ASSIGNMENT # 1
In telecommunications, switching refers to the process in which digital electronics and computerized control are used to connect the circuits of the telephone for the purpose of making the telephone calls
There are two types of switching
1. Packet Switching
2. Circuit Switching.
Packet Switching:
What is packet?
Packets are the blocks or groups of data to be transmitted regardless of the data structure and data type.
Methodology:
In packet switching the data which is to be transmitted is divided into the packets. In this switching the communication path is not dedicated to one communication party but one path or link is used by the packets from different parties. During transmission the packet finds the path to the destination. The paths for the transmission are not defined from the source and they are decided when the packet has reached a certain node. The packet contains the header that carries all the information about the IP addresses of the source and the destination. With the help of this information the switches and the routers in the paths decides which hops are used to reach the specific destination.
Acknowledgement:
If the switch does not find enough resources for the packet, then it sends a message to the source that establishment of connection is not possible and the establishment of connection is failed.
Pros and Cons of Packet Switching:
Packet switching is used as an alternative choice for circuit switching which is used in PSTN or in ISDN for making or establishing voice telephone call connections
In comparison to circuit switching, packet switching has some pros and cons over circuit switching.
Bandwidth efficiency:
Packet switching can use the overall bandwidth of the network more efficiently...
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...ommunication party and the channel is dedicated to the party until the communication ends.
Wasted bandwidth:
During the silent period of the communication when the users are not utilizing the bandwidth than this idle bandwidth cannot be used by the other parties as a result this bandwidth gets wastes.
Blocking:
If the users or calling parties are present and no circuit is available for establishing this new connection then the request for making connections cannot be fulfilled and this state is called blocking.
No variable data:
Circuit switching does not support the transmission of the changeable data rates and the transmission of data from different sources on a single channel or same network path.
Fixed delays:
In circuit switching the delays in communication are fixed because of the dedicated paths between the nodes.
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Routing scheme means to find a path from once place to another on which packets can travel. In most of the cases, we need multiple routers in order to route the packet to the destination. Routing contains three elements:
When there is loss of packet, the sender doesn’t wait for the time out and resends the packets immediately using the mechanism of fast recovery and fast retransmit.
What kinds of information can be sent with IP packets? Almost any of the information sent over the internet can be sent with IP
If the network is badly congested than the ACK for the combined set of packets can be delayed. As the source using the Nagle algorithm awaits the ACK it can introduce an inadvertent additional latency (Wikipedia,
Unknown / unintentional or un-covenanted movements this could be in the form of unpredictable movements whilst the equipment is being maintained or at the reinstatement of power. Other causes may be due to the corruption of software, or damage to the any of the peripherals or programmable electronics.
End to end delay = transmission delay of all the 3 links + propagation delays of all the 3 links + switch process delay
An example of this is the bus line and now he’s at the end of any line that bus could take him. He can’t even transfer to another bus because there are no more buses that will take him any
Frame relay is considered packet switched network because all frames are send through different hops by the servic...
Analog communication employs continuous transmission of an electromagnetic wave form that varies in frequency and amplitude.
Frequently accessed documents are fetched from nearby proxy cache instead of remote data servers, hence the transmission delay is minimized.
Berean¡¦s existing network infrastructure is wire line, and uses a T1. Remote users access the network through a dial-up modem pool. Berean¡¦s wire line network model severely limits the accessibility and effectiveness of the Berean network. For example, employees in Berean facilities are unable to access the network easily from meetings, the cafeteria, or anywhere other than their offices. In addition, the effectiveness of remote users is limited by the slow speed of present-day dial-up modem connections.
This report will describe the two forms of data communications in terms of the physical interfaces and modes of operation. It will describe the features of data communications equipment in relation to synchronous and asynchronous communication including modems, network terminating units and sending and receiving equipment.
b) It is not fully reliable as internet glitches of signals can hinder communication effectively.
Congestion is when the physical capacity of the roads cannot meet the excess demand of vehicles.... ... middle of paper ... ... In analyzing all the traffic congestion policies, I believe this policy alternative will have the greatest impact in reducing traffic congestion.
Making a telephone call no longer should conjure up visions of operators connecting cables by hand or even of electrical signals causing relays to click into place and effect connections during dialing. The telephone system now is just a multilevel computer network with software switches in the network nodes to route calls get through much more quickly and reliably than they did in the past. A disadvantage is the potential for dramatic and widespread failures; for as has happened.