What is Packet Switching?
Packet switching is a process in which data is divided into packets and routed to its destination through networks. It involves the concept of sending and receiving data between two or more computers by dividing it into small chunks called packets, which are individually routed from source to destination over available pathways in the network.
Each packet contains both the sender’s address and the receiver’s address, as well as data. Each packet is then sent separately through the network to its destination, where it is reassembled into the original data stream. Packet switching enables efficient transmission of data across multiple networks because packets can be routed differently depending on the availability of pathways in the network.
When was Packet Switching Invented?
Packet switching technology was developed in the early 1960s and was first used in the ARPANET project. Its original purpose was to provide a more effective way of sending messages between computers over a network, which would allow for faster transmission times than traditional circuit switching or analog systems. The first use of packet switching networks involved connecting two mainframe computers over a dedicated leased line.
Packet switching technology was later used in the development of the Internet and is still used today as one of its core technologies, allowing data to be sent between computers all over the world in packets.
What are the Types of Packet Switching?
There are two main types of packet-switching technologies:
- circuit-switched packets
- datagram packets
Circuit-switched packet (CSP) is a connection-oriented approach to routing data packets in which a virtual circuit has to be established before data can be sent. It uses fixed-length packets, with each packet having a single purpose. The circuit-switched approach is more reliable as each packet travels along the same route and arrives at its destination in the order it was sent, but it is also more expensive due to the overhead associated with setting up the virtual circuit.
Datagram packets are connectionless, meaning that each data packet does not have a fixed destination and is sent independently of any other packet. This makes it less reliable than CSP, as the packets may be reordered or lost along the way. However, it does require less overhead as no virtual circuit needs to be established before data can be sent. Datagram packets are more suitable for applications that do not need guaranteed delivery such as streaming media.
What are the Key Features of a Packet Switching Network?
The key features of a packet-switching network are:
- Efficiency in the use of bandwidth: since each packet is sent independently, multiple packets can be sent at the same time, making it more efficient.
- Error detection and correction: Packet switching uses checksums to detect errors in the data and then correct them.
- Flexible routing: Packets can be routed through different pathways depending on the availability of routes in the network.
- Scalability: Packet-switching networks are easily scalable since additional nodes can be added as needed. This increases capacity without having to upgrade the entire system.
- Security: Packet-switching networks are highly secure since data is encrypted when sent over the network.
- Reliability: Packets can be rerouted if there is an error in one of their pathways, making them more reliable than other types of networks such as circuit switching.
- Cost savings: The cost of packet switching is lower than that of other types of networks since additional resources are not required to establish a virtual circuit before data can be sent.
What are the Use Cases of Packet Switching?
Here are some use cases of packet-switching networks:
- Voice over IP (VoIP): VoIP is a technology that allows digital data to be sent over IP networks, instead of traditional analog telephone lines. This digital data is then converted into voice packets and transmitted using the packet-switching network.
- Video streaming: Video streams are broken into packets and then sent using the packet-switching network. This provides an efficient and reliable way to stream video content over a network.
- Networked gaming: Online games use packet-switching networks to ensure that data is quickly transmitted between players in real time, without any delays or errors.
- Data transmission: Packet switching is used in many types of data transmission, such as transferring files over the internet or sending messages between computers.
- Internet access: Packet switching is used to provide connectionless internet access, allowing multiple users to share a single line without having to establish separate connections for each user.
What does a Layer 2 Switch use to Direct Packets?
Layer 2 switches use MAC (media access control) addresses to direct packets. Each device on a network has a unique MAC address that is used to identify it and allow it to send and receive data. Layer 2 switches read the destination MAC address on a packet before forwarding it to its intended destination.
This makes them more efficient than routers as they do not need to consult a routing table before forwarding the packet. The switch can also use other fields in the packet header such as VLAN tags and QoS (quality of service) markings to further restrict where packets are sent.