Description: This attribute gives the operational mode of the LogicalChannel component. It indicates what kind of transport is being performed on the packets in the channel. There are 7 possible values of this attribute as follows:

unknown - not currently in busy state, type of forwarding not determined yet.

hdlcFrmMux - frames are being multiplexed (multiple LCh/n on same port or channel) using HDLC encapsulation.

aal5FrmMux - frames are being multiplexed (multiple LCh/n on same ATM VCC) using the AAL5 segmentation and recombination protocol.

spoFrmMux - frames are being multiplexed (multiple LCh/n on same ATM VCC) using the Short Path Oriented segmentation and recombination protocol. This is a proprietary protocol which encapsulates voice frames into a single ATM cell unlike AAL5 which would require two cells to transport the 45 byte voice frames.

aal5FrmMap - frames are being mapped (a single LCh/n per ATM VCC) using the AAL5 segmentation and recombination protocol. AAL5 mapped frames are forwarded by hardware in both directions and require no CPU intervention.

spoFrmMap - frames are being mapped (a single LCh/n per ATM VCC) using the Short Path Oriented segmentation and recombination protocol. SPO mapped frames are forwarded by hardware in both directions and require no CPU intervention in all but one special case. In particular CPU is required only if frames are being forwarded to an LCh/n whose mode is spoFrmMux.

cellMap - ATM cells are being relayed directly over the bus with no segmentation and recombination protocol. The segmentation and recombination is only done at transition points between frame based cards and ATM cell based cards so this hop represents a pure tandem cell hop, ATM card to ATM card. No CPU is required to process these cells.