UUCP
A command named uucp is one of the programs in the suite; it provides a user interface for requesting file copy operations.
The UUCP suite also includes uux (user interface for remote command execution), uucico (the communication program that performs the file transfers), uustat (reports statistics on recent activity), uuxqt (execute commands sent from remote machines), and uuname (reports the UUCP name of the local system).
Some versions of the suite include uuencode/uudecode (convert 8-bit binary files to 7-bit text format and vice versa).
The rewrite is referred to as HDB or HoneyDanBer uucp, which was later enhanced, bug fixed, and repackaged as BNU UUCP ("Basic Network Utilities").
Taylor UUCP addressed security holes which allowed some of the original network worms to remotely execute unexpected shell commands.
Packages such as UUSLAVE/GNUUCP (John Gilmore, Garry Paxinos, Tim Pozar), UUPC/extended (Drew Derbyshire of Kendra Electronic Wonderworks) and FSUUCP (Christopher Ambler of IODesign), brought early Internet connectivity to personal computers, expanding the network beyond the interconnected university systems.
As an example, UFGATE (John Galvin, Garry Paxinos, Tim Pozar) was a package that provided a gateway between networks running Fidonet and UUCP protocols.
[citation needed] Before the widespread availability of Internet access, computers were only connected by smaller local area networks within a company or organization.
UUCP's longevity can be attributed to its low cost, extensive logging, native failover to dialup, and persistent queue management.
When uucico runs, it will expect to receive commands from another UUCP program on the caller's machine and begin a session.
The session has three distinct stages: On starting, uucico will respond by sending an identification string, \20Shere=hostname\0, where \20 is the control-P character, and \0 is a trailing null.
These include a secondary channel that can send command data interspersed with a file transfer, and the ability to renegotiate the packet and window sizes during transmission.
[11] Telebit modems used protocol spoofing to improve the performance of g-protocol transfers by noticing end-of-packet markers being sent to the remote system and immediately sending an ACK back to the local host, pretending that the remote system had already received the packet and decoded it correctly.
The data between the two modems was error-corrected using a proprietary protocol based on MNP that ran over Telebit's half-duplex connections much better than g-protocol would normally,[11] because in the common 64x3 case the remote system would be sending a constant stream of ACKs that would overflow the low-speed return channel.
It has no error correction at all, and the protocol consists simply of breaking up command and file data into 512 or 1024-byte packets to easily fit within typical TCP frames.
e-protocol ("e" for Ethernet) was developed by Clem Cole at MASSCOMP and was widely released by Brian Redman in the later HoneyDanBer versions.
The e-protocol differs from the t-protocol only in that commands are not packetized and are instead sent as normal strings, while files are padded to the nearest 20 bytes.
[11][13] The uucp and uuxqt capabilities could be used to send email between machines, with suitable mail user interfaces and delivery agent programs.
Many users would suggest multiple routes from various large well-known sites, providing even better and perhaps faster connection service from the mail sender.
Bang paths of eight to ten machines (or hops) were not uncommon in 1981, and late-night dial-up UUCP links could cause week-long transmission times.
The uucp community administered itself and did not mesh well with the administration methods and regulations governing the DNS; .uucp works where it needs to[where?
This network was very informal, maintained in a spirit of mutual cooperation between systems owned by thousands of private companies, universities, and so on.
These submitted map entries were processed by an automatic program that combined them into a single set of files describing all connections in the network.
With this infrastructure in place, UUCP's strength was that it permitted a site to gain Internet e-mail and Usenet connectivity with only a dial-up modem link to another cooperating computer.
By contrast, a link to the UUCP network could usually be established with a few phone calls to the administrators of prospective neighbor systems.
[citation needed] In addition to legacy use, in 2021 new and innovative UUCP uses are growing, especially for telecommunications in the HF band, for example, for communities in the Amazon rainforest for email exchange and other uses.
A patch to Ian's UUCP was contributed to UUCP Debian Linux package[17] to adapt for the HERMES (High-Frequency Emergency and Rural Multimedia Exchange System) project, which provides UUCP HF connectivity.
for use when a computer does not have any fixed IP addresses but is still willing to run a standard mail transfer agent (MTA) like Sendmail or Postfix.
