I need to set this up so a user can stream audio online.

First of all there is a default filter put in filtcfg exceptions by BM to
do with Real Audio that I deleted last year. Can anyone tell me what this
is? I deleted it because we have never needed to stream real audio and I
needed to tidy up the filters. It is sods law, someone now needs it.

Anyway I have created a new filter in the meanwhile from private to public
on destination port 7070 for RealAudio-st. I have also ticked Real Audio
and RSTP Proxies in BorderManager setup. Plus I have also allowed this in
BM Access Rules definitions.

Yet the problem still remains when a user clicks on this url and gets the
error message:

Unable to locate server. This server does not have a DNS entry. Please
check the server name in the URL and try again.

DNS is fine and it doesn't work if you use it's IP address also.

Any help would be appreciated, URL works fine outside our proxy.