DVG-5121SP User’s Manual
D-Link Corporation
5
1. Introduction
1-1. Product Overview
D-Link®, an industry leader in networking, introduces the DVG-5121SP VoIP Telephone Adapter
for the home environment. The DVG-5121SP VoIP Telephone Adapter converts any existing analog
telephone (corded or cordless) into an IP phone. Also, by plugging in a FAX machine, the
DVG-5121SP will enable users to send and receive faxes the same way as a traditional analog
telephone line.
The DVG-5121SP carries both voice and facsimile over the IP network. It supports the SIP
industry standard call control protocol and is compatible with free registration services or VoIP
service providers’ systems. It also supports the most popular audio CODECs to ensure
compatibility and voice quality.
The DVG-5121SP provides two FXS ports to connect to two analog telephone sets, one PSTN
lifeline port to connect to the phone line, and two Fast Ethernet (10/100) ports to connect to the
VoIP Telephone Adapter to the LAN and WAN.
VoIP service providers can configure service settings such as a server address, CODEC and
STUN settings via TFTP directly to the DVG-5121SP.
For security, all of the configuration settings are encrypted. Only VoIP service providers/resellers
with the authenticated password and user name can access them.
The DVG-5121SP features both VAD (Voice Activity Detection) and CNG (Comfort Noise
Generator) to reduce the bandwidth consumption and to sustain voice quality.
The DVG-5121SP has a built-in QoS setting to provide voice priority in IP networks and prevent
dropped calls.
