GL-18 GLOSSARY
Remote Group
remote module
restricted
channel
restricted
digital data
RFA
RG
robbed-bit
signaling
SDN
secondary
synchronization
reference
senderized
operation
severely
errored second
signaling system
number 7
slip
A feature that allows a group of port circuits — equivalent to one or more port
circuit packs but fewer than one module — to be located up to 100 miles from a
communications system, communicating through digital signal level-l (DS1)
facilities. Telephones and data terminals connected to these circuits operate as if
they were installed at the central location. Digital and EIA-trunk interfaces can
be made remote, but the Remote Group feature does not allow local analog
trunk interfaces to the remote group. Also called Remote Carrier and Remote
Carrier Group. See also remote module.
A hardware configuration that allows one or more network modules to be located
up to 25,000 feet from the common control (CC) by using fiber-optic cable. See
also Remote Group.
A B-channel that meets a ones-density requirement or uses zero code suppression
(ZCS). See also clear channel.
User data that is encoded so that the all-0s octet cannot occur before the data is
presented to the transmission channel. Restricted digital data can be transmitted
over linked facilities that use combinations of zero code suppression (ZCS) and
bipolar with 8-zero substitution (B8ZS) line coding.
See remote frame alarm.
See Remote Group.
Digital signal level-l (DS1) signaling in which up to 8K-bps from each of the 24
64K-bps channels are used for signaling in every sixth frame. The least-
significant bit of each 8-bit sample is replaced by a signaling bit. Also called
DS1 robbed-bit signaling. See also inband signaling.
See Software Defined Network.
A high-quality transmission facility used for providing a backup source to the
primary synchronization reference.
A method of collecting the called number in a sender buffer and then outpulsing
the called number to the distant central office (CO) or communications system.
A l-second interval for which at least 10-6 errors occur.
The standard being developed by the CCITT to provide interoffice signaling —
for example, signaling from a central office (CO) to a toll office, a toll office to
a toll office, and a toll office to a CO. When implemented, signaling system 7
will replace common-channel interoffice signaling (CCIS). See also common-
channel interoffice signaling and Q recommendations.
The deletion or repetition of a single frame caused by differerences in clock
frequencies. Generally, a slip involving the synchronization reference will result
in most or all spans experiencing the repetition or deletion of an 8-bit word.
Slips are not caused by noise on the transmission line.