SIP 484 address incomplete

[vieri]

Hi,

This is the first Yealink SIP hardphone I'm installing.
I'm used to Grandstream phones and their "early dial" feature which allows the user to pick up the phone and start dialing until the SIP /Asterisk server matches a dial pattern and the call connects.
eg. if internal extensions are 4 digits long, the user can go off-hook, dial 1234 and the call connects right after "4" was pressed (no need to wait for any timeout or dial #).

What is the equivalent for Yealink T19P?

The Yealink manual states that "484 address incomplete" is supported but I didn't find anything in the configuration settings to enable or disable it.
If it's enabled by default then it doesn't work.

Any suggestions?

Thanks,

Vieri