Netopia 4753 manual Administration Guide

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.