Message Switching

Message exchange is a network switching technology where data is routed from the source node to the destination node. During message routing, each intermediate switch in the network stores the entire message. If the network-wide resources are occupied or the network is blocked, the message-switched network stores and delays the message until sufficient resources are available to effectively transmit the message.

Prior to advancing packet switching, message exchanges served as an effective alternative to circuit switching. Initially it was used for data communication such as telex network and tape relay system. Message exchanges were largely replaced by packet exchanges, but the technology is still being used for self-organizing sensor networks, military networks and satellite communications networks.

In message exchange, the source node and the target node are not directly connected. Instead, intermediate nodes (mainly switches) serve to transfer messages from one node to the next. Therefore, when sufficient resources become available, each intermediate node in the network must store each message before retransmitting the message. If resources are not available, messages are stored indefinitely. This function is called storage and transfer.

Each message should normally contain a header consisting of routing information such as source and destination, expiration date, priority, etc.

Since message exchange implements store-and-forward technology, it effectively uses the network. In addition, there is no message size limit. However, this method also has some disadvantages.

Because messages are fully packaged at each intermediate node and stored indefinitely, the node needs a lot of storage capacity.

Since processing is done at each node, the message exchange network is very slow and performance may be degraded.

This technology is not suitable for interactive and real-time processes such as multimedia games and voice communications.

The storage transfer method is implemented in the telegraphic message exchange. Today, many major networks and systems are packet switched or circuit switched networks, but their sending processes can be based on message exchanges. For example, in most e-mail systems, the delivery process is based on message exchanges, and the network is actually circuit switching or packet switching.

Prior to advancing packet switching, message exchanges served as an effective alternative to circuit switching. Initially it was used for data communication such as telex network and tape relay system. Message exchanges were largely replaced by packet exchanges, but the technology is still being used for self-organizing sensor networks, military networks and satellite communications networks. In message exchange, the source node and the target node are not directly connected. Instead, intermediate nodes (mainly switches) serve to transfer messages from one node to the next. Therefore, when sufficient resources become available, each intermediate node in the network must store each message before retransmitting the message. If resources are not available, messages are stored indefinitely. This function is called storage and transfer.