Wireless internet CCTV, also known as IP CCTV, communicates
through your broadband line and onwards to the internet. This can cause
problems if your home broadband has a dynamic IP address, because when you want
to connect to your cameras from outside, you won’t know what that address
is. This article shows you how to overcome the problem by using Dynamic
DNS.
Most home ADSL packages still give you a dynamic or changing
IP address, which is simply the address of your home’s network on the
internet. These addresses are allocated from a pool of available
addresses and allow the internet provider to have fewer addresses than customers,
saving money.
This used to work well because early broadband modems
“dialled” a connection when the attached computer requested it, rather like the
old dial-up modems. Nowadays, though, modern wireless modem/routers tend
to remain connected permanently, so we are reaching the point where the
internet provider is having to allow one IP address per customer, and may as
well allocate a static or unchanging one. However, as of today most
people have dynamic addresses and this is an obstacle to contacting your
wireless internet camera from the outside world, as I will explain in the next
section.
Just as your broadband line has an IP address, so your
camera has its own address or port. For example, if your home IP address
is 91.103.218.59 and the camera’s port is 8765, assuming your router is set up
with port forwarding (outside the scope of this article) you can contact your
camera by typing “http:// 91.103.218.59:8765” into a browser window. This
may work today, but by tomorrow that 91.103.218.59 IP address could have
been allocated to someone else, and you will not find your camera on the end of
it any more. This is where Dynamic DNS or just “DDNS” comes in.
DDNS allows you to contact your wireless internet CCTV
camera using an address that never changes, even when your broadband’s IP
address changes. It requires two things in order to work: a DDNS service
provider and a router or camera that offers DDNS support.
Most modern wireless routers offer DDNS support, but few
internet CCTV cameras do. As long as either the camera or the router
offers this feature, all is well. First, you visit the website of the
DDNS service provider and sign up for an account. The most popular
provider is dyndns.com and it’s free. You choose your own unique internet
address such as “mywirelesscamera.dyndns.org” and you will also have a user
name and password. (Incidentally, the purpose of this service is simply
to make that link between your IP address, whatever it happens to be at the
time, and a fixed address or domain name.) Having registered a DDNS
account, next you log into your router’s administration pages and find the DDNS
section.
Here you simply key in the DDNS provider name, your account
details and the address that you chose. Now, whenever your broadband
provider changes your home IP address, your router will tell dyndns.com, and
this means you can always contact your camera from wherever you happen to be,
by keying the same unchanging address into a browser window, in our example:
“http://mywirelesscamera.dyndns.org:8765”.