Correct, they're from OUD DPS.
I am trying to setup a DPS in front of DS ( all within OUD ). I have used the following link to set things up :
Please let me know if you need any additional information.
The link you provided describes all the components you need to configure.
Make sure your workflow object (default userRoot0) has the right base suffix and that it is registered in one networkgroup object .
Is the request forwarded by the OUD proxy to the OUD directory server ? (check OUD directory server access logs)