RAD Data comm IPmux-1 - Manual (Page 30)

Chapter 1 Introduction IPmux-1/1E Installation and Operation Manual
1-22 Functional Description
➤
To calculate Ethernet throughput and intrinsic PDV as a function of
TDM bytes/frame:
Ethernet load (bps) =
[(frame overhead (bytes) + TDM bytes/frame) x 8] x frames/second
Frame overhead = Ethernet overhead + IP overhead = 46 bytes
The frame overhead does not include:
Preamble field: 7 bytes
SFD field: 1 byte
VLAN field (when used): 4 bytes.
Frame/second =
Unframed: 5447/n for a full E1
4107/n for a full T1
Framed: 8000 x k/(46.875 x n)
Where k = number of assigned timeslots
Where n =
48
e bytes/fram TDM
Round Trip Delay
The voice path round-trip delay, which is a function of all connections and
network parameters, is calculated for E1/T1 as follows:
(±2 µs) RTDelay
( µs)
= 2 x (
NTS
n 48×
x 125 (µs) + PDVT buffer (µs) +1000 µs)+ Network Round Trip Delay
where n =
48
ytes/frame TDMb
where NTS = number of timeslots assigned
in unframed E1 interface = 32
T1 interface = 24
End-to-End Alarm Generation
An end-to-end alarm generation mechanism exists in IPmux-1 to facilitate the
following alarms:
Unframed
AIS is transmitted toward the near-end PBX in event of:
• Far-end LOS, AIS
• PDVT underflow/overflow.
Framed Timeslot/CAS configurable alarm pattern is transmitted toward the
near-end PBX in event of:
• Far-end LOS, LOF, AIS
• PDVT underflow/overflow.
Note
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