8841 phone firmware

[Mohd Khairul Nizam]

i have 8841 phone registered in the CUCM but i notice there is several phone that different in firmware.
why is that ?
how to resolve it ?

Actual problem is that the phone with download status fail not able to call using VOIP function. Is that related  ?

[Jaime Valencia]

You're trying to downgrade, not upgrade, the phone might not even support that version, see a sticker on the phone or the box for the minimum version the phone can use. But no, that should not cause any issues with calls, depending on the exact issue, start by doing the basic troubleshooting for it. 

[Mohd Khairul Nizam · Accepted solution]

i was able to rectified and resolved the issue by updating device pack (cmterm-devicepack11.5.1.17112-1.cop.sgn)