WCF error 0xc00e0069 (MQ_ERROR_REMOTE_MACHINE_NOT_AVAILABLE)

I have a WPF app that uses WCF (duplex netMsmqBinding) to talk to a self-hosted service app in our domain. I'm now trying to move this WPF app to the big wide world out there, to talk to the WCF service over the internet (well, make them talk to each other).

I've installed MSMQ and created the services on both, and checked queue and firewall permissions. Based on the reading I've found, what I needed to do then is:

1) Enable MSMQ's HTTP addon.

2) specify the binding's useActiveDirectory=false and queueTransferProtocol="Srmp" to ensure that it uses DIRECT to find the private queue.

However I did that and the WPF app receives the error

An error occurred while opening the queue:Unrecognized开发者_C百科 error -1072824215 (0xc00e0069). The message cannot be sent or received from the queue. Ensure that MSMQ is installed and running. Also ensure that the queue is available to open with the required access mode and authorization.

Which translates to MQ_ERROR_REMOTE_MACHINE_NOT_AVAILABLE.

I can browse to the remote server ok, and the rest services work fine, so I must be missing something with HTTP or the fact that it's self hosting. Any ideas?

MSMQ over HTTP is a push technology (client -> web server). You cannot open a remote queue and pull messages from it.