public JsonResult GetFaxPoolOverView()
{
    var au = GetDetails;
    if (au == null)
    {
        return Json(new JsonResultModel() { LogedOut = true }, JsonRequestBehavior.AllowGet);
    }

    List<PoolOverviewModel> inv = FaxApi.GetDasboardFaxInventory(au);
    return Json(new JsonResultModel(inv) { LogedOut = (inv == null) }, JsonRequestBehavior.AllowGet);
}

private AuthenticationModel GetDetails
{
    get { return Helpers.LoginHelpers.GetAuthenticationDetails(this, ClassName); }
}

public static List<PoolOverviewModel> GetDasboardFaxInventory(AuthenticationModel au)
{
    List<PoolOverviewModel> poolList = new List<PoolOverviewModel>();
    try
    {
        var client = GetWebService();
        {
            //au.CustomerId = 78462
            ListInventoryMarketsResponse response = client.ListInventoryMarkets(new ListInventoryMarketsRequest { Authentication = au.Authentication, CustomerId = au.CustomerId, Filters = null });
            if (response.Success && response.InventoryMarketList != null) {
              //.....
            }
        }
    }
}