VoIP
670 ◆Features Aspire Software Manual
To reduce the echo:
●Suppress the echo from the Aspire system.
●Suppress the echo from outside the Aspire system.
●Remove the unsuppressed echo using the echo canceller in the VOIPU.
●Reduce the telephone’s volume.
On some calls, the echo and side tones can be increased if the telephone volume is set
to a midrange level or higher. Simply press the Volume Down button on the phone to
reduce the level.
A typical example of this adjustment process is as follows:
1. CODEC Packet Size/Jitter Buffer Configuration
The Voice Packet CODEC, packet size, jitter buffer size should be configured to minimize the
voice delay. This data is set in Program 84-xx-xx.
●Set the Audio Capability Priority.
●Set the packet size.
●Set jitter buffer type and adjust the size.
2. Gain Level
A transmit gain level with is set too high for a trunk may cause considerable echo depending
on the level of the voice path route. Adjust the echo controlling this data.
●Change the Trunk Voice Transmit Level in the system to adjust the voice transmit level of
the Aspire.
●Change the Trunk Voice Receive Level in the system to adjust the voice receive level of
the Aspire.
3. CODEC Filter
When connecting an analog trunk, adjust the CODEC filter depending on the damping of the
trunk side. If this is not properly adjusted, you may hear considerable echo depending on the
condition of the line.
●Set the Echo Canceller Mode (Program 84-17-01) to disabled (0) and check the condition
of the echo level by making an outgoing call.
●Set the CODEC Filter Setup for the analog trunk port (Program 81-07) to the configura-
tion which results in the least amount of echo.
4. Echo Canceller Adjustment
The echo canceller should be adjusted after reducing the echo using the previous steps.
●Set the Echo Canceller Mode to enabled (1) [Program 84-01-24 = H.323 trunk, 84-11-20 =
Aspire IP phone, 84-12-20 = H.323 extension], the Echo Canceller NLP Mode to disabled
(0) [Program 84-01-26 = H.323 trunk, 84-11-22 = Aspire IP phone, 84-12-22 = H.323
extension], and check the condition of the echo level by making an outgoing call.
●Adjust the VOIPU Limiter Control Gain Setup (Program 84-16) and choose the configura-
tion which results in the least amount of echo.
●The Echo Canceller NLP Mode should be set to the data which receives the best voice
quality.