Grandstream Networks DUAL FXS PORT HT502 User Manual

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Grandstream Networks, Inc. 
HT-502 User Manual 
Page 7 of 32  
 
Firmware Version 1.0.4.2 Last 
Updated: 
06/2011
 
 
P
RODUCT 
O
VERVIEW
 
The HT502 is a full feature voice and fax-over IP device that offers a high-level of integration including dual 
10M/100Mbps network ports with integrated router, NAT, DHCP server, dual port FXS telephone gateway, 
market-leading sound quality, rich functionalities, and a compact and lightweight design. The VoIP network 
signaling protocol supported is SIP. The HT502 fully compatible with SIP industry standard and can 
interoperate with many other SIP compliant devices and software on the market. Moreover, it supports 
comprehensive voice codecs including G.711 (a/µ-law), G.723.1, G.726 (16/24/32/40 bit rates), AAL2 (all 
G.726), G.729A/B/E and iLBC. 
 
 
Software Features Overview 
•  2 FXS ports 
•  Two RJ-45 ports (switched or routed) 
•  2 SIP accounts & profiles 
•  Supports Voice Codecs:  
G711(a/µ, Annex I & II), G723.1A, G726 (ADPCM with 16/24/32/40 bit rates), G729 A/B/E, iLBC 
•  T.38 Fax  
•  Comprehensive Dial Plan support for Outgoing calls. 
• G.168 
Echo 
Cancellation 
•  Voice Activation Detection (VAD), Comfort Noise Generation (CNG), and Packet Loss 
Concealment (PLC) 
•  Supports PSTN/PBX analog telephone sets or analog trunks 
 
T
ABLE 
3:
  
HT502
 
T
ECHNICAL 
S
PECIFICATIONS
 
 
Telephone Interfaces 
2 FXS ports, 2 SIP accounts   
Network Interface 
1  RJ45  for LAN, 10/100 Base-TX, Full Duplex 
1  RJ45  for WAN,10/100Base-TX, Full Duplex 
LED Indicators 
Power, WAN, LAN, PHONE1 and PHONE2 
Reset Button 
Factory Reset button 
Voice over Packet 
Capabilities 
Voice Activity Detection (VAD) with CNG (comfort noise generation) and PLC (packet 
loss concealment), Dynamic Jitter Buffer, Modem detection & auto-switch to G.711, 
Packetized Voice Protocol Unit (supports RTP/RTCP and AAL2 protocol), G.168 
compliant Echo Cancellation, LEC (line echo cancellation) with NLP, Asymmetric RTP 
stream 
Voice Compression 
G.711 + Annex I (PLC), Annex II (VAD/CNG format) encoder and decoder, G.723.1A, 
G.726(ADPCM), G.729A/B/E, iLBC, G.726 provides proprietary VAD, CNG, and signal 
power estimation, Voice Play Out unit (reordering, fixed and adaptive jitter buffer, clock 
synchronization), AGC (automatic gain control), Status output, Decoder controlling via 
voice packet header 
DHCP Server/Client 
Yes, NAT Router or Switched Mode 
Telnet Server 
Yes 
Fax over IP 
T.38 compliant Group 3 Fax Relay up to 14.4kpbs and auto-switch to G.711 for Fax 
Pass-through, Fax Datapump V.17, V.19, V.27ter, V.29 for T.38 fax relay 
QoS 
Diffserve, TOS, 802.1 P/Q VLAN tagging 
IP Transport 
RTP/RTCP