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Grandstream HT503

Availability: In stock

Your Price: $51.00
Your Price: $51.00
The Grandstream HandyTone 503 is a 2 line ATA (analog telephone adapter) that allows you to use one analog device over an IP infrastructure or over PSTN lines while offering routing capabilities from your LAN to the WAN. Read More
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Grandstream HT503 VoIP Adapter

The Grandstream HT503 HandyTone 503 is a hybrid Analog Telephone Adapter (ATA)and VoIP Router. It features both an FXS (analog telephone) port and an FXO (PSTN) Port so you can have backup lifeline support using the PSTN in the case of a power outage. It also integrates 2 10/100 RJ45 ports with an integrated high performance NAT router. The HT503 includes a status LED indicator for power, telephone, PSTN line, network, and Message Waiting Indication.

Grandstream HT503 VoIP Adapter Overview

The Grandstream HandyTone HT503 VoIP Adapters/IAD series offers a comprehensive line of affordable VoIP access devices based on Grandstream's innovative and proprietary technology platform.

The Grandstream HT503 offers the entry-level IP Telephony user superb audio quality, rich functionalities, interoperability with the leading 3rd party VoIP providers, and compatibility with most service providers.

A compact Grandstream Handytone model, the HT503 is compact, works with any PSTN or cordless phone and fax machines and offers the simplicity of plug and dial, making it ideal for the basic IP telephony user.

Grandstream HT503 Features and Functions

  • IP connectivity for any phone and fax
  • Hop-on/Hop-off calling
  • Web management for easy configuration and installation
  • Offers traditional and advanced telephony features
  • Portable and compact for use at home or on the road

Didn't find the VoIP Adapter you were looking for?

Check out these other Grandstream VoIP adapters:

Handytone 503
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# of FXS Ports
# of FXO Ports
# of Ethernet Ports
Built-In Router
DHCP Capabilities
Protocols Supported
Provisioning Options
Auto Provisioning, HTTP, TFTP, Voice IVR, Web GUI
Grandstream HT503

Joe Shanahan

Direct: 866-583-0920

Why Pay $51.00 for the Grandstream HT503?

  • (1) FXS Port Onboard

  • (1) FXO Port Onboard

  • Dual 10/100 Mbps network ports (RJ45) with integrated high performance NAT router

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Questions on Grandstream HT503

From Sam at 11/11/2014 7:00 PM

Q: I have a VOIP phone line. Is there an adaptor available to use with an antique phone (ROTERY DIALING, RINGER BOX) ?

A: Good Morning,

Yes we offer many different adaptors to convert analog to VoIP. the Grandstream HT502 is available and will work with a ringer box. Below is the link to the page

Do you find this question helpful?  Yes   No

From Rick at 11/13/2015 7:00 PM

Q: Hi,
I have an analog pbx and I like to extend one of my current pbx extensions to a branch office natively in another city, is there an ATA that will allow this extension to ring the remote phone and viceversa, without the need of a sip account by a third party.
Thank you.

A: You might be able to use 2 ATAs that point SIP traffic towards each other with port forwarding rules through your firewalls.

Do you find this question helpful?  Yes   No

From Tom at 5/24/2016 8:00 PM

Q: Do you have an adapter that will my old style pots alarm to dial out over my existing VoIP line?

A: Tom,

Please contact our sales department to further assist your inquiry. What I found that should do the trick would be:

Thank you for choosing VoIP Supply!


Do you find this question helpful?  Yes   No

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Add Your Review

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Customer Reviews

(Submitted on ) | by

Great Adaptor
Work very well, easy to setup.

(Submitted on ) | by

Good audio, documentation is slim
The built-in configuration leaves much to be desired if you're not using it as a full internet gateway. But it does what I need it to do, which is answer calls from my POTS line, and transfer them into Asterisk. I would have continued using my generic x101p, but I was trying to consolidate, and XenServer 5.5 doesn't easily support pass-through PCI devices.

(Submitted on ) | by

HT503 with Trixbox config issues
Configuration of the HT503 with Trixbox, using HT503 as a FXO port has not been easy. Spent a few hours on it and have shelved the project for now. Clear documentation does not exists making configuration that much more difficult.

(Submitted on ) | by

Works OK
The main thing is that there is no busy tone problem with FXO port.

Besides, it was possible to configure “Auto Dial” function on FXO port.

(Submitted on ) | by

No complaints so far
My first HT503 was DOA (ethernet ports wouldnt link up). Fast replacement from Voip Supply. Got it up and running with Asterisk as an incoming outgoing trunk for a POTS line. Its replacing a Linksys SPA3102, which had HORRIBLE echo problems over the POTS line that I could never get to stop. This unit doesn't have any echo issues at all.

(Submitted on ) | by

Has great potential IF..
First unit had horrible noise issues, slow support from Grandstream. Fast replacement from VoipSupply once GS admitted it was defective. Second unit worked great with Asterisk as an FXS/FXO gateway but has failed again with noise problems.

(Submitted on ) | by

Works good with my VoIP Service
I am using the Grandstream Handytone 503 with VoIP service from and it works flawlessly.

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