var call = $.ajax({
    url: 'http://url:port/DynamicsNAV70_Instance/odata/MyService',
    type: "GET",
    crossDomain: true,
    username: "username",
    password: "password",
    dataType: "jsonp",
    headers: {
        Accept: "application/json;odata=verbose"
    }
});

call.done(function (data, textStatus, jqXHR) {
    console.log(data.d);
});

call.fail(function (jqXHR, textStatus, errorThrown) {
    console.log("Call failed. Error: " + jqXHR.statusText);
});

jQuery.support.cors = true;
var call = $.ajax({
    url: 'http://url:port/DynamicsNAV70_Instance/odata/MyService?$format=json',
    type: "GET",
    username: "username",
    password: "password",
    dataType: "json",
    headers: {
        Accept: "application/json;odata=verbose"
    }
});

$.ajax({
    url: 'http://Server:Port/DynamicsNAV80/OData/Service?$format=json&$callback=?',
    contentType: 'application/json; charset=utf-8',
    dataType: "jsonp",
    type: "GET",
    xhrFields: {
        withCredentials: true
    },
    dataType: "jsonp",
    success: function (data) {
        alert(JSON.stringify(data));
    },
    error: function (xhr, textStatus, errorMessage) {
        alert('Error: ' + errorMessage);
    }
});