Best way to send NPC's / Monsters?

[Spike]

Hey, ok I have an application (Using MOO) where players have character accounts, can connect, walk around the world etc on a master server. Then when a player enters a specific "dungeon" area, the game allows the player to create his own server for that dungeon.

Now all this works fine, the problem that im having, or rather, considering, is when the player creates a dungeon game, I need to send the X/Y co-ords of all monsters / NPCs etc in the dungeon to the other players from the host.

So whats the best way to do it without completely sapping bandwidth up? So far ways I have thought about doing it -

- Send co-ords when the monsters change direction / fire / etc the way it would normally be done limiting the information to as little as possible. Some how sharing values across active monsters in the level so that I can use one object for lots of creatures as it were.
- Give each individual monster it's own "ID" and send the data when the players "go near it". However this creates for more difficult coding, I was hoping to try and implement a level editor of some kind.
- Use external files etc to keep track of exactly what is in each dungeon, then use that to somehow send the relative information when players enter certain rooms and sections of the dungeon. Then create the equivalent creature when they enter that section.

And thats pretty much all I have been able to come up with. My main problem is worrying about the amount of bandwidth been used, also having to somehow "seperate" the creatures so that I have to keep track individually of each one (Using one or many active objects or ID'ing them somehow).

So um, yea, any help would be appreciated Thank you.

[uprize]

im not familiar at all with internet games and such, but wouldn't using a binary file be the best option? that way you can save heaps of data as a binary file and when u send the file its only a matter of a few hundred bytes, which would take less than a second to send to virtually any machine.