ZyXEL Communications LTE5366 Series, Руководство пользователя

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Chapter 18 Voice over 3G
LTE5366 Series User’s Guide
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• G.729 is an Analysis-by-Synthesis (AbS) hybrid waveform codec that uses a filter based on information
about how the human vocal tract produces sounds. G.729 provides good sound quality and reduces
the required bandwidth to 8 kbps.
Voice Activity Detection/Silence Suppression
Voice Activity Detection (VAD) detects whether or not speech is present. This lets the LTE5366 reduce
the bandwidth that a call uses by not transmitting “silent packets” when you are not speaking.
Comfort Noise Generation
When using VAD, the LTE5366 generates comfort noise when the other party is not speaking. The
comfort noise lets you know that the line is still connected as total silence could easily be mistaken for a
lost connection.
Echo Cancellation
G.168 is an ITU-T standard for eliminating the echo caused by the sound of your voice reverberating in
the telephone receiver while you talk.
MWI (Message Waiting Indication)
Enable Message Waiting Indication (MWI) enables your phone to give you a message–waiting
(beeping) dial tone when you have a voice message(s). Your VoIP service provider must have a
messaging system that sends message waiting status SIP packets as defined in RFC 3842.
Custom Tones (IVR)
IVR (Interactive Voice Response) is a feature that allows you to use your telephone to interact with the
LTE5366. The LTE5366 allows you to record custom tones for the
Early Media and Music On Hold
functions. The same recordings apply to both the caller ringing and on hold tones.
Recording Custom Tones
Use the following steps if you would like to create new tones or change your tones:
1
Pick up the phone and press “****” on your phone’s keypad and wait for the message that says you are
in the configuration menu.
2
Press a number from 1101~1105 on your phone followed by the “#” key.
Table 59 Custom Tones Details
LABEL DESCRIPTION
Total Time for All Tones 900 seconds for all custom tones combined
Maximum Time per Individual
Tone 180 seconds
Total Number of Tones
Recordable 5
You can record up to 5 different custom tones but the total time must be
900 seconds or less.