Customer has UC540 and SPA525G2 phones. The "phone load" on the UC540 installs firmware 7.5.2a on the phones. The customer wants to use Plantronics headsets with EHS (Electronic Hook Switch) and there is apparently a bug in 7.5.2a that prevents EHS from working. I see 7.5.4 firmware says EHS has been fixed.
So is there a way to add the 7.5.4 onto the UC540 so the phones will downlod it and upgrade themselves? Is there any danger of the phones doing this upgrade over the VPN?