Protocol Definitions in /etc/uucp/Devices File
You can define the protocol to use with each device in
/etc/uucp/Devices. This specification is usually unnecessary because you can
use the default or define the protocol with the particular system you are calling. Refer to UUCP /etc/uucp/Systems File for details. If you do specify the
protocol, you must use the following form:
For example, you can use TCP,te to specify
the TCP/IP protocol.
The following table shows the available protocols for the Devices file.
Table 12-2 Protocols Used in /etc/uucp/Devices
This protocol is commonly used for transmissions over TCP/IP
and other reliable connections. t assumes error-free
This protocol is UUCP's native protocol. g is
slow, reliable, and good for transmission over noisy telephone lines.
This protocol assumes transmission over error-free channels
that are message oriented, as opposed to byte-stream oriented, such
This protocol is used for transmission over X.25 connections. f relies on flow control of the data stream and is meant
for working over links that can (almost) be guaranteed to be error
free, specifically X.25/PAD links. A checksum is enacted over a whole
file only. If a transport fails, the receiver can request retransmission
Here is an example that shows a protocol designation for a device
TCP,te - - Any TCP -
This example indicates that, for device TCP,
you should try to use the t protocol. If the other
end of the transmission refuses, use the e protocol.
Neither e nor t is appropriate for use over
modems. Even if the modem assures error-free transmission, data can still be dropped between the
modem and the CPU.