If the Norwegian passport holders want to apply visa at Vietnam Embassy, they should to know that:
Visa administrative Institution: Vietnam Embassy
Processing time: depends on you how fast you need. But for sure, you should make a call to Vietnam Embassy for details.
Required Documents: passport, money and 1 new envelope with stamp on it and your exact home address in order to avoid losing issues.
How to apply: please take a look at contact information of Vietnam Embassy below
EMBASSY OF VIETNAM IN OSLO, NORWAY
Address: St. Olavs Gate 21C, 0165 Oslo
Phone: +47 222 03 300 | +47 993 43 877
Fax: +47 222 03 301