How to do peer-to-peer communication in an iPhone app? - iphone

I'm trying to write a simple chat application for the iPhone (as an experiment). Is there a simple way for two devices to discover each others' IP addresses, and given the addresses is there a simple API or protocol that would let me send text messages back and forth?
I've investigated SIP (specifically Sofia and eXosip), but these tools exist as C libraries and are beyond my current ability to port them to the iPhone.
Update: I'm trying to connect two devices over the Internet (i.e. not over Bluetooth or a local wireless network, which is what GameKit does).

You're going to need a server that provides the match making service. Game Center makes this pretty easy, but your users will have to have Game Center accounts.
Alternatively, you can set up an XMPP (formerly Jabber, it's what powers Google Chat) server (I've never done this, but there are several available) and use the XMPP Framework for Cocoa. There are instructions for using it in iPhone apps here.
I'm sure there are other chat servers and client source also available. IRC and Mobile Colloquy come to mind.
Finally, you could write your own server using your favorite server language / framework. This isn't too hard (I've done it myself), but it's far from what I'd call simple, and I wouldn't use it for a production system.

There is support for exactly this kind of ad-hoc peer-to-peer networking in GameKit. Have a look at the second half of the GameKit documentation for details:
http://developer.apple.com/library/ios/#documentation/...

NSNetService is a good option.

Take a look at WebRTC Datachannels. WebRTC is a newer option with native iOS support a standard that is still being finalized, but it is more flexible should the iOS app need to communicate with browser or even android peers

Related

Peer-to-peer communication between iOS devices

I am trying to prototype a solution to a problem and am currently exploring multiple routes I could try. Is it possible for one iOS device, running a certain app, to communicate directly with another iOS device, running the same application - without the need to be on the same LAN?
Solutions I am currently investigating are using Bluetooth and ad-hoc wireless connections.
Ideally, the application when installed would ask the user for the required permissions, and then would accept and/or send data to/from another client after a handshake had happened.
My concern with Bluetooth is that 'pairing' would need to happen with every device, rather than happen in the background once the user has installed the app. I have a feeling what I am talking about isn't possible from what I've been reading elsewhere on Stackoverflow.
Take a look at Bluetooth Low Energy.
https://developer.apple.com/library/ios/#samplecode/BTLE_Transfer/Introduction/Intro.html#//apple_ref/doc/uid/DTS40012927
Here is another example,
https://github.com/KhaosT/CBPeripheralManager-Demo
You might also want to look into GameKit and peer-to-peer connectivity there.
I can't tell you anything about it, but you might try looking at iOS 7. If that's an option, I'd take a look. Can't talk about what it is because of NDA though.
Depending on what you need to communicate, you could try checking out this project, which lets you share arrays of strings between iOS devices over Bluetooth LE.
You don't need to "pair" the devices and it can still communicate while the app is in the background. SimpleShare
Hope it helps!
From the documentation of MultipeerGroupChat:
MultipeerGroupChat sample application utilizes the Multipeer Connectivity framework to enable nearby users to discover, connected, and send data between each other. This sample simulates a simple chat interface where up to 8 devices can connect with each other and send text messages or images to each other. Here you will learn how to bring up framework UI for discovery and connections and also how to monitor session state, listen for incoming data and resources, and send data and resources.
This is an excellent example at developer.apple.com here is the link
https://developer.apple.com/library/ios/samplecode/MultipeerGroupChat/Introduction/Intro.html
Also this tutorial from Ralf Ebert demonstrates how to use Multipeer Connectivity framework for peer communication should help you.
https://www.ralfebert.de/tutorials/ios-swift-multipeer-connectivity/

How to create a Mac/PC server app that interacts with iPhone/iPad App?

Can someone please point me in the right direction to create a Mac/PC server app that runs in the background and connects to an iPad app over the local WiFi network?
No matter how I phrase a search on Google it just brings up various apps like Remote Mouse and whatnot and no tutorials or even a hint of where to start.
I just need to send simple commands from iPad to computer over local wifi. A point in the right direction and I can likely fill in the blanks.
Thank you.
Thomas
EDIT: I am using web languages for the iPad version that I will build as a native app using open source tools.
OK, then. It actually depends on what you really need. I made the assumption you need real-time and perhaps binary data transfer.
Your best bet is to write your server application using standard C or C++ so it compiles on both as simply as possible.
If you want to avoid all the burden of writing a protocol for service discovery or asking users to enter the ip address of your server you will use a mDNS implementation for your server and your iPhone app.
If I were you I would try bonjour: http://www.apple.com/support/bonjour/
on iPhone You could start here: http://developer.apple.com/library/mac/#documentation/Networking/Conceptual/NSNetServiceProgGuide/Articles/PublishingServices.html
Once you have your sockets you will have to implement a networking protocol between your server application and your iPhone app.
You will have to be careful about byte ordering and little subtle problems with latency, disconnections and other problems inherent to networking and WiFi.
In windows you will want to register your application as a service and in Mac OS X/UNIX you'll probably want to deamonize it.
Good luck!

Connecting Blackberry Devices

I need to create a blackberry application that connects two phones for information exchange. One of these phones should support several incoming connections at the same time and serve them all. The other phones should not see any other phones except the central one.
What would be the best way to achieve this? Connecting through sockets? Data Services? Internet? What would be the advantages/disadvantages of each?
To asses the advantages and disavantages of each method one would really need to know the full requirments of you project. That said though, I would suggest you look at the BlackBerry Messenger SDK. The SDK nicely abstracts away all the issues with mobile-to-mobile communications.

iPhone peer-to-peer voice chat

I see that Game Kit allows you to develop games with voice chat.
I want to build a more general, peer-to-peer voice chat application, that does not have to live in the Game Center. So a couple questions:
1. What peer to peer system/technologies could be used for this?
2. If I wanted to allow voice chat with a Flash client (i.e. iPhone app <--> Server <---> Flash client on PC) would options for 1 work for this?
I have some experience with RTFMP for Flash to Flash client chat, and no iPhone dev experience, so just want to test out some ideas.
Maybe one idea: build using the Ribbit Platform - they have both Objective-C and Flash SDKs, but this looks more like traditional\SIP calling.
Anyway, would appreciate anything that points me in the right direction.
Thanks.
Now that flash has access to raw Microphone data, you could roll your own client and server; yet, since, currently, it doesn't have UDP sockets in AIR for mobile, you would be forced into considering audio quality vs lagg with even tighter restrictions then usual.
You can now roll your own native extension to make this work; yet, I am assuming you want something that only requires coding in AS3.
Therefore, considering your restrictions, the only real bet would be to use Flash's built-in communications capabilities (e.g. RTMP).
With the above being said, there are opensource alternatives to the array of Adobe's own flash communication servers:
the red5 server, and rtmpd.
IMHO Ribbit's services are kind of pointless.

How can I send simple data from an iPhone to another iPhone, or an Android?

I'm just getting started with mobile development, and after considerable searching I'm still confused about sending a message from my iPhone to another or an Android. For instance, in building a simple Tic-Tac-Toe game, if I want to notify the other phone of a move, what is the best way to do so? Wifi, bluetooth, 3G? And how?
Many methods seem to point to communicating through a web server, but I'd rather send them directly from phone to phone if possible. (this is for native apps of course)
If you don't want to have a server (or even if you do! It depends!) it sounds like you will want to use TCP sockets. Apple doesn't have a generic bluetooth API to use with iPhone-to-android communication and you'll have TCP access anyway with 3G. A 3G network connection is very similar to wifi and you should be able to check for the difference as needed with little change to your overall networking code. I'm not sure if bonjour is supported on android, but I bet someone has ported it for similar reasons already, and it is supported in iOS. Apple has a networking section for iOS that you may find informative.
Additionally if you want to stay within the iOS device only realm you could use GameKit to communicate via bluetooth.
Hope that helps some.
The easiest way is to create a web server with an API and the clients poll the server for new moves (or the server pushes the client an update). This is the only way you're going to be able to do it over 3G unless you can figure out the IP addresses of both phones (do phones even keep the same IP address for a long period of time?) and open up sockets between them and let one phone be the server and the other be the client (could cause potential cheating).
WiFi is not always there - by limiting your users' options to areas with access points, you'll lose sales. Not sure about Bluetooth - how prevalent is it on handsets, how much of the API is exposed. Your best bet, IMHO, is 3G. With some kind of a central presence server (Web or otherwise), with optional proxying. Read up on peer-to-peer networking.
As far as i know does the iphone only support incoming messages over push notifications.
This means, that you have to update the information, by requesting it from web services etc.
The bluetooth API of the iphone doesn't support this either.