HP ProCurve 7000dl Series Basic Management And Configuration Manual page 857

companies owned at least two Bell operating companies. The BOCs were
given the right to provide local phone service while AT&T was allowed to
retain its long distance service. The RBOCs and their constituent BOCs
are LECs.
RBS Robbed-Bit Signaling. A signaling standard used by T-carrier lines. The least
significant bit in the 6th and 12th frame (of a SuperFrame T1) and the 18 and
24th frame (of an Extended SuperFrame T1) are "robbed" and used as
signaling bits.
RC5 Rivest Cipher 5. A symmetric encryption algorithm supported by IPSec. RC5
is a block cipher with variable key length up to 2040 bits.
READSL Reach Extended ADSL. A form of ADSL that is delivered over very long twisted
pairs and provides DSL service to rural areas. Most commonly available in
France.
REN Ringer Equivalency Number, also called Ringer Approximated Loading (RAL).
An arbitrary number that denotes the telephone ringer loading on the line. A
ringer equivalency number of 1 represents the loading effect of a single
"traditional" telephone ringing circuit. Modern telephone equipment may have
a REN significantly lower than 1. For example, you may have a cordless phone
with a REN equivalency of .35, and attached to the same line you have another
older phone with a REN of 1. The total REN is the sum of all RENs on the line.
The total REN on one line must not exceed 5 in the United States, or 4 in the
UK on BT lines.
Repeater An electronic device that receives weak or low-level signals and retransmits
them with a higher signal level so that the signal can cover longer distances
without degradation.
RFC Request For Comment. The core method of publishing Internet specifications.
RFCs are a series of technical documents submitted to IETF and published
on the Internet. An Internet Document can be submitted to the IETF by
anyone, but the IETF decides whether the document becomes an RFC. Even-
tually, if it gains enough interest, the RFC may evolve into an Internet standard.
RIB Routing Information Base. In BGP, the RIB is a database table of entries that
identifies a destination address, the next hop to which packets should be
forwarded to reach that destination, and the routing metric. The metric is used
to determine the best route for a particular packet or class of packets; it may
be based on characteristics of a route, such as its delay properties or its
expected error rate. The RIB may contain information about more than one
next hop to the same destination if it is important to be able to send packets
over different paths. See also BGP.
Appendix B: Glossary
B-43