What are friends for?

I always found that certain people are reluctant, or oblivious or even lazy, to maintain a friendship through means of communication. After all, communication is one of the pillars that friendship is based on. I mean friendship is a relationship- there's nothing to it, that's a given. So without communication, how is it even a relationship. I don't really like the idea that out of the two friends, one of them is the one that usually makes the calls and initiates the 'let's do this together'. It's too much to ask. It's supposed to be a mutual effort.

Even so, I tend to believe certain friendships will forever remain unshaken just because there's this 'feel right' factor to it. I mean consider this: there are occasions when one goes abroad, for say their studies, and when that person comes back the two basically pickup where they left off. That's just amazing.