In-band Frame Relay management mode. A variety of options exist which are differentiated by how PVCs can be provisioned to manage the unit and the resulting impact to the logical processing of Link Management Protocol messages (LMI spoofing and sourcing). The unit is designed to support these management modes even in non-provisioned or failed frame relay networks. This setting also has implications upon how networking protocols such as ARP and InARP are handled by the unit. (1) inactive: in-band management is not enabled (2) local DLCI mode: in-band managed using a private dedicated DLCI accessible via the TO-DTE only. A DLCI value is configured which, through LMI spoofing, will only be visible to the DTE equipment and need not be provisioned on the WAN. All traffic on this DLCI will be terminated by the unit. (3) remote DLCI mode: in-band managed using a private dedicated DLCI accessible via the WAN port only. A DLCI value is configured which, through LMI spoofing, will only be visible from the WAN side and will not be seen by any DTE equipment. All traffic on this DLCI will be terminated by the unit. (4) bidirectional mode: in-band managed using a private dedicated DLCI accessible through either port. A DLCI value is configured which is expected to be fully provisioned in the frame relay network but dedicated to the management function of this particular unit. All traffic on this DLCI will be terminated by the unit. (5) piggyback mode: in-band managed using any DLCI on any interface. A DLCI value is defined that becomes the default DLCI that will be maintained by the unit during network or LMI failure conditions. The unit will terminate and respond accordingly to management and networking data while transparently passing on user data. (6) fixed DCE mode: special mode of operation to support frame relay applications that do not include a switch (frame relay DCE). The unit will independently respond to LMI requests on each interface and will provision the configured DLCI to each Frame Relay DTE device. Except for this, the unit behaves like piggyback.