DVR from my Iphone while away from home but can't what do I need to do
Does you DVR allow you to connect via an iPhone app? If so, to do it away from your network, you need to know what port the app will connect on to your device. Check the DVR's documentation.
Then all you have to do is on your network router, go to port forwarding options.. create a port forward rule that listens on that target port and map it to the same port number for the IP address of the DVR that is on your local network. Most likely, your internal network IP addressing scheme will be 192.168.0.x
Next configure your iPhone app to connect to the public IP address, which is the IP that is configured on the public side of the router. You can get that IP by logging into your router and checking the WAN IP, or from within your network, access a site that detects your public IP such as MySourceIP.com.
to make it easy for you, rather than trying to connect to the public IP, at some point, you may want to look into using a Dynamic IP DNS service such as dyndns.org, or no-ip.com. You can register a hostname to the IP address and these services help you track a public IP address that is dynamic in nature. In other words, for ISP customers where there IP address may change from time to time.
The number one question is, who is your provider that you have. That would be a good starting point. As for this DVR, is it one you made yourself, by using a computer, or is it one that you got with your Satellite, CATV, Fios or IPTV provider.