Telephony Features

● One line registration
● Two call appearances accessed via flash key or hook flash
● Shared line appearance**
● Line status indicator
● Call hold
● Music on hold**
● Call waiting
● Outbound caller ID blocking
● Call transfer: attended and blind
● Three-way conferencing with local mixing
● Multi party call conferencing via external conference bridge**
● Call pickup: selective and group**
● Call park and unpark**
● Call back on busy
● Call blocking: anonymous and selective
● Call forwarding: unconditional, no answer, on busy
● Call return: redial last caller
● Hot line and warm line automatic calling
● Call logs (60 entries each): made, answered, and missed calls, accessed via HTTP server
● Redial last called number
● Do not disturb (callers hear line busy tone) ● Block anonymous incoming calls
● Uniform Resource Identifier (URI) (IP) dialing support (vanity numbers)
● Built-in web server for administration and configuration, with user and administrator access levels
● Built-in interactive voice response system to check status and change configuration
● Date and time with intelligent daylight savings support
● Call start time stored in call logs
● Distinctive ringing
● 10 user-downloadable ring tones
● Speed dial (eight entries)
● Group paging (outbound only)**
● Intercom (outbound only)**
● Set preferred codec per call, all calls
● Configurable dial/numbering plan support ● Ringer and handset volume controls
● Handset input gain adjustment
● DNS SRV and multiple A records for proxy lookup and proxy redundancy
● Syslog, debug, report generation, and event logging
● Secure call encrypted voice communication support
● Network Address Translation (NAT) Traversal
● Automated provisioning, multiple methods; up to 256-bit encryption: (HTTP, HTTPS, Trivial File Transfer Protocol [TFTP])
● Support for Linksys voice system automatic configuration
● Option to require administrator password to reset unit to factory defaults

Hardware Features

● Voicemail message waiting indicator light
● Redial button
● Dedicated flash button
● Volume control button cycles through volume levels; controls ringer and handset volume
● Standard 12-button dialing pad
● High-quality handset and cradle
● Ethernet LAN: 10BASE-T RJ-45
● 5 VDC universal (100–240V) switching power adapter Data networking
● MAC address (IEEE 802.3)
● IPv4 (RFC 791)
● ARP: Address Resolution Protocol
● DNS A record (RFC 1706), SRV record (RFC 2782)
● DHCP client: Dynamic Host Configuration Protocol (RFC 2131)
● ICMP: Internet Control Message Protocol (RFC 792)
● TCP (RFC 793)
● UDP: User Datagram Protocol (RFC 768)
● RTP: Real Time Protocol (RFC 1889, 1890)
● RTCP: Real Time Control Protocol (RFC 1889)
● DiffServ: Differentiated Services (RFC 2475)
● ToS: type of service (RFC 791, 1349)
● VLAN tagging 802.1p/Q; Layer 2 quality of service (QoS)
● SNTP: Simple Network Time Protocol (RFC 2030 Voice gateway
● SIP v2: (RFC 3261, 3262, 3263, 3264)
● SIP proxy redundancy: dynamic via DNS SRV, A records
● Reregistration with primary SIP proxy server
● SIP support in NAT networks (including serial tunnel [STUN])
● SIPFrag (RFC 3420)
● Secure (encrypted) calling via prestandard implementation of Secure RTP
● Codec name assignment
● Voice algorithms: ◦ G.711 (A-law and mu-law) ◦ G.726 (16/24/32/40 kbps) ◦ G.729 A ◦ G.723.1 (6.3 kbps, 5.3 kbps)
● Dynamic payload support
● Adjustable audio frames per packet
● DTMF: in-band and out-of-band (RFC 2833) (SIP INFO)
● Flexible dial plan support with interdigit timers
● IP address/URI dialing support
● Call progress tone generation
● Jitter buffer: adaptive
● Frame loss concealment
● VAD: voice activity detection with silence suppression
● Attenuation/gain adjustments
● MWI: message waiting indicator tones
● VMWI: visual message waiting indicator via NOTIFY, SUBSCRIBE
● Third-party call control (RFC 3725 Securit
● Password-protected system, preset to factory default
● Password-protected access to administrator and user-level features
● HTTPS with factory-installed client certificate
● HTTP digest: encrypted authentication via MD5 (RFC 1321)
● Up to 256-bit Advanced Encryption Standard (AES) encryption

Provisioning, administration, and maintenance

● Integrated web server provides web-based administration and configuration
● Integrated voice response system to report and modify configuration parameters
● Automated provisioning and upgrade via HTTPS, HTTP, TFTP
● Asynchronous notification of upgrade availability via NOTIFY
● Nonintrusive in-service upgrades
● Report generation and event logging
● Statistics transmitted in BYE message
● Syslog and debug server records: configurable per lin

Physical interfaces

● One 10BASE-T RJ-45 Ethernet port (IEEE 802.3)
● Handset: RJ-9 connecto

Power supply

5V, 2A Switching Power Adaptor

● Status LED
● Message waiting indicator LE