Remoting callback error: "This remoting proxy has no channel sink

[Feng]

Hi,

I need my remoting server to callback to my client and I am trying to do
that using delegate. While the client invoking the server OK, I am getting
the following error when the server trying to callback to the client: "This
remoting proxy has no channel sink which means either the server has no
registered server channels that are listening, or this application has no
suitable client channel to talk to the server."

I have try all kinds of ways in tweaking my client side and server side
..config files but nothing seemed to work. Here is the remoting section of my
config files:

Client side:
<system.runtime.remoting>
<application>
<channels>
<channel ref="http" port="0">
<clientProviders>
<formatter ref="soap" />
</clientProviders>
<serverProviders>
<formatter ref="soap" typeFilterLevel="Full"/>
</serverProviders>
</channel>
</channels>
</application>
</system.runtime.remoting>

Server side:
<system.runtime.remoting>
<application>
<service>
<wellknown mode="SingleCall" objectUri="QLManagerFactory.rem"
type="MyHost.QLManagerFactory, MyHost" />
</service>
<channels>
<channel ref="http">
<clientProviders>
<formatter ref="soap" />
</clientProviders>
<serverProviders>
<formatter ref="soap" typeFilterLevel="Full"/>
</serverProviders>
</channel>
</channels>
<lifetime leaseTime="2M" renewOnCallTime="2M" sponsorshipTimeout="1M"
leaseManagerPollTime="30S" />
</application>
</system.runtime.remoting>