This object specifies the encapsulation method to be used. If this object is set to ip_rfc877, the RFC877 compatible encapsulation is selected. The relating interface is only capabable of transferring IP datagrams. All other protocols are not supported. Virtual channels are established only with the CUD field set to CC. If this object is set to ip, the relating interface is also only capable of forwarding IP datagrams. However, the virtual channels are setup with the CUD field set to 80 00 00 00 08 00. The encapsulation ipx allows only forwarding of IPX datagrams. VCs are established using a CUD field of 80 00 00 00 81 37. If this object is set to mpr, the corresponding corresponding interface is capable of IP, IPX and BRIDGING. The different protocols are multiplexed over the same VC. The CUD field is set to 00.