Netopia 4753 2A4NA Administration Manual page 56

8-4 Administration Guide
Echo cancellation is set to Yes by default. For ordinary telephone handsets, echo cancellation should be
set to Yes (turned on) to eliminate echoes on the voice line. Toggling a port to No allows you to connect a
fax machine or modem to the phone port (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 port on the Netopia 4753.
The Compression type is normally set at the voice gateway. It is visible for informational purposes, to
ascertain that the provisioning on the voice gateway is in sync with the Netopia 4753.
LES stands for Loop Emulation Service, an increasingly popular standard among ATM voice gateway
manufacturers.
If the voice gateway is LES-compliant, a pop-up menu allows you to choose between G711 - PCM 64K and
G726 - ADPCM 32K. Your service 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 port, 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 North America. You can also choose a-law, a more common audio format outside
North America.
If your service 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 4753 currently supports LES profile 9 and LES profile 10. LES profile 9 includes only PCM
calls. LES profile 10 includes PCM and ADPCM capabilities.