The patm device driver supports ATM cards based on the IDT77252 chip. It has been tested with ProSums ProATM-155 cards and with IDTs evaluation boards. The driver interfaces with the natm(4) framework, netgraph(4) and HARP. It provides only PVC services. Signalling, ATMARP, ILMI and other higher layer protocols are implemented using netgraph(4) or HARP.
For configuring the card for IP see natmip(4).
The driver supports UBR, CBR, VBR and ABR traffic. Supported AALs are: AAL0 (cell payloads), AAL5 and raw AAL. The driver supports opening of VCI/VPI 0/0 in RX, raw AAL-mode. This VC will receive all incoming cells (even those with non-zero GFC fields and VPI/VCI values outside the allowed range) that are not claimed by other open connections. This may be used for monitoring purposes.
The following sysctls are recognized by the driver additionally to those handled by utopia(4):