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Downgrading is currently not a supported procedure on sipXecs 4.6.0. It can be done and the procedure is documented on Polycom site. Basically, in order to downgrade a phone from 4.0 to 3.2 one must deploy another special bootrom SIP application called Downgrader and a which will downgrade the phone to 3.3.5 firmware revision, and only after that deploy a 3.2 firmware.
You can follow these steps:
- Download the downgrader from Polycom site. You can find it here: http://support.polycom.com/PolycomService/support/us/support/voice/polycom_uc/polycom_uc_software_support_center.html
- Deactivate all Polycom device files.
- Create a new Polycom "Device files" and upload the Upgrader on the SIP Application (zip) field and under 4.0.X firmware (we assume all phones needed to be downgraded are at 4.0.X firmware revision).
- Reboot phones. NOTE: if you have phones with 4.0 firmware which you do not want to downgrade, make sure you do not reboot them.
- Phones will pickup the new bootrom and firmare (3.3.5).
- Create another Device files (or activate it if you already have one) with 3.2 firmware. I used 4.3.1 bootrom, and 3.2.6 firmware. Make sure you set the correct firmware version (3.2.X).
- Change the phone(s) firmware version (either from phone or from group).
- Send profiles to the phone(s).
- Phone(s) will reboot and pickup the bootrom and firmware.
Important
If you have a phone compatible with 4.0 but you DO NOT WANT TO UPGRADE it to 4.0 and keep it to 3.2 (or 3.1) version, you must make sure you do not keep the Upgrader deployed. If you do so, on reboot the phone will pickup the new bootrom and try to find a compatible image in the 3.2.X or 3.1.X folder. Those images are not compatible with the upgrader, and you will get a "Image is incompatible with the phone" error.
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