Martin Angler said: > my name is Martin Angler and I am developing a BACnet MS/TP - enabled netdevice-driver > under GNU/Debian Linux. Now I've seen, that there is no linktype that specifies BACnet > MS/TP. So I wanted to ask whether you could define/implement a corresponding linktype.
I infer from some stuff I've seen that BACnet MS/TP is a link-layer protocol atop which the higher-level BACnet protocols can run (just as they can run atop UDP and 802.2). Will your driver supply "raw" packets with a header specified by the BACnet specification (the ISO standard appears to cost over 350 CHF, so I haven't bought it), or will it supply some form of "cooked" software that might not be what other BACnet MS/TP capture mechanisms might supply? If the former, the linktype should probably be called DLT_BACNET_MS_TP or something such as that; if the latter, the name should probably have something in it to indicate what type of header it is (see, for example, DLT_ARCNET, which should perhaps have been DLT_ARCNET_BSD, and DLT_ARCNET_LINUX, or DLT_APPLE_IP_OVER_IEEE1394, which is not raw Firewire but has a synthetic header). > Other people that worked on an MS/TP dissector (www.abmlinux.de) already tried to > contact you, but without success. I don't think I've seen that on tcpdump-workers. Do they have their own driver and, if so, does it supply the same link-layer header (if not, it'd need a separate DLT_ value)? - This is the tcpdump-workers list. Visit https://lists.sandelman.ca/ to unsubscribe.