This paper proposes new protocols for the interconnection of FIFO- and causal-ordered broadcast systems, thus increasing their scalability. They use several interconnection links between systems, which avoids bottleneck problems due to the network traffic, since messages are not forced to go throughout a single link but instead through the several links we establish. General architectures to interconnect FIFOand causal-ordered systems are proposed. Failure management is also discussed and a performance analysis is given, detailing the benefits introduced by these interconnection approaches that are able to easily increase the resulting interconnection bandwidth.