rebooting my cable modem: why?
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How did you get Windows to stop rebooting for updates?
Where did I say that? The closest approximation to what you're claiming I said is that there are routers that have to be rebooted more frequently than some of my Windows systems (or words to that effect--they're still there for you to go back to and re-read).
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Even if you allocate all memory in the initialization phase and even if you do not use any dynamic tricks - such as recursion, dynamic function calls or the like - there could still be a problem. If the programmer is a bit sloppy s/he could forget to initialize a variable (for example a pointer variable). If that variable is used only in certain situations that could cause a problem then. Another common situation is not to handle all exceptions. An given exception may be very rare and thus forgotten about, until that day of doom when a situation occurs that throws the exception. If that one is not handled or handled in the wrong way we also have a problem that will cause the state of the modem into unknown land. Suddenly a variable may have a new value that stopped parsing or whatever. Communication devices must be designed to deal with any kinds of interrupts at all time. It is complicated to test if the software is stable under all circumstances and the cheaper the device is, the lesser time to test is give the developer. So, lack of testing could also be a problem. It all leads up to the situation:
1 In the beginning - all is fine
2 In due cause something happens
3 That something changes the state of the modem into uncertainty
4 Now the modem is behaving "strange"
5 So: Reboot it and go back to 1.That is my take on why you should reboot your hardware from time to time...
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I was told that the best reason to regularly reboot your router is that when glitches happen, the modem negotiates to find a slower speed that would work, but it never tries to negotiate for a faster speed. So as time goes by and glitches occur, it's going slower and slower until you reset it by rebooting it. Either way, I'm finding weekly reboots are becoming necessary for my router. I should test it to see if a simple software reboot fixes it, or if it truly needs the power off/wait 30 seconds/power on process we've been doing, since I could do the software reboot from anywhere on the wifi, without a trip to the basement.
RDM Jr wrote:
was told that the best reason to regularly reboot your router is that when glitches happen, the modem negotiates to find a slower speed that would work, but it never tries to negotiate for a faster speed. So as time goes by and glitches occur, it's going slower and slower until you reset it by rebooting it.
:thumbsup: That is a very interesting point and seems to match the experience.
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I'm glad I'm not the only analog electronic fan (in some areas) For example I'm fed up with digital switches that keep draining batteries even when you switch off (Hey Sony A7 or Thinkpad8, can you hear me?) or refuse to power on when you switch on and you have to hold the switch down for 1 minute 😡 And then do you want to compare the pleasure and comfort to feel with your fingers a phisical switch you can operate even in the dark vs a touch one? How about the pleasure to fine tune FM radio with an analog tuning wheel vs a beeping digital RDS scanner deciding instead of you which tunes are ok to play and which ones are to bypass? An analog volume amp vs a digital one? The 1st analog walkman and its headphones vs the new digital players with earbuds? The 80s analog HiFi systems vs the current digital micro HiFi? Am i the only analog nostalgic? Please bring back some old school analog devices 🙏 even at premium price I'd buy some
AReady wrote:
How about the pleasure to fine tune FM radio with an analog tuning wheel vs a beeping digital RDS scanner deciding instead of you which tunes are ok to play and which ones are to bypass?
Yes!
AReady wrote:
The 1st analog walkman and its headphones vs the new digital players with earbuds?
:thumbsup::thumbsup::thumbsup: Definitely. I loved my walkman. Some analog items really are nicer. But, link at all the new blinkenlights - that is all that matters now. :D
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How did you get Windows to stop rebooting for updates?
Easy Peasy! Don't go past Win7. I haven't (and won't). No one modifies and reboots MY machine unless I want them to.
"The difference between genius and stupidity is that genius has its limits." - Albert Einstein
"If you are searching for perfection in others, then you seek disappointment. If you seek perfection in yourself, then you will find failure." - Balboos HaGadol Mar 2010
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I'm glad I'm not the only analog electronic fan (in some areas) For example I'm fed up with digital switches that keep draining batteries even when you switch off (Hey Sony A7 or Thinkpad8, can you hear me?) or refuse to power on when you switch on and you have to hold the switch down for 1 minute 😡 And then do you want to compare the pleasure and comfort to feel with your fingers a phisical switch you can operate even in the dark vs a touch one? How about the pleasure to fine tune FM radio with an analog tuning wheel vs a beeping digital RDS scanner deciding instead of you which tunes are ok to play and which ones are to bypass? An analog volume amp vs a digital one? The 1st analog walkman and its headphones vs the new digital players with earbuds? The 80s analog HiFi systems vs the current digital micro HiFi? Am i the only analog nostalgic? Please bring back some old school analog devices 🙏 even at premium price I'd buy some
I partially agree, but maybe for more "abstract" / conceptual reasons. When a value is measured as opposed to counted, it the value is analogous to the real world phenomenon, you have an analog value. I hate digital speedometer, where I must continuously interpret a numeric value and compare it mathematically to the speed limit … It does not require any major mental effort, but it is so indirect! My speed is a natural phenomenon, completely independent on Arabic numerals in a base 10 number system. The speed limit is a point on a continuous scale, and the needle should not move past that point. Simple and direct. Watches are similar: Twice as long time is twice as large movement. Direct and logical. Then comes these who make everything into curves and bars and whathaveyou. I've seen recipes showing that you need five apples as a bar of length 5, rather than as 5 countable apple icons. Please leave countable values in the countable domain! (Or as we computer guys say: As integers.)
AReady wrote:
How about the pleasure to fine tune FM radio with an analog tuning wheel vs a beeping digital RDS scanner
This is where I am beginning to disagree somewhat ... Sound is, in its nature, analog. The selection of one radio channel among a countable set of channels is not an analog operation. Conceptually, it belongs in the digital domain. Furthermore: We have had all digital DAB radio for three years in Norway. Three years completely free of hiss due to poor signal. Free of electrically induced nose - car ignition and such. Free of interference from neighboring channels. From a technical viewpoint it has some great advantages as well: It is extremely modest in frequency and bandwidth requirements: A 2 MHz frequency band covers the entire country; you never need to allocate another transmission channel (frequency) for that set of program channels. A transmitter draws a fraction of the electrical power of an FM transmitter covering the same area, carrying 12-20 program channels rather than a single one. If the signal from the transmitter to the north is too weak, and so is the signal from the one to the south, maybe the sum of those two signals is good enough. If it is not, there is no need to set up a huge full power transmitter between them: A small, cheap transmitter that adds to the two (or more, or one) existing signal to raise it up to the required level. There are several countable, non-continuous aspects
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How did you get Windows to stop rebooting for updates?
I sometimes get nostalgic, remembering that "Made for Windows 95"(*) sticker: To be granted permission to put that on your product (ads, package etc.), there was a set of requirements you had to satisfy. One of them was that installation/uninstallation should not require any restart. This was considered a major step forward - from the DOS days onward, we were used to most software installation requiring a reboot. I believe this was upheld for Win98, but for XP, the no-reboot requirement was gone, and it has been gone since (although the facilities for making no-reboot installers are a lot better today than they were for Win95). I can - sort of - excuse MS for requiring reboot after updates of OS kernel modules (but talk to those making e.g. telephone switch software: Every module, kernel or not, must be replaceable without rebooting the switch). A few years ago, when Windows updates were downloaded and run one by one, most of them did not require a reboot. Nowadays, with everything wrapped up into a composite package, chances are high that at least one of the components sits so deep into the core of the OS that a reboot is required. A small update may happen to comprise only no-reboot components; there is no rule requiring an update after every Windows update. (*) Maybe I do not remember the wording "Made for Windows95" correctly; it may have been slightly different.
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Even if you allocate all memory in the initialization phase and even if you do not use any dynamic tricks - such as recursion, dynamic function calls or the like - there could still be a problem. If the programmer is a bit sloppy s/he could forget to initialize a variable (for example a pointer variable). If that variable is used only in certain situations that could cause a problem then. Another common situation is not to handle all exceptions. An given exception may be very rare and thus forgotten about, until that day of doom when a situation occurs that throws the exception. If that one is not handled or handled in the wrong way we also have a problem that will cause the state of the modem into unknown land. Suddenly a variable may have a new value that stopped parsing or whatever. Communication devices must be designed to deal with any kinds of interrupts at all time. It is complicated to test if the software is stable under all circumstances and the cheaper the device is, the lesser time to test is give the developer. So, lack of testing could also be a problem. It all leads up to the situation:
1 In the beginning - all is fine
2 In due cause something happens
3 That something changes the state of the modem into uncertainty
4 Now the modem is behaving "strange"
5 So: Reboot it and go back to 1.That is my take on why you should reboot your hardware from time to time...
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buttons never had this problem. However, actually - after getting a 1/2 decent car-stereo, I wouldn't buy an analog unit if they were free. The DSP and the included impulse responses can make poorly positioned speakers magically sound like they've moved from calf-height to shoulder height. I could never wrap my head around that before looking at convolution, fast fourier transform and a bunch of other software tricks. Tricks unavailable without a cpu.
enhzflep wrote:
The DSP and the included impulse responses can make poorly positioned speakers magically sound like they've moved from calf-height to shoulder height.
Not only speaker placement and such... In 2016, the last year before Norway closed down FM transmissions in favor of DAB, I spent weekends and summer vacation driving up and down the country to compare signal and sound quality. I upgraded my car radio to a quite expensive one, but also tested with a cheap, battery portable radio, with no fancy circuitry. In locations where the signal was so weak that you could hardly make anything out of the "slightly modulated noise" in the portable, the sound from the expensive, heavily DSP-equipped car radio was … well, certainly not without distortion, but it was certainly well within the acceptable for car listening. The only "problem" if you are in a hurry :-) is that the DSP takes time! Don't synchronize chronometers, one by a primitive, straight through radio, and the other one by a radio with heavy DSP. The latter may be at least a second or two behind.
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Allocating most memory during initialization, based on configuration parameters, is good practice in servers. I worked on telephone switches and never wrote anything recursive. But I did write some interesting code in which function #1 invoked function #2, which in turn invoked function #1. A former boss wrote the code for call waiting. When one of the calls needed something done on the other call, it sent a message. After several releases the code stumbled into an obscure path where the two calls just kept exchanging messages, creating an overload situation. Although there was code to guard against one call getting into an infinite loop, this hadn't been anticipated. When the code was fixed, defensive code was also added to guard against any one call using an unbecoming percentage of the CPU time.
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Greg Utas wrote:
But I did write some interesting code in which function #1 invoked function #2, which in turn invoked function #1.
That counts as (indirect) recursion! I understand that it was unintentional. If that had happened in a no-stack implementation (such as classical Fortran), your program would be likely to crash when control returned to the first function #1, or at least upon return from it - possibly long time after the second call of #1. You did not tell whether this indirect recursion caused problems or not! Did this happen in a stack based environment, saving the situation, or do you recall it because it failed? (recursion, n.: When you first curse because of the crash, then recurse when you understand why it crashed.)
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Greg Utas wrote:
But I did write some interesting code in which function #1 invoked function #2, which in turn invoked function #1.
That counts as (indirect) recursion! I understand that it was unintentional. If that had happened in a no-stack implementation (such as classical Fortran), your program would be likely to crash when control returned to the first function #1, or at least upon return from it - possibly long time after the second call of #1. You did not tell whether this indirect recursion caused problems or not! Did this happen in a stack based environment, saving the situation, or do you recall it because it failed? (recursion, n.: When you first curse because of the crash, then recurse when you understand why it crashed.)
It certainly is recursion. Mutual recursion, perhaps? It was deliberate, and in a stack-based environment, but it would rarely occur. The code is still running after more than 30 years, and I doubt it has ever recursed beyond one level, although it would be possible to set up a test where it did.
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Memory fragmentation. Not all memory allocations are the same size and short of garbage collection memory will eventually fragment, even with the best allocation strategies.
Even garbage collection may leave the heap with external fragmentation. If you want GC to leave a heap with no external fragmentation, either the GC must trace every pointer update in all software, which is rather intrusive. In languages allow casting between pointer and non-pointer types, the task of tracing e.g. the use of an integer that has received a (int)pointer value is non-trivial. Or you must add another level of indirection for all heap access: The code "pointer" is really an index (or "handle") into a pointer table, the only place where the actual heap pointer is found. This strategy is used in some systems, like for some Windows structures, and, I believe, JVM. This adds a (small) execution overhead, but the biggest problem is that it is poorly fit for systems manipulating addresses directly, such as C/C++ pointer arithmetic. In some old architectures, now more or less completely forgotten, indirect memory addressing was directly supported by hardware. One of the few that enjoyed a (short, very short!) commercial life was the Intel 432 CPU. In the 1980s, there was a whole crowd of experimental, one-of-a-kind, such "capability based" machines. Typically, the pointer table also had a lot of access control flags etc., and could support virtual memory. (Sometimes, I wish that Intel brushed up that 432 architecture so that it could be used in modern systems - it did have a number of interesting features!) The primary task of GC is to detect inaccessible memory block blocks to have them freed, and to combine neighboring free blocks into a single larger one. Packing memory blocks comes as an extra.
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Invariably I have to reboot my cable modem. It is more rare than at the last place I lived -- we get much higher speeds here and it is more consistent. However, I still have to reboot sometimes. Will the Real Engineer, Please Standup? Please Standup! Can someone tell me why this helps? Do the bits get stuck in there and clog things up? 1. What are the real reasons that cycling power helps? 2. If that helps, why don't they have a button that lets just the specific firmware be rebooted? (kind of ridiculous question, but it'd be nice.) Ok, now I'll just sit back and wait for the answers to start pouring in. :rolleyes:
One thing that happens to cable modems is that they lose sync with the incoming signal and cannot ever re-acquire sync. When you reboot, it gets to start the sync process from scratch. Another thing may be memory fragmentation. Your router is running a small linux O/S and a piece of software written in C that is about 30 years old, with some company-specific patches slapped in there to make it look different from the generic software. With various network handshakes that can be broken in the middle, it's not too hard to believe that cruft builds up in the memory until the router chokes.
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Good question. Most routers are based on Linux. The Linux weenies claim Linux gets great uptime. So why do some routers need to be rebooted more often than I have to reboot my Windows machine (of all things)...?
Are you sure that it is "real" Linux, or just "Linux-like"? I have never been working with routers specifically, so you may be right. Lots of monitors / OS / executives / kernel (whatever you call it) present themselves as "Linux-like", and it doesn't take very much to claim to be Linux-like. Often it has a tiny little fraction of the API, with "what is needed", with identical function declarations, but the implementation is completely independent and not based on Linux source code. I started working with embedded systems using the 8-bit 8051 architecture. Even for the 8051, there were people claiming to have Linux-like kernels. Chips of today are far more powerful, and many of them could run "true" Linux, but you will usually try to keep RAM size down to reduce both cost and power consumption. There generally is no need for a significant part of the Linux functionality. If you look up "List of embedded operating systems" in Wikipedia, there is a long list not in the "Embedded Linux" category (but the majority of them would claim to be "Linux-like" - or at least many of their users would say so). On the other hand: The task of IP routing requires so much processing resources that I guess the extra burden of running a "full" Linux may not make that much difference. :-) (Nostalgia: 25 years ago, I was supervisor for a student project setting up a 8-to-8 switch: This was a single AT-bus board with eight 155 Mbps lines in, 8 out. Ideally, if none of the outputs were fed more than 155 Mbps, this AT-board could reach a throughput 0f 1.24 Gbps, which was quite a feat in 1995. But that was ATM routing, not IP routing.)
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I was told that the best reason to regularly reboot your router is that when glitches happen, the modem negotiates to find a slower speed that would work, but it never tries to negotiate for a faster speed. So as time goes by and glitches occur, it's going slower and slower until you reset it by rebooting it. Either way, I'm finding weekly reboots are becoming necessary for my router. I should test it to see if a simple software reboot fixes it, or if it truly needs the power off/wait 30 seconds/power on process we've been doing, since I could do the software reboot from anywhere on the wifi, without a trip to the basement.
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One thing that happens to cable modems is that they lose sync with the incoming signal and cannot ever re-acquire sync. When you reboot, it gets to start the sync process from scratch. Another thing may be memory fragmentation. Your router is running a small linux O/S and a piece of software written in C that is about 30 years old, with some company-specific patches slapped in there to make it look different from the generic software. With various network handshakes that can be broken in the middle, it's not too hard to believe that cruft builds up in the memory until the router chokes.
I have never seen any protocol specification were "they lose sync with the incoming signal and cannot ever re-acquire sync". Re-synching has been an integral part of link protocols for something like 40-45 years (SDLC, HDLC). Of course there may be implementations that is incapable of doing a proper resync, but this is not a general and unavoidable problem. (A slightly funny, historical note - I believe that this was in the late 1970s: A newspaper transmitted its data to the print shop using a byte oriented protocol over an analog phone line. For some time, they experienced regular "Framing error"s, which is another way to say "Unable to synchronize properly". It was soon discovered that this occurred when a single byte was transmitted - with two or more bytes, the receiver was able to sync properly. Single-byte messages were used in one specific situation: When a positive ACKnowledge was returned. So for quite a while, until the receiver was tuned up, they interpreted a "Framing error" as a positive ACK.)
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Are you sure that it is "real" Linux, or just "Linux-like"? I have never been working with routers specifically, so you may be right. Lots of monitors / OS / executives / kernel (whatever you call it) present themselves as "Linux-like", and it doesn't take very much to claim to be Linux-like. Often it has a tiny little fraction of the API, with "what is needed", with identical function declarations, but the implementation is completely independent and not based on Linux source code. I started working with embedded systems using the 8-bit 8051 architecture. Even for the 8051, there were people claiming to have Linux-like kernels. Chips of today are far more powerful, and many of them could run "true" Linux, but you will usually try to keep RAM size down to reduce both cost and power consumption. There generally is no need for a significant part of the Linux functionality. If you look up "List of embedded operating systems" in Wikipedia, there is a long list not in the "Embedded Linux" category (but the majority of them would claim to be "Linux-like" - or at least many of their users would say so). On the other hand: The task of IP routing requires so much processing resources that I guess the extra burden of running a "full" Linux may not make that much difference. :-) (Nostalgia: 25 years ago, I was supervisor for a student project setting up a 8-to-8 switch: This was a single AT-bus board with eight 155 Mbps lines in, 8 out. Ideally, if none of the outputs were fed more than 155 Mbps, this AT-board could reach a throughput 0f 1.24 Gbps, which was quite a feat in 1995. But that was ATM routing, not IP routing.)
Member 7989122 wrote:
Are you sure that it is "real" Linux, or just "Linux-like"?
That's really the key, isn't it? In Linux's defense, how hard do you have to work at it to take some Linux source, make a change, and as a result destabilize it so badly that you now have a version that has to be rebooted every few days?
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One thing that happens to cable modems is that they lose sync with the incoming signal and cannot ever re-acquire sync. When you reboot, it gets to start the sync process from scratch. Another thing may be memory fragmentation. Your router is running a small linux O/S and a piece of software written in C that is about 30 years old, with some company-specific patches slapped in there to make it look different from the generic software. With various network handshakes that can be broken in the middle, it's not too hard to believe that cruft builds up in the memory until the router chokes.
Great information, thanks.
SeattleC++ wrote:
and a piece of software written in C that is about 30 years old,
Is this some library you are talking about? I know you're extrapolating the information but I'm curious about which library or component or what you are referring to, just because I'm curious. It is interesting that people take software that works "good enough" and slap another layer onto it. Gotta get 'er dun! :laugh: :laugh:
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Great information, thanks.
SeattleC++ wrote:
and a piece of software written in C that is about 30 years old,
Is this some library you are talking about? I know you're extrapolating the information but I'm curious about which library or component or what you are referring to, just because I'm curious. It is interesting that people take software that works "good enough" and slap another layer onto it. Gotta get 'er dun! :laugh: :laugh:
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I partially agree, but maybe for more "abstract" / conceptual reasons. When a value is measured as opposed to counted, it the value is analogous to the real world phenomenon, you have an analog value. I hate digital speedometer, where I must continuously interpret a numeric value and compare it mathematically to the speed limit … It does not require any major mental effort, but it is so indirect! My speed is a natural phenomenon, completely independent on Arabic numerals in a base 10 number system. The speed limit is a point on a continuous scale, and the needle should not move past that point. Simple and direct. Watches are similar: Twice as long time is twice as large movement. Direct and logical. Then comes these who make everything into curves and bars and whathaveyou. I've seen recipes showing that you need five apples as a bar of length 5, rather than as 5 countable apple icons. Please leave countable values in the countable domain! (Or as we computer guys say: As integers.)
AReady wrote:
How about the pleasure to fine tune FM radio with an analog tuning wheel vs a beeping digital RDS scanner
This is where I am beginning to disagree somewhat ... Sound is, in its nature, analog. The selection of one radio channel among a countable set of channels is not an analog operation. Conceptually, it belongs in the digital domain. Furthermore: We have had all digital DAB radio for three years in Norway. Three years completely free of hiss due to poor signal. Free of electrically induced nose - car ignition and such. Free of interference from neighboring channels. From a technical viewpoint it has some great advantages as well: It is extremely modest in frequency and bandwidth requirements: A 2 MHz frequency band covers the entire country; you never need to allocate another transmission channel (frequency) for that set of program channels. A transmitter draws a fraction of the electrical power of an FM transmitter covering the same area, carrying 12-20 program channels rather than a single one. If the signal from the transmitter to the north is too weak, and so is the signal from the one to the south, maybe the sum of those two signals is good enough. If it is not, there is no need to set up a huge full power transmitter between them: A small, cheap transmitter that adds to the two (or more, or one) existing signal to raise it up to the required level. There are several countable, non-continuous aspects
Wow great post, congrats! I wanted to reply yesterday but my 40EU/month ADSL from Vodafone Italy is completely unusable in the evening, the provider can't handle the incresead traffic due to covid emergency (young people stay at home watching netflix instead of going out) Regarding the 1st part of your comment about converting infinite scale signals into finite entities (digits) I guess it's all about resolution. If the converter has more resolution than our senses can perceive than there is no difference between digital and analog, that can apply to color or sound fidelity for example. My original comment however was more about the "feeling" you get while using a device. With analog devices I could get more physical feelings. When I was a teen in the 80s I had a great experience listening to my pocketable analog stereo radio on my bed using over-the-ear headphones (same as 1st walkman model) . The tuning wheel was so precise and sensitive I could feel like almost catching the waves with my fingers, If I heard a nice song a bit disturbed I could easily adjust the quality by moving a bit the radio in my hands. Overall I could listen a sound full of juice and with wide open stereo, yes maybe a bit of background white noise but overall I got very good vibes and feelings. Current pocketable devices sounds dull in my opinion and the interaction gives no "physical" feelings. It's difficult to describe but I hope you understand what I mean. Another pleasent "analog" experience I forgot to mention is car A/C. Until early 2000 you could find cars with manual A/C, that is you tune the temperature with a mechanical wheel. I loved that because I could fine tune the temperature based on my physical feeling and I could do it while keeping my eyes and focus on the road. Today you have touch screen UI where temperature is chosen by clicking a touch screen icon '<' or '>' and it increments the desired temperature number to 20, 21, etc. with a stupid sensor placed who knows where that decide instead of me how much cool air to pump in. When you click the icon you risk an incident because your eyes and focus go on the touch screen 😱 Car assistant can help but once I rent a car that suddenly started to talk French for a software bug 😱 Even my Philips razor and hair cutter are now digital with touch screen interface, lcd displays and sealed li-ion batteries and often they don't do what I want. The razor software switch now randomly doesn't turn on so I bought a low cost double AA battery razor with analog switch. Such
