LocalPort Property

The UDP port in the local host where MCast binds.

Syntax

 mcast.getLocalPort([callback])
 mcast.setLocalPort( localPort, [callback])

Default Value

Callback

The 'callback' parameter specifies a function which will be called when the operation completes (or an error is encountered). If the 'callback' parameter is not specified, then the method will block and will not return until the operation completes (or an error is encountered).

The callback for the getLocalPort([callback]) method is defined as:

function(err, data){ }

'err' is the error that occurred. If there was no error, then 'err' is 'null'.

'data' is the value returned by the method.

The callback for the setLocalPort([callback]) method is defined as:

function(err){ }

'err' is the error that occurred. If there was no error, then 'err' is 'null'.

'err' has 2 properties which hold detailed information:

err.code
err.message

Remarks

This property must be set before MCast is activated (Active is set to True). It instructs the class to bind to a specific port (or communication endpoint) in the local machine.

Setting it to 0 (default) enables the system to choose a port at random. The chosen port will be shown by this property after the connection is established.

This property cannot be changed once the class is Active. Any attempt to set this property when the class is Active will generate an error.

This property is useful when trying to send data to services that require a trusted port in the client side.

Data Type

Long