Content can be transferred with a custom protocol over the network. This is intended for use with local [[LDN_services|ldn]] networks, however the used IP addresses can be arbitary. This can be used for SystemUpdates via the above Send/Receive commands (which are then used via [[NS_Services#ns:su|ns:su]]). Application content can also be transferred, which uses a similar (?) protocol.
Task [[#Cmd69|creation]] for Receive will eventually use the input addr/port with [[Sockets_services|connect()]], while the Send version will eventually do the same with [[Sockets_services|bind()]]. Hence, Receive system = client, while Send system = server .
Messages (requests/replies) begin with the following 0x10-byte header, then any associated data.