iOS device discovery without Bonjour

Question

I'm creating an app that needs to connect to versions of itself running on other devices on the wifi network. The goal is to set up a broadcast / client relationship between one device to the others.

I know that Bonjour is the accepted method to do this, but I'm reticent to do that because it locks me into iOS devices, when I'd like to branch out to others, at least for clients.

If I start a webserver on the broadcaster on a specific port, like 43231 or something, is it acceptable for the client device to get it's own IP and then scan that block range for the broadcaster? Is there anything bad about pinging all the other random devices on the network with a request like that?

As in, Broadcaster is 192.168.1.11. Client is 192.168.1.4. If the client assumes all the devices are in the 192.168.1.* block, can it just iterate up the line from 1-100 or so looking for the broadcaster?

If this method is crazy, what should I do?

Answer 1

You can use SSDP (used by UPnP) or just multicast a message over the network and listen for it at the same time, ignoring the loopback (if you don't want the sender to receive it's own messages).

Answer 2

Maybe it will be better to use Bluetooth Low Energy for broadcasting/discovery? You can send non-connectable advertisement packets on server (with it's IP address) and listen for them on all other devices. Device founds such packet, reads IP address and connects to it via NSURLConnection (or something like that).