.net客户端将soap错误解析为协议异常

谁能解释一下为什么下面的soap响应是而不是在我的c#客户端反序列化成FaultException ?我得到一个System.ServiceModel.ProtocolException消息"远程服务器返回了一个意外的响应:(400)错误的请求"，与System.Net.WebException作为一个内部异常消息"远程服务器返回了一个错误:(400)错误的请求。"

我的客户端代码使用几个合同定义svcutil.exe(添加服务引用)我对基本或摘要身份验证和soap1.2使用自定义绑定。在此请求中，我使用基本身份验证。
绑定代码在响应soap下面。

HTTP/1.1 400 Bad Request
Server: gSOAP/2.7
Content-Type: application/soap+xml; charset=utf-8
Content-Length: 2087
Connection: close
<?xml version="1.0" encoding="UTF-8"?>
<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://www.w3.org/2003/05/soap-envelope" 
xmlns:SOAP-ENC="http://www.w3.org/2003/05/soap-encoding"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xmlns:xsd="http://www.w3.org/2001/XMLSchema" 
xmlns:tns1="http://www.onvif.org/ver10/topics" 
xmlns:tnsacti="http://www.acti.com/2009/event/topics"
xmlns:http="http://tempuri.org/http.xsd" 
xmlns:wsadis="http://schemas.xmlsoap.org/ws/2004/08/addressing" 
xmlns:wsbf="http://docs.oasis-open.org/wsrf/bf-2" 
xmlns:wstop="http://docs.oasis-open.org/wsn/t-1" 
xmlns:wsr="http://docs.oasis-open.org/wsrf/r-2" 
xmlns:tt="http://www.onvif.org/ver10/schema" 
xmlns:wsaw="http://www.w3.org/2006/05/addressing/wsdl" 
xmlns:wsu="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd" 
xmlns:ns3="http://www.onvif.org/ver10/events/wsdl/PullPointSubscriptionBinding" 
xmlns:ns4="http://www.onvif.org/ver10/events/wsdl/EventBinding" 
xmlns:tev="http://www.onvif.org/ver10/events/wsdl" 
xmlns:ns5="http://www.onvif.org/ver10/events/wsdl/SubscriptionManagerBinding"
xmlns:ns6="http://www.onvif.org/ver10/events/wsdl/NotificationProducerBinding"
xmlns:ns7="http://www.onvif.org/ver10/events/wsdl/NotificationConsumerBinding"
xmlns:wsnt="http://docs.oasis-open.org/wsn/b-2" 
xmlns:tds="http://www.onvif.org/ver10/device/wsdl" 
xmlns:tptz="http://www.onvif.org/ver20/ptz/wsdl"
xmlns:trt="http://www.onvif.org/ver10/media/wsdl"
xmlns:wsa="http://www.w3.org/2005/08/addressing"
xmlns:d="http://schemas.xmlsoap.org/ws/2005/04/discovery" 
xmlns:wsse="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd" 
xmlns:ter="http://www.onvif.org/ver10/error">
    <SOAP-ENV:Body>
        <SOAP-ENV:Fault SOAP-ENV:encodingStyle="http://www.w3.org/2003/05/soap-encoding">
            <SOAP-ENV:Code>
                <SOAP-ENV:Value>SOAP-ENV:Sender</SOAP-ENV:Value>
            </SOAP-ENV:Code>
            <SOAP-ENV:Reason>
                <SOAP-ENV:Text xml:lang="en">Method 'GetImagingSettings' not implemented: method name or namespace not recognized
</SOAP-ENV:Text>
            </SOAP-ENV:Reason>
        </SOAP-ENV:Fault>
    </SOAP-ENV:Body>
</SOAP-ENV:Envelope>

c#代码

private T GetClient(ISecurityTokenSelector securityToken, ref ChannelFactory<T> channelFactory) {
    if (ServiceAddress == null)
        throw new ArgumentNullException(string.Format("The service address to the {0} is null", typeof(T).Name));
    var endpointAddress = new EndpointAddress(ServiceAddress.ToString());
    //Gets custom binding
    var binding = BindingFactory.GetBinding(securityToken, false, false);
    channelFactory = new ChannelFactory<T>(binding, endpointAddress);
    if (securityToken is BasicUserNameSecurityTokenSelector) {
        channelFactory.Endpoint.Behaviors.Remove(typeof(ClientCredentials));
        channelFactory.Credentials.UserName.UserName = UserName;
        channelFactory.Credentials.UserName.Password = Password;
    }
    if (securityToken is DigestSecurityTokenSelector) {
        // configure the username credentials on the channel factory 
        var credentials = new UsernameClientCredentials(new UsernameInfo(UserName, Password));
        // replace ClientCredentials with UsernameClientCredentials
        channelFactory.Endpoint.Behaviors.Remove(typeof(ClientCredentials));
        channelFactory.Endpoint.Behaviors.Add(credentials);
    }
    return channelFactory.CreateChannel();
}
private Binding GetCustomBinding(ISecurityTokenSelector token, bool mtomEncoding, bool wsAddressing) {
    var binding = new CustomBinding(CreateBindingElements(mtomEncoding, wsAddressing, token));
    binding.CloseTimeout = TimeSpan.FromSeconds(30.0);
    binding.OpenTimeout = TimeSpan.FromSeconds(30.0);
    binding.SendTimeout = TimeSpan.FromMinutes(10.0);
    binding.ReceiveTimeout = TimeSpan.FromMinutes(3.0);
    return binding;
}
private static IEnumerable<BindingElement> CreateBindingElements(bool mtomEncoding, bool wsAddressing, ISecurityTokenSelector token) {
    if (token is DigestSecurityTokenSelector) {
        TransportSecurityBindingElement transportSecurity = new TransportSecurityBindingElement();
        transportSecurity.EndpointSupportingTokenParameters.SignedEncrypted.Add(new UsernameTokenParameters());
        // here you can require secure transport, in which case you'd probably replace HTTP with HTTPS as well
        transportSecurity.AllowInsecureTransport = true;
        transportSecurity.IncludeTimestamp = false;
        yield return transportSecurity;
    }
    var msgVer = wsAddressing ? MessageVersion.Soap12WSAddressing10 : MessageVersion.Soap12;
    if (mtomEncoding) {
        var encoding = new MtomMessageEncodingBindingElement(msgVer, Encoding.UTF8);
        encoding.ReaderQuotas.MaxStringContentLength = Int32.MaxValue;
        encoding.MaxBufferSize = Int32.MaxValue;
        yield return encoding;
    } else {
        var encoding = new TextMessageEncodingBindingElement(msgVer, Encoding.UTF8);
        encoding.ReaderQuotas.MaxStringContentLength = Int32.MaxValue; //100 * 1024 * 1024
        yield return encoding;
    }
    HttpTransportBindingElement transport = CreateTransportBindingElement(token);
    transport.MaxReceivedMessageSize = Int32.MaxValue; //100L * 1024L * 1024L
    transport.KeepAliveEnabled = false;
    transport.MaxBufferSize = Int32.MaxValue;
    //transport.ProxyAddress = null;
    //transport.BypassProxyOnLocal = true;
    //transport.UseDefaultWebProxy = false;
    transport.TransferMode = TransferMode.Buffered;
    if (token is BasicUserNameSecurityTokenSelector)
        transport.AuthenticationScheme = AuthenticationSchemes.Basic;
    yield return transport;
}
private static HttpTransportBindingElement CreateTransportBindingElement(ISecurityTokenSelector token) {
    if (token != null && token.UseTls) {
        var transport = new HttpsTransportBindingElement();
        transport.RequireClientCertificate = false;
        return transport;
    } else {
        return new HttpTransportBindingElement();
    }
}

System.ServiceModel.ProtocolException: The remote server returned an unexpected response: (400) Bad Request. ---> System.Net.WebException: The remote server returned an error: (400) Bad Request. 
   at System.Net.HttpWebRequest.GetResponse() 
   at System.ServiceModel.Channels.HttpChannelFactory`1.HttpRequestChannel.HttpChannelRequest.WaitForReply(TimeSpan timeout) 
   --- End of inner exception stack trace ---