The MIB module contains ATM Trunk statistics.
PVC: Permanent Virtual Circuit
OAM: Operation and Management
CRC: Cyclic redundancy check
AIS: Alarm Indication Signal
TDM: Time Division Multiplex
FERF: Far End Receive Failure
CPS: Common Part Sub-layer
PDU: Protocol Data Unit
HEC: Header Error Control
DSP: Digital Signal Processing
CID: Channel Identifier
UUI: User-to-User Information
VoIP: Voice over IP
CCS: Common Channel Signaling
VoAAL2: Voice over AAL2
SDU: Service Data Unit
HDLC: High Level Data Link Control
SAR: Segmantation and Reassembly
External AIS - is an Alarm Indication Signal associated
with a maintenance alarm detected on a defective
maintenance span, that is transmitted in the direction
of the defect as a substitute for normal signal.
The purpose is to show the downstream entities that
a defect has been identified and to prevent other
maintenance alarms consequent to this first defect.
External AIS bit stream is represented by an all 1's
Ref - ITU-T Rec. M.20 sec. 5.4.2 a
External RAI - is a Remote Alarm Indication signal
that is transmitted upstream from an entity that has
detected defects persisting long enough to constitute
a received signal failure. Its purpose is to report in
the backward direction that there is an interruption
of service in the forward direction.
The forward direction is from the originating end of
the alarm to the remote end.
The backward direction is from the remote end to the
orginating end of the alarm.
Ref - ITU-T Rec. G.704 section 22.214.171.124.3
I.366.2 - ANNEX N
External Connection AIS - is a Alarm Indicating Signal
transmitted in the downstream direction from the AAL
type 2 connecting point that first detects a defect
affecting the AAL type 2 connection; this includes
defects indicated by lower layers.
Ref - ITU-T Rec. I.610 sec 126.96.36.199.1.1
External Connection RDI - is a signal transmitted upstream
by an AAl type 2 endpoint that is in an alarm state as the
result of having received an AAL type2 connection AIS or
having detected a defect that affects the AAL type2
All ATM alarm definitions are specified in I.610