Computer Networks Flashcards
1
Q
Define network’s
A
A system of interconnected computer’s and computerized peripherals
2
Q
Computer’s may connect to one another by……………..
A
Wired or wireless media
3
Q
Type’s of computer network
A
- Personal Area Network
- Local Area Network
- Metropolitan Area Network
4 Wide Area Network - Internetwork
4
Q
Discuss Personal Area Network (PAN)
A
- A PAN is the smallest network and us very personal to a user.
- PAN may include Bluetooth enabled devices or infra-red enabled devices
- PAN has a connectivity range of up to 10 meters
- PAN may include wireless computer keyboard and mouse, Bluetooth headphones, wireless printers and TV remotes
- PAN may take up to eight devices in a master - slave fashion
5
Q
Discuss Local Area Network (LAN)
A
- LAN is a computer network that covers inside a building and operated under a single administrative system
- LAN covers an organization’s offices, colleges or universities.
- The number of systems connected in LAN may vary from 2 to as much as 16 million.
- LAN provides a useful way of Sharing resources between end users
- These resources include: printers, scanners and the internet that are sharable among computers.
- LAN are composed of Networking and routing equipment such as hubs, switches and routers.
- A LAN may be contain local servers serving file storage and other locally shared applications.
- A LAN mostly operates on private IP address and does not involve heavy routing
- LAN works under a local domain and controlled centrally
- LAN uses either Ethernet or Token - ring technology.
- Ethernet is the mostly widely employed LAN technology
- A LAN can be wired, wireless or both form at anytime.
6
Q
Discuss Metropolitan Area Network (MAN)
A
- MAN is computer network that covers an entire city, such as cable TV network’s
- MAN can use Ethernet, Token - ring , Asynchronous Transfer mode ( ATM), or Fiber Distributed interface (FDDI)
- Metro Ethernet is a service provided by ISP’s
- This service enables users to expand Thier LANs.
- For example, MAN can help an organization to connect all of it’s offices in a city.
- The backbone of a MAN is high - capacity and high - speed fiber optics.
- MAN works in between LAN and Wide Area Network ( WAN )
- MAN provides the uplink for LANs to WANs or internet.
7
Q
Discuss Wide Area Network
A
- WAN covers a large area which may be a province or a country
- Telecommunication network are WANs
- These network’s provide connectivity to MANs and LANs.
- WAN are equipped with high speed backbone.
- WAN may use advanced technologies such as Asynchronous Transfer Mode ( ATM ), Frame relay, and Synchronous Optical Network ( SONET).
- WAN may be managed by multiple administration
8
Q
Discuss internetwork
A
- Internetwork is the network of network’s and simply referred to as internet.
- The internet is the largest network on the planet
- It connects all WANs thus bringing connections to homes and offices aka LANs
- The internet uses TCP/ IP protocol suite and uses IP as the addressing protocol.
- The internet allows users to share and access enormous amount of information using World Wide Web (WWW), FTP, email services and a host of others
- The internet is based on the client-server architecture
- Internet uses speed fiber optics backbone as the medium of transmission.
- To inter- connect the various continent, fiber optics cables are laid under the sea and referred to as “ submarine communication cables”
- Internet is widely deployed on the WWW service’s using HTML linked pages and accessible by client software known as the Web Browsers.
- The internet serves many purposes and is involved in many aspects our lives such as web sites, E-mail, instant messaging, blogging, social media, networking, audio and video streaming.
9
Q
Discuss internet protocol (IP)
A
- A layer 3 ( Network Layer, OSI/TCP-IP) protocol.
- A set of rules that governs the format for sending data through network.
- The IP contains addressing information and some information that enables packets to be routed
- Together with the transmission Control Protocol (TCP), IP represents the heart of the internet protocols
10
Q
What’re the primary responsibilities of IP ( Internet Protocol)
A
- Providing connectionless , best effort delivery of datagrams through an internetwork
- Providing fragmentation and reassembly of datagrams to support data links with different maximum transmission unit (MTU) sizes.
11
Q
What are the two fundamental network layer services that IP provides
A
- Logical addressing: provides a unique address that identifies both the host and network it is connected to.
- Routing: determines the best path to a particular destination network, and then routes data accordingly.
12
Q
IP protocol is divided I two distinct versions which are??
A
- IP version 4(IPv4)
- IP version 6(IPv6)
13
Q
A packet is ??
A
An encapsulated data from the network layer is referred to as packet
14
Q
Discuss IPv4
A
- Up until recently, IPv4 is the most commonly used internet protocol and currently the dominant
- The IPv4 is a 32-bit value that uniquely identifies (address) every device that is attached to the data network
15
Q
Discuss IPv4: header
A
- Version: this is a 4-bit field that indicates the version of the IP currently being used
- IP Header Length (IHL): indicates the datagrams header length in 32-bit words and points to the beginning of the data
- Type-of-Service field is an 8-bit field that indicates the desired quality of service. The field defines precedence, delay, throughput and reliability.
16
Q
Type’s of field
A
- Total length field specifies the length, in byte of the entire packet.
- The length includes the packet header and the data
- The maximum length is 65, 535 bytes
- Host are prepared to accept datagram up to 576 bytes. - Identification field contains an integer that identifies the current datagram
- This field is assigned by sender to help the reciever reassemble the packets fragments. - Flags is a 3-bit field
- The two low-order bits control fragmentation.
- The low-order bit tells if packet can be fragmented
- The middle bit Indicate whether this packet is the last fragment in a series of fragmented packets.
- The high-order bit is unused. - Fragment offset is a 3-bit that indicates the position of the fragments data
- This allows the destination IP to process and properly reconstruct the original datagram. - Time-to-Live is a counter that gradually decrements vto zero
- When the counter gets to zero, the packet is discarded.
- This field keeps packets from looping endlessly.
6.Protocol field indicates which upper-layer protocol receives incoming packets after IP processing in complete.
- Header checksum helps ensure IP Header integrity
- Source address specifies the sending node.
- Destination address - specifies the receives node.
- Options allow IP to support various options such as security.
- Data this field contains upper- layer( application layer through transport layer) information.
17
Q
Discuss IPv4 addressing
A
- As earlier stated, IPv4 is a 32-bit value that identifies (an address for ) every device on a network
- IP addressing is integral to the process of routing datagrams through the internet.
- Each IP address has specific components and follows a basic format.
- Each device on a network is assigned its own unique 32-bit logical address
- The addressing is divided into two main parts:
- Network address identifies the network to which an IP belongs. An ISP can obtain a block of network numbers.
- host address identifies a host on the network. This number is unique throughout the network and it assigned by local network administrator. - The network address field of the IP address is referred to as the network prefix.
- The leading portion of the IP address identifies the network address.
- All hosts/devices on a given network share the same network address but each has a unique host address
- Hosts on different network have different network address
