C# – WCF Timeout Problem

I have the following code

public bool StartWCF()
    {
        try
        {
            // Select the first entry. I hope it's this maschines IP
            // IPAddress _ipAddress = ips.AddressList[0];
            var ipAddress = new IPAddress(new byte[] { 127, 0, 0, 1 });

            // Create the url that is needed to specify where the service should be started
            this.m_UrlMetaServiceComm = "net.tcp://" + ipAddress + ":8000/VSMDBCommunication";
            this.m_UrlMetaServicePart = "net.tcp://" + ipAddress + ":8000/VSMDBPartType";

            string endPointAddrComm = this.m_UrlMetaServiceComm;
            var tcpBindingComm = new NetTcpBinding
                {
                    TransactionFlow = false,
                    MaxReceivedMessageSize = 20000000,
                    MaxBufferSize = 20000000,
                    MaxBufferPoolSize = 20000000,
                    ReaderQuotas = { MaxNameTableCharCount = 20000000 },
                    OpenTimeout = new TimeSpan(0, 5, 0),
                    SendTimeout = new TimeSpan(0, 5, 0),
                    CloseTimeout = new TimeSpan(0, 5, 0)
                };
            tcpBindingComm.Security.Transport.ProtectionLevel = ProtectionLevel.EncryptAndSign;
            tcpBindingComm.Security.Transport.ClientCredentialType = TcpClientCredentialType.Windows;
            tcpBindingComm.Security.Mode = SecurityMode.None;

            var endpointAddressComm = new EndpointAddress(endPointAddrComm);
            this.m_ChannelCommunication = ChannelFactory<IVSMDBCommunication>.CreateChannel(
                tcpBindingComm, endpointAddressComm);
            ((IContextChannel)m_ChannelCommunication).OperationTimeout = new TimeSpan(0, 5, 0);
            string endPointAddrPart = this.m_UrlMetaServicePart;
            var tcpBindingPart = new NetTcpBinding
                {
                    TransactionFlow = false,
                    MaxReceivedMessageSize = 20000000,
                    MaxBufferSize = 20000000,
                    MaxBufferPoolSize = 20000000,
                    ReaderQuotas = { MaxNameTableCharCount = 20000000 },
                    OpenTimeout = new TimeSpan(0, 5, 0),
                    SendTimeout = new TimeSpan(0, 5, 0),
                    CloseTimeout = new TimeSpan(0, 5, 0)
                };
            tcpBindingPart.Security.Transport.ProtectionLevel = ProtectionLevel.EncryptAndSign;
            tcpBindingPart.Security.Transport.ClientCredentialType = TcpClientCredentialType.Windows;
            tcpBindingPart.Security.Mode = SecurityMode.None;

            var endpointAddressPart = new EndpointAddress(endPointAddrPart);
            this.m_ChannelPartTypes = ChannelFactory<IVSMDBPartType>.CreateChannel(
                tcpBindingPart, endpointAddressPart);
            ((IContextChannel)m_ChannelPartTypes).OperationTimeout = new TimeSpan(0, 5, 0);
            return true;
        }
        catch (CommunicationObjectFaultedException faultEx)
        {
            // System.Diagnostics.Trace.TraceError(faultEx.ToString());
            Console.WriteLine("An unknown exception was received. " + faultEx.Message + faultEx.StackTrace);
            Console.Read();
            return false;
        }
        catch (EndpointNotFoundException endEx)
        {
            // System.Diagnostics.Trace.TraceError(endEx.ToString());
            Console.WriteLine("An unknown exception was received. " + endEx.Message + endEx.StackTrace);
            Console.Read();
            return false;
        }
    }

and I occasionally get the following error when the underlying process takes more than a minute.

Message:

This request operation sent to
net.tcp://127.0.0.1:8000/VSMDBCommunication
did not receive a reply within the
configured timeout (00:01:00). The
time allotted to this operation may
have been a portion of a longer
timeout. This may be because the
service is still processing the
operation or because the service was
unable to send a reply message.
Please consider increasing the
operation timeout (by casting the
channel/proxy to IContextChannel and
setting the OperationTimeout property)
and ensure that the service is able to
connect to the client.

How can I cast the channel in a different way than I am doing to avoid this error, which makes sense because the underlying request can take slightly over a minute to compute.