Справочник Пользователя для RAD Data comm IPmux-1

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 =

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

(

= 2 x (

NTS

48×

x 125 (µs) + PDVT buffer (µs) +1000 µs)+ Network Round Trip Delay

where n =

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

Order from: Cutter Networks

Ph:727-398-5252/Fax:727-397-9610