Can't connect to .ics calendar file with iPhone

[natbr]

I am trying to sync my iPhone calendars with the calendar on my PC that is in .ics format. The .ics file is located on a home server that allows both me and my wife to see each other’s calendars and its been working great. Now, I want to be able to see my calendar from my iPhone 4 (with OS 5.1.1) .. and I’ve tried setting it up with: settings à mail, contacts,calendars à add account à other à add subscribed Calendar.
With every possible config I can think of, I get the same response: "Calendar Subscription -- Unable to verify account information"
For server name, I’ve tried actual servername, ip address, etc; we do have security on the server but I put in the account name and password … ‘nuthin! “Unable to verify …”
Through the phone's browser, I am able to open up the folder on our server and see the.ics file. The path is xxxx.homeserver.com/webcal/nat_calendar.ics. I've tried sending an invite to myself, opening it in the phone, clicking on the link and I get this error: Cannot Subscribe: Could not subscribe to the calendar "nat_calendar.ics from "myservername".
Seems simple, what am I missing here.
Any ideas?
-- Nat

 

[ClavisHon]

Seems you are trying to subscribe to an ICS file and not to an actual active calendar account. I doubt this is possible. For example, when you are syncing your iPhone calendar with the iCloud, you do not "sync" with an ICS file which exists on your iCloud account but with the active calendar account. I believe ICS files are only used for transfer purposes - i.e. transfer calendar from your computer to your iPhone or from your Google calendar to your Outlook on your coumputer but certainly not for sync purposes.