By default, NetBIOS is blocked by DrayTek 130 modem, even if the Modem is configured to run in Bridge Mode (Bridged)
Below is switch to disabled this option:
mngt defenseworm off (Telnet)
It appears after reading a few other forums over the years, DrayTek by default do not allow NetBIOS traffic to pass from WAN to LAN, WAN to LAN and LAN to LAN (Non Bridge) etc, this is supposedly to reduce effect of defenseworm (NetBIOS) threats.
In essence, it is safer to leave this filter block enabled, unless you notice any operation challenges with you network (access to shared resources) etc.
What is NetBIOS:
NetBIOS is a transport protocol that Microsoft Windows systems use to share resources. For example, if a PC running Windows wants to connect to and access a share on a file server, it probably uses NetBIOS. There have been some changes in recent days, however, that allow this connection without it. SMB, the method used to access file and printer shares, can also run independently of NetBIOS over TCP ports 139 and 445. Both of these approaches, however, tend to increase the attack surface of a network