Tom, Watchdog timers like you describe are useful, but they tend to be less valuable than they used to be because newer software tends to be multi-threaded instead of single threaded and also the interfaces are smarter and do more processing on their own. This means there are more paths that the software is taking that may not be part of the watchdog timer. It is nice to have a watchdog timer to catch some things, but I think not having one is less of a show stopper than it used to be. We use external power controllers that can ping devices and can power cycle them if they do not respond. So far, I like that better because more of the system is probably tested by an external ping than by an internal watchdog timer. At least that is the theory. :)
Thanks, Mark On 12/20/09 12:30 PM, "Tom Sharples" <tsharp...@qorvus.com> wrote: > A hardware watchdog timer, typically, watches only one thing - is the > software and/or CPU still alive? If a software pinger fails to reset a > hardware counter or timer every few seconds or so, the timer reaches the end > of its count and resets the motherboard. It is a failsafe if everything else > goes wrong - something that happens more often than one would like when > you're using developmental drivers. Software watchdogs are a poor substitute > for obvious reasons - if the software or CPU is completely hung, the > software watchdog won't work either! > > Tom S. > > ----- Original Message ----- > From: "Mark Stephenson" <m...@countryconnections.net> > To: "WISPA General List" <wireless@wispa.org> > Sent: Sunday, December 20, 2009 4:12 AM > Subject: Re: [WISPA] Ubiquiti ready for prime time? > > >> Tom, >> >> Do you happen to know what a hardware watchdog timer watches? Perhaps >> there >> is something it can watch like whether or not the device is sending on the >> Ethernet port or the program counter. But, it seems that as embedded >> systems >> add more software, a useful hardware watchdog timer becomes less possible >> because there are more things that can go wrong and it is >> difficult/expensive to make the hardware capable of checking those things. >> >> Thanks, Mark >> >> >> On 12/20/09 2:01 AM, "Tom Sharples" <tsharp...@qorvus.com> wrote: >> >>> A software watchdog timer is not the same thing as a hardware watchdog >>> timer. >>> And SNMP has nothing to do with either. >>> >>> Tom S. >>> >>> ----- Original Message ----- >>> From: jai...@budget.net >>> To: Tom Sharples ; WISPA General List >>> Sent: Saturday, December 19, 2009 9:03 PM >>> Subject: Re: [WISPA] Ubiquiti ready for prime time? >>> >>> >>> Please don't take me wrong on this but your statement (b) bothers me. >>> You >>> are either running a very old version of Air OS or you have no clue what >>> your >>> talking about. UBNT has support for SNMP which I use to monitor not only >>> uptime but signal strength and a few other key items check out ZenOss if >>> you >>> need to watch these devices or any other network device for that matter. >>> AirOS >>> also has a "Watchdog timer" in the software that will automatically >>> reboot a >>> device that fails a ping time you set. I have never had to power cycle a >>> UBNT >>> device. In fact I had to reboot a Mikrotik router because it had a locked >>> process in the packet sniffer application that drove the CPU to 100% so >>> the >>> UBNT gear has a higher uptime than the core router. >>> >>> Jaimie >>> >>> >>> On Sat 12/19/09 12:24 PM , "Tom Sharples" tsharp...@qorvus.com sent: >>> >>> My biggest concern with these units is (a) lack of mechanical >>> robustness - >>> little plastic bits leak or break off quite easily and (b) lack of a >>> hardware watchdog timer which personally I think is essential esp. >>> when >>> you're using "development stage" firmware. We did most of the work to >>> port >>> our Qcode to run on the ubnt platform, but have decided to shelf that >>> project for another year, waiting for things to really settle down. >>> In the >>> CCTV business, there's no-one around to power-cycle the equipment and >>> unrecoverable device hangs are really a disaster. I realize that the >>> ISP >>> business is a little different because the customer can always reboot >>> the >>> CPE! >>> >>> Tom S. >>> >>> ----- Original Message ----- >>> From: "Robert West" <robert.w...@just-micro.com> >>> To: <jai...@budget.net>; "'WISPA General List'" <wireless@wispa.org> >>> Sent: Saturday, December 19, 2009 7:55 AM >>> Subject: Re: [WISPA] Ubiquiti ready for prime time? >>> >>> >>>> I'm with ya on all that, Jamie. We've had minor issues but I expected >>>> things to not be perfect, they never are with version 1.0! The trade off >>>> is >>>> worth it, for me anyhow. >>>> >>>> Bob- >>>> >>>> >>>> -----Original Message----- >>>> From: wireless-boun...@wispa.org [wireless-boun...@wispa.org] On >>>> Behalf Of jai...@budget.net >>>> Sent: Saturday, December 19, 2009 10:26 AM >>>> To: WISPA General List >>>> Subject: Re: [WISPA] Ubiquiti ready for prime time? >>>> >>>> >>>> We use all UBNT and I have been very happy with the equipment. >>>> Tower has 2 Rocket M5s With 120 sectors, backhaul is Rocket M5s with >>>> the Rocket Dish. CPEs are Nano M5. Durring testing at 4 Miles with >>>> CPE to AP I was able to sustain symmetrical speeds of 75M to our >>>> test server on the other end of the backhaul. I was really amazed at >>>> how well they preformed for the price. I have read all the horror >>>> stories in the UBNT forums but have yet to have one problem. Probably >>>> just cursed myself and should of kept my mouth shut. But so far so >>>> good. >>>> On Sat 12/19/09 6:35 AM , Mike m...@aweiowa.com sent: >>>> I was almost ready to pull the trigger on some Ubiquiti equipment >>>> for >>>> a new project. The scent of low price is alluring. Then I start >>>> reading about connectors pulling out, connectors not soldered on >>>> properly, and the wrong boot code on boards. >>>> Is it too early? Should I wait a bit before I dive in? Has the >>>> haste to get product into the distribution stream compromised >>>> quality >>>> control? Is the low price just too good to be true? I'd be >>>> interested in some constructive thoughts and analysis. >>>> Thanks mg >>>> >>>> --------------------------------------------------------------------------->>>> - >>>> ---- >>>> WISPA Wants You! 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