It seems that you are having some issues when trying to connect to your Slingbox.
We encourage you to include further details about the issues you are dealing with (error messages, network configuration, etc). This way, the community will be able to provide you with accurate recommendations.
There really isn't much more detail to explain. I can connect and stream video through various other services but not Comcast. Unfortunately Comcast is my supplier, I wouldn't have contracted with them had I known the Slingbox wouldn't work . The connection goes through until loading the remote but it never or very rearely succeeds in loading the remote, times out and gives the fail to connect message. On the 1 or 2 ocassions it has got through to loading the remote it just hangs almost immediately afterwards. The only possible reason I've read on the internet is that the Slingbox optimisation of video quality conflicts with Comcasts own system to minimise bandwidth to need, I've switched the router firewall off but it makes no difference.