public override async Task <IEnumerable <Mapping> > GetAllMappingsAsync()
        {
            var index    = 0;
            var mappings = new List <Mapping>();

            NatDiscoverer.TraceSource.LogInfo("GetAllMappingsAsync - Getting all mappings");
            while (true)
            {
                try
                {
                    var message = new GetGenericPortMappingEntry(index++);

                    var responseData = await _soapClient
                                       .InvokeAsync("GetGenericPortMappingEntry", message.ToXml())
                                       .TimeoutAfter(TimeSpan.FromSeconds(4));

                    var responseMessage = new GetPortMappingEntryResponseMessage(responseData, DeviceInfo.ServiceType, true);

                    IPAddress internalClientIp;
                    if (!IPAddress.TryParse(responseMessage.InternalClient, out internalClientIp))
                    {
                        NatDiscoverer.TraceSource.LogWarn("InternalClient is not an IP address. Mapping ignored!");
                        continue;
                    }

                    var mapping = new Mapping(responseMessage.NetworkProtocolType
                                              , internalClientIp
                                              , responseMessage.InternalPort
                                              , responseMessage.ExternalPort
                                              , responseMessage.LeaseDuration
                                              , responseMessage.PortMappingDescription);
                    mappings.Add(mapping);
                }
                catch (MappingException e)
                {
                    // there are no more mappings
                    if (e.ErrorCode == UpnpConstants.SpecifiedArrayIndexInvalid ||
                        e.ErrorCode == UpnpConstants.NoSuchEntryInArray
                        // DD-WRT Linux base router (and others probably) fails with 402-InvalidArgument when index is out of range
                        || e.ErrorCode == UpnpConstants.InvalidArguments
                        // LINKSYS WRT1900AC AC1900 it returns errocode 501-PAL_UPNP_SOAP_E_ACTION_FAILED
                        || e.ErrorCode == UpnpConstants.ActionFailed)
                    {
                        NatDiscoverer.TraceSource.LogWarn("Router failed with {0}-{1}. No more mappings is assumed.", e.ErrorCode, e.ErrorText);
                        break;
                    }
                    throw;
                }
            }

            return(mappings.ToArray());
        }
        public void GetGenericMappingAsync(int index, List <Mapping> mappings,
                                           TaskCompletionSource <IEnumerable <Mapping> > taskCompletionSource)
        {
            var message = new GetGenericPortMappingEntry(index);

            _soapClient
            .InvokeAsync("GetGenericPortMappingEntry", message.ToXml())
            .TimeoutAfter(TimeSpan.FromSeconds(4))
            .ContinueWith(task =>
            {
                if (!task.IsFaulted)
                {
                    var responseData    = task.Result;
                    var responseMessage = new GetPortMappingEntryResponseMessage(responseData,
                                                                                 DeviceInfo.ServiceType, true);

                    IPAddress internalClientIp;
                    if (!IPAddress.TryParse(responseMessage.InternalClient, out internalClientIp))
                    {
                        NatDiscoverer.TraceSource.LogWarn("InternalClient is not an IP address. Mapping ignored!");
                    }
                    else
                    {
                        var mapping = new Mapping(responseMessage.Protocol
                                                  , internalClientIp
                                                  , responseMessage.InternalPort
                                                  , responseMessage.ExternalPort
                                                  , responseMessage.LeaseDuration
                                                  , responseMessage.PortMappingDescription);
                        mappings.Add(mapping);
                    }

                    GetGenericMappingAsync(index + 1, mappings, taskCompletionSource);
                }
                else
                {
                    MappingException e = task.Exception.InnerException as MappingException;

                    if (e == null)
                    {
                        throw task.Exception.InnerException;
                    }

                    if (e.ErrorCode == UpnpConstants.SpecifiedArrayIndexInvalid ||
                        e.ErrorCode == UpnpConstants.NoSuchEntryInArray)
                    {
                        // there are no more mappings
                        taskCompletionSource.SetResult(mappings);
                        return;
                    }

                    // DD-WRT Linux base router (and others probably) fails with 402-InvalidArgument when index is out of range
                    if (e.ErrorCode == UpnpConstants.InvalidArguments)
                    {
                        NatDiscoverer.TraceSource.LogWarn("Router failed with 402-InvalidArgument. No more mappings is assumed.");
                        taskCompletionSource.SetResult(mappings);
                        return;
                    }

                    throw task.Exception.InnerException;
                }
            });
        }