The Soundwin SR100/SR200 Analogue Telephone Adaptor is equipped with one/two telephone jacks to connect your existing phones. With an appropriate Internet telephone service provider, you'll get VoIP telephone service.
The Soundwin Telephone Adapter is compatible with these and all of the other special telephone features that are available from your internet telephone service provider, such as Call Transfer, Call Waiting, Call Forwarding etc

Telephony
Voice Codec:
G.711(A-law /�g-law),G.729 AB,G.723 (6.3 Kbps / 5.3Kbps), G.276 (16,24,32,40 Kbps), GSM-FR
Call Waiting
Call Hold/Resume
Call Transfer: Blind Transfer
Call Forward:
On Busy Forward /
No Condition forward /
No Answer Forward
DND
Multi-Line Appearance
DTMF Relay : In-band DTMF Relay / Out-of-band DTMF Relay (RFC2833) / SIP-Info
3-Way Conference

IP Specifications:
SIP (RFC 3261), SDP (RFC 2327),
STUN (RFC3489)
RTP Payload for DTMF Digits (RFC2833),
Outbound Proxy Support
WAN: PPPoE client, DHCP client, Fix IP Address
QoS : IP TOS (IP Precedence) / DiffServ
Call Features
Adjustable volume : - 32 db ~ 32 db
VAD (Voice Activity Detection)
Dynamic Jitter Buffer
Caller ID Generation: DTMF CID / Bellcore CID
/ ETSI CID /NTT CID Generation
Peer to Peer Call by Dial Plan
Different Country Tone Table