I'm new to understanding how interprocess communication works. I"m working with two applications on my localmachine, a Source Application and a Server Application. The Source application broadcasts files through a configured port on my pc. The Server application listens for those files and exposes them to the internet for users to stream.
I want to remove the Server application from the equation and write a new application to communicate with the Source application.
So far I have my application connected to the port and listening. I am able to receive a message from the port. The message i am receiving appears to be metadata, no file. My assumption is the Server Application sends a response once it has picked up this metadata information to obtain the file. Therefore my application needs to mimic the server application. However I have no idea how to respond to the source application's port.
1) Is there a tool I can use to monitor the communication between the Source application and the server application? I believe this would be a tool to watch for tcp messages? All the tools I come across appear to only look for http messages. Would a packet analyzer be of any use?
2) If I can't view the communication between the source and the server application, what else can I do? Is there a tool I can use to broadcast the meta information I"m receiving on a port, then point the server application to that port and receive a response?
Any resources to help me better understand this intercomunication process would be greatly appreciated.
Yes, you can use Wireshark. It can monitor any TCP (and mucn more) communication, including local.
Use Microsoft Network Monitor 3.3, very easy to use.
Related
We would like to develop a desktop tool for checking the packet loss between server and client. Tool will be running on client machine. The client has port 4172 TCP and UDP open and can communicate on that port.
Is it possible to identify data transfer in both direction?
Are there any .net api to do this?
I have checked some tools like Pcap.Net and WinPcap
.Net has some Ping classes that make this pretty easy. This guy has some sample code that should get you started: http://forum.codecall.net/topic/37643-c-packet-lossping-program/
Situation: We have a web application running on a server. This application needs to fetch data from some other PC(Clients), which are on a different network.
On the clients' pc there are WCF hosted in Windows Services using its their local Sql db. i want to make duplex communication between server and clients for share data with each other.
data share mean share data-table,data-set,string etc between clients and server .
Problem :
1) I have no control over the firewall, proxy, NAT on the client side PC. Mostly company Employee PCs have lots of network security e.g firewall block ICMP traffic and some port too, some Router might be Disabled port-forwarding etc etc , client can change network place.
I don't want to make any setting on client side Router,proxy,firewall though .
during communication how can i handle that's kind of issue of client side?
as you know skype is working perfect in that situation.
firewalls very often block inbound connections to clients; the client may not be reachable from the server, it may be using NAT translation behind a router and so cannot be contacted without port forwarding being set up on the router and some new router disabled port forwarding .
2) On clients side there is no IIS .
I don't want to allow remote access on clients PC.
There are more than 100 Clients and only one Server. one server need communicate with many clients on different network .
3) One side my client application is using window application and wcf hosted in window service ,Other side on my server i'm using Web application . so its mean communication is between desktop pc and web pc , that's issue .
If both using a web application then it was not issue to make duplex communication.because i know WEBRTC is fit there lol.
Technology which i had already test and find issue
WSDualHttpBinding: Not work if client behind NAT. check this for detail click here
MSMQ : its bad technique if clients more than 1 and performance issue also because its use RAM memory . check here click here
Xsocket: Its also not work if ICMP traffic block by firewall on client. check here click
WebRTC: Its work fine but its support web to web communication .as my client side i have win app.
Socket.io: Its need to set up node.js and many other thing , hard to implement because i need implement on existence application , i am not making new application.
C# Socket Program: Its wouldn't work if client behind NAT.check here click for detail
Service Bus relay: Its not free even for testing .
socketPro: I studied i find its good but i can't find any right sample on google .so that i could test that.
Genuine Channels: I can't find any sample on google .
Lets see SignalR issue .: Server side i run a console application and Client side i run two application ,one is console and other web. when i was running console client application than it was not initiating connection with Server but when i was using web client application then it was working fine.
sample link is here SignalR two way communication
I can't understand why thas??
Please tell me What is best most secure and fast way to handle this situation? what approach should i use ?
SignalR seems to fit for this solution, because it's flexible.
It negotiates the fastest available channel of communication and that is what you are looking for.
You should investigate the problem with it and signalR will eventually work.
I'm using SignalR extensively to communicate between the servers (C#), between server and mobile apps (C#, Xamarin, iOS, Android). The servers are at different locations and the mobile apps can be anywhere. It all works very reliable.
Take a look at: http://www.asp.net/signalr/overview/deployment/tutorial-signalr-self-host and here http://www.asp.net/signalr/overview/guide-to-the-api/hubs-api-guide-net-client
I've been working in my spare time with sockets (admittedly in c++, not c# but there shouldn't be a difference), and I've never had an issue connecting to clients behind a firewall/router, even without port forwarding.
Routers and firewalls generally don't like server-like programs, eg. programs that bind the socket to a port number. Does your client do anything related to binding? Because it shouldn't.
Needless to say, I would suggest a socket program. The way I see it, it's the most flexible way.
I am writing a desktop application that will have to communicate with a windows mobile application in the compact framework 3.5. The communication must occur over the internet between these two applications to send data between them on command if the connection is available.
The system will send messages and objects like Images between device and desktop application and check to see if the desktop can see the device by sending a command and have a timeout on response. (Application will then know that the device is not available).
The mobile device will send a message to the desktop application when online as well that the desktop knows that the mobile is connected(Type of registering for communication)
Can someone please inform me of the best way to follow to accomplish this.
I did some research and found this site is near to something like event based driven communication I would want but do not have the availability of setting up an email on each device.
Battery life and internet open on device is not an issue.
Should I check in on working with the System.Net.Socket class for this type of communication between the two application and if so how will I set up so firewalls will not interfere and have my desktop application be seen over the internet by the mobile application ?
Hope someone can spread some light over this for me, if you have a answer please provide a link so I can read up on it.
your description is something basic. OK, regardless of what TCP/IP communication you decide for (HTTP, sockets) you must always have your internet router forward packages on a specified incoming port to your PC and the firwall must accept these incoming requests.
So, the device will have to send data to the PC and vice versa. So you need a server and a client on the PC and on the PC.
Possibly you can use an already available cloud like Dropbox to exchange files between PC and device.
What are about your skills in socket programming? The main server (PC) must be written multithread to be able to server multiple device client requests.
A simple socket comm is done in my SocketWedge [http://www.hjgode.de/wp/2010/05/27/transmit-data-from-winmo-device-to-pc-socketwedge-and-socketsend/]. A way of multithreaded communication using a web server on the device is available here [http://www.hjgode.de/wp/2012/10/19/windows-mobile-a-simple-web-server-with-extended-features/].
Will SQL with data synchronization be a possible choice?
Can you describe the application in more detail?
~josef
For practical purposes, what SqlDataSourceEnumerator does is find all instances of SQL server running on the various PCs on a LAN.
Is there an equivalent for finding running instances of an arbitrary application?
Edit: OK, so this only works because these apps have a pre-defined method of cooperation. Is there a straightforward way of determining if a given file (the exe, say) exists on some machine on the LAN even if the app itself itself is not running at the time? Understood that permissions must be taken into account.
What SQL enumeration does it broadcasts an UDP packet (port 1434) on the entire lan segment (subnet mask). The SQL Browser Agent service running on various hosts listens for this packet and responds with the list of local instances. So for the enumeration to happens, a number of ducks are already aligned for you:
there is a well know protocol for SQL isntance discovery, the UDP 1434 broadcast and response
there is a service listening for this broadcast, installed by SQL Server setup
there is a client library to implement the broadcast request formatting and response parsing which you leverage
For an arbitrary application to behave the same, the said application would have to implement these missing parts. Discovering arbitrary processes running on arbitrary hosts in a subnet segment is basically impossible for all practical means.
The difference is that SqlDataSourceEnumerator finds all instances "that it can see" on a LAN. If the server process is configured not to respond to that request, then it won't be seen.
Along that same line, you can scan for any application that has some way of making its presence known remotely. At its simplest, the application would be listening for and responding to connections. The application could, for example, bind to a TCP port and listen for any request and send back a response saying that it's alive and running, and hosts on a network can be scanned for those replies.
As for "an arbitrary application" however, most applications don't have such a mechanism for network discovery. If you control the arbitrary application then you can build that functionality into it. But if you do not then you'll need some way to look for that application on any given host, which means it'll need some kind of network interaction.
No, there isn't.
The reason that works for SQL server is that SQL server has a listener that listens on the network for "discovery" requests. An app can then send out a broadcast message on the network and listen for responses to that request to discover SQL server instances.
I suppose you could write a program that would do this generically though - It could listen for discovery requests, use some windows API functions to enumerate the processes running on that computer, and respond if the requested program is running.
I am wanting to send some data to a server from a client application to the server via port 5555. I don't have a window's server. My question is if I purchase a .Net Framework hosting service. Would I be able to connect the client application to this server. and could I do it by sending a Post. I am new to this, so excuse me if it doesn't entire make sense. but I am looking for just some little direction. If someone could explain what port 5555 is used for that would be great.
Most hosting provides will only allow incoming connections on the standard web ports (80 for unencrypted traffic/http and 443 for encrypted/https). Outgoing connections are less likely to be restricted, but it is not uncommon that only a few specific ports are open.
If you're developing a custom solution and you do not need a connection that allows you to continually send data back and forth, then a hosted solution will do fine. If you do need the live link or custom port numbers then you'll need to upgrade to a virtual managed server, which is essentially your own virtual copy of a Windows server. This costs more but allows you to listen on custom ports - essentially do as you please.
As for determining the specific use of a port, most networked applications have simply picked one or more numbers without much research. IANA maintains a list of protocols/applications/services and their associated port numbers, but being listed requires that an application is sent and approved.
Custom port for data exchange + tcp/ip has been identified to be very difficult across the Internet, due to firewalls/gateways everywhere.
Why not use REST web service or SOAP web service for data exchange? That has been proved to be a firewall friendly approach as it uses port 80 or 443.