It is the producer of console output's responsibility to find some recipient, connect to them and deliver the console output to them.
A Wanda machine looks in its environment for the variable TTYSERVER. If present the string is parsed for a dotted notation address and port. The network console code will attempt to connect to, and deliver all its console output to that MSNL SAP. The well known port number 0.0.0.225 has been allocated for network console, and most recipients listen on this port number. If the network console believes that it is running in a ROM kernel (specifically one with no host information), then when it receives a rarp reply, it will use the MSNL address of the sender of the rarp reply, and the default port 0.0.0.225 and use that as the SAP of the recipient.
A network console block consists of a single integer in the first four octets which is, in network standard form, the number of characters of console output present in that block. It is followed by that number of characters. No sequence number or checksum is present, as the switch fabric is reliable.