On my Bt phne there ia Settings mode for Answerphone.Do you have the user guide that should have come with your phone.If not there is a help line on 0800 145 6789.
Do you mean the telphone belonging to the person you are calling only rings a couple of times?
If so, you can't do anything about it, it is their phone settings that determines how long it rings for and you can't alter it
I agree withdavebro and barry, its the receiver's phone that decides when answerfone cuts in. Am pretty sure that the more stacked up messages there are the quicker the answerfone message come's in so maybe your friends need to clear there message's.