I expect the timing issue is due to the fact that in the telephony world, if you have a phone switch (a Class 5 Phone switch) and are using a TDM circuit from that switch (A T-1/DS-1, DS-3, OC-3, and so on) you must submit to the timing produced on the circuit from the phone switch...if you didn't, and produced your own timing, then inevitably, you would end up with echo. (This is the way it works in all traditional telephony.) If the device at the other end isn't providing a timing source, you must provide one, so a timing "generator" (loosely defined - read more about Digital Channels and Time Division Multiplexing (TDM)) is included in most equipment that acts as a digital device that would serve a connection to an endpoint (A T-1 to a PBX, for instance)
In any case, that is why the Asterisk code relies on the timing from their PRI/T-1 cards, since you *must* do so to avoid echo, if the other end is providing the timing source. If it isn't, Asterisk still relies on that clock, if it exists, since it will produce the timing for any circuits connected to it. If no such card exists, Asterisk tries to get the timing from some other source - a special module in the kernel, or the USB stack, trying to derive some source of timing that will remain reliable and steady over time.
I'm not saying that there aren't other ways to do this, but coming from a telephony background, it was a decent decision at the time. There are also external timing sources used in a lot of telephony devices, and I'm certain Digium could find, or has found, a way to make use of them as well. This is all dependent on the fact that you'll be interfacing with the PSTN. If you are working with pure VoIP, the timing in this sense is irrelevant, and you need to coordinate other things (such as jitter, QoS, packet delay, and bandwidth) and you shouldn't need a timing source. Apparently, Asterisk still needs this timing source due to the structure of it's code.
Another one that seems to be gaining a lot of traction and backed by a lot of online help, is PBX in a Flash - it is created and supported by Nerd Vittles.
They have loads of info on their site, including the obvious requests, like how to setup a new system quick & easy, what phones to look for, what hardware cards or peripherals to use to interface with POTS lines, as well as a list of VoIP providers that they have reviewed and recommend (or don't,) which you can read at Providers - The Best of Nerd Vittles
They also have some stuff you might not think of, such as setting up services on your Asterisk box to tell you the weather report for a zipcode you enter on your phone's keypad, or "MailCall" which allows you to get your e-mail via the phone, or a telephone reminder system... there are lots of options, and you can find out about most of them at Applications - The Best of Nerd Vittles
Oops - redundant mod set by accident. Posting to the thread to try and negate my mod points in this discussion - stupid, laggy computer combined with dropdowns that do instant modding...oiy.
Even if you have only given your address to real human beings (that you trust not to send your address on in mass e-mail forwards,) if even one person gets a virus/piece-of-malware that grabs e-mail addresses from their computer and ships those addresses off to a repository somewhere, then your address has been compromised and will probably always be on some spammer's list somewhere.
Exactly what I was thinking! (The way LCD's produce black is to energize all the pixels that need to be black, "illuminating" them, which makes them opaque, and "get in the way" of the backlight, which is always on.) So, this would effectively *increase* the power consumption of LCD monitors, which are more prevalent everyday, and probably the majority of monitor sales these days.
In addition, you can achieve very good performance with Windows on Xen (utilizing VT/SVM processors) if you also install the Xen Paravirtualized drivers under Windows, once you have the base OS installed. You can get these drivers in the XenServer edition on the xensource.com site. (Actually, I think my coworker got the drivers running in the XenExpress edition.)
In any case, performance was significantly better with the PV drivers - in fact, when we first installed a copy of Windows under Xen, disk performance was so bad that a five-year old machine that is overloaded was serving up a website faster than the virtualized version of Windows. After we installed the PV drivers (and rebooted the Windows VM,) performance was near native (we have two of these servers, and were doing exhaustive tests on both at the same time using both benchmarking tools and real-life tests, one had Windows installed natively, one had Xen + Windows.)
After further testing, we were so impressed, we put it into production. On the Xen machine, there are two Windows guests and one Linux guest. Windows 1 hosts the Asp.NET website, Windows 2 hosts MS SQL Server 2005 Express, and the Linux VM hosts DNS services. There are real-world websites running on this platform and performance is great. Notice, I didn't say "adequate" or "good" - it really is great, and we plan to put four more servers into production with a similar type of configuration for various purposes.
I, too, still rattle off things that I learned on that show that amaze people. Like one poster above, I remember the ping pong balls and mousetraps in a plexiglass box, I remember why wind always (naturally) blows from cold places to hot places (he did the experiment in a fish tank with a shaded side that had ice in it, and a hot side that had a light bulb or heat lamp over it, then lit and blew out a match to let the smoke follow the natural current in the fish tank), and I always remember something about "powered oxygen" or something like that - he sprinkled it on some sugar-loaded cereal, then spritzed some water on it and it burst into flames, consuming the sugar as fuel.
I loved that show! It was one of my favorite shows growing up, too.
Rest in peace, Mr. Herbert! You inspired many and will be missed.
Watching the video reminded me of the gameplay of Castelvania: Symphony of the Night, as well - the general layout of passageways, getting locked off with a boss (the one under-water statue-looking thing definitely reminded me of SOTN) and just some of the general movement styles/techniques... and yes, I agree, reminiscent of Super Metroid, as well. I loved both of those games, and although the last PC games I played with any devotion of time were Unreal Tournament and Starcraft, I want to give this one a try!
However, there are some of us out there that, even though we are buying a dirt-cheap computer, will wipe out the partitions on the hard drive (yes, even the dreaded Dell recovery partition), reinstall Windows, and set things up the way we would if we had purchased the hardware piece-meal and assembled it ourselves. I, personally, would prefer to get the separate hardware and build it myself. But even if I bought a Dell, I'd repartition and "start from scratch."
This applies in a business I used to work for - they wanted the absolute cheapest computer they could get...preassembled...and they wanted it to say "Dell" on the front...heh. Then, a few months (or less) from the original purchase, the boss would come to me and ask if I could install XYZ package on that computer, then want to know why it was running so slow, or why that machine was running out of hard drive space, etc....and it was always b/c it was a rock-bottom machine. If I had built it myself with the same budget, I would have cut corners in one place, and added in others (larger, faster hard drive, more memory, cheaper case, good power supply (and that doesn't mean 1000 Watts; it just means high quality, low noise, lasts for years,) etc...)
Or that El-Cheapo machine would suddenly be turned into a server for some new service we were building....and the network card or video card wouldn't work in FreeBSD, Linux, or Novell Netware 4.x series (whichever was necessary for the task at hand.)
So, go ahead and criticize the people trying to post proof that a system can be built for the same price, or cheaper, than a Dell (or other common name brand with big discounts at their stores, whether online resellers, or local electronics shops), but this thread is relevant and helpful to some out there who might just need a little bit of motivation to build it themselves, or a little bit of motivation to put together the business argument to take to their boss, showing why the cheapest Dell computer is a bad option compared to what could be built in-house....
Fortunately, I no longer work for those cheapo's....I work for other, equally thoughtless cheapo's....but I have more of a say in what we buy here.:-)
The trouble is that there are certain kinds of work for which the OSS community shows a lot of excitement, but there are other things that they don't like to work on. Software testing isn't so much fun. Reimplementing someone else's huge, complicated, ugly spec isn't so much fun. Ditto for getting feedback from users, and fixing common problems.
While I agree that perhaps the community as a whole may not show much excitement for this kind of work, there are people that do enjoy it. I know that when I was coding professionally (switched IT career about 2 years ago), I loved, and got a thrill out of, times that I had to integrate new code into an existing architecture that wasn't very well documented, if at all.
Coding away at something, then testing it and seeing that the thing *you* just created is working with a product that no-one else wants to try to integrate with b/c it is so "difficult", is such a thrill and personally satisfying! (For me, at least.) I'm no newbie coder fresh out of college, either, but I find that when anything sufficiently difficult you are working on Just Works, it is exciting. And I'm not saying there is a mystery to it, as I wrote the code, I know exactly what went into it and how it works, but it is still very satisfying to have it interoperate with something that is considered a "black box" (and doesn't have any documentation on it's protocols or file formats, and doesn't follow any standards.)
I know not everyone coding away at things gets that kind of satisfaction out of seemingly "simple" concepts, but I doubt I'm the only one. If I wasn't married with a 5-month old at home, and getting up at 5AM everyday to get to work, I'd be spending my nights at home working on something OSS like this - something that would benefit tons of people and is perhaps not all that exciting for some people to work on...and I definitely miss coding fulltime and I'm trying to find a way to break back into that world while still supporting my family, but right now, I can barely "hold down the fort" at home & work while getting 5-6 hours of sleep a night...so it will be a while before I can spend my evenings coding away. Perhaps once the little tyke gets a little older...but she'll probably want to play even more then...who knows?!
I strongly recommend against purchasing a Behringer mixer. I have reports from reliable people that as a company, Behringer goes out and buys a competitor's product, disassembles it, then builds one of their own using ultra-cheap components. Often times, they will keep the color scheme and in some cases, even the model name or number. This gets you a very poor-quality product having an unpredictable lifetime.
Nevermind that you get a piss-poor product for a low price - I'm ok with that, as I buy cheapo products "on the cheap" at times. The bigger problem I have is that Behringer is a completely unethical company, and will sell you crap claiming it is gold. I don't mind companies that put out crap when they spend their own money and time researching and developing said crap.
If you want a very quiet mixer (little noise introduced into the system from the mixer itself), try Allen & Heath, or one or two others, though I hear Mackey boards have a noise problem (sounds like static on the output.)
I'm not bashing Behringer because I got burned by them or anything like that - I just don't want to see anyone getting bad products from an unethical company that should be run out of business, when there are much higher-quality products that are very similar or exactly the same, for just a little bit more money.
I believe you mean "NEBS Compliance" not "NUBS" -- in particular, the most common reference is NEBS Level 3 compliance, which is most often related to "Carrier Class" equipment. This generally means the equipment will operate for years (decades, perhaps) at a time without being turned off and must have certain redundant parts, fire resistance, etc.
I, too, use a spreadsheet for quick spot checking of data prior to actually processing it in any more meaningful way, be that through a short script, inserted into a db for whatever reason, etc. I, too, am irritated by the row limit in Access and OO.o, and am looking for the same answer as you.
I just wanted to support your question and situation and let you know that I understand your use of the spreadsheet for quick checks of data consistency, median values, etc. If I find a good solution to your situation, of course I'll post it for all to see.
Slashdot Mirror
Mercedes Benz does often put the battery in the trunk or under the rear seat.
I expect the timing issue is due to the fact that in the telephony world, if you have a phone switch (a Class 5 Phone switch) and are using a TDM circuit from that switch (A T-1/DS-1, DS-3, OC-3, and so on) you must submit to the timing produced on the circuit from the phone switch...if you didn't, and produced your own timing, then inevitably, you would end up with echo. (This is the way it works in all traditional telephony.) If the device at the other end isn't providing a timing source, you must provide one, so a timing "generator" (loosely defined - read more about Digital Channels and Time Division Multiplexing (TDM)) is included in most equipment that acts as a digital device that would serve a connection to an endpoint (A T-1 to a PBX, for instance)
In any case, that is why the Asterisk code relies on the timing from their PRI/T-1 cards, since you *must* do so to avoid echo, if the other end is providing the timing source. If it isn't, Asterisk still relies on that clock, if it exists, since it will produce the timing for any circuits connected to it. If no such card exists, Asterisk tries to get the timing from some other source - a special module in the kernel, or the USB stack, trying to derive some source of timing that will remain reliable and steady over time.
I'm not saying that there aren't other ways to do this, but coming from a telephony background, it was a decent decision at the time. There are also external timing sources used in a lot of telephony devices, and I'm certain Digium could find, or has found, a way to make use of them as well. This is all dependent on the fact that you'll be interfacing with the PSTN. If you are working with pure VoIP, the timing in this sense is irrelevant, and you need to coordinate other things (such as jitter, QoS, packet delay, and bandwidth) and you shouldn't need a timing source. Apparently, Asterisk still needs this timing source due to the structure of it's code.
Another one that seems to be gaining a lot of traction and backed by a lot of online help, is PBX in a Flash - it is created and supported by Nerd Vittles.
They have loads of info on their site, including the obvious requests, like how to setup a new system quick & easy, what phones to look for, what hardware cards or peripherals to use to interface with POTS lines, as well as a list of VoIP providers that they have reviewed and recommend (or don't,) which you can read at Providers - The Best of Nerd Vittles
They also have some stuff you might not think of, such as setting up services on your Asterisk box to tell you the weather report for a zipcode you enter on your phone's keypad, or "MailCall" which allows you to get your e-mail via the phone, or a telephone reminder system... there are lots of options, and you can find out about most of them at Applications - The Best of Nerd Vittles
There are also forums for lots of this stuff:
Nerd Vittles Forum
Voxilla VoIP Forum
PBX in a Flash Script Site
And, of course, the venerable VoIP Wiki at voip-info.org
Oops - redundant mod set by accident. Posting to the thread to try and negate my mod points in this discussion - stupid, laggy computer combined with dropdowns that do instant modding...oiy.
Even if you have only given your address to real human beings (that you trust not to send your address on in mass e-mail forwards,) if even one person gets a virus/piece-of-malware that grabs e-mail addresses from their computer and ships those addresses off to a repository somewhere, then your address has been compromised and will probably always be on some spammer's list somewhere.
Exactly what I was thinking! (The way LCD's produce black is to energize all the pixels that need to be black, "illuminating" them, which makes them opaque, and "get in the way" of the backlight, which is always on.) So, this would effectively *increase* the power consumption of LCD monitors, which are more prevalent everyday, and probably the majority of monitor sales these days.
In addition, you can achieve very good performance with Windows on Xen (utilizing VT/SVM processors) if you also install the Xen Paravirtualized drivers under Windows, once you have the base OS installed. You can get these drivers in the XenServer edition on the xensource.com site. (Actually, I think my coworker got the drivers running in the XenExpress edition.)
In any case, performance was significantly better with the PV drivers - in fact, when we first installed a copy of Windows under Xen, disk performance was so bad that a five-year old machine that is overloaded was serving up a website faster than the virtualized version of Windows. After we installed the PV drivers (and rebooted the Windows VM,) performance was near native (we have two of these servers, and were doing exhaustive tests on both at the same time using both benchmarking tools and real-life tests, one had Windows installed natively, one had Xen + Windows.)
After further testing, we were so impressed, we put it into production. On the Xen machine, there are two Windows guests and one Linux guest. Windows 1 hosts the Asp.NET website, Windows 2 hosts MS SQL Server 2005 Express, and the Linux VM hosts DNS services. There are real-world websites running on this platform and performance is great. Notice, I didn't say "adequate" or "good" - it really is great, and we plan to put four more servers into production with a similar type of configuration for various purposes.
I, too, still rattle off things that I learned on that show that amaze people. Like one poster above, I remember the ping pong balls and mousetraps in a plexiglass box, I remember why wind always (naturally) blows from cold places to hot places (he did the experiment in a fish tank with a shaded side that had ice in it, and a hot side that had a light bulb or heat lamp over it, then lit and blew out a match to let the smoke follow the natural current in the fish tank), and I always remember something about "powered oxygen" or something like that - he sprinkled it on some sugar-loaded cereal, then spritzed some water on it and it burst into flames, consuming the sugar as fuel.
I loved that show! It was one of my favorite shows growing up, too.
Rest in peace, Mr. Herbert! You inspired many and will be missed.
Watching the video reminded me of the gameplay of Castelvania: Symphony of the Night, as well - the general layout of passageways, getting locked off with a boss (the one under-water statue-looking thing definitely reminded me of SOTN) and just some of the general movement styles/techniques... and yes, I agree, reminiscent of Super Metroid, as well. I loved both of those games, and although the last PC games I played with any devotion of time were Unreal Tournament and Starcraft, I want to give this one a try!
However, there are some of us out there that, even though we are buying a dirt-cheap computer, will wipe out the partitions on the hard drive (yes, even the dreaded Dell recovery partition), reinstall Windows, and set things up the way we would if we had purchased the hardware piece-meal and assembled it ourselves. I, personally, would prefer to get the separate hardware and build it myself. But even if I bought a Dell, I'd repartition and "start from scratch."
:-)
This applies in a business I used to work for - they wanted the absolute cheapest computer they could get...preassembled...and they wanted it to say "Dell" on the front...heh. Then, a few months (or less) from the original purchase, the boss would come to me and ask if I could install XYZ package on that computer, then want to know why it was running so slow, or why that machine was running out of hard drive space, etc....and it was always b/c it was a rock-bottom machine. If I had built it myself with the same budget, I would have cut corners in one place, and added in others (larger, faster hard drive, more memory, cheaper case, good power supply (and that doesn't mean 1000 Watts; it just means high quality, low noise, lasts for years,) etc...)
Or that El-Cheapo machine would suddenly be turned into a server for some new service we were building....and the network card or video card wouldn't work in FreeBSD, Linux, or Novell Netware 4.x series (whichever was necessary for the task at hand.)
So, go ahead and criticize the people trying to post proof that a system can be built for the same price, or cheaper, than a Dell (or other common name brand with big discounts at their stores, whether online resellers, or local electronics shops), but this thread is relevant and helpful to some out there who might just need a little bit of motivation to build it themselves, or a little bit of motivation to put together the business argument to take to their boss, showing why the cheapest Dell computer is a bad option compared to what could be built in-house....
Fortunately, I no longer work for those cheapo's....I work for other, equally thoughtless cheapo's....but I have more of a say in what we buy here.
Yep, it's called WSUS (Windows Server Update Services) and can be found at: http://www.microsoft.com/windowsserversystem/updat eservices/default.mspx
(Or if you can't cut & paste, simply type www.microsoft.com/wsus)
Coding away at something, then testing it and seeing that the thing *you* just created is working with a product that no-one else wants to try to integrate with b/c it is so "difficult", is such a thrill and personally satisfying! (For me, at least.) I'm no newbie coder fresh out of college, either, but I find that when anything sufficiently difficult you are working on Just Works, it is exciting. And I'm not saying there is a mystery to it, as I wrote the code, I know exactly what went into it and how it works, but it is still very satisfying to have it interoperate with something that is considered a "black box" (and doesn't have any documentation on it's protocols or file formats, and doesn't follow any standards.)
I know not everyone coding away at things gets that kind of satisfaction out of seemingly "simple" concepts, but I doubt I'm the only one. If I wasn't married with a 5-month old at home, and getting up at 5AM everyday to get to work, I'd be spending my nights at home working on something OSS like this - something that would benefit tons of people and is perhaps not all that exciting for some people to work on...and I definitely miss coding fulltime and I'm trying to find a way to break back into that world while still supporting my family, but right now, I can barely "hold down the fort" at home & work while getting 5-6 hours of sleep a night...so it will be a while before I can spend my evenings coding away. Perhaps once the little tyke gets a little older...but she'll probably want to play even more then...who knows?!
I strongly recommend against purchasing a Behringer mixer. I have reports from reliable people that as a company, Behringer goes out and buys a competitor's product, disassembles it, then builds one of their own using ultra-cheap components. Often times, they will keep the color scheme and in some cases, even the model name or number. This gets you a very poor-quality product having an unpredictable lifetime.
o r/products_detail.php?product_id=616)
Nevermind that you get a piss-poor product for a low price - I'm ok with that, as I buy cheapo products "on the cheap" at times. The bigger problem I have is that Behringer is a completely unethical company, and will sell you crap claiming it is gold. I don't mind companies that put out crap when they spend their own money and time researching and developing said crap.
If you want a very quiet mixer (little noise introduced into the system from the mixer itself), try Allen & Heath, or one or two others, though I hear Mackey boards have a noise problem (sounds like static on the output.)
The particular Behringer board referenced above appears to be a copy of a Phonic mixer - perhaps the Phonic AM 642D (http://210.243.85.5/partner/modules/product_expl
I'm not bashing Behringer because I got burned by them or anything like that - I just don't want to see anyone getting bad products from an unethical company that should be run out of business, when there are much higher-quality products that are very similar or exactly the same, for just a little bit more money.
I believe you mean "NEBS Compliance" not "NUBS" -- in particular, the most common reference is NEBS Level 3 compliance, which is most often related to "Carrier Class" equipment. This generally means the equipment will operate for years (decades, perhaps) at a time without being turned off and must have certain redundant parts, fire resistance, etc.
Read more here:
http://www.nebs-faq.com/what_is_nebs_level_3.htm
http://en.wikipedia.org/wiki/NEBS
Cheers!
--DS
I second that!
I, too, use a spreadsheet for quick spot checking of data prior to actually processing it in any more meaningful way, be that through a short script, inserted into a db for whatever reason, etc. I, too, am irritated by the row limit in Access and OO.o, and am looking for the same answer as you.
I just wanted to support your question and situation and let you know that I understand your use of the spreadsheet for quick checks of data consistency, median values, etc. If I find a good solution to your situation, of course I'll post it for all to see.