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Full Version: T48S after Firmware update to 66.9.0.80 no Downgrade possible?
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Hi all,

we want to update one of our T48S (SfB) devices to 66.9.0.80.
According to the firmware changelog (page 3)Changelog,

a downgrade is not possible anymore.
What exactly does the whole text mean in the changelog? Shall we prefer the previous version 66.9.0.78? Are there other limitations with version 66.9.0.80?
Thanks and regards
Thomas
(06-24-2019 01:33 PM)thomas.hauff Wrote: [ -> ]Hi all,

we want to update one of our T48S (SfB) devices to 66.9.0.80.
According to the firmware changelog (page 3)Changelog,

a downgrade is not possible anymore.
What exactly does the whole text mean in the changelog? Shall we prefer the previous version 66.9.0.78? Are there other limitations with version 66.9.0.80?
Thanks and regards
Thomas

Hi Thomas,

Yealink wants to strengthen the regulation of SFB phones, so we released firmware 66.9.0.80 to disable the ability of downgrading to Open SIP version. There is no other limitation.

If customers need to downgrade the firmware from SFB to Open SIP, please create a Ticket for us, we will follow up.
https://ticket.yealink.com/

Best Regards,
East
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