Variable Bit Rate real-time multimedia services like highly compressed video or audio tend to be very sensitive to transmission errors. This paper investigates cell and frame loss as well as delay and timing issues in an ATM-based B-ISDN environment that carries such services. The figures derived through simulation using artificial as well as real world sources motivate the introduction of forward error correction (FEC) mechanisms. We describe an approach that combines FEC mechanisms with extended loss recovery properties and cell interleaving and that is capable of dealing with variable bit rate services. If parameters and components are properly chosen the loss figures can be reduced significantly while still keeping the complexity of the FEC mechanism within acceptable bounds