Yealink SIP-T28P

Audio Features
- HD voice: HD handset, HD speaker
> Codecs: G.722, G.711(A/μ), G.723.1, G.729AB,
G.726, iLBC
- DTMF: In-band, Out-of-band(RFC 2833) and SIP
INFO
- Full-duplex hands-free speakerphone with AEC
- VAD, CNG, AEC, PLC, AJB, AGC

IP-PBX Features
- Busy Lamp Field (BLF)
- Bridged Line Apperance(BLA)
- Anonymous call, anonymous call rejection
- Hot-desking, emergency call
- Message Waiting Indicator (MWI)
- Voice mail
- Call park, call pickup
- Intercom, paging
- Music on hold
- Call completion
- Call recording

Phone Features
- 6 VoIP accounts
- Call hold, mute, DND
- One-touch speed dial, hotline
- Call forward, call waiting, call transfer
- Group listening, SMS
- Redial, call return, auto answer
- Local 3-way conferencing
- Direct IP call without SIP proxy
- Ring tone selection/import/delete
- Set date time manually or automatically
- Dial plan
- XML Browser
- Action URL/URI

Directory
- Loal phonebook up to 1000 entries
- Black list
- XML/LDAP remote phonebook
- Intelligent search method
- Phonebook search/import/export
- Call history: dialed/received/missed/forwarded

IP-PBX Features
- Busy Lamp Field (BLF)
- Bridged Line Apperance(BLA)
- Anonymous call, anonymous call rejection
- Hot-desking, emergency call
- Message Waiting Indicator (MWI)
- Voice mail
- Call park, call pickup
- Intercom, paging
- Music on hold
- Call completion
- Call recording

Display and Indicator
- 320x160-pixel graphical LCD with backlight
- LED for call and message waiting indication
- Dual-color (red or green) illuminated LEDs for
line status information
- Intuitive user interface with icons and soft keys
- National language selection
- Caller ID with name, number

Feature keys
- 48 keys including 16 freely programmable keys
- 8 features keys: message, headset, hold, mute,
ran, redial, conf, hands-free speakerphone
- 4 context-sensitive “soft” keys
- 6 navigation keys
- Volume control keys

Interface

- 2xRJ45 10/100M Ethernet ports
- Power over Ethernet (IEEE 802.3af), class 2
- 1xRJ9 (4P4C) handset port
- 1xRJ9 (4P4C) headset port
- 1XRJ12 (6P6C) EXT port:
- Supports up to 6 Expansion Modules for an attendant console application

Network and Security
- SIP v1 (RFC2543), v2 (RFC3261)
- Call server redundancy supported
- NAT transverse: STUN mode
- Proxy mode and peer-to-peer SIP link mode
- IP assignment: static/DHCP/PPPoE
- HTTP/HTTPS web server
- Time and date synchronization using SNTP
- UDP/TCP/DNS-SRV(RFC 3263)
- QoS: 802.1p/Q tagging (VLAN), Layer 3 ToS
DSCP
- SRTP for voice
- Transport Layer Security (TLS)
- HTTPS certificate manager
- AES encryption for configuration file
- Digest authentication using MD5/MD5-sess
- OpenVPN, IEEE802.1X
- IPv6