How to tell the host from the client in iPhone bluetooth with GameKit

Question

I have made a multiplayer game using the GameKit Framework where 2 iPhones/iPods can connect to each other via bluetooth and play.

I am thinking of a way to choose which device will be able to play first. So the logical solution is to pick the host of the connection. Is there even a server and a client in the GKSession? Are they all peers? Which route shall I take to achieve what I need?

Answer 1

Basically, it is up to you to configure your session as you like.

From the Apple documentation:

Sessions discover other peers on the network based on a session mode which is set when the session is initialized. Your application can configure the session to be a server, which advertises a service type on the network; a client, which searches for advertising servers; or a peer, which advertises like a server and searches like a client simultaneously.

A copy of your application acting as a server initializes the session by calling initWithSessionID:displayName:sessionMode: with a session mode of either GKSessionModeServer or GKSessionModePeer. After the application configures the session, it advertises the service by setting the session’s isAvailable property to YES.

A copy of your application acting as a client initializes the session by calling initWithSessionID:displayName:sessionMode: with a session mode of either GKSessionModeClient or GKSessionModePeer. After configuring the session, your application searches the network for advertising servers by setting the session’s isAvailable property to YES. If the session is configured with the GKSessionModePeer session mode it also advertises itself as a server, as described above.

Therefore, if you use GKSessionModePeer to initialize the session, you have peers (acting both as server and client). If you want to distinguish a server from its clients, initialize it with GKSessionModeServer.

Kind regards.