I see regularly users post they have a problem synching between the desktop & app, so I thought it useful to write up a small step-by-step guide to make sure the problems aren't network or router related. Here goes:

Step 1: assign a fixed IP address to your PC (and preferably all network devices)
Why? Well, for two reasons:
- assigning a fixed IP address to all devices prevents the possibility of an address conflict. If you let your router randomly assign IP address (this is called DHCP), it could happen that two devices (say an iPhone and a laptop) happen to be attributed the same IP address, and that causes connection problems.
- in order to open a port, for most routers you'll need to open that port for a specific address. DVDP needs you to open a port on your PC, so we'll start by assigning a fixed IP address to your PC.
How?
Check out this guide:
http://portforward.com/networking/staticip.htm

Step 2: set DVDP’s settings:
- Go to Tools > Options > Sharing
- Check which port is open and write it down. Default is 32847. If that port is already used by other software, you’ll have to choose a different one. You might only notice that it’s been used by other software once you start fiddling in your router’s settings, so you might have to come back to this step.
- Flag the checkbox next to “Share my collection on the network”
- you can also set a password for access and for changes, but this is not mandatory

Step 3: open the port on your router
Each router is different, but to open the port you’ll need to access your router’s settings. For most routers, you do this by entering this IP address in your web browser:
192.168.1.1
Now, you’ll need to add a line in the port forwarding section. You can name that line “DVDP” or whatever you like. Two settings are important:
- use the DVDP port we identified in step 2 (and make sure it isn’t already being forwarded for other software yet, otherwise you’ll need to choose another rone)
- use the PC desktop fixed IP address we set up in step 1
If your router makes a difference between TCP and UDP, make a line for each, one for TCP and one for UDP, just to be on the safe side.
For a detailed guide per router type and screenshots on how to do this, check here:
http://portforward.com/

Step 4: set up your Apple device
Final step is to setup up your Apple device using Invelos’ setup guide. Remember that before doing this, it can’t hurt to have given your Apple device a fixed IP on your network (like we did for the PC in step 1). You can do this in the settings > Wifi section. Also, in the previous steps we’ve identified the port that DVDP will be using.

That should cover the basics. Additional info is welcome and I’ll adapt this brief guide as users post it.

Thanks for these additional details, Dr. Very useful points indeed!

ok i'm hopeless with all this sort of thing but i think i have done everything that has been mentioned on here. i setup the static ip address using the portforwarding guide which i assume worked out ok as i can still use the net.  i've setup dvdp and used the port forwarding guide to setup the port forwarding for 32847 like it says to do but i still get nothing. i'm not sure if i've actually set up the ip address properly as when i do the test in dvdp it comes up a different ip address everytime, is this normal???  anyway if you can help that would be great, as i said i don't really have an idea when it comes to this stuff

Quoting Simon2511:

Quote:
i'm not sure if i've actually set up the ip address properly as when i do the test in dvdp it comes up a different ip address everytime, is this normal???

when you do the test in dvd profiler it is displaying the IP address of your router (not the PC). This could change each time if you are reconnecting to the internet each time.

What you want is the IP address of the PC - which is displayed at the bottom of the window in dvd profiler. Assuming you are just connecting within the network then that is all you need to input into the IOS version in order to sync

Just ignore the external IP address of the router