STS (Security Token Service) using TCP transport

Hi,

We are considering using STS for authentication and authorization. As far as
I understand STS requires wsFederationHttpBinding which uses transport of
HTTP, but I would like to use it with TCP transport. I've tried creating a
customBinding with TCP transport but I get an exception about the order of
the elements in the channel stack.

The following section is the custom binding from the server's config
file(based on the Federation sample). If I change the transport to Http
(currently in remark) it works:

<bindings>
<customBinding>
<binding name="CustomBinding">
<security authenticationMode="IssuedToken">
<issuedTokenParameters
tokenType="http://docs.oasis-open.org/wss/oasis-wss-saml-token-profile-1.1#SAMLV1.1">
<issuer address="http://localhost/FederationSample/BookStoreSTS/STS.svc"
binding="wsHttpBinding" />

<issuerMetadata
address="http://localhost/FederationSample/BookStoreSTS/STS.svc/mex" />

</issuedTokenParameters>

<secureConversationBootstrap />

</security>
<!--<httpTransport />-->
<tcpTransport />
</binding>
</customBinding>
</bindings>


Thanks.