What does Grandstream make, and when do you need an adapter rather than a phone?

Who Grandstream is

Grandstream is an American company that has been making telephony and networking equipment for more than twenty years. In the Israeli market it is known especially for its adapters — small boxes that let you connect an old analog device to the new world of VoIP.

Beyond adapters, it makes desktop phones, cordless phones, cameras, intercoms and routers. Here we focus on the two areas most relevant to an office: phones and adapters.

Phones: the GRP and GXP series

GXP is the older series of desktop phones, with models such as the basic GXP1610. GRP is the newer series, designed for service providers and cloud PBXs, with models such as the basic GRP2601 and the GRP2612 with a color screen.

As with other manufacturers, the number hints at the level: a low model is a simple phone with a small screen, and a higher model gets a color screen, more lines and more programmable keys. Models change every few years, so check which model is current before buying.

Grandstream phones have programmable keys, a speakerphone, a headset jack and, in many models, PoE and a second network port for a computer. Like phones from other manufacturers, they connect to the PBX over the SIP protocol and receive their extension from it.

What an adapter is, and why it is needed

An adapter (ATA — Analog Telephone Adapter) is a small box with two kinds of ports: a network port that connects to the internet, and regular phone ports where you plug in an old device. The adapter "translates" between the two: to the PBX it is a digital extension, and to the old phone it is a regular line with a dial tone.

The port you plug a phone into is called FXS. The number of FXS ports on the adapter determines how many devices you can connect to it. Each port is a separate extension on the PBX, with its own number.

Thanks to the adapter, a cordless home phone, an old wall phone in the kitchen or a special device keeps working after the move to a cloud PBX.

What matters is understanding that the adapter itself "knows" almost nothing about the office. It doesn't decide where a call goes and doesn't save messages. All the decisions — IVR menu, queue, forwarding when there is no answer, voicemail box — are made on the PBX, just as with an IP phone. So an extension connected through an adapter gets the same routing as any other extension.

The HT series: small adapters

HT802 is an adapter with two phone ports — suitable for a home, a small room or two individual devices. HT814 comes with four ports, and HT818 with eight. They suit a small office or a floor with several analog phones.

The series also has models with just one port, and models that include an FXO port — a port that connects to an existing phone line, not to a phone. These are meant for special cases, such as connecting an old line that hasn't been ported yet.

The adapter has a browser-based management interface, like an IP phone, but in most cases you don't need to enter it: it arrives already configured.

A common example: an office of three employees moving to the cloud, each of whom already has a cordless home phone they are used to. One HT814 adapter next to the router is enough to connect all three, with a free port left for another device in the future.

The GXW series: dozens of ports in a cabinet

When a building has dozens of analog phones — for example a dormitory with a phone in every room, or an old institution with existing phone wiring on every floor — a small adapter isn't enough. For this there is the GXW series: large adapters that fit in the network rack and provide dozens of ports in a single device.

The big advantage: you can leave the old wiring in the walls and the old phones on the desks, and just replace the old PBX in the cabinet with a single adapter connected to the internet. This is a common way to move to the cloud without rewiring an entire building.

The series also has models meant for connecting existing phone lines (FXO), but in a full move to the cloud you usually don't need them.

When to use an adapter and when an IP phone

The simple rule: an IP phone gives you more, but needs a network jack. An adapter keeps what you already have. Many offices use a mix of both.

Fax and alarm — why not every adapter fits

A regular phone is forgiving: if the audio cuts out for a fraction of a second, the ear fills in the gap. A fax and an alarm dialer are not forgiving. They send precise tones, and a small disruption breaks the whole transmission. A fax page comes out half printed, or the alarm fails to report to the monitoring center.

For this reason, fax and alarm use an adapter configured specifically for that role, with settings suited to transmitting tones and not just speech. Connecting a fax to a regular adapter, "like a phone," is a common cause of complaints.

If you only need to send and receive faxes, and don't necessarily keep a machine, you can also consider a virtual fax — a fax that arrives by email and is sent from a file.

Power, network and placement

A small adapter usually has its own power supply, and not every model gets power over the network. So place it next to a power outlet and a network jack. A large adapter goes in the cabinet and gets power from the UPS.

If the adapter serves an alarm, it is especially important that both it and the router have backup power. An alarm that can't dial during a power outage loses part of its purpose.

One more thing: an adapter is connected by network cable, not Wi-Fi. That is what gives it stability.

A good spot for a small adapter is next to the router, on a shelf or on the wall, and not on the floor under a desk where it gets kicked and unplugged. It's also worth sticking a small label on it: "Phone adapter — do not unplug," so no one pulls it out of the outlet to charge a mobile phone.

Management interface and updates

Grandstream adapters and phones also have a browser-based management interface, where you set up the SIP account, audio settings and clock. As with any network equipment, change the default password.

The manufacturer occasionally releases firmware updates that fix bugs and improve security. For equipment set up through auto-provisioning, updates can be managed centrally.

A field example: a Talmud Torah with old wiring

At the "Beit Yosef" Talmud Torah (a made-up name) there were thirty analog phones: in every classroom, in the office, in the teachers' room and in the kitchen. The wiring ran through the walls twenty years ago, and the old PBX in the cabinet had started to fail.

Instead of rewiring the whole building, the old PBX was replaced with one large adapter in the cabinet. Each wall line was connected to a port on the adapter, and each classroom got an extension on the cloud PBX — with the same device on the wall.

In the office, on the other hand, an IP phone with extension keys was installed, because most calls go through there. The fax machine was connected to a dedicated adapter. This way the move was done without replacing thirty devices, and without days of electrician work.

What the adapter doesn't give you

An analog phone connected to an adapter stays a simple phone. It has no screen showing who is available, no BLF keys, and no call log menu. It can dial, answer, and use the codes the PBX recognizes.

Most actions are still possible through codes: transferring a call with a short press on the Flash key (or a short hang-up) followed by an extension number, listening to the voicemail box with a code, and picking up a ringing call. But this is less convenient than a dedicated key with a name.

Caller ID on the display also depends on the device itself. An old phone with no display won't show a name, even if the PBX sends it. And a phone with an old display may show only numbers, without Hebrew names.

So at stations where people use the phone a lot, moving to an IP phone usually pays off. The adapter suits stations where a "phone that works" is enough.

Audio quality on an adapter

Call quality through an adapter depends on three things: the quality of the internet, the quality of the old device, and the condition of the wiring between the adapter and the phone. A very long phone cord, an old one, or one with loose connections can add noise or hum.

When there is hum on the line, first check the physical connection: connect the phone directly to the adapter with a short cord. If the noise disappears, the problem is in the wiring, not in the adapter or the PBX.

And if the audio cuts out or sounds "robotic," the cause is usually the network — a loaded internet connection or a router setting. We recommend turning off SIP ALG in the router, a feature meant to "help" calls that often breaks them.