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.
On the T27G, the menu order is Settings -> Basic - the additional Settings menu comes first.
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