packet consists of two kinds of data: control information and user data (payload). IP packets are composed of a header and payload. The control information provides data the network needs to deliver the user data, (Ex: source and destination addresses, error detection codes, and sequencing information etc). Different communications protocols formats data differently.
In OSI model, a 'packet' refers to a a data unit at the Network Layer.
In the Data Link Layer data unit is a frame..
In the Transport layer it's a segment or data gram.
The term frame is used to refer to a packet at data link layer.
The packets get encapsulated into frames so that they can be transferred over different media to the end destination. It is still the same data with a frame header.They are split up differently due to varying window size.
A host computer simply arranged the data in the correct packet format, insert the address of the destination host computer, and sent the message to the Message Processor. Once the message was delivered to the destination host, an acknowledgement was delivered to the sending host. If the network could not deliver the message, it would send an error message back to the sending host.
Packet framing
A packet consists of two kinds of data: control information and user data (payload). IP packets are composed of a header and payload. The control information provides data the network needs to deliver the user data, (Ex: source and destination addresses, error detection codes, and sequencing information etc). Different communications protocols formats data differently.
In OSI model, a 'packet' refers to a a data unit at the Network Layer.
In the Data Link Layer data unit is a frame..
In the Transport layer it's a segment or data gram.
The term frame is used to refer to a packet at data link layer.
The packets get encapsulated into frames so that they can be transferred over different media to the end destination. It is still the same data with a frame header.They are split up differently due to varying window size.
A host computer simply arranged the data in the correct packet format, insert the address of the destination host computer, and sent the message to the Message Processor. Once the message was delivered to the destination host, an acknowledgement was delivered to the sending host. If the network could not deliver the message, it would send an error message back to the sending host.
Tuesday, April 24, 2012
Networking Revision
Explain how IP addressing works.
IP addresses are 32-bit addresses written as four octets in dotted-decimal notation, such as 192.168.5.18. To communicate on an IP network, a host also needs a subnet mask, which may look something like 255.255.255.0.
What DHCP and DNS do?
On TCP/IP networks, the DHCP server can provide IP configuration information to hosts. A DNS server resolves hostnames to IP addresses.
What are bandwidth and latency?
Bandwidth is the amount of data that can go through a device or cable. For example, Category 3 UTP has a maximum bandwidth of 10Mbps whereas the wireless standard 802.11g supports bandwidth of up to 54Mbps. Latency is how much delay there is between sending a data request and receiving a response.
What are status indicators?
Most network adapters and connectivity devices will have LED lights on them that are status indicators. If there is an active connection, the light will turn on. Many status indicators will blink if traffic is going through that port.
What protocols do? and name common protocols.
Protocols are the language of communication for computers. The most common protocol is TCP/IP. Other protocols you might see are NetBEUI/NetBIOS, IPX/SPX, and AppleTalk.
What is the difference between simplex, full-duplex and half-duplex transmission?
In a full-duplex environment, the devices can talk to each other in both directions at the same time. In half-duplex, only one side can talk at one time and the other side has to wait until the first one is done to send information.
What is the difference between workgroups and domains in a network?A workgroup is often referred to as a peer-to-peer network, and there is no centralized administration. A domain is a server-based network, where the server (often called a domain controller) manages user accounts and security for the network. Workgroups are best suited for networks with 10 or fewer computers and low security requirements.
What are common TCP/IP ports?
A port is a special location in memory where we write and read data in communication.
Some common protocol and ports pairs are HTTP (80), FTP (21), SMTP (25), POP3 (110), Telnet (23), and HTTPS (443).
What is the difference between a LAN, MAN and WAN?
A LAN is a local area network, which typically means a network in one centralized location. A WAN is a wide area network, which means several LANs in remote locations connected to each other. MAN is a metropolita area network connecting different places in a city.
What hubs, switches, and routers are?
These are all network connectivity devices. Hubs and switches are used to connect several computers or groups of computers to each other. Routers are more complex devices that are often used to connect network segments or networks to each other. Routers route data packets/frames received from hosts and other routers.
What is a VPN?
A virtual private network is a network where computers are connected via a WAN connection, but the connection is secured and appears to be a LAN connection.
How to identify Class A, B, and C IP addresses?
Class A addresses will have a first octet in the 1-126 range. B is from 128 to 191, and C is from 192 to 223.
What types of cables are used in networking and the connectors for each?
Common network cables include coaxial, STP, UTP (Category 5/5e and Category 6), and fiber optic. Coax cables use BNC connectors, STP and UTP use RJ-45 connectors, and fiber optic uses SC and ST connectors. (You may also be tested on phone connectors, which are called RJ-11.)
What are the different types of broadband connections?
Broadband connections include DSL, cable, satellite, and fiber optic.
What is required to access the Internet through a dial-up connection?
To use dial-up, you need a modem in your computer, a phone cord, a phone line, and an account with an Internet service provider (ISP).
What are different IEEE 802.11 standards?
Standards you should be familiar with are 802.11a, 802.11b, 802.11g, and 802.11n.
What are the security mechanisms used for wireless networking?
Wireless security mechanisms include WEP, WPA, SSID management, and MAC filtering.
What wireless technologies that are available for data transmissions?
Common wireless technologies are Bluetooth, infrared, Wi-Fi and cellular.
What are common LAN typologies?BUS, Star, Token Ring, Mesh, Hybrid
Tuesday, February 14, 2012
Python Programming for Beginers
Python is a general-purpose, high-level programming language. It's design is emphasized by code readability. Python has a very clear syntax with a large and comprehensive standard library.
Python multiple programming paradigms object-oriented and functional programming styles. It has a dynamic type system and automatic memory management (dynamic languages).
Day 1 Download Python , Installing, Basic Mathwww.python.org under GNU GPL. It was first
Day 5Conditions help you compare data to help branching of the programming flow. They make you switch between different instruction paths based on condition.
Python Programming Tutorial - else and elif
Day 6
Day 7Nested Statements and Looping
Day 9Lists and List Functions Python Programming Tutorial - Sequences and Lists Python
Day 10 Methods Python Programming Tutorial - Introduction to Methods
Day 11 Python Programming Tutorial - Sort and Tuples
Day 12 Python Programming Tutorial - Dictionaries
Day 15 Functions can have default set of variables called parameters that can be used to pass variable data. Parameters can make functions to act on different Data sets and return results.
Python Programming Tutorial - Default Parameters
Day 16 Parameters can have different types and you can pass tuples , lists and dictionaries as paramerters. Python Programming Tutorial - Parameter Types
Day 18Classes as objects and they can be referenced as Self inside objects.
Python Programming Tutorial - Classes and Self
Python Programming Tutorial - Subclasses Superclasses
Day 19Sub classes are created from Classes. Super classes are parents of sub classes. Sub classes created from Super classes can have common as well as different properties, events and methods which help them behave differently.
Day 20In OOP you can override variables in sub classless
Python Programming Tutorial - Overwrite Variable on Sub
Day 21Classes can have multiple parents.
Python Programming Tutorial - Multiple Parent Classes
Day 22Creating Classes and Initializing their properties with data.Python Programming Tutorial - Constructors
Day 24Python Programming Tutorial - Reload Modules
Python Programming Tutorial - Getting Module InfoPython Programming Tutorial - Building Functionsfunctions help us develop smaller programs by repeated using a code block as a procedure that can be called as one instruction. Then the code block runs as a re-usable unit of code. Python Programming Tutorial - For and While Loops Data Inputs are two different types in Python. You can input data as numbers or raw. If you enter numeric data as raw you need to convert type to numeric before using in calculations. String are input as raw. Strings help us keep alphanumeric data as a sequence of characters with varying length.
Python Programming Tutorial - More Methods
Python Programming Tutorial - Strings n Stuff
Python Programming Tutorial - String Methods
Python Programming Tutorial - Infinite Loops and Break
Python Programming Tutorial - And and Or
Python multiple programming paradigms object-oriented and functional programming styles. It has a dynamic type system and automatic memory management (dynamic languages).
Python is often used as a scripting language, and also used in non-scripting contexts. Using third-party tools, Python code can be packaged into standalone executable programs. Python interpreters are available for many operating systems.
Day 1 Download Python , Installing, Basic Mathwww.python.org under GNU GPL. It was first
Python is FOSS (Free and Open Source Software) available from
Day 2
Variables and ProgramsVariables are containers in memory used by programs to keep run time data, edit them and strore new value. They can be accessed with names assigned to them. Variables have different types numeric, strings and logical are the basic data types.
The program is a rows of programming instructions to the computer to store data, recall data, calculate, perform operations and test certain conditions etc. It can be re used when saved in hard disk and re-loaded to memory to run its task.
Day 3
Strings and their Uses
Day 4
- Python Programming Tutorial - Raw Input
Day 5Conditions help you compare data to help branching of the programming flow. They make you switch between different instruction paths based on condition.
Python Programming Tutorial - else and elif
- Python Programming Tutorial - If Statement
Day 6
Comparing numbers, strings and or conditions. Different comparison operators let you compare numbers and conditions during run time to switch to different conditions and options to run different code.
Day 7Nested Statements and Looping
You can run code inside another code block to execute different instruction lines. Each nested code are is a code block.
- Python Programming Tutorial - Nesting Statements
Day 8LoopingPython lets you run a code block repeated until a certain condition is met. For ...Next and Do .... Loop repetitions can be used in python.
Day 9Lists and List Functions Python Programming Tutorial - Sequences and Lists Python
Programming Tutorial - List Slicing
Lists are like arrays which keeps multiple data items in a single variable. Each data item is referenced by its element id. Consider a list as a container of containers with each container can hold more containers. This is a very strong data structure in python compared to other programming languages. Slicing is getting a desired set of elements from a list. Lists have list processing Functions.
Day 10 Methods Python Programming Tutorial - Introduction to Methods
Day 11 Python Programming Tutorial - Sort and Tuples
Tuples are simple lists. But not editable during run time.
Day 12 Python Programming Tutorial - Dictionaries
Dictionaries are lists where element id is a keyword or alphanumeric identifier.
Files Operations , data Reading and Writing
- Python Programming Tutorial - Working with Files
- Python Programming Tutorial - Reading and Writing
- Python Programming Tutorial - Writing Line
Day 14
Day 15 Functions can have default set of variables called parameters that can be used to pass variable data. Parameters can make functions to act on different Data sets and return results.
Python Programming Tutorial - Default Parameters
Day 16 Parameters can have different types and you can pass tuples , lists and dictionaries as paramerters. Python Programming Tutorial - Parameter Types
Day 17OOP uses objects with properties , and events and methods. OOP helps you create objects and store data as properties. Objects responds to events executing their methods.
Python Programming Tutorial - Object Oriented Program
Day 18Classes as objects and they can be referenced as Self inside objects.
Python Programming Tutorial - Classes and Self
Python Programming Tutorial - Subclasses Superclasses
Day 19Sub classes are created from Classes. Super classes are parents of sub classes. Sub classes created from Super classes can have common as well as different properties, events and methods which help them behave differently.
Day 20In OOP you can override variables in sub classless
Python Programming Tutorial - Overwrite Variable on Sub
Day 21Classes can have multiple parents.
Python Programming Tutorial - Multiple Parent Classes
Day 22Creating Classes and Initializing their properties with data.
Modules are separate programs that can be used in multiple programs as different code units. Much effiecient way than using functions. Help programs to be modular and efficeient. Modules make programming easy and sharable by multiple programmers to provide specific functionality in a program.
Day 24Python Programming Tutorial - Reload Modules
Python Programming Tutorial - Getting Module InfoPython Programming Tutorial - Building Functionsfunctions help us develop smaller programs by repeated using a code block as a procedure that can be called as one instruction. Then the code block runs as a re-usable unit of code. Python Programming Tutorial - For and While Loops Data Inputs are two different types in Python. You can input data as numbers or raw. If you enter numeric data as raw you need to convert type to numeric before using in calculations. String are input as raw. Strings help us keep alphanumeric data as a sequence of characters with varying length.
developed by Guido van Rossum of Netherlands as a successor to the ABC programming languageas. Python is a object oriented programming language. Python runs on all platforms including mobiles. Python is an interpreter language and also can be used as compiled. Handing numbers and math is important in programming. Numbers have different types integer, long, double and float etc for different accuracy needs in calculations.
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