For NetSocket clients, if this field is set with an IP address or domain name prior to initialisation, an attempt to connect to that location will be made when the object is initialised. Post-initialisation this field cannot be set by the client, however calls to Connect() will result in it being updated so that it always reflects the named address of the current connection.

For NetServer listeners, this inherited field identifies the local address to bind before initialisation. Use localhost, *, an IPv4 address or an IPv6 address.

This is a free-entry field value that can store client data for future reference.

This field describes the last error that occurred during a NetSocket operation:

In the case where a NetSocket object enters the NTC::DISCONNECTED state from the NTC::CONNECTED state, this field can be used to determine how a TCP connection was closed.

The client can define a function in this field to receive notifications whenever the state of the socket changes - typically connection messages.

For NetSocket clients, the function must follow the prototype Function(*NetSocket, NTC State). For NetServer listeners, the inherited field uses Function(*NetServer, *ClientSocket, NTC State).

The first parameter refers to the object to which the function is subscribed. For NetServer listeners, ClientSocket refers to the ClientSocket on which the state has changed.

The Incoming field can be set with a custom function that will be called whenever the socket receives data. The function prototype for C++ is ERR Incoming(*NetSocket, APTR Meta). For Tiri use function Incoming(NetSocket).

The NetSocket parameter refers to the NetSocket object. Meta is optional userdata from the FUNCTION. For NetServer listeners, this inherited field receives Incoming(*NetServer, *ClientSocket, APTR Meta) in C++ or function Incoming(NetServer, ClientSocket) in Tiri, and data must be read from the supplied ClientSocket.

Retrieve data from the socket with the Read() action. Reading at least some of the data from the socket is compulsory - if the function does not do this then the data will be cleared from the socket when the function returns. If the callback function returns/raises ERR::Terminate then the Incoming field will be cleared and the function will no longer be called. All other error codes are ignored.

This field sets the maximum size in bytes for UDP packets when sending or receiving data. It only applies to UDP sockets and is ignored for TCP connections. The default value is 65507 bytes, which is the maximum payload size for UDP packets (65535 - 8 bytes UDP header - 20 bytes IP header).

If you attempt to send a packet larger than MaxPacketSize, a warning will be logged and the operation may fail. When receiving data, packets larger than this size will be truncated.

This field limits the size of incoming and outgoing message queues (each socket connection receives two queues assigned to both incoming and outgoing messages). The size is defined in bytes. Sending or receiving messages that overflow the queue results in the connection being terminated with an error.

The default setting is 1 megabyte.

This field sets the time-to-live (TTL) value for multicast packets sent from UDP sockets. The TTL determines how many network hops (routers) a multicast packet can traverse before being discarded. This helps prevent multicast traffic from flooding the network indefinitely.

The default TTL is 1, which restricts multicast to the local network segment. Higher values allow multicast packets to traverse more network boundaries:

• 1: Local network segment only
• 32: Within the local site
• 64: Within the local region
• 128: Within the local continent
• 255: Unrestricted (global)

The Outgoing field can be set with a custom function that will be called whenever the socket is ready to send data. For NetSocket clients the function must be in the format ERR Outgoing(*NetSocket, APTR Meta). For NetServer listeners, the inherited field uses ERR Outgoing(*NetServer, *ClientSocket, APTR Meta).

To send data from a NetSocket object, call the Write() action. To send data from a NetServer to a connected client, call ClientSocket⇒Write() on the target client socket. If the callback function returns an error other than ERR::Okay then the Outgoing field will be cleared and the function will no longer be called.

For NetSocket clients, this is the remote port used by Connect(). For NetServer listeners, this inherited field is the local port to bind during initialisation.

The State reflects the connection state of the NetSocket. If the Feedback field is defined with a function, it will be called automatically whenever the state is changed. Note that the ClientSocket parameter will be NULL when the Feedback function is called.

For NetServer listeners this State value should not be used as it cannot reflect the state of all connected client sockets. When read from a NetServer, this inherited field reports NTC::MULTISTATE; each ClientSocket carries its own independent State value for accepted TCP connections.