The Character Generator protocol (CharGen) is a "testing" protocol, used to verify proper reception from a server. When contacted, the server responds by returning a continuous stream of repetitive ASCII character patterns. The protocol is quite useful for verifying that no interruptions are occuring during a long 'receive'. Interestingly, most versions of Microsoft Windows contain a built-in CharGen server that can be easily activated. CharGen servers can be accessed using a TelNet client. Below are addresses to various free public access CharGen servers.
[IANA Port assignment = 19]