ADTRAN DSU III AR User Manual page 156

Appendix H. Glossary
router
A device that supports LAN-to-LAN communications. Routers may be
equipped to provide frame relay support to the LAN devices they serve. A
frame-relay-capable router encapsulates LAN frames in a frame relay frames
and feeds those frame relay frames to a frame relay switch for transmission
across the network. A frame-relay-capable router also receives frame relay
frames from the network, strips the frame relay frame off each frame to produce
the original LAN frame, and passes the LAN frame on to the end device. Routers
connect multiple LAN segments to each other or to a WAN. Routers route traffic
on the Level 3 LAN protocol (e.g., the internet protocol address). See also bridge.
sealing current
A designation for a powering situation that consists of a wet loop without span
power.
service
The provision of telecommunications to customers by a common carrier, admin-
istration, or private operating agency, using voice, data, and/or video technolo-
gies.
SNA
systems network architecture. The IBM protocol group which governs main-
frame communication.
SNMP
simple network management protocol. A control and reporting scheme widely
used to manage devices from different vendors. SNMP operates on top of the
Internet protocol.
SPID
service profile IDentifier. A sequence of digits identifying ISDN terminal equip-
ment to the ISDN switch when more than one ISDN set has been attached to the
same central office. The SPID is assigned by the telco when the ISDN line is
installed and normally resembles a phone number.
SR
data set ready. A signal on the EIA-232 interface that indicates if the communica-
tions is connected and ready to start handshaking control signals so communica-
tions can begin.
H-8 DSU IV ESP User Manual 61204011L1-1