I found a packet that was being sent by the client that holocore is not decoding. "LagReport" (0xC5ED2F85). The packet contains a single data item, that being a long value which i assume is a client calculated lag value.
Since the Forwarder handles the UDP communication that the client is complaining about in that message, the Forwarder would be the place to implement that packet. Holocore just sends the data via TCP into a buffer on the Forwarder.
I also believe the purpose of the packet is to request slower transmission of data (which we ignore), but I could be wrong.
I didn't mean it was a client issue or a UDP issue. I meant that that packet is being received by the server, but is not decoded (no packet class exists for that packet yet). I created a packet class in my copy of the code. I'm sure that packet isn't super important, just passing on the information.