1und1 IP Phone with Twinkle

• 1&1 Sip-Server = sip.1und1.de
• 1&1 STUN-Server = stun.1und1.de
• 1&1 realm = 1und1.de

The Username is build from your countrynumber (49 = Germany) plus your complete IP-Phonenumber like this: (

49PreNumberYourNumber (without '+ and the leading 0 for the pre number) 

ex: 49123412345

The password must be set in the 1&1 control-center (login.1und1.de).

You can use the answer-machine, too.

Set the same number as your username and choose „RFC 3842“ for MWI Type. The mailbox server ist

sip.1und1.de

Remember to set the SIP-Port to 5070 and forward it from your router.