Exactly how much information does the server send the client when a spell is cast or cast upon the user?

With the new durration increasers buffs last longer. The client has to know how long, even if it's cast on you instead of by you.

In addition there was a funny bug with charm. The druid/necro/enchanter would charm a mob. A bit later they'd invis to dispell the charm. Some point after that they'd usually get a message that charm just broke. Is is possibel that the server broke charm when the invis happened but the client didn't recognize it and was waiting until the XXX time? Does the client know the durration?


If we this information is being sent it could make handling things such as spell timers much easier, effecient.