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:
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Frame relay is considered packet switched network because all frames are send through different hops by the servic...