Product specifications

Administrator's Manual A. Product Specifications
Version 2.0.1 85 May 2013
A Product Specifications
The table below details the 420HD IP Phones specifications.
Table A-1: 420HD IP Phone Specifications
Feature
Details
VoIP Signaling Protocols
 SIP: RFC 3261, RFC 2327 (SDP)
Data Protocols
 IPv4, TCP, UDP, ICMP, ARP, DNS and DNS SRV for SIP Signaling
 SIP over TLS (SIPS)
 802.1p/Q for Traffic Priority and QoS
 VLAN Discovery Mechanism (CDP, LLDP)
 ToS (Type of Service) field, indicating desired QoS DHCP Client
 NTP Client
Media Processing
 Voice Coders: G.711, G.729A/B, G.722
 Acoustic Echo Cancelation: G.168-2004 compliant, 64-msec tail
length
 Adaptive Jitter Buffer 300 msec
 Voice Activity Detection
 Comfort Noise Generation
 Packet Lost Concealment
 RTP/RTCP Packetization (RFC 3550, RFC 3551), SRTP (RFC
3711)
 DTMF Relay (RFC 2833)
Telephony Features
 Call Hold / Un-Hold
 Call Transfer
 3-Way Conferencing (with local mixing)
 Redial
 Caller ID Notification
 Call Waiting Indication
 Message Waiting Indication (including MWI LED)
 Local and Corporate Directories
 Automatic On-hook Dialing
 Automatic Answering (Alert-Info header and "talk" event)
 CWRR (Call Waiting Reminder Ring)
 Secondary Dial Tone
 Call Logs: Missed/Received Calls and Dialed Numbers
 Speed Dial (Including BLF support for Asterisk and BroadWorks
TM
)
 URL Dialing
 Call Forward (Unconditional, Busy, No Answer)
 Remote Conferencing (RFC 4240)