I'm currently writing a desktop application that integrates facebook using the graph API. I'd like to implement real-time updates (http://developers.facebook.com/docs/api/realtime/), but in the doc it say's that you have to establish a http server that facebook will address to send the updates to. My problem is now that my box is sitting behind a router with only one IP-address (so the router uses NAT).
Will it still be possible for facebook to contact my webserver for sending me updates?
#kohlehydrat: Every webserver needs to have an IP address that can be reached from "anywhere" on the internet. Since your webserver is sitting behind a NAT with only one IP, I seriously doubt Facebook can reach your webserver.
However, see if you can configure the NAT in such a way to reserve a dedicated port for your application.
For example:
10.122.48.222:4231
traffic to port 4231 is directed towards your application.
10.122.48.222 is outward facing NAT IP address.
I am not sure if we can do this, but its an idea.
The router should catch port 80 requests (or whatever port your webserver is supposed to listen on) and forward it to your internal computer port 80, preferably in a consistent NAT style.
Basically, IP based communication with proper routing should not be an issue if both parties can find each other.
You Need to Do what is called as "PORT FORWARDING".
I had a similar issue initially, Then I forwarded my port where in my IP was Made Public from being local only to the company.
And now my issue is solved.
hope this helps.
this question is already closed, but since you have not received this particular answer (which is what I believe most facebook developers do in order to develop behind firewalls) I will post it here:
You can reverse tunnel your machine to any machine with a publically available ip.
see blog post on this topic
in a lot of facebook sdks, this functionality is even included ( for instance, facebooker, a ruby gem provides the functionality to rake facebooker:tunnel:start after you setup the appropriate settings)
Related
First I want to define my question:
1, I am talking about computer program doing the IM, not mobile app. The program should be working in every home, or office environment.
2, Right now all (or most) home computers are behind a router, protected by ISP's security policy. It is not like 20 years ago, when a computer connects to an adapter, it gets a universal IP, as good as Microsoft.com and whitehouse.gov. 10 years ago, you can advise user to do port forwarding, or use UPnP to stealthily perform the port forwarding task. But now in the name of security, ISP is taking port forwarding out from the ISP-managed router (xfinity is doing that, as far as I know).
I know how to do IM in LAN setting, or the universal IP setting, that you get the IP of the friend, establish connection using TCP or UDP, then transfer information. Now when all computers are behind the routers, what is the feasible way / popular way / right way to do IM again? Using a central server to transfer information, by establishing connections of UserA-Server and UserB-Server? I know it would work, but not very "instant", in my humble opinion.
Please advise, thanks.
Upnp and NAT-PMP can still work, it will map a external port like punchhole. The problem is that our external IP may not be sure. So if you want to send IM, there are two choices, DHT or Central Controller.
I suggest you to use DHT and a central server using ICE structure, if DHT can work then it is ok, or we can use the central server to do the UDP/TCP traversal. In some circumstances like symmetric NAT, the server need to do relay, but in others, it just start the connection and then it is a p2p connection without server.
I am trying to set up what is possibly a webserver that can detect the IP addresses of the clients that try to access the webpage. In the simplest terms.
1)Let there be a table on the website.
2)Each time a client requests the website, its IP address gets added to the entry of the table.
I have made a webserver before using apache tomcat and even nodejs. But I have no idea how to detect IP adresses. I would also like to know if its possible to set this up online, in the cheapest possible way.
Perhaps nodejs would work using request.connection.remoteAddress, as in this example.
I've read tons of questions about this all over the web, and can't seem to find a solid answer. If I have an iPhone that's running on cellular data and another iOS device on wifi (in two separate locations), is it possible for them to send data to each other directly without sending it first to a web server, then retrieving it? Are the only options sending and receiving from a server/Apple's iCloud? What if I knew the devices' ip addresses? Note that the iPhone has WiFi disabled.
I'm not looking to put this in the app store, it is for personal use. I know NSNotificationCenter isn't an option.
Using the gamekit framework you can send data between two iOS devices. It is easy to implement. Other than that I don't think there is any other way to send data between two iOS devices.
Actually, it IS possible. You may want to google for something called "UDP hole punching" or "TCP hole punching".
The main approach in short: Assuming you got something like a relay server, that is some server in the internet that is publicly addressable from every private LAN that is connected to the www. No you have your two clients A and B in (different) private LANs, with some Network address translation (NAT) going on, that want to establish a peer to peer connection.
First of all both will tell the server their IP address and the port they have in their own LAN. In the UDP or TCP packet, the server will find the public address and port of the device (or the NAT (router)). So the server knows the private and the public IP address as well as the ports.
If now A wants to communicate with B, it asks the server for help. The server will send a message to B that A wants to communicate with her telling her A's public and private IP and port. A gets back B's public and private information and port.
Now here is where the magic happens. Both clients now send packets out to establish a connection simultaneously to the private and public addresses of the other party and thus punching a whole in their NATs such that incoming connections will not be blocked. Even if one party's connection establishing packets will arrive before this whole is created, the other's packets will get through to such that a connection can be created.
Beware of some NATs that scan the data for IP addresses and translate them as well, but if you encrypt your data or change the appearance of the address (complement, ...) you will be fine.
Now the master question, how can the server communicate with one of the clients without an active connection. Well in this case you can use "connection reversal" and apple's "push notifications". Use the "push notifications" (pn) to tell a client behind a NAT that there is something of interest going on and that it should contact the server. Once it has done that the connection is active and can be used in the previous described fashion.
I hope this helps some people that get to this problem although the post is quite old!
You can only use direct IP address communications if the IP address are publicly reachable IP addresses accessible over the internet, and they are static (enough) so that they are not changing on you regularly as devices get assigned to addresses dynamically. In many (most) cases, that won't be true because your devices will be assigned their IP address dynamically and those addresses are frequently going to be self-assigned IP addresses that aren't publicly addressable.
As others have commented, using Apple-provided mechanisms like iCloud are probably the easiest options. If that's not something you'd like to entertain, there are probably ways to make use of a dynamic DNS service like DynDNS to manage the actual IP addresses of your devices. With something like that you might be able to use a direct IP connection between devices based on a named DNS lookup. You'd probably have to jump through some hoops to make that happen though and I'm not sure you'd want to go to that extent.
I think that Bluetooth would be a good option for you
I am still learning about SIP and all its protocols, specifically trying to integrate PJSIP into an iPhone application to make p2p calls.
I have a question about a peer 2 peer connection using PJSUA. I am able to
make calls perfectly to other clients on my local network by calling directly using the URI:
sip:192...*:5060
I am curious if this will work for
making direct calls to other SIP URIs that are not on the local
network without using server configuration - if not this way, is there another way of making p2p calls without server configuration?
thanks in advance,
You can make calls without server configuration, as a general principle, but something needs configuring. As mattjgalloway points out in the comments below your question, the most robust solution is a can of worms involving ICE which provides a kind of "umbrella" protocol for things like STUN.
Last time I touched this issue, I had the requirement that I couldn't use internet-based SIP servers to help. I came up with the idea of a registry of sorts: your client can define a bunch of "address spaces" with particular routing requirements. For SIP URIs in your LAN, you define no routing; for URIs in your company's VPN-accessed network, you define a route passing through your VPN connection; for everything else you define a route through your internet router.
By "define a route", I mean that when you place a call to a URI in some particular address space, you store what IP will go into a Contact header, what Route headers you might need, and so on.
Thus, the process of making a call becomes:
Look up in the set of address spaces for a match.
Ask that address space for the suitable bits needed to make a workable INVITE (appropriate Contact header details, Route headers, etc.)
Construct a normal INVITE, mutating as necessary for the previous step.
Send the INVITE as normal.
This essentially reproduces half of what ICE would give you, in a manually administrated form. "Half", because this ensures that one SIP agent can make calls such that the SIP routing all works. The missing half is you still need some kind of registrar somewhere, and each agent in your contact list needs to have the necessary setup to receive incoming calls. (If an agent's behind a NATting internet router, the router would need to either run a SIP proxy, or forward ports 5060, 5061 to a particular machine (which might be an agent, or a proxy serving the LAN's agents).
It is, indeed, a large can of worms.
The basic issue is to solve the problem of getting transport ports anywhere on the internet for multimedia traffic.
Many companies/experts have tried to solve this situation. A possible way out of is to buy a domain and setup a basic registrar using YATE or Asterisk on an address accessible from the internet and configure it to also use ICE as needed. Your iphone application at both ends could register automatically to it upon start. Then make P2P calls.
I am aware of how many times this has been asked based on searching StackOverflow, but I am still hoping someone could tell me whether I am wrong...
I am creating a peer-to-peer chat app for the iPhone. My initial idea was to avoid using a server, so Bonjour came to mind. I was happy coding for quite a while and implemented a lot of fancy features, but two days ago I started testing with two clients from different subnets and found that the clients couldn't connect to each other! I suddenly realized that Bonjour is meant for local networks and that a DNS server is necessary for wide area service broadcasting. Do I really need a server for Internet peer-to-peer chat? Are there any other options that do not involve using a server on the iOS platform?
I am wondering how you can do a chat app without using a server. There are many cheap solutions out there, Amazon has its own service, Google does as well. You can try first without even having to pay a cent.
I found the following from apple developer guide. This should answer your question -
Does Bonjour work between multiple subnets?
Yes. The first release of DNS Service Discovery (DNS-SD) for Mac OS X concentrated on Multicast DNS (mDNS) for single-link networks because this was the environment worst served by IP software. Starting in Mac OS X 10.4, Bonjour now uses Dynamic DNS Update (RFC 2316) and unicast DNS queries to enable wide-area service discovery.
To answer the question, the only way is for you to carry a list of all possible participants, and their current IP address, and for each possible participant to report to all others each time their IP Address changes. So, if you have 100 possible participants, then you must tell 99 others when your IP Address changes, and those 99 must tell you when their IP Address changes.
Bonjour may work on a LAN, a WAN or even a WAN, but it will never work on the internet.
The role of the server is so that each end point only need to tell one end point (the server) when it changes. My advice is get a cheap internet host, with a basic PHP / MySQL capabilities, and write yourself a very simple script to post and get user identities.