Newbie setting up a DVR using

Hi All, new to all this but managed to set up my home dvr and opened ports etc and successfully set up a dns address to view remotely .... tried it for first time at work this morning , nothing , but duriing the day tried again and got it twice ... tried tonight again nothing ... I think maybe its the server I am forwading to , but how can I check this to find the fault ( if any ) the company I am using is flashserv
is this a good server or ? perhaps you could guide me to advise if there are any software toos I can run to check everything or indeed another server provider if this is my issue

kind regards