UPnP failing for router which support only permanent leases. about nbitcoin HOT 4 CLOSED

            catch(MappingException me)
            {
                switch (me.ErrorCode)
                {
                    case UpnpConstants.OnlyPermanentLeasesSupported:
                        NatUtility.TraceSource.LogWarn("Only Permanent Leases Supported - There is no warranty it will be closed");
                        mapping.Lifetime = 0;
                        break;
                    case UpnpConstants.SamePortValuesRequired:
                        NatUtility.TraceSource.LogWarn("Same Port Values Required - Using internal port {0}", mapping.PrivatePort);
                        mapping.PublicPort = mapping.PrivatePort;
                        break;
                    case UpnpConstants.RemoteHostOnlySupportsWildcard:
                        NatUtility.TraceSource.LogWarn("Remote Host Only Supports Wildcard");
                        mapping.PublicIP = IPAddress.None;
                        break;
                    case UpnpConstants.ExternalPortOnlySupportsWildcard:
                        NatUtility.TraceSource.LogWarn("External Port Only Supports Wildcard");
                        break;
                }
                message = new CreatePortMappingRequestMessage(mapping);
                _soapClient
                    .InvokeAsync("AddPortMapping", message.ToXml())
                    .TimeoutAfter(TimeSpan.FromSeconds(3));
                RegisterMapping(mapping);
            }