Hypothetical...

7 days on reserve. Get a 4 day trip followed by a 11 hour rest period. Once the trip is over, if they don't already have a trip or short call assigned, when is the soonest they can assign something? Also, what if any obligation is there to answer the phone during the rest period? Trying to figure out if they can extend that rest to 24 hours while I'm in the rest period to make me legal for another 3 day assignment or do they have to wait until the rest period is over to assign more rest (thus breaking the rest)

I'm sure that's ridiculously confusing.