There is a domestic cat that looks like a fox. It's red like an Abyssinian, with white spotted tummy, large black ears, and ear tufts. I'll be very grateful if you can tell me the name of this breed.
Sounds like a longhair crossbreed. It could be an actual breed, but it's hard to tell without a picture.
I don't know if there is a domestic cat like that, but what you've described sounds pretty much like a Caracal to me. They are no domestic cats. They are about the size of a Labrador and aren't typically kept as pets.
There you go. Watch this video from YouTube. Is it the cat you were talking about?

Oh wow, what a beautiful big cat! Emotion: surprise I wish there were smaller versions of this beauty. Emotion: love
Do you mean a Somali?
I think the original poster meant a cat that's on the video. The description matches it very well. Emotion: smile The Somali doesn't have such distinct black ears as far as I know.

Abyssinian's aren't very red at all. More brown. But what you're leading to is a Caracal that is not a domestic cat. It is wild and rarely kept as pets. But the breed of cat that looks like a fox the most is definately the Somali. (I have on.) They are bushy tailed and are red like a fox with bushy tails sometimes white or a white tip. Hope this helped!