Requirements Of Delay Times; Provision Of Qos In Data Networks - Siemens HiPath 3000 Series Service Documentation

start_h5.fm
Startup and Administration HiPath 5000
Server Networking
Accordingly, the minimum bandwidth required is as follows:
The necessary bandwidth must be calculated using N as the number of simultaneous connec-
tions:
Required bandwidth
With ITU G.711
With ITU G723.1
N = number of simultaneous voice connections
When configuring fax or modem transmissions using the formula described above (outband
transmission) the following are also required for each configured connection:
For fax group 3 (V.17, 14 Kbps): approx. 20 Kbps
●
For modem connections (V.34, 33.6 Kbps): approx. 40 Kbps
●
6.5.2.3

Requirements of Delay Times

For natural communication, the delay should amount to a maximum of 50 ms (one-way delay)
for voice connections (network delay). Delays of more than 50 ms in one direction impair natural
communication. The effect is similar to that experienced with voice connections over satellite.
The maximum number of HOPs must not exceed 15.
Priority control is a particularly efficient means of reducing the delay (see next section). Please
proceed with caution if the network is operated using lines with a low bit rate (for example, con-
nection of a branch to headquarters at a rate of 128 Kbps). The maximum number of trunk lines
can be determined by calculating the necessary bandwidth.
6.5.2.4

Provision of QoS in Data Networks

To guarantee the Quality of Service (QoS) described in the two previous sections, the following
standards must be met:
All the components involved in transmitting voice data must support min. IEEE 802.1q (lay-
●
er 2).
In addition, all components require routing according to the Diffserv standard RFC 2474
●
and the ToS standard (Type of Service) RFC 791.
6-14
Formula (Kbps) of approximate values
.. N x 90 (voice)
+ N x 4 (BLF+CDR)
+ 10 (ACD/TAPI)
.. N x 22 or 19 (voice)
+ N x 4 (BLF+CDR)
+ 10 (ACD/TAPI)
Nur für den internen Gebrauch
A31003-H3590-S100-7-7620, 06/2012
HiPath 3000/5000 V9, Service documentation