999?

You mean where the emergency services all have separate emergency (999, 911) numbers? Or where they each have their own normal phone number? My understanding is that in most (if not all) cases the emergency dispatcher simply dispatches the correct type of ES personal. IE, if you call 911 and report a fire, they send a fire truck. If you call 911 and report a heart attack, they send an ambulance. If you call and merely say "help", they send police, who then call in reinforcements if necessary.

I don't understand your question, which sounds like two ways of saying the same thing to me.

I mean where there is no central number (no 999, no 911). You call, say, 12 to get fire & rescue, 13 for medical, 14 for police. Who does 112 get you? Greece operates such a system: http://www.greeklandscapes.com/travel/emergency_numbers.html

Note direct numbers for police, fire, ambulance; yet 112 is listed as "Police/Medical/Fire". Do they have a few folk redirecting calls, or does it go to the police to sort out, or.... ?

112, for those who don't know, is a central number valid accross the EU and I don't know where else.

Ah ok. Here there are two types of service: Either you have 911 or there is no emergency services number, and you have to directly call the police/fire/EMS station by their proper phone number IE, 1-408-222-3523 (this is increasing rare, even in distant rural areas). 911 which calls a central routing place. You talk to the operators, who decide for themselves what type of ES to dispatch. They don't reroute you to a separate dispatcher, AFAIK.

We don't have separate emergency numbers for police, fire, or EMS. If you need fire fighters, you call 911. Same with police, and same with EMS. In my city we each pay a small amount on every phone bill (like, 20 cents per month or something) to maintain the central routing service for emergency services.