public static int NbClientConn()
{
return knownChains.Count(row => row.Side != ChainSide.SERVER_CONN && row[0] is TcpReceiver);
/*lock (lockChainManagement)
{
return knownChains.Count(row => row.Side != ChainSide.SERVER_CONN && row[0] is TcpReceiver);
}*/
}