Why do summons keep failing?

Greetings,
New DS noob player here and hoping you all can help?
I've encountered a lot of summon failures whenever I go human and are looking for people to co op and help me at certain levels of the game.
I'd say about 80% of the time, the summons fail.

Are there any special settings within the game, on my PS3, and/or my router that I need to adjust so that this doesn't happen so often?

I read the post on here about port forwarding, and I think I've set that up correctly, but it made no difference.

Anyway, hoping some kind folks on here can help me out. I would greatly appreciate it!

Praise the Sun!

It is very common, but there's a GREAT way to combat this. Try to summon someone, and stand over their sign to keep track of it, as SOON as you can, summon that person again. It will most likely grab them, if they haven't been summoned by another. The reason these fail so often is because the game is looking through the players for an invade constantly, and a lot of people go human and wait for an invade while they wait to be summoned. This way, they get action no matter what. But because they're human, they can't really be summoned easily. Doing what I did up there will take them off the invade list the first time you try, then the second try should grab them

Short answer: no, you can't really optimize your PS3 further.

Unfortunately, summon fails are common, and there seem to be multiple causes. The most obvious is just basic network issues where you and/or your summon have dodgy internet and are just having a hard time connecting. Even if you do manage to connect, you often get dumped back to your world within a few minutes. You can sometimes self-select around this by not trying to summon people with user ids that are likely from halfway around the world.

Summon signs can appear in other people's worlds almost the moment you put them down, but it is also possible to try to summon someone who has since reset their sign or even died, resulting in an automatic fail (and worse, one that sometimes takes a few minutes to inform you it failed). There is also known condition where you completely lose the ability to summon OR be invaded even while human, and even though you are still seeing summoning signs appearing and other network activity. If you get a long string of failed summons and also don't actually get invaded -- particularly if fog gates or bonfires keep turning on and off but no invaders actually show up -- quit and reload and it usually clears it.

Fowl is right, if your summons are constantly failing it's a fault with the game's player groupings or something, just quit/reload it it should be fine.

Thank you all for the information!
Oh well I was secretly hoping there was some technical trick to make it smoother.

The failed situations described have happened to me, but never thought about restarting the game. I'll keep that in mind next time I'm human and get a long series of failed summons.

Thanks again and Praise be Sun!

Usually internet connection is not swell with the player. I have had this a couple of times, it usually is the internet's problem. Might need to check your connection with the rest of the world.

My superstition is to quit and reload anytime I die after I was summoned or the host dies during a session.

My belief is that it helps clear the net code.