GossipRouter supports both NIO (ByteBuffer) and TCP (stream-based) connections. In both cases, however, the entire message is read and then routed to the destination address.
It would be better to only read the cluster name and target address, and then use efficient stream-to-stream (or channel-to-channel) transfer mechanisms, which avoids temporary copies of data and the full reading of messages.
Also look into routing of entire message batches.
Investigate whether this is possible.