Netopia Firmware 4000-Series - Manual (Page 210)

8-4 Firmware User Guide
Echo cancellation is set to Yes by default. For ordinar y telephone handsets, echo cancellation should be
set to Yes (turned on) to eliminate echoes on the voice line. Toggling a por t to No allows you to connect a
fax machine or modem to the phone por t (since fax machines and modems automatically cancel echoes).
If you want to disable echo cancellation, toggle this item to No. You can enable or disable echo cancellation
for each telephone por t.
■ The Compression type is normally set at the voice gateway. It is visible for informational purposes, to
ascer tain that the provisioning on the voice gateway is in sync with the IAD.
LES stands for Loop Emulation Ser vice, an increasingly popular standard among ATM voice gateway
manufacturers.
If the voice gateway is LES-compliant (see LES Profile Number below), a pop-up menu allows you to choose
between G711 - PCM 64K and G726 - ADPCM 32K. Your ser vice provider must supply you with the correct
provisioning information. The reason is that in those gateway types the voice gateway expects this type of
provisioning to be done prior to making any voice calls.
If the voice gateway is not LES-compliant, the pop-up menus are not available, and these fields are for
information only.
Once you have made your settings for each voice por t, press Escape to return to the Voice Configuration
menu.
■ Select Voice Coding and press Return. From the pop-up menu choose the voice coding method you will be
using. The default is mu-law, which is the standard 8-bit, 8 kHz, mono format intended primarily for the
requirements of voice in Nor th America. You can also choose a-law, a more common audio format outside
Nor th America.
■ If your ser vice provider is using an LES-compliant voice gateway, the LES Profile Number option becomes
visible. From the pop-up menu choose either Profile 9 or Profile 10.
The Netopia Firmware Version 5.4 suppor ts LES profile 9 and LES profile 10. LES profile 9 includes only
PCM calls. LES profile 10 includes PCM and ADPCM capabilities.