The global network of datacenters is emerging as an important distributed systems paradigm -- commodity clusters running high-performance applications, connected by high-speed `lambda' networks across hundreds of milliseconds of network latency. Packet loss on long-haul networks can cripple application performance -- a loss rate of 0.1% is sufficient to reduce TCP/IP throughput by an order of magnitude on a 1 Gbps link with 50ms latency. Maelstrom is an edge appliance that masks packet loss transparently and quickly from inter-cluster protocols, aggregating traffic for high-speed encoding and using a new Forward Error Correction scheme to handle bursty loss.