Message switching is a telecommunications data transfer method that was first introduced in 1961; unlike packet switching that came after, message switching sends the entire message as one unit. To transfer the message, the message is first stored and then transferred via hops until it reaches the destination. Most messages are too large for random access memory (RAM), so the messages are temporarily stored in the hard drive. While message switching is not the primary method for data transfer, because it is slower and experiences delays when sending, it is still used widely with sending email. The advantages of this method are lower bandwidth costs, better management of network congestion, and the easy transfer of messages to different destinations.
When a user sends a message using message switching, this method first saves the entire message and then designates an address for the message, so it knows where the message is going. Once saved, the message is sent to the router, which switches it to the first hop, or node. At each hop, the message is inspected for problems or errors before being sent on to the next hop. The message keeps hopping around until it reaches its final destination.
In packet switching, a message is turned into small packets that are sent immediately, but message switching sends the message as a whole unit. Sending the whole unit takes up more memory. To keep the computer from slowing down, these messages are saved in the hard drive, unlike packet switching that holds the packets in the RAM. Most users will not even realize the message is saved temporarily, because it only takes a few seconds or minutes before the message sends.
Message switching is a slower form of data transfer but, despite this, it is often used for emailing. Emails are typically longer than packets of bits, so this allows users to create larger emails than if packet switching were used. This data transfer method also may be used for low-priority messages over networks to save bandwidth for high-priority messages.
Despite being an older and slower method than packet switching, message switching has some advantages. Since it is slower, and messages can be stored at nodes, these messages can easily glide through networks with heavy congestion. This method also is better for sending a message to several people at once, and it uses less bandwidth overall.