I think it's better to use TCP, even if it's for use over LAN. Here's a multi-client server you can edit to fit your needs:
$iMaxConnections = 25
Global $iCurrentSocket = 0, $oListenSocket, $oConnectedSocket[$iMaxConnections]
TCPStartup()
$oListenSocket = TCPListen(@IPAddress1, 8044, $iMaxConnections)
If $oListenSocket = -1 Then Exit
While 1
$oConnectedSocket[$iCurrentSocket] = TCPAccept($oListenSocket)
ConsoleWrite($oConnectedSocket[$iCurrentSocket]&@CR)
If $oConnectedSocket[$iCurrentSocket] <> -1 Then
$iCurrentSocket = $iCurrentSocket + 1
EndIf
For $i = 0 To $iMaxConnections-1
If $oConnectedSocket[$i] <> -1 Or $oConnectedSocket[$i] <> "" Then
$sResv = TCPRecv($oConnectedSocket[$i], 512)
If $sResv <> "" Then
;
EndIf
EndIf
Next
Sleep(20)
WEnd