Logstash-forwarder listening in a port

Is possible to have logstash forwarder listening in a port?
I have changed logstash from my client server to logstash forwarder, because it is supossed to have a minimum package loss ratio and it's more lightweight.
I would like logstash forwarder to be listening to an UDP port, but in all the examples and docummentation I see it always appears with syslog.
This is the idea I want to implement>

   |   logstash forwarder  |                            |  redis         |
   |     (it listens UDP)  |                            |  logstash      |  
                                                        |      ES        |

Logstash Forwarder and FileBeat, which is replacing Logstash Forwarder, only accepts files as input. Logstash does however have TCP and UDP input plugins.

Thank you @Christian_Dahlqvist My problem is with memory consumption for that reason I wanted to changed logstash to a logstash shipper. Is there any logstash shipper that could allow me to obtain the messages that cames from one port?

Not currently, no.