Which networking library/engine

Hi,

I’ve been trying to explore different networking libraries/engines, but decided to ask here some advise.

What would be required for following:
Standalone masterserver, where clients&gameservers connects.
Gameservers would be also standalone servers, which are distributed to users and they can host games.

As far I understand, with unity’s build-in networking or with Photon, this case isnt possible. What would you suggest?

Unity’s networking was build exactly for this kind of setup. Also Lidgren is possible. Photon isn’t what your looking for.