//on one node
class EndpointManager extends TypedActor with EndpointManager{
remote.start()
remote.registerTypedActor(Constants.endpointManagerServiceId, this)
//...
dispatcher ! Register(hostname, port)
def getTrue: Boolean = true
}

//on one other node
remote.start()
def receive = {
case Register(hostname, port)=> {
      val endpointManager = Actor.remote.typedActorFor(classOf[EndpointManager],   Constants.endpointManagerServiceId, 5000L, hostname, port)
      println(endpointManager.getTrue)
  }
//...
}

//and the result is
21:35:04.563 [akka:event-driven:dispatcher:event:handler-12] DEBUG akka.event.slf4j.Slf4jEventHandler -
    [RemoteClientStarted(akka.remote.netty.NettyRemoteSupport@60a1e929,/192.168.1.44:2552)]
21:35:04.563 [akka:event-driven:dispatcher:event:handler-12] DEBUG akka.event.slf4j.Slf4jEventHandler -
    [RemoteClientConnected(akka.remote.netty.NettyRemoteSupport@60a1e929,/192.168.1.44:2552)]
21:35:14.723 [akka:event-driven:dispatcher:event:handler-16] DEBUG akka.event.slf4j.Slf4jEventHandler -
    [RemoteClientShutdown(akka.remote.netty.NettyRemoteSupport@60a1e929,/192.168.1.44:2552)]
21:35:14.742 [akka:event-driven:dispatcher:event:handler-17] DEBUG akka.event.slf4j.Slf4jEventHandler -
    [RemoteClientDisconnected(akka.remote.netty.NettyRemoteSupport@60a1e929,/192.168.1.44:2552)]
21:35:49.183 [akka:event-driven:dispatcher:event:handler-20] DEBUG akka.event.slf4j.Slf4jEventHandler -
    [RemoteServerClientConnected(akka.remote.netty.NettyRemoteSupport@60a1e929,Some(/192.168.1.44:53581))]
21:35:49.184 [akka:event-driven:dispatcher:event:handler-20] ERROR akka.event.slf4j.Slf4jEventHandler -
    [akka.remote.netty.RemoteServerHandler]
    [null]
    [java.lang.NullPointerException
    at akka.remote.netty.RemoteServerHandler.dispatchToTypedActor(NettyRemoteSupport.scala:1165)
    at akka.remote.netty.RemoteServerHandler.handleRemoteMessageProtocol(NettyRemoteSupport.scala:1020)
    at akka.remote.netty.RemoteServerHandler.messageReceived(NettyRemoteSupport.scala:1002)
    at org.jboss.netty.channel.SimpleChannelUpstreamHandler.handleUpstream(SimpleChannelUpstreamHandler.java:80)
    at org.jboss.netty.channel.StaticChannelPipeline.sendUpstream(StaticChannelPipeline.java:372)
    at org.jboss.netty.channel.StaticChannelPipeline$StaticChannelHandlerContext.sendUpstream(StaticChannelPipeline.java:534)
    at org.jboss.netty.handler.execution.ChannelEventRunnable.run(ChannelEventRunnable.java:69)
    at org.jboss.netty.handler.execution.OrderedMemoryAwareThreadPoolExecutor$ChildExecutor.run(OrderedMemoryAwareThreadPoolExecutor.java:316)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
    at java.lang.Thread.run(Thread.java:662)
]
21:35:49.196 [akka:event-driven:dispatcher:event:handler-21] DEBUG akka.event.slf4j.Slf4jEventHandler -
    [RemoteServerError(java.lang.NullPointerException,akka.remote.netty.NettyRemoteSupport@60a1e929)]
21:35:59.309 [akka:event-driven:dispatcher:event:handler-22] DEBUG akka.event.slf4j.Slf4jEventHandler -
    [RemoteServerClientDisconnected(akka.remote.netty.NettyRemoteSupport@60a1e929,Some(/192.168.1.44:53581))]
21:35:59.311 [akka:event-driven:dispatcher:event:handler-23] DEBUG akka.event.slf4j.Slf4jEventHandler -
    [RemoteServerClientClosed(akka.remote.netty.NettyRemoteSupport@60a1e929,Some(/192.168.1.44:53581))]