maximum protection

hi guys, first timer on this site hope you can help me solve some design issues with an idea i have. Firstly loads of experience in the security alarm game but lagging behind on the pc based/cctv transmission side of the industry.Ok then my idea is this,I have access to a pc dvr manufacturer who has made a pci card and software package available which will record and transmit cctv footage locally and also can be copied remotely via the internet.I intend to use a broadband connection with static i.p. address's allocated to both pc units with a router at either end.This is straight forward enough, but is it possible to use the router to transmit data via the extra ports that are available on the units? I have seen a unit which will allow for communication between the routers(voice only)would i be able to transmit data by modem if i use a adsl filter at both ends.The reason for this is that i want to piggyback data transmission from the security system also located on site with the cctv system. any ideas?

sorry if i didn't make myself clear. I'm trying to use one port for the cctv transmission,the system can be accessed remotely via broadband and can also transmit to a monitoring centre,any triggered alarm events.Broadband will only be used when a guard tour is selected for that site.The system will record locally. As well as this, i'm trying to send on a separate port, modem information, again remotely accessable but will communicate alarm events between two intruder alarm systems.One will be a central receiver and one the transmitter.My question is related to possible data conflicts/system crashes due to the data transfere.I understand that they will use separate ip addresses etc. but can a modem talk to another modem directly or will this idea not work.Any ideas????