采用TI TITAN芯片组及TI音频引擎 
320x160像素图形化4级灰度液晶显示屏
六线路，通过BrOAdsoft、Avaya、Asterisk认证
高清（HD）音质：HD 编码, HD手柄, HD免提电话
外置48个按键, 其中包括16个可编程键
支持三方会议、短消息、语音信箱
支持线路共享（BLA）、占线指示灯（BLF）等高级功能 
支持包括中文在内的20多种语言 
支持多种自动配置方式: FTP/TFTP/HTTP/PnP
支持SRTP/TLS/HTTPS等加密协议
支持线路供电（PoE）、耳机、双网口
可外接6个扩展台，达228个按键

话机特性
支持6线路、热线、紧急号码呼出
支持呼叫等待、通话转接、来电转移
通话保持、静音、自动应答、重拨
三方通话、免打扰、速拨号
XML远程电话簿搜索/导出/导入
黑名单、通话记录（100条）
音量调节、铃声选择
国家信号音、系统日志
多国语言（20多种）
支持6个扩展台共228个按键

IP-PBX功能
呼叫规则，立即呼出
SMS短消息，语音信箱，MWI消息提示
BLF/BLA，对话机（Intercom），Paging
截答（Call pickup），Call Park
区别振铃
音频特性
宽带编码: G.722
窄带编码：G.711, G723.1, G726, G.729AB
支持VAD, CNG , AEC, PLC, AJB, AGC等音频处理
全双工免提，带自动回音消除

网络特性
支持SIP v1(RFC2543),V2(RFC3261)协议
支持STUN内网穿透
支持三种IP获取方式：静态IP/DHCP/PPPoE拨号
支持三种DTMF模式：带内（In-band）、RFC2833、SIP INFO
支持PC口桥接/路由模式
内置HTTP/HTTPS Web服务器用于配置管理
支持SNTP时间协议
支持Telnet
内置DNS/TFTP/FTP客户端

配置管理
支持FTP/TFTP/HTTP/PnP方式的Auto provision
支持三种配置模式：网页、话机及自动配置
支持IP直拨
支持通过SIP服务器拨号码
支持通过SIP服务器拨URL地址                                
安全性
支持HTTPS协议(客户端/服务器端)
支持SRTP协议（RFC3711）
支持TLS（Transport Layer Security）协议
支持QoS : IEEE 802.1p/q (VLAN)
支持信息验证机制MD5/MD5-SESS
支持AES加密协议
支持话机锁
支持管理员/用户分层模式

物理特性
内嵌TI（美国德州仪器）TITAN 芯片组
带背光320x160分辨率图形液晶屏，四级灰度
外置共48个按键（含16个可编程按键）
1个RJ9（4P4C）手柄接口
1个RJ9（4P4C）耳麦接口
2个RJ45 10/100M以太网口
1个RJ12（6P6C）扩展台接口
电源适配器：AC 100-240V输入，DC 5V/1.2A输出
支持以太网供电（PoE）：IEEE 802.3af Class 2

功耗：1.6-2.6W
净重：1.05KG
裸机尺寸：273&tiMES;204×42MM
操作环境湿度：10-95%
储存温度：60℃以下

Yealink® SIP-T28G

Yealink SIP-T28P represents the next generation VoIP phone which designed for the business user who needs rich telephony features, friendly UI and super voice quality. It is equipped with the TI TITAN chipset, offers high definition voice quality through TI voice engine, HD handset, HD speaker and HD codec (G.722).
By the large, high-resolution graphical display, and together with all the 48 keys, SIP-T28P offers an excellent user experience to configure, make calls, express XML browser, etc. Moreover, to avoid problems with unwanted violations of your audio data, Yealink SIP-T28P supports the security standards TLS, SRTP, HTTPS, 802.1x, Open VPN and AES encryption which are necessary to protect agAInst electronic eavesdropping and data theft.

Specification

Phone Features

• 6 VoIP accounts, Hotline, Emergency call
• Call hold, Call waiting, Call forward, Call return
• Call transfer (blind/semi-attended/attended)
• Caller ID display, Redial, Mute, DND
• Auto-answer, 3-way conferencing
• Speed dial, SMS, Voicemail
• MESsage Waiting Indication (MWI) LED
• Tone scheme, Volume control
• Direct IP call without SIP proxy
• Ring tone selection/import/delete
• Phonebook (300 entries), Black list
• Call history: dialed/received/missed/forwarded
• Menu-driven user interface
• Localized language and input method
• Soft keys programmable
• Supports up to 6 expansion modules(EXP38 and EXP39)
• Supports Wireless Headset Adapter(EHS36)

Advanced Features

• XML phonebook search/import
• LDAP phonebook
• XML Browser, Hot-desking
• PUSH XML
• Action URL & Active URI

IP PBX System Integration

• Busy lamp field (BLF), BLF list
• Bridged line appearance (BLA)
• DND&Forward synchronization
• Intercom, Paging, Music on hold
• Call park, Call pickup
• Call recording, Call completion
• Group listening, Group pickup
• Anonymous call, Anonymous call rejection
• Network conference
• Distinctive ringtone
• Dial Plan, Dial-now

Codecs and Voice Features

• Wideband codec: G.722
• Narrowband codec: G.711μ/A, G.723.1, G.726, G.729AB
• VAD, CNG, AEC, PLC, AJB, AGC
• Full-duplex speakerphone with AEC

Network Features

• SIP v1 (RFC2543), v2 (RFC3261)
• IPV6
• DNS SRV (RFC3263)
• Redundant server support
• NAT Traversal: STUN mode
• DTMF: In-Band, RFC2833, SIP Info
• Proxy mode and peer-to-peer SIP link mode
• IP Assignment: Static/DHCP/PPPoE
• Bridge/router mode for PC port
• TFTP/DHCP/PPPoE client
• Telnet/HTTP/HTTPS server
• DNS client, NAT/DHCP server
• Logout

Management

• Auto-provision via FTP/TFTP/HTTP/HTTPS
• Auto-provision with PnP
• SNMP V1/2 optional, TR069 optional
• Configuration: browser/phone/auto-provision
• Factory configuration customized
• Trace package and system log export

Security

• Open VPN, 802.1x, VLAN QoS (802.1pq), LLDP
• Transport Layer Security (TLS)
• HTTPS (server/client), SRTP (RFC3711)
• Digest authentication using MD5/MD5-sess
• Secure configuration file via AES encryption
• Phone lock for personal privacy protection
• Admin/VAR/User 3-level configuration mode

Physical Features

• TI TITAN chipset
• 320x160 graphic LCD with 4-level grayscales
• 48 keys including 16 programmable keys
• 1xRJ9 (4P4C) handset port
• 1xRJ9 (4P4C) headset port
• 2xRJ45 10/100M Ethernet ports
• 1XRJ12 (6P6C) EXT port
• Power adapter: AC 100~240V input and DC 5V/1.2A output
• Power over Ethernet (IEEE 802.3af)
• Power consumption: 1.6-2.6W
• Net weight: 1.05KG
• Dimension: 273x204x42MM
• Operating humidity: 10~95%
• Storage temperature: up to 60°C
•