https://community.cisco.com/t5/voice-systems-and-accessories-small-business/spa525g2-fw-downgrade-anyone/m-p/3298129#M55227 Hello Community, I'm getting increasingly desperate in trying to downgrade the SPA525's firmware. For reasons, see below. I've tried setting the "downgrade rev limit" parameter to no avail, always getting the "forbidden image for this hardware" message. Tried under http/web gui as well as tftp, all the same. Have latest release 7.6.2c on it, but need 7.5.2 because the UC320W I want to use it on thinks this is the latest and greatest, sending the phone into an endless update/resynch loop. So, if I have not misunderstood anything, I either need a way to erase the phone's flash (like e.g. 7961 special key-seq.) if possible - or, even better, how can I tell the UC320W to replace 7.5.2 with 7.6.2? BTW, I'd be very happy if it could be possible to release the UC320W telnet credentials to the public, since nobody cares to support it anymore, I could merrily poke around on my own... Regards, André Thu, 21 Mar 2019 16:09:40 GMT cisconaut 2019-03-21T16:09:40Z https://community.cisco.com/t5/voice-systems-and-accessories-small-business/spa525g2-fw-downgrade-anyone/m-p/3298129#M55227 Hello Community, I'm getting increasingly desperate in trying to downgrade the SPA525's firmware. For reasons, see below. I've tried setting the "downgrade rev limit" parameter to no avail, always getting the "forbidden image for this hardware" message. Tried under http/web gui as well as tftp, all the same. Have latest release 7.6.2c on it, but need 7.5.2 because the UC320W I want to use it on thinks this is the latest and greatest, sending the phone into an endless update/resynch loop. So, if I have not misunderstood anything, I either need a way to erase the phone's flash (like e.g. 7961 special key-seq.) if possible - or, even better, how can I tell the UC320W to replace 7.5.2 with 7.6.2? BTW, I'd be very happy if it could be possible to release the UC320W telnet credentials to the public, since nobody cares to support it anymore, I could merrily poke around on my own... Regards, André Thu, 21 Mar 2019 16:09:40 GMT https://community.cisco.com/t5/voice-systems-and-accessories-small-business/spa525g2-fw-downgrade-anyone/m-p/3298129#M55227 cisconaut 2019-03-21T16:09:40Z https://community.cisco.com/t5/voice-systems-and-accessories-small-business/spa525g2-fw-downgrade-anyone/m-p/3300876#M55228 <P>Dear interested readers,</P> <P>the downgrade problem has found an explanation. Newer hardware (obviously I have two different generations of SPA525G2)&nbsp; is not compatible with older firmware (not lower than 7.5.5c, I understand).</P> <P>I can indeed downgrade from 7.6.2 to 7.5.6, but 7.5.4 or 7.5.2, as the UC320W wants it, no way.</P> <P>&nbsp;</P> <P>Case halfway solved. Ideas w.r.t. UC320W still welcome.</P> <P>André</P> <P>&nbsp;</P> Fri, 22 Dec 2017 15:20:47 GMT https://community.cisco.com/t5/voice-systems-and-accessories-small-business/spa525g2-fw-downgrade-anyone/m-p/3300876#M55228 cisconaut 2017-12-22T15:20:47Z