4 sip account voip set phone comprehensive jitter buffer functions

Key Features

• Open Standard VoIP Protocols (ITU H.323 V4 and IETF SIP V2)
• All standard PBX functions
• Four call appearances support two simultaneous calls
• Two 10/100 Ethernet circuits connect to the LAN and an additional device
• 3-Line LCD (Icons, Alphabets/Numbers, Numbers)
• Buttons and keys for all commonly used functions
• Message waiting indicator
• Speech quality ensured by QoS at the Ethernet and IP layers and comprehensive jitter buffer
• Full duplex speaker phone
• VLAN and QoS support
• NAT Transversal and router functions
• Power over Ethernet (PoE) or AC/DC adapter
• Menu, HTTP Web, Auto Provision support for configuration and updates
• Highly stable embedded Linux operating system in high performance ARM 9 Processor

Basic Phone Features

• Call forward
• Call transfer
• Call hold
• Mute
• Redial
• Display caller ID
• Display call duration
• Display date and time
• Access voice mail
• Send DTMF tones
• Message waiting indication (MWI)
• 100 phone book entries
• 30 most recent call records for dialed, incoming, and missed calls
• Adjustment of LCD contrast (4 levels)
• Adjustment of handset volume (6 levels)
• Adjustment of speaker phone volume (6 levels)
• Enhanced Features
• Dynamic selection of codec
• Advanced jitter buffer
• Automatic traversal of NAT and firewall
• VLAN / Qos
• Router
• Echo cancellation for Speakerphone
• Comfort noise generation (CNG)
• Voice activity detection (VAD)
• Auto provisioning (requires auto provisioning server)
• On line firmware upgrade
• Multi-language support: English and Chinese

Supported Standards

• ITU: H.323 V4, H.225, H.235, H.245, H.450
• RFC 1889 - RTP/RTCP
• RFC 2327 - SDP
• RFC 2833 - RTP Payload for DTMF Digits, Telephony Tones and Telephony Signals
• RFC 2976 - SIP INFO Method
• RFC 3261 - SIP
• RFC 3264 - Offer/Answer model with SDP
• RFC 3515 - SIP REFER Method
• RFC 3842 - A Message Summary and Message Waiting Indicator
• RFC 3489 - Simple Traversal of User Datagram Protocol (UDP) Through Network Address Translators (NATs)
• RFC 3891 - SIP “Replaces” Header
• RFC 3892 - SIP Referred-By Mechanism
• draft-ietf-sipping-cc-transfer-04 -  Session Initiation Protocol Call Control - Transfer
• Codec: G.711 (A/µ law), GSM, G.729A/B, G.723.1
• DTMF: RFC 2833, In-band DTMF, SIP INFO

Hardware Specifications

• Processor: ARM9E 133MHz
• DSP: VPDSP101 196MHz
• Memory: RAM 16MB/ Flash 4MB
• Power: Input AC100V ~ 240V, output 12 Vdc 500 mA
• Power consumption: 3W maximum
• Operating temperature: 10°C to 40°C (32°F to 104°F)
• Storage temperature: 0°C to 50°C (32°F to 122°F)
• Working Humidity: 40% ~ 90% Not congealed
• Weight: 650 g (1 lb) (Including AC/DC Adapter)
• Warranty: one year