Ubuntu Connect To SSTP VPN

May be sstp-client can do it? And here is network-manager support for it.

There are now Ubuntu packages for recent distributions, so you should be able to add the PPA for eivnaes/network-manager-sstp and install the packages:

$ sudo add-apt-repository ppa:eivnaes/network-manager-sstp
...
$ sudo apt-get update
$ sudo apt-get install sstp-client
$ sudo apt-get install network-manager-sstp-gnome # NM configuration GUI