A Brief Guide to Packet Switching

Packet switching is a networking communications method mostly used in telecommunications. Data is stored in “packets” and is then sent through a network to a destination that has been assigned to each packet.

Breaking up the information into these packets allows multiple different users to share the same network paths. The packets will take their own route through a network to reach their destination without interfering with each other.


This makes the transfer of data and information far more efficient and allows the network to carry the file transfer weight better.

A Brief Guide to Packet Switching

What Exactly Is a Packet?

As we stated before, a packet is a designated unit of data that is routed through a network. It could be anything from a GIF file to an HTML file.

When you send a file through a packet-based transmission, the Transmission Control Protocol, or TCP, breaks up the file into smaller chunks, or “packets”, and numbers them. They then travel through the network to their designated destination.


This method of file transfer is very efficient because each packet finds its way through the network on its own based on the fastest route. Once they all arrive at their destination, the TCP on the receiving end puts the packets in order, reassembling them into their original file format.

The Structure of a Packet

There is a basic layout to the structure of a packet that depends on the protocol used to transmit them. Some structures may include more than what is listed below, but this is simply a list of some of the basic features of each packet’s structure.


Each packet contains two addresses – one from the sender and one for the destination. These addresses help control the destination and path of the packets as they travel through the network.



Some packets contain additional information that identifies the packet length. This ties into some other features for easy identification, but most network types determine the length of packets by the duration of transmission, rendering this additional information redundant.

Error Handling

Packets will almost always contain error checking in the form of checksum, cyclic redundancy, or parity bits checks. All of these exist to catch errors that may pop up in transmission.

Upon sending the packet, a preliminary check is done at the transmitter, which is stored in the packet. Once the packet is received, it does another check, which it then compares to the first one that was done, correcting or discarding discrepancies.

Hop Counts

Sometimes, there are errors that we cannot pick up regardless of the measures we put in place, and one such error can be a packet traversing a closed circuit in the network. If left unchecked, it will eventually keep building up and draining the network’s resources until it merely fails and shuts down.

However, just because we can’t pick it up doesn’t mean we can’t plan for such an event. That is where this feature comes in handy.

The hop count is a field with a set value that decreases each time the packet passes through a network node. Once this value hits zero, the packet is discarded and deemed faulty.


On a network with a Quality of Service, or QoS, some packets will gain priority over others. The priority field of packets allows the packet to identify which packet queue to use.

The result of this is that high priority packets are dealt with first. Meanwhile, others will take a bit longer.


Quite simply, the payload is the data or information that the user of the network wants to send.

Advantages of Packet Switching

  • Less of a delay in delivery
  • No need for massive amounts of storage
  • Allows different users to use the same network line

Disadvantages of Packet Switching

  • Pricey installation
  • Requires complex protocols
  • Packet loss can lead to loss of important information
A Brief Guide to Packet Switching


Packet switching is a valuable means of transmitting information and data across a network in a much more efficient and timely manner. It allows your files to be transferred across a shared network without larger files destroying the bandwidth and speeds.

There is much more to packet switching than what is mentioned here, but hopefully this brief guide gave you a good foundation for understanding the topic!