Adrian-
I assume you are talking about a live channel setp on a CE by a CDM? Exactly who is adding the parameters to the url?
Normally, when you setup a channel, each CE that will be sending out a stream by itself. The reference NSC file to access the multicast parameters would be an http link with an FQDN of the CE itself, and a nsc file with the name of the video/channel. There would not generally be parameters passed into it.
Regards,
Chris