Could it be 'call up'?
I don't know your age, Harrowden, but when men were conscripted into the armed forces, they were 'called up'. The trouble is, I can't see where 'friend' comes into this, but then again, I'm not doing this quiz and don't know the quality of the clues :-)
Thanks for suggestion...I am certainly of the OAP bracket and can remember the call up but like you cannot see the connection with friend. I have tried combinations of call, ring, dial, buzz with pal, mate etc but cannot find a realistic answer.