nat

问题 Is there any way to use UPnP for NAT traversal on Android with a 3G/4G connection, and if so, is it carrier dependent? 回答1: No, for the time being thee is no way to do that, for the simple reason that the mobile carriers don't use residential-class NATs - what they have is "Carrier-Grade NATs" CGN, see here http://en.wikipedia.org/wiki/Carrier-grade_NAT, and these devices have very different port allocation and management mechanisms from the residential gateways. See the Carrier-Grade NAT

问题 We want to establish TCP/IP connection between two android devices. For now we thought that it would be simpler if we make the connection device to device. So there is no server that is between the two phones. Most of the time (if not always) one has no real IP address (NAT and so on). Is this a problem for creating a TCP socket? I didn't manage to find any exact information for this. Any advice and opinion will be highly appreciated. Thanks 回答1: Is this a problem for creating a TCP socket?

问题 I started to explore the option of connecting with other using a p2p connection, so I coded a simple socket program in JAVA for android devices in which the users can share simple messages p2p (I didn't have any idea about NAT then). I got to know about NAT, so I now need to establish a TCP connection with another user which uses a server for discovery but payload is transferred p2p. I have also looked at XMPP(a very good and detailed explanation of how protocol works is here) and UPnP but I

问题 I want to do TCP Hole Punching (NAT Traversal) in C#. It can be done with a rendezvous server if needed. I found http://sharpstunt.codeplex.com/ but can not get this to work. Ideally i need some method which i give a Port Number (int) as parameter that after a call to this method is available ("Port Forwarded") at the NAT. It would be also OK if the method just returns some port number which is then available at the NAT. Has anybody done this in C# ? Can you give me working examples for

问题 I'm writing a P2P application. Peers regularly ping a main server to update their current IP/port, so when a peer wants to reach another one it can ask the server for that information. For now peers use UPnP to configure the NAT (for classic home setups) to be accessible from outside. So everything works, except when a peer's client tries to reach another (or the same) peer's server and both are behind the same NAT. Since in that case the client is trying to reach its own "external" (public)

问题 I've come across an interesting problem. Basically I have 2 mobile phones that are both behind NATs. I want to communicate directly between the 2 devices using UDP. I know if I initiate a connection from the phones to a server then I can push data back down that connection to the phone (ie send it back from the same port that received the message to the same ip and port that it was received from). So I can easily communicate between the 2 devices by connecting both phones to the server. Then

问题 The scenario is the following. I have two machines A and B: A: Client (behind NAT) B: Server (behind NAT) I want B to be able to listen on any given port, so that A can send packets to B through that specific TCP port and receive any response. If both machines are not behind a NAT it is pretty straight foward process. However how do I make it work so that it works even when B is behind a router, without him having to go change the router configuration enable some port forwarding etc... For

问题 Which software libraries does exist for such task for Linux, Windows OS? Does it exist some info in RFC how people should do it? I'm interesting how can I create functionality for my C++ project like presented here in that software: https://secure.logmein.com/ru/products/hamachi/download.aspx 回答1: There is not much difference if you want to make a connection through TURN relay server. The only difference is how TCP and UDP creates connection and nothing else. There are some big differences if

问题 I need to establish a P2P UDP and TCP Connection between two Users. Both of them are behind a NAT. A little research leads me to STUN, TURN and ICE. Is there any Java solution (library) except jSTUN which seems to work only on UDP. And TURN, ICE is much better for the symmetric NAT Problem. 回答1: Not to toot my own horn too much, but might I recommend trying IcedJava. (It's a part of the SipTools project) It's actively being developed, has a stable release 0.9 version, and supports use cases

问题 I am trying to accomplish UDP hole punching. I am basing my theory on this article and this WIKI page, but I am facing some issues with the C# coding of it. Here is my problem: Using the code that was posted here I am now able to connect to a remote machine and listen on the same port for incoming connections (Bind 2 UDP clients to the same port). For some reason the two bindings to the same port block each other from receiving any data. I have a UDP server that responds to my connection so