IP Telephony network engineering overview
280 Avaya Application Solutions IP Telephony Deployment Guide
The critical objective factors in assessing IP Telephony quality are delay, jitter, and packet loss.
To ensure good and consistent levels of voice quality,
Table 66: Factors that affect voice quality
lists Avaya’s suggested network requirements. These requirements are true for both LAN only
and for LAN and WAN connections.
For more information see
Voice quality network requirements
.
Table 66: Factors that affect voice quality
Network factor
Measurement
1
1. All measurement values are between endpoints because this document assumes that IP Telephony is
not yet implemented. All values therefore reflect the performance of the network without endpoint
consideration.
Delay
(one-way between
endpoints)
●
A delay of 80 ms or less can, but may not, yield the best
quality.
●
A delay of 80 ms to 180 ms can yield
business-communication quality. Business-communication
quality is much better than cell-phone quality, and is
well-suited for the majority of businesses.
2
●
Delays that exceed 180 ms might still be quite acceptable
depending on customer expectations, analog trunks used,
codec type, and so on.
2. Also, “business-communication quality” is defined as less than toll quality, but much better than
cell-phone quality.
Jitter
(variability of the delay
between endpoints)
●
20 ms, or less than half the sample size, for the best quality.
Note:
Note:
This value has some latitude, depending on the
type of service that the jitter buffer has in
relationship to other router buffers, the packet size
used, and so on.
Packet loss
(maximum packet/
frame loss between
endpoints)
●
<1% can yield the best quality, depending on many factors.
●
<3% should give business-communications quality, which is
much better than cell-phone quality.
2
●
>3% might be acceptable for voice, but might interfere with
signaling.
Содержание Application Solutions
Страница 1: ...Avaya Application Solutions IP Telephony Deployment Guide 555 245 600 Issue 3 4 1 June 2005 ...
Страница 20: ...About This Book 20 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 21: ...Issue 3 4 1 June 2005 21 Section 1 Avaya Application Solutions product guide ...
Страница 22: ...22 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 74: ...Avaya Application Solutions platforms 74 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 106: ...Call processing 106 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 124: ...Avaya LAN switching products 124 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 139: ...Issue 3 4 1 June 2005 139 Section 2 Deploying IP Telephony ...
Страница 140: ...140 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 186: ...Traffic engineering 186 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 204: ...Security 204 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 214: ...Voice quality network requirements 214 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 228: ...Avaya Integrated Management 228 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 239: ...Reliability Issue 3 4 1 June 2005 239 Figure 69 S8700 Media Server in a high reliability configuration ...
Страница 274: ...Reliability and Recovery 274 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 275: ...Issue 3 4 1 June 2005 275 Section 3 Getting the IP network ready for telephony ...
Страница 276: ...276 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 350: ...Implementing Communication Manager on a data network 350 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 356: ...Network recovery 356 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 366: ...Network assessment offer 366 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 367: ...Issue 3 4 1 June 2005 367 Appendixes ...
Страница 368: ...Appendixes 368 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 394: ...Access list 394 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 414: ...DHCP TFTP 414 Avaya Application Solutions IP Telephony Deployment Guide ...