RAD Data comm IPmux-1E operation manual Round Trip Delay, End-to-End Alarm Generation

Chapter 1 Introduction IPmux-1/1EInstallation and Operation Manual

➤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

Note 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 =	TDM bytes/frame
	48

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(∝s) = 2 x ( 48 ⋅n x 125 (∝s) + PDVT buffer (∝s) +1000 ∝s)+ Network Round Trip Delay

NTS

where n = TDM bytes/frame 48

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.

1-22 Functional Description

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