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Grandstream analog telephone adapter, 1 analog FXS port, 1 PSTN line FXO port

  • SKU: HT503
  • Manufacturer: Grandstream
  • Data Sheet: Download
  • Availability: Direct Ship Item Usually ships same day direct from Manufacturer Email me when this product is in stock!

Specifications HT503

Telephone Interfaces 1 FXS telephone port (RJ11), 1 FXO PSTN line port (RJ11) with lifeline support
Network Interfaces Two (2) 10/100Mbps ports (RJ45) with integrated NAT router and auto-detection and support for either straight through or crossover cables
LED Indicators Power,WAN, LAN, PHONE and LINE
Factory Reset Button Yes
Voice, Fax, Modem
Telephony Features Caller ID display or block, call waiting, flash, blind or attended transfer, forward, hold, do not disturb, 3-way conference
Voice Codecs G.711 with Annex I (PLC) and Annex II (VAD/CNG), G.723.1A, G.729A/B/E, G.728, G.726-40/32/24/16, iLBC
Voice over Packet Capabilities Voice Activity Detection (VAD) with comfort noise generation (CNG) and packet loss concealment (PLC), dyanmic jitter buffer, G.168 compliant line echo cancellation
Fax Over IP T.38 compliant Group 3 fax relay up to 14.4kbps, Fax datapump V.17, V.19, V.27ter, V.29 for T.38 fax relay
Short/Long Haul Ring Load REN 3: Up to 150 ft on 24 AWG lines
Caller ID Bellcore type 1 & 2, ETSI, BT, NTT and DTMF-based CID
Disconnect Methods Polarity Reversal/Wink
DHCP Serve/Client NAT Router Yes, can operate in NAT router or switched mode
QoS Layer 2 (802.1Q VLAN/802.1p) and Layer 3 (ToS, Diffserv, MPLS)
DTMF Method RFC2833 and/or SIP INFO
Provisioning and Control UPnP, HTTP, HTTPS, TELNET, TFTP, TR069, secure and automated provisioning using AES encryption, syslog

Grandstream HT503

The HT503 is an analog telephone adapter featuring 1 analog telephone FXS port and 1 PSTN line FXO port. The integration of a FXO and FXS port enables remote call origination and termination to and from the PSTN line, known as "hop-on and hop-off" calling. The 1 FXS port allows for extension of a VoIP service to 1 analog phone. In addition to being SIP compliant, the product features support for up to 2 SIP account profiles, excellent voice quality and advanced telephony features.


  • 1 FXS analog telephone ports (RJ11), 1 PSTN line FXO port, dual 10/100 Mbps ports with integrated NAT router
  • Advanced telephony features include caller ID, call waiting
  • 3-way voice conference, transfer, forward, do not disturb, message indicator, multi-language voice prompts, T.38 fax, flexible dial plan and more
  • Supports up to 2 SIP accounts
  • Status LED for power, telephone and network ports, and message waiting indication