Ip cameras

[#1]

Just wondering if someone could help with the set up of the ip cameras i have got around the house. Have them set up fine around the house but want to be able to view them externally ie on my phone. I have forwarded port 80 on the camera ip 192.168.1.15 but don't know if that is right. Can someone help me out please.

[#2]

Are the cameras connected to a DVR or directly to the router?
A little more details please:
Make / model of the dvr if any?
Number of cameras, wired or wireless?
Make / model of the cameras?
Router --TG582n ?

[#3]

Have a dvr box and then that runs through the router.
We have 4 cameras on the house all wired.
TG582
I had the cameras working on my last router but just this router i can't get it going.

[#4]

The dvr will probably need 3 ports forwarding to the dvs's ip address.
Do you know these port? If not the make and model may enable us to fine a manual for it which hopefully will show the ports numbers.
Failing that you can find the ports used in the dvr's settings.
There's been a few post asking for help with IP cameras and the plusnet router, if you search the forum you may find the answers you need.