Avaya 4600 User Manual

Page of 150
QoS
Issue 2.2 April 2005
77
 
Network Audio Quality Display on 4600 Series IP Telephones
With the exceptions of the 4601, 4606, 4612, 4624, and 4690 IP Telephones, all Series 4600 IP 
Telephones are by default administered to allow the end user an opportunity to monitor network 
audio performance while on a call. The user guides for each phone provide specific detail on 
getting to the appropriate screen, what the end user sees, and what the information means. 
For 4610SW/4620/4620SW/4621SW/4622SW/4625SW/4630/4630SW IP Telephones, these 
parameters display in real-time to users on the appropriate screens, while on a call:
For 4602/4602SW IP Telephones, the Network Audio Quality Screen gives the user a qualitative 
assessment of the current overall audio quality. This assessment is based on separate 
evaluations of:
the Packet Loss, and 
the total Network Delay, which is the sum of Packetization Delay, One-way Network Delay, 
and Network Jitter Compensation Delay, and 
consideration of the codec in use. 
Table 5: Parameters in Real-Time
Parameter
Possible Values
Audio 
Connection 
Present?
Yes if a receive RTP stream was established.
No if a receive RTP stream was not established.
Received 
Audio Coding 
G.711G.726A, or G.729.
Silence 
Suppression
Yes if the telephone knows the far-end has silence suppression Enabled.
No if the telephone knows the far-end has silence suppression Disabled, or 
the telephone does not know either way.
Packet Loss
No data or a decimal percentage. Late and out-of-sequence packets are 
counted as lost if they are discarded. Packets are not counted as lost until a 
subsequent packet is received and the loss confirmed by the RTP sequence 
number.
Packetization 
Delay
No data or an integer number of milliseconds. The number reflects the 
amount of delay in received audio packets, and includes any look-ahead 
delay associated with the codec.
One-way 
Network Delay
No data or an integer number of milliseconds. The number is one-half the 
value RTCP computes for the round-trip delay. 
Network Jitter 
Compensation 
Delay
No data or an integer number of milliseconds reporting the average delay 
introduced by the telephone’s jitter buffer.