The value of this object identifies the VC encapsulation type on an SPE.
The values are as follows:
fr
atm-aal5-sdu
atm-trans-cell
vlan
ethernet
hdlc
ppp
atm-nto1-vcc
atm-nto1-vpc
ip-layer2
atm-1to1-vcc
atm-1to1-vpc
atm-aal5-pdu
satop-e1
satop-t1
esopsn-basic
ip-interworking