Since Sterling C:D for HP NonStop version 3.6.0 there is no way to limit the total number of concurrent sessions. This used to be the case by means of the License file which was used by version 3.5.0.
The only way now is to configure the number of LU's equal to the maximum concurrent sessions that you want (or are allowed to use).
In this way you can not distinquish LU's anymore for the different nodes. When each remote node has its own set of LU's you can easily tell when a transfer for a certain node is running.
A maxprocess parameter, like on other C:D installations, would be preferable.