Avaya Communication Server 1000 Installation And Commissioning Manual page 75

Figure 11: Maximum delay, jitter and packet loss
Strict timing requirements dictate that the WLAN IP Telephony Manager 2245 must be placed
as close as possible to the handsets, ideally in the same subnet.
End-to-end jitter, delay and packet loss budget is a general VoIP best practice:
• End-to-end delay is the time it takes for voice to go from the microphone of the sending
telephone to the earpiece of the receiving telephone.
• End-to-end jitter must not exceed 30 ms north of the WLAN IP Telephony Manager 2245
(PBX to the WLAN IP Telephony Manager 2245) and must not exceed 1 ms south of the
WLAN IP Telephony Manager 2245 (the WLAN IP Telephony Manager 2245 to the AP).
• End-to-end packet loss is the number of packets that are lost in the network.
To achieve excellent voice quality, Avaya recommends using G711 CODEC with the following
configuration:
• End-to-end delay < = 150 ms (one way)
• Packet loss < = 0.5%
• The maximum jitter buffer for the handsets set as low as possible.
For more information, see Converging the Data Network with VoIP Fundamentals
(NN43001-260).
The jitter budget for the link south of the WLAN IP Telephony Manager 2245 ensures that
packets arrive at the handset within the 30 ms arrival window. The evenly spaced packet flow
Avaya WLAN IP Telephony Installation and Commissioning
Placement guidelines for the WLAN IP Telephony Manager 2245
November 2010 75