2 isdn line, 3 voice activity detection/silence suppression, 4 comfort noise generation – ZyXEL Communications P-2602HWLNI User Manual
Page 184: 5 echo cancellation, 8 analog phone, 1 phone port call types

Chapter 11 Voice
P-2602HWLNI User’s Guide
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You can also use the PSTN Line screen to specify phone numbers that should always use the
regular phone service (without having to dial a prefix number). Do this for emergency
numbers (like those for contacting police, fire or emergency medical services).
11.7.2 ISDN Line
With an ISDN line you can make and receive regular ISDN phone calls. Use a prefix number
to make a regular call.
You can also use the ISDN Line screen to specify phone numbers that should always use the
regular phone service (without having to dial a prefix number). Do this for emergency
numbers (like those for contacting police, fire or emergency medical services).
11.7.3 Voice Activity Detection/Silence Suppression
Voice Activity Detection (VAD) detects whether or not speech is present. This lets the ZyXEL
Device reduce the bandwidth that a call uses by not transmitting “silent packets” when you are
not speaking.
11.7.4 Comfort Noise Generation
When using VAD, the ZyXEL Device 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.
11.7.5 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.
11.8 Analog Phone
This screen allows you to configure the PHONE 1 and PHONE 2 ports on the ZyXEL
Device. These ports are for connecting analog phones to the ZyXEL Device. You can
configure different settings for each PHONE port.
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If you connect more than one analog phone to a single PHONE port, the
settings you configure on the port apply to all phones connected to the port.
11.8.1 PHONE Port Call Types
You can use the analog phones connected to the ZyXEL Device’s PHONE 1 and PHONE 2
ports to make and receive three kinds of call: