Grandstream GXP1620 IP Phone | 2 Lines, 2 SIP Accounts | 2.9-Inch LCD Display | Dual-Port 10/100 Ethernet

This is a "Basic" IP phone, per the vendor, and that's reflected in the price point. If you expect the device to be on-par with a high-end Cisco or Avaya phone you may be disappointed. However if you want a quality, economical phone with a good feature set then this is a good choice. I found it to be easy to configure, I had it set up in my Asterisk server in under 10 minutes. I was also pleased to see it natively supports OpenVPN, I was able to set up a off-site phone to connect in over VPN without needing to deploy a remove VPN client. It also has support for a LDAP phone book and central configuration, but I haven't had time to set that up.The biggest things I don't like are the screen is a bit basic, I've noticed sometimes incoming caller ID is truncated. Better than it looking like a flip-phone UI circa 2001 though. An administrative concern is that it is hard to manually update the firmware on this. The firmware is openly available from Grandstream, which is nice, but there's no option to just upload the new bin file to it. It needs to be set up to a provisioning server, which is just a HTTP server, and the error feedback is pretty much non-existent. Plan to run a syslog and provisioning HTTP server for these alongside your PBX.Overall I am pleased with it. Audio quality is good. I have a Grandstream Budgetone I bought circa 2007 that's still kicking and it feels like the build quality had improved since then, so I'm optimistic this will last.

Good phone, pretty cheap and functions. Call quality is pretty good.

This phone did its job until one day it just stopped receiving the ethernet signal no matter what I tried including the firmware update. Our provider didn't change nor did our LAN. It is also way too light if that makes sense. A phone needs to be sturdy when sitting on an office desk or it will slide around too much like this one.

Funciona muy bien, en enlace en las llamadas, la interfaz es muy fácil. Pero la pantalla nunca se apaga. Quiero pensar que es un problema de fabrica.

FUNCIONA BIEN

For an IP phone it was fairly easy to setup and works well. It sometimes would ring randomly but that had to do with accepting incoming calls other than from the proxy. Basically you have to tell your phone not to take calls unless the call routed through your PBX box first, that makes the random calls go away but it is not a problem with the phone but rather people just port scanning on the internet.

The wires come out of the bottom of the phone, so it won't sit flat on a table. The plastic base it sits on is machined poorly, so it took a great deal of force and finesse to attach it. Most annoying of all, you have to enter all your SIP config info using the number keypad. They even have a config page you can access with your browser! Why can't you just type the SIP info there??I did get it working, and the sound quality was fine.

This phone provides quality sound and reliable service over two different VoIP providers, VoIP.ms and Call Centric.After I plugged the power adapter and Cat 5 Internet cables into the bottom, I saw that they stick out past the snap-on stand and make the phone wobble badly. Until I have a better solution, I use a thick book on which to rest the rear half of the phone. This is not perfectly stable and is ugly, but I will find cables with 90-degree plugs or make a better-shaped platform.The VoIP.ms service worked well early on, but Call Centric took weeks (including time off for frustration relief) of experimental configuration settings. I needed to use the online documentation by Grandstream (GS) and both voip services to get the work done. GS challenged me with different terms for certain things than I expected, and I never saw a glossary. For example they used PCMU as the name for a codec, which was okay except the services used another name for it, G711u. Neither mentioned the alternative name.Allow for a long learning curve if you don't have a head start in VoIP terminology. I had a head start, having programmed Obihai and Lynksys ATA devices and was still blind-sighted. Good luck--I proved the concept and you probably can too! :-)