Currently, you have to take into account the additional Covid rules such as vaccination requirements, tests (and how far in advance they can be taken), blacklists, quarantines, etc. Each of the two tickets may be considered independently by airlines or local authorities. So if you need to have a test "taken less than 24 hours" to enter your final destination for instance, it will probably need to be taken at the transit airport.
Time. A "real" connection on the same ticket can be extremely short, and is defined as a "minimum connection time" (MCT), which can be as short as 30 minutes in some cases (varies depending on airport, airlines, type of flight -- international or domestic, etc.).
When self-connecting, it is very likely it will take longer, unless the stars and the Moon and the Sun are aligned. And if you need to go through immigration, check-in and security, it can take a lot longer in some circumstances (especially these days).
If you need to do a check-in at a desk (or even at a transfer desk) at the connection airport, you have to do it before the check-in deadline. Again, this varies a lot, from 15 minutes to well over an hour, but 45-60 minutes for international flights at large airports is common. If you are not in time, you will be considered a no-show, and your ticket will most likely be cancelled (unless it's flexible and allows for that), possibly along with all further flights on that ticket!
When self-connecting, it is very likely it will take longer, unless the stars and the Moon and the Sun are aligned. And if you need to go through immigration, check-in and security, it can take a lot longer in some circumstances (especially these days).
If you need to do a check-in at a desk (or even at a transfer desk) at the connection airport, you have to do it before the check-in deadline. Again, this varies a lot, from 15 minutes to well over an hour, but 45-60 minutes for international flights at large airports is common. If you are not in time, you will be considered a no-show, and your ticket will most likely be cancelled (unless it's flexible and allows for that), possibly along with all further flights on that ticket!
- Time. If your incoming flight is late and you miss your onward flight (or even just the check-in deadline), the second airline will not care. You are late, that's it, you're a no show.
Time. If your incoming flight is late and you miss your onward flight (or even just the check-in deadline), the second airline will not care. You are late, that's it, you're a no show.
Same thing if there is any issue with immigration, customs, luggage (if you have any).
In all cases where you miss your onward flight, you will have to find, book an pay for a new one on the spot. At last-minute prices. Possibly days later if the route has few flights and it's a busy period (like, say, right now). All hotels and meals and all other costs in the meantime are on you.
Same thing if there is any issue with immigration, customs, luggage (if you have any).
In all cases where you miss your onward flight, you will have to find, book an pay for a new one on the spot. At last-minute prices. Possibly days later if the route has few flights and it's a busy period (like, say, right now). All hotels and meals and all other costs in the meantime are on you.
Cancellations. If one flight is cancelled, you will usually be able to get a refund or rebooking for all the flights on the same ticket. Not for any of the flights on the other ticket. In ever-changing COVID rules times, this is even more important than usually.
Schedule changes. Same thing. If one of the flights sees its schedule changed so that connections to other flights on the same ticket no longer work, the airline will (or at least should) work with you to find a solution. Self-connecting? They don't care if suddenly your incoming flight arrives after your onward flight.
Lost luggage on the first leg. The airline won’t ship it to your final destination, you will have to go through the lost luggage claim process on arrival in Qatar (see above re missing your onward flight) and you'll have to figure out how to deal with your stuff stuck in Qatar.