T28P and the auth-user-pass mistery

[spectrum]

Dear all,

i would like to connect to a vpn server that asks user-password authetication.

Some voices in the net says this optoin is not supported, but:

1) this thread says that T2X model should support the "auth-user-pass" option:

http://forum.yealink.com/forum/showthread.php?tid=332

2) the famous pdf
http://www.yealink.com/Upload/T2X/201311...Phones.pdf
says:

Quote:OpenVPN operates as a client-server application. After enabling the Open VPN feature on IP phones, the IP phones act as VPN clients and use pre-shared secret keys, certificates, or user name/password to authenticate the Open VPN server

So, i am still not able to connect. Is someone here been able to connect with auth-user-pass in T28P phones ? I upgraded now to last firmware 2.73.0.40, nothing changes.

Every help is really appreciated.
Thanks