When you install a new IP camera it is most likely that you're going to want
to view it from outside of the network on which it's installed - your local
network. To do this you need two things:
- You need to know your external IP, or WAN address
- You need port forwarding or Network Address Translation (NAT) rules
active on your router
Why does it have to be so complicated?
It doesn't. Your WAN, external, or public IP address (all terms for the same
thing) is the internet protocol number which links your broadband router or
modem to the Internet. It is the gateway through which all network traffic
exits, or crucially in this case, enters your network. You need to know this
address to be able to connect back into your camera.
You can very quickly discover what this address is with a quick visit to any
site which can display your WAN IP such as www.whatismyip.com. Once you know this
address, the fun really starts!
It's a safe bet that unless you know you have a static IP address, you'll
have a dynamic WAN IP - one that changes on a regular basis, perhaps even each
day. This clearly makes it difficult to connect to your camera conveniently when
you're away since you need to be at your actual local network to determine what
your external IP address is. Sheesh
And the answer is
You could simply ask your ISP to assign you a static IP address, but this is
not always possible. The answer lies with Dynamic DNS (DDNS).
DDNS is a fancy way of saying that an IP address (like 217.145.34.55) is
translated to an easy to remember domain, or hostname like
mynewwebcam.viewnetcam.com each time it changes. The DDNS system knows that the
new IP needs to be assigned to the hostname.
Here you have another choice: do you use the DDNS service built into the
camera (if supported), or use a third-party DDNS service such as DynDNS or NO-IP. Our
preference is for DynDNS (we like to call them din-dins�, but some of the
others are just as reliable.
The downside with DDNS services is that whenever the WAN IP address changes
the DDNS service must be notified. This is either done automatically by the
camera, or perhaps the router supports DDNS. A third option is to run a DDNS
client on a PC which can update the service. In all likelihood the router will
support DDNS if the camera does not.
DDNS automagically by camera
Some IP cameras already have DDNS services installed, often provided by the
manufacturer themselves. In particular, Panasonic provide their Viewnetcam.com
service and Axis their Axiscam.net service. Both services work in the same way.
The camera watches for WAN IP address changes and notifies the DDNS service of
the new IP address. On-camera DDNS is often the most reliable way to ensure a
permanent connection to your camera.
More complication. Or is it?
Once your DDNS service is in operation the last step is to ensure that when
you access your WAN address it is the camera you see and not something else. You
do this by setting up port Forwarding or network Address Translation rules
on your router. These are names for the essentially the same thing. You can find
instructions for how to do this on your router at the helpful website www.portforward.com.
A further option is to place the camera's IP address in the DMZ for the
router. Every broadband router or modem has a DMZ (short for De-militarized
Zone). Once in here your camera will receive any traffic entering the router
from your WAN IP address. Whilst this is not a security risk with most cameras,
it is worth noting that all ports and protocols are accessible in this way. It
is always advisable to forward a single port number to your camera, rather than
all ports.
Summary
Whilst DDNS setup seems complicated it's really not that involved. For the
most part the whole dirty process can be managed from the camera. Panasonic's
Viewnetcam.com service in particular is very easy to use and highly reliable and
is highly recommended. For the simplest operation, however,
your router should support Universal Plug and Play (uP&P) since the camera
will automatically set up the port forwarding rules for you (they're very
clever).
Dynamic DNS has finally come of age and is not only ideal for the home user,
but is now suitable for businesses use as well. We use it and so should you.
