Locate and transfer data - iphone

I would like make an app like whatsapp but i dont know how to transfer data if i dont know the ip or location of the other device.
My idea is like whatsapp, get the ip device and send it the data... and dont use email.
My problem is that i dont know how get the ip of the device, how to send the data.
My idea is use a server and when you use the app save your iphone number or telephone number like primary key in database from server, foreign key ip from device.
Is good idea???
How i can get the ip of the device?
Wich class use to send NSData to the server??
Thanks

You should not use the Ip of the device, since most device are used on a cellular network which could be using NAT.
This would mean that only one IP address is used for multiple device.
Whatsapp use an XMPP server as there backend, which is just an IM server.
When the App get background they disconnect from the IM server and when the user receives a messages the server will just send them a push notification.
XMPP is open source and can easily be modified and there are a lot op opensource libraries to use. Just have a look on http://xmpp.org/

Related

Exchange data between Iphone (App) and gsm modem

Im' trying to implement an App which is able to conect to a remote GSM Modem.
To etablish something like this I need a dialin process in the app which call the "Phone number" of the remote Modem and exchange data with it. On the GSM Modem is no posibility to connect the web. It can only accept incoming calls and response.
Does anyone know if there is a practiacal solution?
No not really, there is no way to use the any of the phone functions (meaning voice/data) other the internet connection.
You can't dail a number and then send data of the line, because as soon as you dail the phone app closes you app (or backgrounds it) and takes over.

Can an iPhone app act as a server to send messages or push notifications?

I want to write an iOS app that can act as a client and a server to other iPhones over the cellular data network (i.e., without a typical centralized server). The goal is to share series of about 200 short event messages, one at a time, from the iPhone server to multiple iPhone clients by some means of notification. Apple Push Notification service would be fine for such notifications, but there is no need to use it specifically.
I think sending push notifications from one iPhone to another is possible by connecting to gateway.push.apple.com from the serving iPhone as described in the Local and Push Notification Programming Guide, but I can't find anyone else discussing this approach (maybe it's too obvious?).
The reason for all this is an attempt to avoid the overhead of infrastructure. If this isn't feasible, alternatives which minimize or avoid additional hardware are welcome.
Requirements:
Communication must be [strictly] over cellular data network
Wi-Fi isn't available
Bluetooth doesn't have enough range
Unidirectional communication with an iPhone server multicasting to many iPhone clients
No jailbreaking
Ideally the serving phone's battery will be able to handle this without a recharge
Update 5/4/11 2:12 AM EST: Just to be clear, I don't have any particular requirement to use APNs; I thought it may have been feasible in this setup, but from the discussion below, it sounds like that's not the case. However, I'm still interested in any other system that could help me achieve the same end result with some type of message passing or similar form of communication.
Theoretically you should be able to write a iOS app that can connect to the APNS and send notifications to other devices running your applications. However, your main problem will be to actually acquire the 'tokens' of other devices. When you have a centralized server doing the job, its always online and thus, the clients can 'talk' to it via http and register them self (giving their tokens to the server in the process). Thus the server knows the client token and it can use them to send notifications to the clients via APNS.
However this is not possible in the scenario you are talking about. But this is not to say its impossible. May be you could use an email account X, to store all client tokens. Every client will send a email to this account with their token in it. So when a another 'client' want to send a notification to another client, it can find out the token by reffering to the inbox of the email account (you can cache this stuff and optimize it in a zillion ways of course).
But the point is some how a (third party(ex: email service provider)/your own) server that is online 24/7 will be involved in the process.
Let us know how you progress with this. It would be interesting to know.

How to send data from iphone to MAC/PC via serial port?

I'm new to these things, and have no idea how to achieve this thing.
I want to send some data from iphone to MAC/PC and also want to receive data sent from MAC to iphone.
Please help me out or give me some clue, where I can start from.
Most apps solve this issue by including a small http server in the app and providing a web interface to upload/download data to the app.

if I have an iphone's IP address is there anyway I can communicate with it?

are there any services running by default on an iphone that would let another ip address communicate with it if the iphone's ip is known?
Yes, technically, you can. There are a couple of issues though:
Mobile IP addresses usually change
When the phone is in sleep mode, its network interface is probably not reachable.
So I don't think you can rely on that for initiating a communication with the phone.
There aren't many options out of the box on a non jail-broken phone. However, you can write your own client application that runs on the phone. It accepts or initiates the remote connection.
And in that case, the protocol is entirely up to you.
If you jailbreak your phone, you can install the OpenSSH package and have SSH and SFTP access to your phone.
I don't know exactly what you want to do with your app, but you can consider create a thread detached from the main one (using gcd) and use it to send/receive informations from a server using JSON objects for example. Sure you can use sockets and write a client or something like that.
I suggested a new thread because you can put it running forever (on a enterprise app, I don't know if Apple will approve a thread running on an App for AppStore).
I had to develop an app with a consistent client/server relationship and it was the way I got it working.

Is it possible to connect a socket between two mobile devices (iPhones) over the internet?

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.