Edit: Please be aware that it's been FIVE years since this solution was posted. The multiplayer population decreased considerably and DLC maps are rarely played. If you follow the instructions below but no server comes up, it might just be that theres no match running with the required setup at the moment. Sadly if you have no luck finding a match, you may need to join/create a boosting session.
If your region gives you trouble when matchmaking through the Operations menu and you keep getting disconnected, then this guide is for you.
What you'll need to do is
manually join a server:
- Go to server browser
- Press Y to filter.
- On Game mode, select Operations and turn everything else off.
- On Maps, select Cape Helles and Achi Baba and turn everything else off. These are the only maps that are in the Operation Gallipoli rotation.
- On Slots, allow the filter to show full servers. You may have to wait in the queue if that's the case.
- On the Region section, turn everything on. Depending on your country's default region, it may be hard to find an ongoing server for this game mode.
This solution also apply for this other operation, by selecting it's maps.