Cadence Flash F200-2 Guia de Resolução de Problemas descarregar pdf (Página 59)

DSP and voice quality troubleshooting 59

1. Collect the statistics (see “Collecting statistics for echo problems”

(page 57) ).

2. Eliminate all other sources of echo due to improper configuration.

Enable the signal limiter.

3. Determine the loss plan and the codec used.

4. If possible, obtain the average voice level transmitted in T1 or E1 links

in the PSTN network or a local network if echo is perceived in local

analog telephones.

Chose an appropriate SLim value for the signal limiter. To start, assign

a value of 5 to SLim (least aggressive) and gradually increase the

aggressiveness by assigning the SLim value a smaller number until

echo disappears.

If echo disappears at an acceptable level with a moderate SLim value

that does not significantly degrade voice quality, leave SLim at this

value.

If echo disappears at a SLim value where the voice quality is

unacceptably degraded, find a compromise between the two sides

and set the SLim value accordingly. Adjust the SLim values and watch

for echo and voice quality as perceived by the users of the system in

hand.

PCM audio capture If the call uses G.711, use the Data Capture tool on

the VGMC to collect a capture of the audio during the problem.

Choppy speech

Choppy speech is usually a side effect of network problems, such as

packet loss. Packets are lost or arrive late and the DSP must fill in or drop

packets. See “TLAN packet loss errors” (page 51)for more information

about debugging this type of problem.

Wavering voice or tones

This problem is typically reported on handsfree calls. Sometimes users

report that the receive volume fluctuates during tones. Wavering voice

or tones can be caused by an interaction of the telephone speaker and

microphone and the handsfree algorithm. To determine the cause,

mute the handsfree and press the digits again; the DTMF tones should

sound without waver. A similar problem can occur during handsfree

conversations when room noise, drafts, or other disturbances cause the

handsfree receive volume to fluctuate. Turn down the speaker receive

volume to help or eliminate the problem.

Nortel Communication Server 1000

Troubleshooting Guide for Distributors

NN43001-730 02.02 31 December 2009

1 2 ... 54 55 56 57 58 59 60 61 62 63 64 ... 503 504

Sem comentários

Cadence Flash F200-2 Guia de Resolução de Problemas Página 59