Persistent HTTP

RFC2068, [9], describes an improvement to HTTP which maintains a continuous connection to a HTTP server for multiple requests, P-HTTP. This removes the inefficiency of continually reconnecting to a web server to download multiple images from the same page. The constant connection and reconnection results in a lot of unnecessary overhead.

Some advantages over the original HTTP protocol are:

1. By opening and closing fewer TCP connections, CPU time and memory are saved.
2. Multiple HTTP requests and responses can be sent without waiting for a response which would otherwise be necessary when opening and closing multiple connections.
3. Network congestion is reduced since there are fewer packets.

This technique is one step away from T/TCP. Instead of using transactions, it uses persistent connections much like the TELNET [13] protocol. In this situation T/TCP would not be of much benefit, the connection will remain open for a length of time, with multiple requests being exchanged. This violates the transaction characteristics discussed in section 4.1.