Netopia 4000-Series Manuale Utente

Pagina di 314
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.