[Solved]-Scala Case Classes vs. Protocol Buffers with Akka over the network-scala

Akka uses Java serialization or Google Protobufs by default (see here and here). You can define your own serializers, if you think you can code up something that's more optimized for your application.

If you want to optimize your network protocol, you'll have to break out your favorite network sniffer to find out what's actually being sent back and forth. Then you can better decide what to do.

In general, though, you can probably create a better optimized network protocol by hand, but it's more likely to be brittle and break when you need to make changes (unless you've got a lot of experience writing network protocols).