Develop Reference

determining the current link speed of WiFi in C#

I am writing a program that does one thing, it finds out the current link speed of the wifi connection and reports it to the user in real time. the problem I am having is that it does not seem to be able to find out the current link speed, only the max link speed of the device (300 Mbps). the reason I am writing this is that I have a problem where, periodically the link speed will drop drastically (down to 1-2 Mbps) and I want to be able to see when that happens. with this code it will simply give me the maximum speed that the adapter supports, not the current link speed of the connection.
private void update(object state)
{
System.Net.NetworkInformation.NetworkInterface[] nics = null;
nics = System.Net.NetworkInformation.NetworkInterface.GetAllNetworkInterfaces();
long speed = 0;
string adapter = "";
foreach (System.Net.NetworkInformation.NetworkInterface net in nics)
{
if (net.Name.Contains("Wireless") || net.Name.Contains("WiFi") || net.Name.Contains("802.11") || net.Name.Contains("Wi-Fi"))
{
speed = net.Speed;
adapter = net.Name;
break;
}
}
string temp;
if (speed == 0)
{
temp = "There is currently no Wi-Fi connection";
}
else
{
temp = "Current Wi-Fi Speed: " + (speed / 1000000) + "Mbps on " + adapter;
}
if (label1.InvokeRequired)
{
SetTextCallback d = new SetTextCallback(update);
label1.Invoke(d, new object[] { temp });
}
else
{
label1.Text = temp;
}
}
this run by calling
System.Threading.Timer ticker = new System.Threading.Timer(update, label1, 0, 1000);
in the main method.

Considering that it literally took me the whole entire day to find what the solution to this was, I figured I'd at least show StackOverflow for future reference what I came across and what did and did not work for this question.
tl;dr: Scroll to the The Code section
What I found
Good ol' control panel
If you are looking for the really easy way to do this you can simply go and open Contol Panel. Depending on what version of Windows you are on (in my case I'm on Windows 8), the path to the page is Control Panel >> Network and Internet >> Network and Sharing Center and then you can click on the link next to "Connections: " which will give you a window that looks like what is below.
The current link speed is highlighted in red which in my case is 36.0 Mbps. Though, of course, this might not satisfy your original question if you were intending to integrate some code with the actual value.
WMI
With a mix of Googling and whatnot, I thought I might have found something in Windows Management Instrumentation.
Long story short, AFAIK, WMI does not have what we're looking for.
WMI, in short, is a giant object database (that
can also be queried through SQL) that allows you to query information about a
Windows machine such as process, disks, etc. In WMI, everything is
represented by a class with a series of instances each with a set of
properties.
Anyhow, WMI Explorer allows you to view all of this on your machine.
I (supposedly) found two classes on MSDN that might have the info on link speed but from WMI Explorer, there was nothing useful.
The first class, MSFT_NetAdapter, did not even show up in WMI Explorer on my machine.
The second class, Win32_NetworkAdapter, showed up in WMI Explorer, but the Speed property was still incorrect. The same network adapter was showing a value of 168000000 or 168 Mbps which is not right. Though I find this strange because there was already a MaxSpeed but it was blank.
Scratch WMI off the list.
Win32 P/Invoke
Yes, of course, the solution to everything is always calling unmanaged Win32 APIs using P/Invoke magic.
This is the route used to solve the problem.
Luckily, the IP_ADAPTER_ADDRESSES structure solves the problem. If you look at the MSDN page, it's a fairly large structure but what is important here is TransmitLinkSpeed which actually works.
Calling the GetAdaptersAddresses() function will return the actual structure.
Now, the actual C# P/Invoke code. Luckily, pinvoke.net already had interop for this function which I've added. This is all that was necessary.
The Code
Finally, here is your code patched up with the new P/Invoke black magic. I've made it work as a console application for demo purposes:
Using Statements:
using System;
using System.Threading;
Code:
class Program
{
private static void Main(string[] args)
{
Timer ticker = new Timer(Update, null, 0, 1000);
// Keep the main thread from dying
while (true)
{
Thread.Sleep(1000);
}
}
private static void Update(object state)
{
ulong speed = 0;
string adapter = "";
string[] nameSearches = { "Wireless", "WiFi", "802.11", "Wi-Fi" };
// The enum value of `AF_INET` will select only IPv4 adapters.
// You can change this to `AF_INET6` for IPv6 likewise
// And `AF_UNSPEC` for either one
foreach (IPIntertop.IP_ADAPTER_ADDRESSES net in IPIntertop.GetIPAdapters(IPIntertop.FAMILY.AF_INET))
{
bool containsName = false;
foreach (string name in nameSearches)
{
if (net.FriendlyName.Contains(name))
{
containsName = true;
}
}
if (!containsName) continue;
speed = net.TrasmitLinkSpeed;
adapter = net.FriendlyName;
break;
}
string temp;
if (speed == 0)
{
temp = "There is currently no Wi-Fi connection";
}
else
{
temp = string.Format("Current Wi-Fi Speed: {0} Mbps on {1}", (speed / 1000000.0), adapter);
}
Console.WriteLine(temp);
}
}
You are then going to be looking for the actual IPIntertop class that I updated. Since it's pretty big you can find it updated at pinvoke.net or on this PasteBin in case something goes down.
Bottom Line
Windows has a lot of APIs which are somewhat broken (WMI), can have a few "leaky abstractions" (.Net), or can be a pain to work with (Win32).
Sigh, that is a lot and I hope it helps.

I come accross the same issue, and need to get windows wifi link speed which is current negotiated.
and thanks to #Jaxrtech's WMI approach, that really works.
the correct class is CIM_NetworkAdapter(i'm using windows7), and query the speed column to get the current speed.
while wifi current negotiated speed is changing, this speed is changing too. i tested it, this matched ok.
select Description , DeviceID, Speed from CIM_NetworkAdapter
get:
D-Link DWA-140 RangeBooster N USB Adapter 17 285000000

Since no-one here mentioned it yet: why not use https://learn.microsoft.com/en-us/dotnet/api/system.net.networkinformation.networkinterface.speed?view=net-5.0#System_Net_NetworkInformation_NetworkInterface_Speed
This is, if the table on this site is correct included since .NET Framework 2.0 and seem to included in all other versions of .net including .net core.

Performance monitor on Vpn

I am using the windows performance monitor classes in my C# project to measure bytes sents etc via the network card and all seems fine. I am using the network index number to determine the network interface to use to record performance data. I can see the network index numbers via the command prompt (netsh int ipv4 show int)
However, I have connected to the vpn and changed the network index number to refer to the vpn and when I try to read the performance monitor "nextValue()" I get an exception.
So my question is, can I use the "System.Diagnostic.PerformanceCounters" to get packets sent etc from the VPN or is there another way to do this?

Try to use the powershell performance counters, they have a lot of power...
The way guide to the power shell commands (import-counter) can be found here..
http://ss64.com/ps/
I have added some example code below for you to see how they are called:
private static void LoadBLG(string CounterPath)
{
PowerShell ps = PowerShell.Create();
ps.AddCommand("import-counter");
ps.AddArgument(CounterPath);
Console.WriteLine(CounterPath);
Console.WriteLine("------------------------");
foreach (PSObject result in ps.Invoke())
{
if (result.ImmediateBaseObject is PerformanceCounterSampleSet)
{
PerformanceCounterSampleSet Counters = result.ImmediateBaseObject as PerformanceCounterSampleSet;
foreach (PerformanceCounterSample sample in Counters.CounterSamples)
Console.WriteLine("{0,-20}{1}",
sample.Path, sample.RawValue);
}
} // End foreach.
Good luck
Matthew

Thread Monitor class in c#

In my c# application multiple clients will access the same server, to process one client ata a time below code is written.In the code i used Moniter class and also the queue class.will this code affect the performance.if i use Monitor class, then shall i remove queue class from the code.
Sometimes my remote server machine where my application running as service is totally down.is the below code is the reasond behind, coz all the clients go in a queue, when i check the netstatus -an command using command prompt, for 8 clients it shows 50 connections are holding in Time-wait...
Below is my code where client acces the server ...
if (Id == "")
{
System.Threading.Monitor.Enter(this);
try
{
if (Request.AcceptTypes == null)
{
queue.Enqueue(Request.QueryString["sessionid"].Value);
string que = "";
que = queue.Dequeue();
TypeController.session_id = que;
langStr = SessionDatabase.Language;
filter = new AllThingzFilter(SessionDatabase, parameters, langStr);
TypeController.session_id = "";
filter.Execute();
Request.Clear();
return filter.XML;
}
else
{
TypeController.session_id = "";
filter = new AllThingzFilter(SessionDatabase, parameters, langStr);
filter.Execute();
}
}
finally
{
System.Threading.Monitor.Exit(this);
}
}

Locking this is pretty wrong, it won't work at all if every thread uses a different instance of whatever class this code lives in. It isn't clear from the snippet if that's the case but fix that first. Create a separate object just to store the lock and make it static or give it the same scope as the shared object you are trying to protect (also not clear).
You might still have trouble since this sounds like a deadlock rather than a race. Deadlocks are pretty easy to troubleshoot with the debugger since the code got stuck and is not executing at all. Debug + Break All, then Debug + Windows + Threads. Locate the worker threads in the thread list. Double click one to select it and use Debug + Call Stack to see where it got stuck. Repeat for other threads. Look back through the stack trace to see where one of them acquired a lock and compare to other threads to see what lock they are blocking on.
That could still be tricky if the deadlock is intricate and involves multiple interleaved locks. In which case logging might help. Really hard to diagnose mandelbugs might require a rewrite that cuts back on the amount of threading.

Starting application from service running as SYSTEM that can interact with the user

I currently have a single application that needs to be started from a windows service that i am coding in .net 3.5. This application is currently running as the user who ran the service, in my case the SYSTEM user. If running as the SYSTEM user it does not show the application to the users desktop. Thoughts? advice?
//constructor
private Process ETCHNotify = new Process();
//StartService()
ETCHNotify.StartInfo.FileName = baseDir + "\\EtchNotify.exe";
ETCHNotify.StartInfo.UseShellExecute = false;
//BackgroundWorkerThread_DoWork()
if (!systemData.GetUserName().Equals(""))
{
// start ETCHNotify
try {
ETCHNotify.Start();
}
catch (Exception ex)
{
systemData.Run("ERR: Notify can't start: " + ex.Message);
}
}
I only execute the try/catch if the function i have written GetUserName() (which determines the username of the user running explorer.exe) is not null
again to reiterate: desired functionality is that this starts ETCHNotify in a state that allows it to interact with the currently logged in user as determined by GetUserName()

Collage of some post found around (this and this)
Note that as of Windows Vista, services are strictly forbidden from interacting directly with a user:
Important: Services cannot directly interact with a user as of Windows
Vista. Therefore, the techniques mentioned in the section titled Using
an Interactive Service should not be used in new code.
This "feature" is broken, and conventional wisdom dictates that you shouldn't have been relying on it anyway. Services are not meant to provide a UI or allow any type of direct user interaction. Microsoft has been cautioning that this feature be avoided since the early days of Windows NT because of the possible security risks.
There are some possible workarounds, however, if you absolutely must have this functionality. But I strongly urge you to consider its necessity carefully and explore alternative designs for your service.
Use WTSEnumerateSessions to find the right desktop, then CreateProcessAsUser to start the application on that desktop (you pass it the handle of the desktop as part of the STARTUPINFO structure) is correct.
However, I would strongly recommend against doing this. In some environments, such as Terminal Server hosts with many active users, determining which desktop is the 'active' one isn't easy, and may not even be possible.
A more conventional approach would be to put a shortcut to a small client app for your service in the global startup group. This app will then launch along with every user session, and can be used start other apps (if so desired) without any juggling of user credentials, sessions and/or desktops.

Ultimately in order to solve this i took the advice of #marco and the posts he mentioned. I have created the service to be entirely independent of the tray application that interacts with the user. I did however install the Tray application via registry 'start up' methods with the service. The Service installer will now install the application which interacts with the user as well... This was the safest and most complete method.
thanks for your help everyone.

I wasn't going to answer this since you already answered it, (and it's oh, what? going on 2.5 years OLD now!?) But there are ALWAYS those people who are searching for this same topic, and reading the answers...
In order to get my service to Interact with the Desktop, no matter WHAT desktop, nor, how MANY desktops, nor if the service was even running on the SAME COMPUTER as the desktop app!! None of that matters with what I got here... I won't bore you with the details, I'll just give you the meat and potatoes, and you and let me know if you want to see more...
Ok. First thing I did was create an Advertisement Service. This is a thread that the service runs, opens up a UDP socket to listen for broadcasts on the network. Then, using the same piece of code, I shared it with the client app, but it calls up Advertise.CLIENT, rather than Advertise.SERVER... The CLIENT opens the port I expect the service to be on, and broadcasts a message, "Hello... Is there anybody out there??", asking if they're there ANY servers listening, and if so, reply back to THIS IP address with your computer name, IP Address and port # where I can find the .NET remoting Services..." Then it waits a small amount of time-out time, gathers up the responses it gets, and if it's more than one, it presents the user with a dialog box and a list of services that responded... The Client then selects one, or, if only ONE responded, it will call Connect((TServerResponse) res); on that, to get connected up. At this point, the server is using Remoting Services with the WellKnownClientType, and WellKnownServerType to put itself out there...
I don't think you are too interested in my "Auto-Service locater", because a lot of people frown on UDP, even more so when your app start broadcasting on large networks. So, I'm assuming you'd be more interested in my RemotingHelper, that gets the client connected up to the server. It looks like this:
public static Object GetObject(Type type)
{
try {
if(_wellKnownTypes == null) {
InitTypeCache();
}
WellKnownClientTypeEntry entr = (WellKnownClientTypeEntry)_wellKnownTypes[type];
if(entr == null) {
throw new RemotingException("Type not found!");
}
return System.Activator.GetObject(entr.ObjectType, entr.ObjectUrl);
} catch(System.Net.Sockets.SocketException sex) {
DebugHelper.Debug.OutputDebugString("SocketException occured in RemotingHelper::GetObject(). Error: {0}.", sex.Message);
Disconnect();
if(Connect()) {
return GetObject(type);
}
}
return null;
}
private static void InitTypeCache()
{
if(m_AdvertiseServer == null) {
throw new RemotingException("AdvertisementServer cannot be null when connecting to a server.");
}
_wellKnownTypes = new Dictionary<Type, WellKnownClientTypeEntry>();
Dictionary<string, object> channelProperties = new Dictionary<string, object>();
channelProperties["port"] = 0;
channelProperties["name"] = m_AdvertiseServer.ChannelName;
Dictionary<string, object> binFormatterProperties = new Dictionary<string, object>();
binFormatterProperties["typeFilterLevel"] = "Full";
if(Environment.UserInteractive) {
BinaryServerFormatterSinkProvider binFormatterProvider = new BinaryServerFormatterSinkProvider(binFormatterProperties, null);
_serverChannel = new TcpServerChannel(channelProperties, binFormatterProvider);
// LEF: Only if we are coming form OUTSIDE the SERVICE do we want to register the channel, since the SERVICE already has this
// channel registered in this AppDomain.
ChannelServices.RegisterChannel(_serverChannel, false);
}
System.Diagnostics.Debug.Write(string.Format("Registering: {0}...\n", typeof(IPawnStatServiceStatus)));
RegisterType(typeof(IPawnStatServiceStatus),m_AdvertiseServer.RunningStatusURL.ToString());
System.Diagnostics.Debug.Write(string.Format("Registering: {0}...\n", typeof(IPawnStatService)));
RegisterType(typeof(IPawnStatService), m_AdvertiseServer.RunningServerURL.ToString());
System.Diagnostics.Debug.Write(string.Format("Registering: {0}...\n", typeof(IServiceConfiguration)));
RegisterType(typeof(IServiceConfiguration), m_AdvertiseServer.RunningConfigURL.ToString());
}
[SecurityPermission(SecurityAction.Demand, Flags=SecurityPermissionFlag.RemotingConfiguration, RemotingConfiguration=true)]
public static void RegisterType(Type type, string serviceUrl)
{
WellKnownClientTypeEntry clientType = new WellKnownClientTypeEntry(type, serviceUrl);
if(clientType != RemotingConfiguration.IsWellKnownClientType(type)) {
RemotingConfiguration.RegisterWellKnownClientType(clientType);
}
_wellKnownTypes[type] = clientType;
}
public static bool Connect()
{
// Init the Advertisement Service, and Locate any listening services out there...
m_AdvertiseServer.InitClient();
if(m_AdvertiseServer.LocateServices(iTimeout)) {
if(!Connected) {
bConnected = true;
}
} else {
bConnected = false;
}
return Connected;
}
public static void Disconnect()
{
if(_wellKnownTypes != null) {
_wellKnownTypes.Clear();
}
_wellKnownTypes = null;
if(_serverChannel != null) {
if(Environment.UserInteractive) {
// LEF: Don't unregister the channel, because we are running from the service, and we don't want to unregister the channel...
ChannelServices.UnregisterChannel(_serverChannel);
// LEF: If we are coming from the SERVICE, we do *NOT* want to unregister the channel, since it is already registered!
_serverChannel = null;
}
}
bConnected = false;
}
}
So, THAT is meat of my remoting code, and allowed me to write a client that didn't have to be aware of where the services was installed, or how many services were running on the network. This allowed me to communicate with it over the network, or on the local machine. And it wasn't a problem to have two or more people running the app, however, yours might. Now, I have some complicated callback code in mine, where I register events to go across the remoting channel, so I have to have code that checks to see if the client is even still connected before I send the notification to the client that something happened. Plus, if you are running for more than one user, you might not want to use Singleton objects. It was fine for me, because the server OWNS the objects, and they are whatever the server SAYS they are. So, my STATS object, for example, is a Singleton. No reason to create an instance of it for EVERY connection, when everyone is going to see the same data, right?
I can provide more chunks of code if necessary. This is, of course, one TINY bit of the overall picture of what makes this work... Not to mention the subscription providers, and all that.
For the sake of completeness, I'm including the code chunk to keep your service connected for the life of the process.
public override object InitializeLifetimeService()
{
ILease lease = (ILease)base.InitializeLifetimeService();
if(lease.CurrentState == LeaseState.Initial) {
lease.InitialLeaseTime = TimeSpan.FromHours(24);
lease.SponsorshipTimeout = TimeSpan.FromSeconds(30);
lease.RenewOnCallTime = TimeSpan.FromHours(1);
}
return lease;
}
#region ISponsor Members
[SecurityPermissionAttribute(SecurityAction.LinkDemand, Flags=SecurityPermissionFlag.Infrastructure)]
public TimeSpan Renewal(ILease lease)
{
return TimeSpan.FromHours(12);
}
#endregion
If you include the ISponsor interface as part of your server object, you can implement the above code.
Hope SOME of this is useful.

When you register your service, you can tell it to allow interactions with the desktop. You can read this oldie link http://www.codeproject.com/KB/install/cswindowsservicedesktop.aspx
Also, don't forget that you can have multiple users logged in at the same time.
Apparently on Windows Vista and newer interacting with the desktop has been made more difficult. Read this for a potential solution: http://www.codeproject.com/KB/cs/ServiceDesktopInteraction.aspx

How to simulate network failure for test purposes (in C#)?

I'm building what could be called the DAL for a new app. Unfortunately, network connectivity to the database is a real problem.
I'd like to be able to temporarily block network access within the scope of my test so that I can ensure my DAL behaves as expected under those circumstances.
UPDATE: There are many manual ways to disable the network, but it sure would be nice if I could enable/disable within the test itself.

For the time being, I'm just "disabling" the network by setting a bogus static IP as follows:
using System.Management;
class NetworkController
{
public static void Disable()
{
SetIP("192.168.0.4", "255.255.255.0");
}
public static void Enable()
{
SetDHCP();
}
private static void SetIP(string ip_address, string subnet_mask)
{
ManagementClass objMC = new ManagementClass("Win32_NetworkAdapterConfiguration");
ManagementObjectCollection objMOC = objMC.GetInstances();
foreach (ManagementObject objMO in objMOC) {
if ((bool)objMO("IPEnabled")) {
try {
ManagementBaseObject setIP = default(ManagementBaseObject);
ManagementBaseObject newIP = objMO.GetMethodParameters("EnableStatic");
newIP("IPAddress") = new string[] { ip_address };
newIP("SubnetMask") = new string[] { subnet_mask };
setIP = objMO.InvokeMethod("EnableStatic", newIP, null);
}
catch (Exception generatedExceptionName) {
throw;
}
}
}
}
private static void SetDHCP()
{
ManagementClass mc = new ManagementClass("Win32_NetworkAdapterConfiguration");
ManagementObjectCollection moc = mc.GetInstances();
foreach (ManagementObject mo in moc) {
// Make sure this is a IP enabled device. Not something like memory card or VM Ware
if ((bool)mo("IPEnabled")) {
ManagementBaseObject newDNS = mo.GetMethodParameters("SetDNSServerSearchOrder");
newDNS("DNSServerSearchOrder") = null;
ManagementBaseObject enableDHCP = mo.InvokeMethod("EnableDHCP", null, null);
ManagementBaseObject setDNS = mo.InvokeMethod("SetDNSServerSearchOrder", newDNS, null);
}
}
}
}

Write a wrapper to the network class connectivity class you're using (e.g. WebClient) with an on-off switch :)
Either that, or block your application in the firewall.

Try blocking the connection with a firewall midway through the session maybe?
I like the wrapper idea as well, but thats kind of abstracting the problem and you prolly might not get exact real world behavior. Also, inserting the wrapper layer and then removing it may be more trouble than its worth.
Edit: Run a script that turns the Network adapter on/off randomly or at set intervals?

If you are trying a complete network outage for your application unplugging the network cable will work. Sometimes you might have a data access layer with multiple data sources (on different machines) in which case you can simulate an exception in your tests with a Mock Framework like Rhino Mocks. Here is some pseudo-code that you may have in your test
void TestUserDBFailure()
{
// ***** THIS IS PSEUDO-CODE *******
//setting up the stage - retrieval of the user info create an exception
Expect.Call(_userRepository.GetUser(null))
.IgnoreArguments()
.Return(new Exception());
// Call that uses the getuser function, see how it reacts
User selectedUser = _dataLoader.GetUserData("testuser", "password");
}

Probably not helpful for simulating "real" network issues, but you could just point your DB connection string to a non-existent machine while within the scope of your test.

Depends on what particular network problem you wish to simulate. For most folks, it's as simple as "server unreachable", in which case you'd just try to connect to a non existent server. Be careful, though, because you want something that is routable but does not answer. Trying to connect to dkjdsjk.com will fail immediately (DNS lookup), but trying to connect to www.google.com:1433 will (probably) time out due to a firewall - which is how your app will behave when your DB server is down.

Try Toxiproxi, it can simulate network outage.
They have REST API and even .NET Client API to change the network simulation programatically (from your test code)
https://github.com/shopify/toxiproxy

Look for a WAN simulator that will allow you to restrict bandwidth (and cut it off completely) I always find it interesting to see how the user experience changes when my apps are run in a bandwidth restricted environment. Look here for some information.

There is a tool you can use for simulating High Latency and Low Bandwidth in Testing of Database Applications as explained in this blog entry.

Just found an alternative that allows to directly close TCP connections:
http://lamahashim.blogspot.ch/2010/03/disabling-network-using-c.html
It is based on Windows IP Helper API (uses DllImport):
http://msdn.microsoft.com/en-us/library/windows/desktop/aa366073(v=vs.85).aspx

Use mock objects to create configurable, destructible versions of the real thing--in this case, the database.