ZyXEL Communications P-2602R-DxA Series User Manual

P-2602R/RL-DxA Series User’s Guide

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Chapter 1 Getting To Know the ZyXEL Device

You can simultaneously use multiple voice (SIP) accounts and assign them to one or both 
telephone ports.

Your device can simultaneously handle multiple voice channels (telephone calls). 
Additionally you can answer an incoming phone call on a VoIP account, even while someone 
else is using the account for a phone call.

Voice Activity Detection (VAD) reduces the bandwidth that a call uses by not transmitting 
when you are not speaking. 

Your 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). 

You 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.

Quality of Service (QoS) mechanisms help to provide better service on a per-flow basis. Your 
device supports Type of Service (ToS) tagging and Differentiated Services (DiffServ) tagging. 
This allows the device to tag voice frames so they can be prioritized over the network.

Your device is a SIP Application Layer Gateway (ALG). It allows VoIP calls to pass through 
NAT for devices behind it (such as a SIP-based VoIP software application on a computer). 

Your device and other UPnP enabled devices can use the standard TCP/IP protocol to 
dynamically join a network, obtain an IP address and convey their capabilities to each other.

PPPoE (Point-to-Point Protocol over Ethernet) emulates a dial-up connection. It allows your 
ISP to use their existing network configuration with newer broadband technologies such as 
ADSL. The PPPoE driver on your device is transparent to the computers on the LAN, which 
see only Ethernet and are not aware of PPPoE thus saving you from having to manage PPPoE 
clients on individual computers.