Glossary-27
request to send (RTS)
An RS232 interface signal, sent from a data terminal equipment (DTE) to
the data communications equipment (DCE), that indicates the DTE has data
to transmit.
RI, ring indicator
An RS232 interface signal, sent from the modem to the data terminal
equipment (DTE), that indicates that an incoming call is present.
ring topology
A form of mesh topology where three or more nodes are connected to one
another in the form of a ring (similar to a daisy chain with the loop closed).
In the event of link failure, there is an alternate path between nodes.
See
also
mesh topology.
RJtype connector
A modular connector that complies with certain telco standards.
ROM, readonly memory
A nonvolatile semiconductor storage device manufactured with predefined
contents.
router
A device that looks at a local area network (LAN) packet's destination
address to determine which LAN network is its destination. The router will
then find the best path to use to send the packet across the network(s).
RS232
An Electronics Industry Association recommended standard that is the most
common for connecting serial data processing devices. RS232 specifies the
electrical characteristics of the signals in cables that connect a data terminal
equipment (DTE) to a data communications equipment (DCE). An RS232
standard is functionally identical to ITTTSU V.24/V.28.
RS422
An Electronics Industry Association recommended standard for cable lengths
that extended the RS232 50 foot limit. Although introduced as a companion
standard with RS449, RS422 is most frequently implemented on unused
pins of DB25 (RS232) connectors. Electrically compatible with ITTTSU
recommendation V.11.
RS423
An Electronics Industry Association recommended standard for cable lengths
that extended the RS232 50foot limit. Although introduced as a companion
standard with RS422, RS423 is not widely used. Electrically compatible
with ITTTSU recommendation V.10.
