Using ebay purchased secondhand VoIP phones during the lockdown

As part of our work to support one the local Covid-19 support groups we are lending VoIP phone handsets to some of the organisers. The handsets are programmed to use the special range of distinctive numbers allocated by us to the team. To ensure good quality voice on the phone we are using Polycom desktop handsets, these are business quality devices designed for office use.  We're also helping the Belper Covid-19 Mutual Aid Group, but they have less complex telephone requirements.

Once programmed by us, it should be just a matter of plugging the Polycom devices into the the RJ45 LAN outlet on the broadband router in the home and, after power is supplied, the devices automatically connected to the Sipgate service. The organiser team then obtain the full facilities of a distributed office PABX in their own home. It also protects the personal phone numbers of the organisers from general public exposure. There always are some weirdo's who would want to exploit personal phone numbers.

When purchased new, these handset have a price of circa £75 - £100 as they have quite powerful micro computers embedded in the device. In order to keep costs down we've purchased secondhand units from Ebay. These are fully functional older units no longer required by businesses, but look like new devices. They cost less than £20 to purchase including delivery.  The particular model we are purchasing have dual power options. You can either buyer dedicated mains power supply units delivering 24V, or they can use PoE (Power over Ethernet cable) which has power delivered via the network cable. The PoE option greatly tidies the cabling associated with using the phone, all that is needed is a single CAT5e network cable plus, in the home environment, a power injector unit close to the Broadband Router.

When used in conjunction with the Sipgate web browser interface you get "click and call" facilities from the VoIP phone with no need to dial the phone number via the handset keypad. You just click on the number and your handset rings. As soon as you pick up the phone handset, or press the speakerphone button, Sipgate will connect the call.

Well, that's all of the theory, now for the practice. When we received the secondhand devices, we found the units still had their programming from their previous owners. Some the previous programming was quite specialised. Normal configuration programming by us did not allow the phones to function correctly and connect to Sipgate. After a lot of research, we realised we had to completely wipe the memory on the phones, not just a standard "factory reset", we had to reformat the memory using a well hidden function on the phones. We then set up a FTP software server to hold the appropriate historic version of the software and basic configuration files. We were able to track the software and files down on the Polycom support website. It took quite a lot of Google research and the downloading of multipage administrator manual pdf files. Normally telecoms engineers go on training courses to learn these processes, we didn't have that luxury and spent about five hours hard work and experimentation to getting it done. Now the phone automatically visit the servers via the Internet, to pick up the latest configuration when they are powered up or restarted.

However once we'd "cleaned" the handset memory and reloaded the phones with new copies of the software they work just fine. Now that we understand the process, it is quick and easy to remotely program the handsets. It was time well spent. We're about to handover the devices to the volunteers, plus network cables and power units, all suitably sterilized with isopropyl-alcohol wipedown and exposure to UV-C disinfection lamp. 

We already use VoIP phones in the holiday cottage, but there we'd installed a brand new handset so we didn't have any configuration problems.

Edit: 21st April 2020
The only remaining problem is get the recipients of these VoIP handset to plug them in and to use them  So far the reprogrammed handsets have not been connected following delivery. There are no reported problems.