Grandstream Networks HT503 User Manual page 18

Device Management Web interface or via secure (AES encrypted) central configuration file for mass
deployment
Support device configuration via built-in IVR, Web browser or central
configuration file through TFTP, HTTP or HTTPS
Support Layer 2 (802.1Q, VLAN, 802.1p) and Layer 3 QoS (ToS, DiffServ, MPLS)
Auto/manual provisioning system
NAT-friendly remote software upgrade (via TFTP/HTTP/HTTPS) for deployed
devices including behind firewall/NAT
Syslog support
DHCP Server/Client Yes
Audio Features Advanced Digital Signal Processing (DSP)
Dynamic negotiation of codec and voice payload length
Support for G.723, G.729/E, G.711, G.726-40/32/24/16, iLBC, T.38 codecs
In-band and out-of-band DTMF (in audio, RFC2833, SIP INFO)
Silence Suppression, VAD (voice activity detection), CNG (comfort noise
generation), ANG (automatic gain control)
Adaptive jitter buffer control
Packet delay & loss concealment (PLC) & G.168 compliant Line Echo
Cancellation
Support volume amplification
Support configurable Call Progress Tones
Call Handling Caller ID display or block, Call waiting caller ID, Call waiting/flash, Call transfer,
Features hold, call forward, do not disturb, 3-way conferencing
Network and Manual or dynamic host configuration protocol (DHCP) network setup; RTP and
HT503 User Manual
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