ZyXEL Communications P-2302R-P1 Series, User Manual, Page: 32 / 294

P-2302R-P1 Series User’s Guide
32 Chapter 1 Introducing the ZyXEL Device
Voice Coding
The ZyXEL Device can use the following voice codecs (coder/decoders).
• G.711
• G.729
Voice Activity Detection/Silence Suppression
Voice Activity Detection (VAD) reduces the bandwidth that a call uses by not transmitting
when you are not speaking.
Comfort Noise Generation
The ZyXEL Device generates background noise to fill moments of silence when the other
device in a call stops transmitting because the other party is not speaking (as total silence
could easily be mistaken for a lost connection).
Echo Cancellation
The ZyXEL Device supports G.168, an ITU-T standard for eliminating the echo caused by the
sound of your voice reverberating in the telephone receiver while you talk.
QoS (Quality of Service)
Quality of Service (QoS) mechanisms help to provide better service on a per-flow basis. The
ZyXEL Device supports Type of Service (ToS) and Differentiated Services (DiffServ). This
allows the ZyXEL Device to tag voice frames so they can be prioritized over the network.
Fax Tone Detection and Pass-through
The ZyXEL Device automatically detects fax messages and sends them over PCM G.711 or
T.38.
Auto-provisioning
Your VoIP service provider (the company that lets you make phone calls over the Internet) can
automatically update your ZyXEL Device’s configuration via an auto-provisioning server.
Firmware Upgrades
Use the web configurator to upload updated firmware to your ZyXEL Device.
Auto Firmware Upgrade
The ZyXEL Device gives you the option to upgrade to a newer firmware version if it finds one
during auto-provisioning. Your VoIP service provider must have an auto-provisioning server
and a server set up with firmware in order for this feature to work.