GrandStream HT503 1-FXS/1-FXO Port Analog Telephone 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