I was wondering is there an easy way to communicate between iphones over the Internet(Not LAN/Bluetooth) or must there be a dedicated server in which all the iphones running an application needs to connect to?
For instance, suppose I'm writing a game which works on the Internet. Once four clients joins a room, game starts. must I implement a server in which every Iphone client connects to (for instance if server was developed on Windows it could be a Service) or is there another way to address this when developing Internet-based application?
Thank you
We have an online game that uses the iPhone (see www.ownthisworld.com if you want an idea of what we have done). Basically we use a php back end that accepts requests and returns xml data to the phone. It works quite well, but it depends on how much data you would be sending and your expected response times. In any event, our architecture of PHP/MySql backend works fine for our needs. By using the normal internet route, you do not have to worry about firewalls so much either.
You'd at the very least need some sort of central match making service so that the iPhones would be able to find each other, which would require some sort of dedicated server.
Secondly, devices on the internet can't always simply do a direct connection with each other. If all of the devices are behind a NAT or a firewall that doesn't allow incoming connections, you'd need a central dedicated server to host the game on. If at least one of the iPhones can accept incoming direct connections, you could have that iPhone host the game for the others.
There are some ways to punch through a NAT, but they're generally pretty horrifying in their complexity, and you'd still need the central match making service to pair up players.
Related
I want to connect multiple devices through socket without any server implementation.I will use that only for getting the IP addresses of the devices that will register.
There are two major problems to peer-to-peer communications: discovery, and reachability.
First, you need to know the IP address of the other peers to connect to them. Once you're connected to a mesh of peers, they can all keep each other updated on the state of the network, suggesting better peers to each other, passing around notifications of new peers who've joined and left, etc. But you have to design and implement a mechanism for trading that information. More importantly, you need to jumpstart things in some way, because when a new peer starts up, it's in a mesh of just itself, and it has no information to give itself.
One possibility is to have a handful of well-known "superpeers" (that you run) that are always connected, and bake their addresses into the app. Or you can have "introduction servers" instead of peers, serving much the same function. Or you can have some external way of trading addresses (the simplest is that users trade them on a web forum or an IRC channel or in person and type them in manually), which can be automated to various degrees. There are also shortcuts that can help—Bonjour can get other peers onto the mesh as long as one peer on the LAN is already there; GameCenter/GameKit can be used as an automated external trading network; etc.
Once you've solved the discovery problem, you still have the reachability problem. Most iOS devices usually don't have publicly-accessible IP addresses; instead, they're behind routers that do Network Address Translation, whether they be a home WiFi router or a cell carrier's 3G network. This means you need some way to do NAT Hole Punching to get two iPhones talking to each other. Somebody who knows both the public address and the internal address of each device can arrange for them to set up a connection to each other. You can have either normal peers do this (although that makes the jumpstart problem even bigger) or have your superpeers/introduction servers/etc. do it.
If you want to build all of this yourself, you probably want to look at other implementations. BitTorrent (including trackers and DHT) is well-understood and documented at a continuum of levels ranging from "lies-to-children" for curious end users to detailed protocol specs and open source implementations. And then look at some other P2P networks, because BitTorrent is not perfect, and doesn't try to do everything that everyone's come up with.
You can use GameKit. It has the matchmaking api that can help you.
It can be used for non game apps.
I've been working on something similar and it's a giant pain in the ass. There are 3 considerations: 1) Reachability 2) Discovery 3) The connection itself.
1) Don't even consider using 3g/4g, it just won't work well for keeping an open socket connection.
2) I'd use some sort of broker service between the two on the internet to connect the two. For discovery, you can just list what devices are available on the service.
3) For the connection, I find the IOS socket libraries to be rather painful to use, but if you go down to the BSD socket level it's not as bad. I think it'd be very interesting to use zmq sockets; that might simplify writing the broker service.
You can't. If the device is all online with wifi, it maybe possible and rely on the router setting just like pc connect. If some device is connected with 3g or gprs protocal , they may have no ip address at all.
Im developing an app where one iOS device act as "server", and other devices are acting like clients.
Im getting hard time with understanding if I can make this using Bonjour
If I make an example:
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All devices have same app installed. All users are connected to the same WIFI.
User must login into app, and when it does, chat rooms are populated from CMS (web server) from internet.
All of them see e.g. all "chat rooms". But at the beginning chat rooms are all read only. Anyone can browse these, but nobody can write into them.
When administrator (user with admin privileges) opens one of the chat rooms; all clients are now able to write into "open" chat rooms.
Of course when one user writes something down, the other users see the newest comment from him.
Administrator should see all clients in chat room but clients cannot see each other.
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All samples which I have found (WiTap, videos from WWDC,...) are using two devices only. I've installed WiTap on 4 devices. And I can establish connection and working "sample" game with two devices.
Can Bonjour service be used in such way that multiple cients are connected to one "server"?
Any hints are very welcome!
Yes, Bonjour can be used like that: for example Apache on Mac OS X has mod_bonjour so that web browsers can find a web server on the local network. That can mean having one server but multiple browsers: exactly the situation you describe.
One limitation is that the way Bonjour is configured in iOS means that the server and clients need to be on the same local network. It doesn't sound like the situation you describe is compatible with using Bonjour in that way, but then I also don't think you need to. You can use the DNS name of your chat server in the app, so any app can discover the server. The server can also be responsible for discovering which clients are connected and allowing people to find each other (indeed, I guess that's what the chat rooms are for).
This is a good place to start. http://mobileorchard.com/tutorial-networking-and-bonjour-on-iphone/ I have build the same Server and client with the help of chatty. But you will face one problem in iOS5 only, when the iphone will go to sleep mode, the socket connection lost. I am not able to solve this problem. So, looking for help. :)
is it possible with javascript, PHP (or anything!) to see if the iphone is using 3g or wifi from a website? We want to load low-res content if its 3G you see,
I found SCNetworkReachabilityFlags but that is just for apps...
Any pointers would be great!
Dan
I wouldn't expect this to be possible at all from the server side. From the client side, as you said, you could use the System Configuration Framework and the SCReachabilityFlags, but only client side.
As far as your server is concerned, it knows nothing about the type of connection any request is coming in on, apart from the immediate connection it has to the internet.
A request from an iPhone may pass through firewalls, routers, bridges, hubs, wireless, wired, almost any kind of network on it's way to you server.
The 3G part is only the connection between the phone and the data provider (AT&T, O2, etc), and after that, it's anybodies guess and will most certainly differ depending on the route between the data provider and your server.
The best advice I can give is to have a landing page, and let the user decide whether or not to load a high or low res version of the site. At least then it's off your hands if they run up a huge data bill...
I want to send some Text plus a image from one iphone application to other iphone app but restriction is I should not use a web server in between communication,Is there any way to fulfill it ?
Details: There are two independent devices and could be far enough say out of network. My requirement one app adds some text with a image and sends it to another iphone which can be at any long distance , and the app installed in another iphone will read that info and image into itself.
Actually there is a solution that meets your needs — and that fits to bbums answer:
Create a HTTP-Server on the iPhone, using cocoahttpserver. than you will ask some webservice like whatismyip.com for your public ip. with this your iPhone can be connected worldwide.
But very likely ur wifi-network is not forwarding your port to the iPhone. Ash.
And even if: Now it gets difficult. How to publish your ip from one phone to the other? hmmm... — I got it: I will exchange the information in a centralized space! In the web!
... wait — that would be a Webserver.
You see: Without any kind of server in the Web the users would need to exchange ip manually and have full admin power and knowledge about the local network.
So IMHO bbums answer is the only way to go.
PS: I am working with http server running on iPhones. In local network that works great, especially with bonjour. And you can use them over distance network — but only with reconfiguration of your router — something you shouldn't force your user to do
There is far from enough information to provide a specific answer.
two apps on two different devices?
are the two devices on the same network?
are the two devices both on WiFi?
do you need the user to receive a notification or something if the app isn't running?
If on same device, you can define a custom URL handler in the destination app and then openURL: in the source app to pass the data over. Encode your image and text into the URL, but be careful of size limitations.
If on different devices, there are many possible solutions, but answering the above questions will be critical to actually knowing what solution is appropriate.
Given your comment -- two apps, different devices, arbitrary networks -- then you are going to have to have some kind of server in between. Note that the recently added Game Center does have the ability to rendezvous two users, but it has a very particular user experience that may not be appropriate to your needs.
I would suggest that you investigate using push notifications to notify the receiving user of the availability of content. As for moving the content between, no direct connection is possible and you will have to have some kind of store-and-forward server in between. And, yes, a web server is going to be the easiest possible solution simply because HTTP is ubiquitous these days.
If there's no network of any kind available, but both parties have amateur radio licenses, then hooking the two devices up to HF packet radios might work.
THIS is super EASY.
I would code up some software that can turn data into modem signal, like the good old dial up modem. The device would actually make those annoying buzzing sounds.
You get the phone number for your friends nearest landline and call him.
He places his iPhone near the phones receiver in listen mode and you connect to his phone using your audible modem.
Bingo, via the power of sounds you have sent data which is decoded on his device and all for the very cheap price of a phone call, there are pretty cheap these days especially if you use Skype.
Easy Way (relatively speaking)
A way two apps on different networks can communicate without setting up a web server of some sort is as follows.
Use an existing third party storage system like DropBox.
Each app would need the login and password for your DropBox. Then both apps can read and write files that the other app can see.
An existing app that does this is a shopping list app called ShopShop.
The app on my phone and my wife's phone both link to the same DropBox account and the app keeps the shopping list synced up when one of us adds something to the list.
Based on a college-project I'm trying to realize a relatively simple game (Poker) where an iPad acts as Server and multiple iPod-Touchs connect to it as Clients.
Gamekit seems to drop out, since those old ipod-touch-devices don't have bluetooth-support.
Are there already some Frameworks out there simplifying the process, or do I have to fall back on TCP-Streaming-Sockets and implement it myself?
For your task I suggest you have a look at ThoMoNetworking or AsyncSocket.
ThoMoNet is a very simple setup that is specifically developed for fast and easy prototyping and easy to set up. Is will automatically create a bi-partite graph between all instances of you application it finds in the local network. So If you keep your iPad as the server and the iPhones as clients this will come down to less than 10 lines of code to set up.
AsyncSocket is a commonly used framework with ports to PC as well but requires more code to write. On the other hand it will allow you to do more fancy things, should you need them.
Distributed objects are not yet available on iPhone OS, so excluding GameKit you may try using Bonjour networking. Otherwise, you may try using web services with some of the available libraries. If Bonjour and web services are not a choice/possibility, then you have to revert to old plain sockets.