((a)) ** Service** Every order of the Commission shall be forthwith served upon the designated agent of the carrier in the city of Washington or in such other manner as may be provided by law.

((b)) ** Suspension or modification** Except as otherwise provided in this chapter, the Commission is authorized to suspend or modify its orders upon such notice and in such manner as it shall deem proper.

((c)) ** Compliance** It shall be the duty of every person, its agents and employees, and any receiver or trustee thereof, to observe and comply with such orders so long as the same shall remain in effect.