public class ContosoChatHub : Hub
{
    public void NewContosoChatMessage(string name, string message)
    {
        Clients.All.addContosoChatMessageToPage(name, message);
    }
}

var contosoChatHubProxy = $.connection.contosoChatHub;
contosoChatHubProxy.client.addContosoChatMessageToPage = function (name, message) {
    console.log(name + ' ' + message);
};
$.connection.hub.start().done(function () {
    // Wire up Send button to call NewContosoChatMessage on the server.
    $('#newContosoChatMessage').click(function () {
         contosoChatHubProxy.server.newContosoChatMessage($('#displayname').val(), $('#message').val());
         $('#message').val('').focus();
     });
});

var connection = $.hubConnection();
var contosoChatHubProxy = connection.createHubProxy('contosoChatHub');
contosoChatHubProxy.on('addContosoChatMessageToPage', function(name, message) {
    console.log(name + ' ' + message);
});
connection.start().done(function() {
    // Wire up Send button to call NewContosoChatMessage on the server.
    $('#newContosoChatMessage').click(function () {
        contosoChatHubProxy.invoke('newContosoChatMessage', $('#displayname').val(), $('#message').val());
        $('#message').val('').focus();
                });
    })

<script src="Scripts/jquery-1.10.2.min.js"></script>
<script src="Scripts/jquery.signalR-2.1.0.min.js"></script>
<script src="signalr/hubs"></script>

<script src="~/signalr/hubs"></script>

<script src="@Url.Content("~/signalr/hubs")"></script>

<script src='<%: ResolveClientUrl("~/signalr/hubs") %>'></script>

var contosoChatHubProxy = $.connection.contosoChatHub;
contosoChatHubProxy.client.addContosoChatMessageToPage = function (name, message) {
    console.log(userName + ' ' + message);
};
$.connection.hub.start()
    .done(function(){ console.log('Now connected, connection ID=' + $.connection.hub.id); })
    .fail(function(){ console.log('Could not Connect!'); });

var connection = $.hubConnection();
var contosoChatHubProxy = connection.createHubProxy('contosoChatHub');
contosoChatHubProxy.on('addContosoChatMessageToPage', function(userName, message) {
    console.log(userName + ' ' + message);
});
connection.start()
    .done(function(){ console.log('Now connected, connection ID=' + connection.id); })
    .fail(function(){ console.log('Could not connect'); });

using Microsoft.AspNet.SignalR;
using Microsoft.Owin.Cors;
using Owin;
namespace MyWebApplication
{
    public class Startup
    {
        public void Configuration(IAppBuilder app)
        {
            // Branch the pipeline here for requests that start with "/signalr"
            app.Map("/signalr", map =>
            {
                // Setup the CORS middleware to run before SignalR.
                // By default this will allow all origins. You can 
                // configure the set of origins and/or http verbs by
                // providing a cors options with a different policy.
                map.UseCors(CorsOptions.AllowAll);
                var hubConfiguration = new HubConfiguration 
                {
                    // You can enable JSONP by uncommenting line below.
                    // JSONP requests are insecure but some older browsers (and some
                    // versions of IE) require JSONP to work cross domain
                    // EnableJSONP = true
                };
                // Run the SignalR pipeline. We're not using MapSignalR
                // since this branch already runs under the "/signalr"
                // path.
                map.RunSignalR(hubConfiguration);
            });
        }
    }
}

$.connection.hub.connectionSlow(function () {
    console.log('We are currently experiencing difficulties with the connection.')
});

var connection = $.hubConnection();
connection.connectionSlow(function () {
    console.log('We are currently experiencing difficulties with the connection.')
});

var hubConfiguration = new HubConfiguration();
hubConfiguration.EnableDetailedErrors = true;
app.MapSignalR(hubConfiguration);

$.connection.hub.error(function (error) {
    console.log('SignalR error: ' + error)
});

var connection = $.hubConnection();
connection.error(function (error) {
    console.log('SignalR error: ' + error)
});

contosoChatHubProxy.newContosoChatMessage(userName, message)
    .fail(function(error) { 
        console.log( 'newContosoChatMessage error: ' + error) 
    });

contosoChatHubProxy.invoke('newContosoChatMessage', userName, message)
    .fail(function(error) { 
        console.log( 'newContosoChatMessage error: ' + error) 
    });

$.connection.hub.logging = true;
$.connection.hub.start();

var connection = $.hubConnection();
connection.logging = true;
connection.start();