OPC Tunneling (sometimes spelled OPC Tunnelling), is a concept that enables OPC communication to bypass DCOM and use TCP/IP directly. This enables OPC communication to take place where DCOM would be inappropriate. This would be needed when the available network is highly unreliable (marked by a high number of communication disruptions), low bandwidth, or firewalls that block DCOM communication. OPC Tunneling also enables users to bypass most (and sometimes all) DCOM configuration. Therefore, OPC Tunneling might be easier to use for people who do not know how to configure DCOM.