Just connect YX-11221 series gateways to the PSTN line or analog phone and Ethernet then it will benefit from the VoIP. With the powerful function, gateways could fit to any of the VoIP application such as IP PBX, IP Centrex. YX-11221 series gateways provide flexible audio codec with compressed (8K vocoder,G.729A) and uncompressed (64K PCM,G.711aLaw/G.711uLaw) voice, 5.3k/6.3k of G.723.1 also supported by special request. It is compatible with the PSTN with support for Standard of JATE numbering plan. It operates as a second phone line to support local and long distance calling (IP-to-IP, and IP-to-PSTN). It also support the PSTN backup for the emergency call when power failure or network failure.

• Protocol :SIP(RFC 3261), MGCP, H.323v2
• Telephone Interfaces:RJ11 interfaces connecting 2 analog phones and 2 PSTN
• LAN Interface: 1 ports 10/100 Base-T, RJ45
• Codec: G.711 a-Law/u-Law, G.729A, G.723.1
• In Band/Out Band DTMF(RFC 2833)
• Voice Quality: VAD, CNG, AEC(G.168),Jitter Buffering
• Selection Signals: Pulse Dialing 10/20 pps, DTMF Dialing
• Tone: DTMF, Ring Tone, 4 selectable tone, Ring Back Tone (local and remote), Dial Ton,  Busy Tone, User Define Tone
• IP Assignment: DHCP Client /Static IP Address /PPPoE
• FAX Support: G.711 by pass
• QoS: ToS
• Call Function:
  Call Forward (Busy/No answer/Unconditional), Call Hold/Retrieve, Call Transfer (Attended), Call WaitingCaller ID Number Display/ Caller ID Blocking ,Anonymous Call Blocking
• Update: Firmware update by TFTP/ Auto Provisioning System (option) 
• NAT Traversal : UPnP and STUN
• PSTN Backup: Power failure, Network failure or service failure, Special number on PSTN dialing table
• Configuration : Web Browser, Command Line Interface (Console port, Telnet), Auto Provisioning System