What dgramws does

Dgramws connects to a websocket URL and sends a preconfigured UUID value as a text message. The websocket server is supposed to be a relay like https://github.com/cisoakk/wsServer/tree/master/examples/relay or https://git.int.sw4me.com/akovalenko/wsrelay , connecting predefined pairs of clients authenticated by UUIDs.

Dgramws also binds one or more UDP sockets, assigning a virtual channel number (0-65535) to each of them. Incoming UDP packets to this socket are sent out on Websocket as a MessageType 2 (binary), prefixed by a big-endian 16-bit virtual channel number. Incoming Websocket packets, also prefixed with a virtual channel number, are sent out to an UDP address specified by the client setting.

{
  "relay":"wss://relay.example.com/relay-path",
  "uuid":"1e6479a4-5060-414a-a03e-bc083b4d93cb",
  "channels": [
    {"id": 1,
     "udp": {
       "bind": "127.0.0.1:4080",
       "client": "127.0.0.1:4081"
     }
    }
  ]
}

When client is present in the channel description, UDP datagrams from its address are forwarded to websocket, and all other UDP datagrams are discarded. When client is absent or empty, the source host and port of a first datagram arriving to bind address is remembered and all other, non-matching datagrams are filtered out.

Why use dgramws

You most probably don't need it. I'm using it in an experiment, forwarding Wireguard over websocket in the environment where UDP is restricted.