TRICKLE
TRICKLE was a file-forwarding service on the BITNET (EARN/NetNorth/GulfNet) network.
When it was created, many sites in Europe only had access to BITNET or compatible networks, and not to the Internet.
Therefore, there was a great need to access files that were available only on the Internet.
The TRICKLE server allowed anyone on the BITNET-compatible networks to access hundreds of thousands of files from many popular FTP servers around the world.
The TRICKLE server was a 'concentrator' of FTP sites into central servers. Each server had its own (large) cache disk to store files
that have been recently ordered by users, and was in communication with all other TRICKLE servers about the contents of its cache.
When a user ordered a file that is not in local cache, TRICKLE could usually forward this command to one other TRICKLE server that was
known to hold the file. In some cases, "broadcasts" to all other TRICKLEs for this file is necessary, and if the file is new, or
accessed very infrequently, it was requested from one of the 3 FTP slave-servers it had. These 3 were special servers who fetch the
file via FTP and send it via NJE to TRICKLE.