Nortel Networks NN43001-504 User Manual

Page 67

Placement guidelines for the WLAN IP Telephony Manager 2245

To achieve excellent voice quality, Nortel 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 on the outbound side of the WLAN
IP Telephony Manager 2245 allows the handset to conserve battery life by
not using extra battery power to wait for late arriving packets. It also allows
efficient roaming while the handset moves from one AP coverage area to
another. See

Figure 11 "Jitter removal for packets going to the AP" (page

67)

Figure 11
Jitter removal for packets going to the AP

The following figures describe end-to-end delay for differing topologies:

•

For an example of an end-to-end delay for a LAN, see

Figure 12

"Example 1: End-to-end delay and packet loss for a LAN" (page 68)

Nortel Communication Server 1000

WLAN IP Telephony Installation and Commissioning

NN43001-504

01.02