IEEE 1394 (FireWire) Testing?

Cadre asks: "Can a regular COTS FireWire card be used for monitoring data (kind of like a regular COTS ethernet card can be put into promiscuous mode and the data can be monitored with libpcap)? I work for an organization that does a lot of databus monitoring and hardware-in-the-loop testing of large systems. Firewire has become popular (Ethernet too, but we've solved that problem with libpcap) and we're looking for a solution to monitor and simulate data. There are a couple manufactures that sell specialized equipment for FireWire testing that include onboard FPGAs but they seem more geared towards testing the FireWire bus than testing the overall systems on the bus."

Comments

COTS

[zhiwenchong]

Before anyone asks, COTS = Commercial Off the Shelf

At least that's what Google says.

The short answer: No.

[__david__]

For some moronic reason (I've heard it was bowing to pressure from content providers to make the firewire bus hard to sniff for the commoner--take that with a grain of salt), the OHCI spec (which 99% of all cards adhere to) does not include a way to enter promiscuous mode. So if you buy a cheap card you will not be able to monitor the bus.

TI used to make a non-OHCI chip called the PCI Lynx that had a sniffing mode. Apple has a nice FireWire protocol analyzer called FireBug that works with the Lynx chip. I believe I may have seen Linux software at some point that does similar packet sniffing. But these PCI Lynx based cards can be hard to find. At my old job (where we did lots of Firewire stuff) we bought a big bulk purchase of Cardbus Lynx cards and converted a bunch of cheap old powerbooks into mobile firewire analyzers.

-David

Re:Study the spec, then look at the chipsets.

[__david__]

Because of the way endpoints and bus controllers are determined, and how data flows you may have to be careful about the placement of the snooping computer on the bus.

Wrong. FireWire is a broadcast protocol and the Phys are like ethernet hubs not ethernet switches. So every device on the bus gets all data delivered to it.

The real trick is getting the chipset datasheet from the manufacturer.

99% of all 1394 cards follow the OHCI spec (hence no need to get data from the manufacturer). The OHCI spec does not allow snoop mode. Annoying, eh?

-David