The World of Peer-to-Peer (P2P)/Networks and Protocols/Direct Connect

Direct Connect
Direct connect is a peer-to-peer file sharing protocol/network but it uses a central server, this reliance on a central point can also be seen on the old Napster network, in that each server build an independent network (not an hybrid like for instance with eMule). One should note that some clients are now also implementing DHTs that will result in unifying used networks. The Direct Connect protocol was originally developed by Jonathan Hess for use on the Neo-Modus Direct Connect (NMDC) v1, released September 2001 and partially in NMDC v2, released in July 2003.

Direct Connect defines the servers as HUBs. Clients connect to a central hub and that hub feature a list of clients or users connected to it. Users can then search for files to download, or as chat with other users present (on that server).

Direct Connect also implements Tiger tree hashing (TTH) for for file transfers.

NMDC Protocol
created by Jon Hess at Neo-modus protocol mirror ( http://www.teamfair.info/wiki/index.php )

ADC Protocol
The ADC protocol ( http://dcplusplus.sourceforge.net/ADC.html ) is similar to the Neo-Modus Direct Connect (NMDC) protocol. It consists of a text protocol for a client-server network, created with goal to be simple, yet extensible.

Jon Hess contributed to the creation of this protocol with the original Direct Connect idea through the Neo-Modus Direct Connect client / hub. Other major contributing source was Jan Vidar Krey's DCTNG draft that lead to subsequent work by Dustin Brody, Walter Doekes, Timmo Stange, Fredrik Ullner, Fredrik Stenberg and others.

HUB Software Implementations

 * DConnect Daemon ( http://www.dc.ds.pg.gda.pl/ ), an open source Direct Connect's hub (working as daemon) written in C. Works currently under GNU Linux and FreeBSD, but is planned to be able to work on all Unixes and Windows. As a daemon it works in background and does not require any Xwindow system. Supports a telnet administration console.

Client Software Implementations

 * NeoModus Direct Connect
 * DC++ ( http://dcpp.net/ or http://sourceforge.net/projects/dcplusplus/ ), a project aimed at producing a file sharing client using the ADC protocol. It also supports connecting to the Direct Connect network, open source under GPL, using C++/MFC running on Windows. It is developed primarily by Jacek Sieka, nicknamed arnetheduck.
 * BCDC++
 * RevConnect ( http://www.revconnect.com/ ), supports also Kademlia, Open Source under GPL, using C++/MFC running on Windows.
 * Strong DC++ ( http://strongdc.berlios.de/download.php?lang=eng ), Open Source under GPL, using C++/MFC running on Windows.
 * ApexDC++ ( http://www.peerwebdc.tk/ - http://sourceforge.net/projects/apexdc/ ), based on Strong DC++. It has numerous features such as a plugin to block IP addresses (uses PeerGuardian blocklist), super seeding, customization, themes, and a nice Vista-type general user, Open Source under GPL, using C++/MFC running on Windows.
 * TkDC++ ( http://tkdcpp.com ), Open Source under GPL, using C++/MFC running on Windows.
 * GtkDC (http://gna.org/projects/gtkdc/), a Direct Connect client written in C, based on a GIMP toolkit 2.0 GUI. It is intended to run on UNIX-based platforms, but with a little port it should be executable on Windows platform with Gtk libraries. Licensed under the GNU General Public License V2 or later.
 * FlylinkDC++ ( http://www.flylinkdc.com and http://www.flylinkdc.ru ), based on StrongDC++