IFS LSP
Since this LSP provides the Winsock client program a legitimate Operating-system handle, this particular LSP does not have to put into action all of the LSP functions, but merely the only one it demands – which in turn is usually an advantage. Even so, the negative aspect is that an IFS LSP can not intercept asynchronous operations and overlapped
operations, for instance when WriteFile & ReadFile is employed together with the IFS handle.
Non-IFS LSP
Considering that a Non-IFS LSP reads the IFS handles, it will need to implement all the LSP functions. If it does not, untranslated handles will then reach the operating system API and result in a fault, mainly because the operating system is unaware of these kinds of manufactured handles.
One particular advantage of this LSP would be the potential to intercept each individual IFS function which makes use of this particular socket handle (WriteFile/ReadFile). And another profit will be the capability to receive notices from asynchronous mechanisms.
Chris