Skype LAN capabilities

Question

My roommates and I were playing a game online; we were all in the same Skype call.

Our ISP went down due to weather conditions, and our router lost internet access. We all lost connectivity to the game, but we remained connected in the Skype call.

Does Skype prefer connecting via LAN instead of through the internet?

If so, is there a specific protocol that is used to separate LAN vs non-LAN calls? If my assumptions are not correct, how does Skype keep LAN users connected in the event of unexpected network problems?

Solution

A Skype call is mostly hosted by one user in the call (Most of the times, this is the person who started the call). If the person who started the call is on your network, then traffic does not have to pass through the router as the router knows the destination of the traffic as a device in it's own LAN network.
Your user will however be disconnected from the Skype network which will make you likely to be unable to send or receive messages or create new calls.
Due to the nature of the person who started the call being the host computer (essentially the computer acting as a server for the call) this also means that if any device in the call is unable to connect to the host it will disconnect, or in the case that the host loses internet connection the call can end for all users who do not have a connection to the host anymore. Skype does however not have a special protocol difference between LAN and non-LAN calls.

Comments

[Peter]

Your LAN is the internet. Or part of it, anyways. Internet routing tries to find a cheap route from one device connected to the internet to another. In your case the cheapest route that was found stayed inside your LAN. Torrents will also download faster if you find a peer or a seed in your LAN. Keep in mind the cheapest route that is found isn't always the cheapest route that exists.

[Chris Cirefice]

@Peter After finishing a networking class at my university, this is very obvious to me now... Well, the more you know!