Direct Connect is a peer-to-peer written by Jon Hess NeoModus. Upon creation, other clients have appeared to implement the Direct Connect protocol. Direct Connect clients connect to a central hub.
The protocol is based on FTP. Originally protocol closed, it was able to implement as free software exist different customers for the network, such as MLDonkey, DC + + (implemented in C + + and first client Free Software for Direct Connect) and ODC (based on DC + +) for Windows or Shakespear for Mac OS X .
Its operation is based on central servers called hubs. This hub contains a list of all customers who have connected to it, and all the files you are sharing. When you do a search on the hub, it returns all files that relate to the customers wanted and what you have, then the requesting client downloads the file in question via FTP directly from the client that owns the file searched, completely disassociating makes the computer hub (in this sense, the hub can be interpreted as a directory of files that only shows who has what). No problems with excessive bandwidth, because when there is a machine on the hub you can find all the files you share with your hash, being able to find other files with the same hash but different name for whatever reason under theory are the same file hashes.
The person riding a hub can put all the features that customers want to have to use it: open sockets (number of concurrent downloads), number of gigabytes shared banning of content (eg pornography) … This allows for minimum standards of quality in different subnets that are created with each hub, avoiding lammers.