Bind Method  
 

Bind the socket to the specified local address and port number.

Syntax

object.Bind( [LocalAddress], [LocalPort], [Protocol], [Timeout], [Options] )

Parameters

LocalAddress
An optional string value that specifies the local Internet address that the socket should be bound to. To bind to any valid network interface on the local system, specify the address 0.0.0.0. Applications should only specify a particular address if it is absolutely necessary. In most cases a local address is not required when establishing a client connection. If this value is not specified, the LocalAddress property will be used to determine the default value.
LocalPort
An optional integer value that specifies a local port number that the socket should be bound to. To bind to any available port number, specify a port number of 0. Applications should only specify a particular port number if it is absolutely necessary. The maximum valid port number is 65535. If this argument is not specified, the LocalPort property will be used to determine the default value.
Protocol
An optional integer value that specifies the protocol that should be used when establishing the connection. If this argument is not specified, the value of the Protocol property will be used as the default. One of the following values may be used:
Value Constant Description
6 swProtocolTcp Specifies the Transmission Control Protocol. This protocol provides a reliable means of communication between two computers using a client/server architecture. The data is exchanged as a stream of bytes, with the protocol ensuring that the data arrives in the same byte order that it was sent, without duplication or missing data. This protocol is designed for accuracy and not speed, therefore TCP can sometimes incur relatively long delays while waiting for out-of-order packets and the retransmission of data which can make it unsuitable for some applications such as streaming video or audio.
17 swProtocolUdp Specifies the User Datagram Protocol. This is a stateless, peer-to-peer message oriented protocol, with the data sent in discrete packets. UDP is a simpler network protocol that does not have the inherent reliability of TCP, but it has less overhead and is ideal for real-time applications where a dropped packet is preferable to the delay of waiting for a packet to be retransmitted. It also supports the broadcasting of datagrams over local networks, and is commonly used by services that must exchange a relatively small amount of data with a large number of clients.
Timeout
An optional integer value that specifies the amount of time until a blocking operation fails. If this argument is not specified, the Timeout property will be used to determine the default value.
Options
An optional integer value that specifies one or more options which are to be used when establishing the connection. The value is created by combining the options using a bitwise Or operator. Note that if this argument is specified, it will override any property values that are related to that option.
Value Constant Description
1 swOptionBroadcast This option specifies that broadcasting should be enabled for datagrams. This option is invalid for stream sockets.
2 swOptionDontRoute This option specifies default routing should not be used. This option should not be specified unless absolutely necessary.
4 swOptionKeepAlive This option specifies that packets are to be sent to the remote system when no data is being exchanged to keep the connection active. This option is only valid for stream sockets.
8 swOptionReuseAddress This option specifies the local address can be reused. This option is commonly used by server applications.
16 swOptionNoDelay This option disables the Nagle algorithm, which buffers unacknowledged data and insures that a full-size packet can be sent to the remote host.
32 swOptionInLine This option specifies that out-of-band data should be received inline with the standard data stream. This option is only valid for stream sockets.

Return Value

A value of zero is returned if the connection was successful. Otherwise, a non-zero error code is returned which indicates the cause of the failure.

Remarks

When this method is called with swProtocolUdp as the specified protocol, it will immediately create the datagram socket and bind it to the given address. When this method is called with swProtocolTcp as the specified protocol, creation of the socket is deferred until the Connect method is called. For stream sockets, this method will set the local address, port number and default options used when the socket is actually created.

See Also

Broadcast Property, LocalAddress Property, LocalPort Property, Timeout Property, Connect Method, Disconnect Method