Origin	China
Model Number	SY-840
Brand Name	SY
Size	306×175×130mm
Weight	1.2kg

Product Description

SY-840 IP phone is an internet based voice network phone terminal. PHONE series IP phone adopts multiple voice control protocols and voice compression coding methods to directly convert analog voice into IP packet for internet transport, thus effectively using the existing bandwidth to provide PSTN quality voice service.
    SY-840 IP phone supports SIP protocols,Support Bridge and Router model.Support 4 Public sip server, offers Two Ethernet interface and is compatible with various softswitch systems and VoIP voice gateways to provide broadband IP voice service.

Features
Support SIP 2.0 (RFC3261) and correlative RFCs
Supprt IAX2
Codec:G.711A/u, G.7231 high/low, G.729, G.722
Echo cancellation: Support G.168, and Hands-free can support 96ms, Hand free Speaker Phone
Support Voice Gain Setting, VAD, CNG
Full duplex hands-free speakerphone
NAT transverse:support STUN client
SIP support SIP domain, SIP authentication (none, basic, MD5), DNS name of server, Peer to Peer/ IP call
SIP support Pubic & Private server. Can connect to Public SIP and Private SIP server at the same time
DTMF:Support SIP info, DTMF Relay, RFC2833
SIP application: support Call forward/transfer/holding/waiting
Call control features: Flexible dial map, Hotline, Empty calling reject, Black list for reject authenticated call, limit call, No disturb, Caller ID.
Support three way conference call
Support voice record, 240 seconds max or 3 record max, user-defined record prompt with 1 minute max
Support Phonebook 500 records
Incoming calls / Outgoing calls / Missing calls. Each support 100 records.
Support conference and voice record on SIP server
8 kind of ring type
English, Spanish, Czechoslovak alternative