Hello Richard,
I made a search about TCP ot 9001
http://www.auditmypc.com/port/tcp-port-9001.asp
http://isc2.sans.org/port.html?port=9001
I think you can and you should filter it. It is of no use on a router as far as I know and also on your internal network
kastenxpipe
somewhere associated to tcp/udp
kastenxpipe 36865/tcp # KastenX Pipe
kastenxpipe 36865/udp # KastenX Pipe
It can be some form of streaming you should be able to stay without
http://www.xfreedom.it/services.html
Hope to help
Giuseppe