I've tried, I really have. I feel like I've read every linked FAQ on this subject and I am still no closer to updating these phones.
Purchased a refurbished Soundstation IP550 and IP335 to use with Zoom. Gave them an IP, logged in and set the Zoom Provisioning path, but the phones wouldn't do anything.
The 550 is running 4.0.11.0583 and Zoom supports 4.0.14.1580, so I figured we should update the firmware first.
I've now spent most of the day and can't figure what I'm doing wrong.
Neither phone will connect to the Polycom Hosted Server.
I don't know if this is a problem with the FTP (though it is setup according to documentation) or with the phones themselves. I wish they would just talk to Polycom's Hosted Server and this wouldn't be an issue.
Wireshark shows the device sending a standard query to downloads.polycom.com, but then getting the error in the browser I highlighted above.
The same happens with provpp.zoom.us when set as the provisioning server, but again I don't know if that's just because the firmware is outdated and Zoom don't support it.