Specifications

hg-09.fm
A31003-H3580-M103-2-76A9, 01-2009
HiPath 3000/5000 V8 - HG 1500 V8, Administrator Documentation
9-3
Nur für den internen Gebrauch
Technical Concepts
Bandwidth Requirements in LAN/WAN Environments
Bandwidth Availability
The bandwidth required for voice must be available at all times in the network. You must mea-
sure and analyze the network to ensure this is the case before installing components.
Payload connections with RTP (Real-Time Transport Protocol) in a LAN environment:
The bandwidth required for voice transmission in an IP network can be calculated using the fol-
lowing table:
The LAN load is calculated for a single route. The bandwidth must be doubled for payload con-
nections in both directions. HG 1500 supports VAD with codecs G.7231A and G.729AB. If you
use these codecs, bandwidth requirements vary in relation to the length of idle periods in voice
signals.
VLAN tagging based on IEEE 802 1q is also performed as part of the calculation. Packet length
is shorter by 4 bytes without VLAN tagging.
Codec type Packetiz-
ing param-
eter
Packet
interval/
Frame size
(msec)
Payload
(bytes)
Ethernet
packet
length
(bytes)
Payload
packet
(overhead
in percent)
Ethernet
Load (incl.)
header
(Kbps)
G.711 20 20 160 230 44% 92
G.711 30 30 240 310 29% 82.7
G.711 40 40 320 390 22% 78
G.711 60 60 480 550 15% 73.3
G.723.1 1 30 24 94 292% 25.1
G.723.1 2 60 48 118 146% 15.7
G.729A 1 20 20 90 350% 36
G.729A 2 40 40 110 175% 22
G.729A 3 60 60 130 117% 17.3
RTCP 5000 280 0.4
Table 9-1 Codec-Based Bandwidth Requirements