Depends on the type of lawsuit and which level of court it's going through. I sometimes have to perfect service within 30 days of the filing, other times it's 20 days, 45 days, etc. I don't know the exact "rules" on the time limits, but it varies from one type of suit to the other. I am in Ohio.
Most of mine have been civil suits ( divorce, child support, consumer cases, etc. ).