I do a lot of development that requires creating local networks on my machine in order to connect to them on my mobile devices. When you create a network, you disconnect from your existing network and lose internet access. Is there any way to programmatically create a network while still maintaining a second WiFi connection that can access the Internet?
As an aside, it's possible on the iPhone - when an iPhone connects to a locally created network, it somehow detects that it's not a real Internet connection and maintains its 3G connection while also being able to interact locally with the host computer.
No. It's not a matter of the software; most wifi chipsets only support being associated with a single network at a time.
The iPhone is able to avoid this because its 3G connection is a separate network interface from the wifi connection. If you have another method of connecting your laptop to the Internet, though, such as wired Ethernet, you can use that to get the same effect.
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I'm currently working on a project that requires the iPhone to connect to another device using an Ad-Hoc network (WiFi). Simultaneously, I require a connection to the internet in order to upload data to a server also using WiFi.
My question is: is the iPhone capable of connecting to multiple networks?
If not, is it possible (and viable) to switch between networks assuming the data rate is low? For example, iPhone receives data via Ad-Hoc, disconnects, connects to other WiFi network, established connection with server, sends data, disconnects from network, reconnects to Ad-Hoc network etc?
If the data rate is low and you are talking to another iOS device, check out GameKit.
This is Bluetooth, though.
I have not seen a way to connect to multiple wi-fi networks simultaneously.
I have try to make chat application with socket programing and I am using Chatty source code and its working perfect on same network. But not work for different network.
Is chatty work for different network iPhone?
I have tried chatty for different network in iPhone but no success.
Any idea about chatty for different network for iPhone?
From looking at the source code for Chatty, it seems that it just uses an IP and port number to connect to a different device, and that's the reason why you can't connect when users are in a different network. Being able to connect or not will depend a lot on the network configuration you both of your devices have.
For example: it works if you're in the same wifi, because there's no firewall between the devices, and the IP is reachable (192.168.x.x, for example). If you take one of the phones to a 3G network, it won't be able to reach the other one in the wifi, but the one in the wifi might still be able to reach the one on the 3G, depending on your career and port number, and if the network stack is on in the phone. So, conclusion is: this will be highly unreliable.
Usually, for this kind of communication, apps rely on a third party, so both of your phones connect first to a webserver, that is always available on the internet, and the web server sends the messages to each of the apps. This also solves the problem of one app going off the network (when you take an elevator, for example).
I'm building an app that connects to peers using GameKit. Until now, I've been testing without much concern over what network was used to connect (BlueTooth vs Wireless), but I just started testing with bluetooth turned off, and the peers don't seem to be able to discovery one another at all (and they are both on the same wireless network).
With wireless turned off and bluetooth turned on, it works just fine.
Anyone know what I might need to be doing differently to ensure the peers find each other on a wireless network? If it matters, I can tell you that I'm using Client/Server modes instead of Peer mode.
I want to create an iPhone application that can call web services on a computer, and then upload those files over the iPhone 3g connection. Is there an elegant way to do this?
I tried connecting the phone to local Wifi, but connecting to Wifi disables 3g, even though the Wifi is local network only.
I assume the same problem would arise if I could network the phone with the computer via bluetooth.
Any other ideas? The purpose is to go up to a special demo PC we created, pull some data off, then upload to the Internet, all within proximity of the machine. Unfortunately, it appears that I can't use one connection for pulling data, and another for pushing.
Your assumption is correct. When connecting to both 3G and Wifi, the Wifi connection will be used. Sounds like your local network has no route to the Internet. Perhaps that could be fixed.
Apple does not prefer its iPhones to be used as routers.
If you're working on something that will not be distributed through the App Store, you may have some success looking at "tethering" applications and their source code, which can be found by some clever Googling.
Is it possible to connect a socket between two mobile devices (iPhones) over the internet?
I am trying to discover the IP of each device and connect directly. I know it can be done with Bonjour but that only works on local networks. I need a high speed connection between two devices over the internet.
Thanks.
If you had both the IP's and they were both routable, it should be possible. I'm not sure though if the IP's given out by the 3G network are routable. If you are using WIFI, the IP you get is almost certainly not routable. Assuming you have a routable IP though, it should be possible.
The trick is just discovering the IP of the other device. The best way to do that would probably be to have each device register its IP with a web service when your app starts up, then query that service to find the IPs of other devices.
It might get a bit tricky managing "unregistering" IPs when the app is closed or when an IP changes though, but it should be doable.
ETA:
If you have a server that they can both connect to, you should be able to implement a solution using that server (i.e. without the phones actually directly connecting to each other). This would avoid the issue of having routable IPs for the phones.
As for how to bridge the sockets together - your server program would basicly work like an old-school phone switchboard operator. You'd have some kind of registration & discovery protocol built into the server software that would allow a phone to register itself with the server, query a list of the other phones currently connected to the server, indicate which phone it wants to talk to, and accept connections from other phones.
Once it knows who wants to talk to whom, your server software would connect the two together by reading from one phone's socket and writing that data to the other phone's socket.
Only a suggestion, but if you can get each of them to connect to a third site, you'll then know the address of each. Send the address of phone A to phone B (and/or phone B to phone A) and then have them connect as you see fit.
Have you looked through all the 3.0 features? Specifically peer networking (the existence of which is public).
WiFi routers often have a feature called "Port Triggering" which allows internal hosts (in this case an iPhone) to inform the router that they would like to have a connections on particular port forwarded to them. I have no idea if the iPhone supports this protocol.
For IP lookup you may consider using DynamicDNS if the two hosts are known ahead of time OR as stated above a custom web service if they are not (i.e. friends exchanging hostnames vs. strangers discovering each other)
This is an old thread, but I just came across it. You could use a STUN server (or NAT-PMP) to get the public IP address/port combo and then SMS it over to the other phone. So long as you open a listening port on the first device, then your second device can just connect directly using the publi IP address/port you sent to it in the SMS (SMS push registry can automatically wake up your app on the second device to do this)
I have run into this issue with an app I was developing. I was trying to connect to a PC cell card from an iPhone. The problem is that AT&T doesn't enable mobile termination for iPhones so it is physically impossible for two phones on an AT&T network to connect to one another. This is straight from an AT&T antenna engineer.
I was able to get this to work by having the iPhone VPN into a server and then connect to the PC cell card but other than that, it wouldn't work.
I have a very strong feeling (but no evidence) that the iPhone address is going to be non-routable. Of course it actually depends on the operator but AT&T give out 10.x.x.x addresses.
Apple have sample (desktop) code that uses Bonjour to implement portmapping on a WiFi router that supports UnPnP.