RAD Data comm TDMoIP Gateway IPmux-16 - Manual (Page 22)

Chapter 1 Introduction IPmux-16 Installation and Operation Manual
1-14 Functional Description
Table 1-4. Ethernet Throughput – Unframed T1
TDM
bytes/frame Frame
length
(bytes) Over head
(bytes) Over head
(%) Packets
(per
second) Throughput
(Mbps)
48 94 46 96 4107 3.08
96 142 46 48 2054 2.32
144 190 46 32 1369 2.07
192 238 46 24 1027 1.95
240 286 46 19 821 1.87
288 334 46 16 685 1.82
336 382 46 14 587 1.78
384 430 46 12 513 1.76
➤
To calculate Ethernet throughput and intrinsic PDV as a function of
TDM bytes/frame:
Ethernet load (bps) = [(frame overhead (bytes) + TDM bytes/frame) Ч 8] Ч frames/second
Frame overhead = Ethernet overhead + IP overhead = 46 bytes
Frame/second =
unframed: 5447/n for a full E1
4107/n for a full T1
framed: 8000Xk / (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:
RTDelay
( µs)
= 2 x (
NTS
n 48×
x 125 (µs) + PDVT buffer (µs) +500 (µs))+ Network round trip delay
Where n =
48
e bytes/fram TDM
Where NTS = number of timeslots assigned
in unframed E1 interface = 32
T1 interface = 24