Cabletron Systems HSIM-W87 Switch User Manual


 
WAN Terms and Acronyms
HSIM-W87 User’s Guide C-5
PLB Payload Loop Back, ESF loopback including the facilities
datalink.
Point of Presence The point between the carrier provided equipment
and services and the customer provided equipment and services.
PPP Point-to-Point Protocol, provides a method for transmitting
datagrams over serial point-to-point links.
PRI Primary Rate Interface, an ISDN service providing 23 “B”
(Bearer) channels of 64 Kbps and one 64 Kbps “D” (Data) channel for
signaling and control.
PVC Permanent Virtual Circuit, a virtual circuit that provides the
equivalent of a dedicated private line service.
Q.933-A Q.933 Annex A, an ITU link management protocol
specification used in Frame Relay.
RAI Remote Alarm Indicator, is declared in C-bit Parity DS3
applications, after detecting the Yellow Alarm Signal on the alarm
channel.
SDLC Synchronous Data Link Control, layer 2 (link layer) protocol
developed by IBM for SNA connectivity. Basis for HDLC.
SEFS Severely Errored Framing Seconds, is a second with one or
more OOF errors or a detected incoming AIS.
SNA Systems Network Architecture, data communication network
architecture developed by IBM in the 1970’s.
T1 A Bell System term that refers to the physical carrier, or system of
transmission media and regenerators, used to transmit a digital signal at
1.544 Mbps.
T1.617-D — T1.617 Annex D, an ANSI link management protocol
specification used in Frame Relay.
TDM Time Division Multiplexing, a technique in which separate data
or voice signals are transmitted simultaneously over a single
communications medium based on time interleaving.
Timeslot A standard 64,000 bit/second channel. Synonymous with
DS0 (Digital Signal, level 0).