Sometimes you need to update the configuration of a phone. While this can be accomplished by rebooting or power cycling, it is often faster to trigger the phone to instant-update. This may cause a reboot on completion, but it can save time.
On many phones, long pressing "Redial" should accomplish the same thing.
For related procedures on W56H and CP930W please see related articles below.
Yealink SIP-T21P-E2, Yealink SIP-T48G, Yealink SIP-T29G, Yealink CP860 (EOL), Yealink CP920, Yealink CP960