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ATAs & VoIP Adapters

Analog telephone adapters (ATAs) or VoIP adapters connect analog units to a VoIP system. Adapters let you migrate your legacy system to IP at your own pace.

Here's an example. Let's say that you want to integrate an analog phone that you already own with your IP-PBX to give yourself better control and enhance your communications. You can connect the legacy phone to the FXS port on the ATA, then connect the adapter to your IP phone system, and the adapter will convert the signal from analog to IP. It's that simple.

ATAs work not just for analog telephones, but also for fax machines (Fax over IP), modems, paging speakers and more. ATAs can have either FXS or FXO ports, or both. IP Phone Warehouse has been helping companies integrate their legacy equipment with analog telephone adapters for a decade. Find the solution for you with our full portfolio of ATAs!

ATAs & VoIP Adapters by Product Type

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AudioCodes MP112-FXS AudioCodes MP-112 2 FXS Port ATA Ships the Same Business Day
List Price: $193.00
Price: $156.99
In Stock
AudioCodes MP114 AudioCodes MP-114 2 FXS / 2 FXO ATA Ships the Same Business Day
List Price: $394.00
Price: $318.99
In Stock
AudioCodes MP118 AudioCodes MP-118 4 FXS / 4 FXO ATA Ships the Same Business Day
List Price: $699.00
Price: $564.99
In Stock
AudioCodes MP118-FXS AudioCodes MP-118 8 FXS Port VoIP Adapter Ships the Same Business Day
List Price: $668.00
Price: $539.99
In Stock
AudioCodes MP124 AudioCodes MP-124 24 FXS Port Gateway Ships the Same Business Day
List Price: $1,470.00
Price: $1,189.99
In Stock
Cisco SPA8000 Gateway Cisco SPA8000 8 FXS Port Gateway - spa8000-g1 Ships the Same Business Day
List Price: $320.00
Price: $227.99
In Stock
AudioCodes MP204 AudioCodes MP-204 4 FXS Port ATA Ships the Same Business Day
List Price: $245.00
Price: $193.99
In Stock
Cisco SPA8800 Cisco SPA8800 4 FXS 4 FXO Gateway - spa8800 Ships the Same Business Day
List Price: $600.00
Price: $426.99
In Stock
Cisco SPA112 Cisco SPA112 2 FXS Port ATA - SPA112 Ships the Same Business Day
List Price: $69.00
Price: $49.99
(Out of Stock)
Cisco SPA122 Cisco SPA122 2 FXS Port ATA with Router - SPA122 Ships the Same Business Day
List Price: $84.00
Price: $39.99
In Stock
Patton M-ATA Patton SmartNode M-ATA 1 FXS Port ATA Ships the Same Business Day
List Price: $75.00
Price: $73.99
In Stock
Obihai OBi110 VoIP Telephone Adapter Obihai OBi110 1 FXS / 1 FXO ATA Discontinued
Price: $73.99
(Out of Stock)
Obihai OBi202 VoIP Telephone Adapter Obihai OBi202 2 FXS Port ATA with USB Ships the Same Business Day
List Price: $99.99
Price: $83.99
(Out of Stock)
Obihai OBi508 VoIP Telephone Adapter Obihai OBi508vs 8 FXS Port ATA with Failover Ships the Same Business Day
List Price: $399.99
Price: $404.99
In Stock
Obihai OBi300 VoIP Telephone Adapter Obihai OBi300 1 FXS Port ATA with USB Ships the Same Business Day
List Price: $90.00
Price: $53.99
In Stock

What Does an ATA or VoIP Adapter Do?

Analog phone lines once ruled the world. Submerged telegraph lines crossed oceans and connected distant lands. Then, the telephone sparked the creation of exchanges and phone systems.

Today, the technology behind these marvels is outdated. Manufacturers rarely apply new features to analog phone technology. VoIP is becoming the standard because of its greater return on investment and feature set.

The problem with transitioning to VoIP is that a lot of businesses still have their analog equipment. The two technologies are drastically different. Replacing analog devices with IP devices can be incredibly expensive, or a business may not want to get rid of their battle-proven office equipment.

Analog telephone adapters are the solution for interfacing a couple of analog devices with a VoIP service or phone system. An analog telephone adapter, or ATA, typically features up to four FXS ports for connecting to phones, fax machines or modems, plus an Ethernet port for connecting to the IP PBX or VoIP service.

Need some quick suggestions? Here are five of our customers’ favorite ATAs:


Cisco SPA112

Cisco SPA122

Grandstream HT701

AudioCodes MP112

Patton M-ATA

Ports on the Adapters

FXS ports link to analog phones, fax machines and legacy equipment. FXS ports, or Foreign eXchange Subscriber ports, interface with the FXO ports on the back of the analog devices.

An RJ45, Ethernet or WAN port (there are a few names for it) connects the ATA to your VoIP service. The basic ATA features FXS ports and a single RJ45 port.

Rather than cancelling the connection to the PSTN or analog telephone service, a lot of businesses like to keep this subscription. An analog telephone adapter with an FXO port can connect to the PSTN. The FXO port can provide a failover telephone line should the primary VoIP service become disconnected.

Some ATAs feature built-in routers, meaning that in addition to the WAN port it also includes a LAN port. The LAN port connects the adapter to a local network.

USB ports provide analog telephone adapters with links to storage devices, firmware updates or anything else that the ATA can support.

Protocols, Codecs & Audio Quality

VoIP relies on protocols. A protocol tells end points and services how to signal each other. A protocol is similar to how humans use language to communicate. Two people with dissimilar languages will have a very hard time communicating, and the same holds true for VoIP end points and services.

SIP is an incredibly popular protocol that’s becoming the standard for VoIP telephony. When VoIP was first developed, manufacturers created their own protocols, which resulted in a lot of incompatibility between VoIP services and devices. Having a standard protocol benefits both users and manufacturers. The open source SIP protocol is quickly turning into that standard.

Voice quality is generally determined by codecs and audio enhancement technology. ATAs may support wideband and/or narrowband codecs, and enhancements like digital signal processing (DSP) and echo cancellation.

Wideband audio codecs provide the best voice quality possible. Wideband is sometimes referred to as HD voice because it can produce true-to-life sounds and natural conversations. Narrowband audio codecs are preferred in networks that have limited bandwidth.

Digital signal processing can improve telephony or music playback by intelligently enhancing speech and audio. It can also provide echo cancellation, background noise suppression and other tools to cleanup sound performance.

Fax over IP

A VoIP phone can be dialed by finding its IP address. An IP address is assigned to any device connected to a network or the Internet, giving the device a recognizable label. Analog fax machines can also be assigned IP addresses when they are connected to an ATA. The technology is referred to as “Fax over IP” (VoIP = “Voice over IP).

Traditionally, sending a fax requires dialing the receiving machine’s telephone number. The fax is stored and then transmitted over the analog line. Analog telephone adapters that support the T.38 protocol can provide real-time faxing, letting messages be sent and receive instantly. Computers can also send faxes through the T.38 protocol by dialing the machine’s IP address, which greatly increases productivity.

Support for Standard Features

Make sure that the ATA or VoIP adapter supports important telephony features. If it is a business-grade adapter, then the odds are extremely high that it will support a standard set of features. These features include (but are certainly not limited to):

Hosted VoIP phone systems and premise-based phone systems offer a similar line of features. The difference is how much you are paying for these features, whether you need them, how quickly you can customize or change the features, and so on and so on. With a premise-based solution, you are in complete control.

Paging Features

Certain ATAs can do more than connect an analog phone or fax machine to a VoIP phone system. They can also connect your existing analog paging system to the IP PBX. With this setup, pick up the handset on your VoIP phone to issue an alert or notification across the paging system.

The page will go from the VoIP solution, to the ATA, to the telephone adapter module (if applicable), and finally to the analog paging system.

In order for this setup to work correctly, the analog telephone adapter should support calling party control, also known as CPC disconnect. Calling party control tells the paging system that the end user has hung up the handset or microphone. A telephone adapter module may be necessary to interpret the signal from the ATA.

Calling party control is explained in more detail in our blog post: Hang Up with Calling Party Control.

Shopping for an ATA or VoIP Adapter

IP Phone Warehouse staffs a vender certified sales support team. Contact us for shopping assistance, including finding the right analog telephone adapter or VoIP adapter for your current setup. Our experienced team can pair your phones and services with a compatible ATA, ensuring you get the best experience possible out of your telephony solutions.

Our technicians and engineers have five years of experience. If our sales team cannot find an immediate answer, they know someone who can.

An ATA can provide a return on investment by letting you keep your existing analog phones while migrating your phone system to VoIP. An analog phone cannot support as many features as a VoIP phone, but it is an excellent secondary solution.

Knowledge & Technical Support

Read the articles in The Dock to learn more about ATAs. Articles include:

"How to Connect Remote Employees with an ATA"

“Bogged Down by Analog? Meet the ATA”

• And more!

Discover the full range of what analog telephone adapters and VoIP adapters can do. An ATA can be more than just an interface between your analog phone and an IP PBX.

IP Phone Warehouse also offers buyer’s guides. Print these documents for future reference when shopping for ATAs.

Need a more personal touch? Contact our free pre-sales tech support. We’ll help you understand the basics when shopping for ATAs and VoIP adapters.

Web Management

Analog telephone adapters that support web-based user interfaces are easy to manage. Open a web browser to access the ATA, and provision and configure its settings. Maximize performance and boost voice quality by simply tweaking a few settings.

Some VoIP adapters also support firewall and security technology. Keep your telephony secure from eavesdroppers or service attacks.

ATAs for VoIP Providers

If you purchased an analog telephone adapter or VoIP adapter from a VoIP service provider, it might be impossible to change any settings on the device. Sometimes, service providers will lock the user out of the user interface. The reason for this is because the ATA has been provisioned to work exclusively with that service. Cellular service providers do the same thing with cell phones that they issue to customers.

To ensure that an analog telephone adapter or VoIP adapter available on IP Phone Warehouse is compatible with your VoIP service, contact our free pre-sales tech support. We’ll cross reference the device or let you know what adapters are available to your specific service.

If you are a VoIP service provider, check out our programs for VoIP providers. We can provision ATAs and ship them directly to your end users.

Brands & Configurations

ATAs are available in one-FXS, two-FXS and four-FXS models, plus models with FXO ports to connect to a PSTN or other source. Most are ready for SIP and T.38 protocols for standard-based VoIP and faxing support.

A number of brands are available, including:







AudioCodes builds ATAs in a number of different configurations. They also manufacture rack-mountable VoIP gateways with dozens of ports for larger deployments.

The Cisco SPA112 and Cisco SPA122 ATAs are incredibly popular. These ATAs feature two FXS ports, with the latter model offering a built-in router. The ease of use and large feature set makes them highly suitable for most telephony environments.

Obihai ATAs can connect to applications like Google Voice. Google Voice lets you conveniently manage your phones. It is not a phone service, but a way to leverage your existing telephony with a powerful management application.

Another unique analog telephone adapter is the Patton SmartNode M-ATA. This adapter is incredibly compact. Use this device to interface a single analog phone or fax machine with SIP-based telephony or T.38 faxing.

What is the Best ATA or VoIP Adapter?

From a distance, it looks like all ATAs and VoIP adapters do the same thing. Up close, they are a lot different. Here is a roundup of our customers’ favorite analog telephone adapters based on prices, reviews and features.

Cisco SPA112

Receive the benefits of VoIP without losing your analog phones or fax machines. The Cisco SPA112 uses advanced QoS, SIP and other essential standards to produce high-quality voice. The ATA also supports simultaneous voice and data use, ideal for fax machines. Two FXS ports and a single Ethernet port are available.

Learn More >

Cisco SPA122

Keep your analog desk phones, conference phones and fax machines with the Cisco SPA122 ATA. The adapter has a built-in router with WAN and LAN Ethernet ports. Both FXS ports on the device have their own dedicated number, and both voice and data services can be running simultaneously.

Learn More >

AudioCodes MP-202

High-end features like T.38 fax relay and echo cancellation, without the high-end price tag, give the AudioCodes MP-202 one of the best feature sets available for an affordable ATA. Easily integrate the adapter with VoIP networks, analog devices and your business’ telephony.

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Patton SmartNode M-ATA

The Patton SmartNode M-ATA (micro-ATA) is branded as “the world’s smallest analog telephone adapter.” It brings big VoIP gateway functions to an ultra-miniature form factor. Connect a single analog device to your VoIP network or IP PBX with this space-saving adapter.

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Grandstream HT702

Strong security protection and advanced telephony features equip the Grandstream HT702 ATA for a variety of uses. Deploy it with analog phones or fax machines, ready for small businesses that rely on a number of different VoIP features to fully serve their employees’ telephony requirements.

Learn More >