We have offices in the U.S. and one in Germany. Is it possible to use the softphone in Germany just as we do in the U.S. that we can just dial extensions as if we were all in the same office? Or does it require a special international plan?
Assuming normal network connectivity, it should act as you expect and no special plan or configurations would be needed. Keep in mind if you dial a number in Germany it would be treated as long distance from your US plan.
You may not get ideal voice quality since you would be connecting to servers in the US and if that turns out to be the case you could explore the Global Office options.