Oh great, and my phone even has a CPU meter

These fancy-dancy IP phones never cease to make me wonder what our world has come to. I remember when a telephone was a bucket of carbon granules and a momentary switch, and the rotary dial was just a mechanism for going on and off hook at a precise frequency. (Indeed, sometimes for fun, I'll pulse-dial a phone by tapping on the hook.)

The other day, somebody sent out an email message:

I'm amusing myself watching the "CPU Load" graph on the phone. Then again, I'm easily amused.

Naturally, the CPU meter is useless, because you can only switch to it when you're not using the phone. Once you pick up the handset, the CPU meter dismisses itself so you can see information about the call you're on.

Oh wait, you can go through the menus to switch back to the CPU meter after it auto-dismisses itself. Woo-hoo, now I can tell people, "Sorry, can you talk slower? My phone's CPU is maxing out."

This what-barely-qualifies-as-amusement didn't last long. A year later, the units were replaced with a different model phone that didn't have a CPU meter. Progress.

Comments (33)
  1. CmraLvr2 says:

    That’s funny.  I can think of several extended amusements.  For instance, telling someone "My phone CPU used to max out with a three-way call.  That’s why I overclocked it and added liquid cooling.  Now she hums along at 20%…"

  2. TJ says:

    The sad thing is that the company spent time developing and testing that CPU meter when, at least in my opinion, it doesn’t do anything to improve the usability or reliability of the phone. It’s a feature that unnecessarily increases the price of the phone.

    [Well, it might have been a diagnostic tool that they needed to develop anyway for debugging purposes. Just guessing. -Raymond]
  3. DWalker says:

    Wow, I used to sometimes dial the phone by tapping on the hook or hang-up button.  You had to be reasonably consistent.  One friend had a phone number with lots of zeros (10 taps) and nines, so that one was hard.

  4. Micah says:

    CmraLvr2, clearly the underlying problem is that you need a dual core cpu to use three way calling.

  5. A_me! says:

    I like this entry, simply due to the fact that by the time it was published the CPU meter had already been removed.

    "Don’t you hate the pace of progress when it’s in a useless direction?  Oh wait, it’s history now."

  6. someone else says:

    Aren’t phones real-time applications anyway? So the maximum cpu load should have been known even before compilation (or at least before deployment)!

    The CPU meter does seem quite useless, then.

  7. joel8360 says:

    "So the maximum cpu load should have been known…"

    The maximum cpu load should have been PREDICTED.

    But yeah, if it’s a diagnostic tool, it seems odd that the meter would have been deployed to consumers.

  8. someone else says:

    Real-time algorithms are usually deterministic, so the upper bound for cpu load should indeed be known.

  9. bramster says:

    Tapping the hang-up button.  I remember a place that would put a lock on the dial, so that no un-authorized long distance calls could be made by say, the cleaning staff.   Well, guess what. . .  just for fun. . .

  10. Dennis says:

    "Wow, I used to sometimes dial the phone by tapping on the hook or hang-up button.  You had to be reasonably consistent.  One friend had a phone number with lots of zeros (10 taps) and nines, so that one was hard."

    Man, I thought I was a geek! ;-)

  11. Mike says:

    I could never do the tap the hook thing.  I was able to whistle at 300 baud modems precisely enough to get them to think I was trying to connect.

  12. J says:

    "The sad thing is that the company spent time developing and testing that CPU meter when, at least in my opinion, it doesn’t do anything to improve the usability or reliability of the phone."

    Meh.  You’d be surprised how much lag time there can be between software code complete and production-level hardware.  on the phone products I worked on, I filled that time implementing new features, refactoring code, and improving usability.  You may not be able to re-allocate the engineers and test group while you wait for hardware because you might not be able to re-allocate them back easily when you need them again.


    "So the maximum cpu load should have been known…"

    Maybe like 10+ years ago.  These days you buy a chip from a vendor and say "Hey, how many concurrent calls can this support?" and they tell you.  It’s the DSP doing the real time work, and your vendor is the one who knows how much load it can support (usually in MIPS).  When you implement the non real-time stuff, you know how many MIPS you have to work with, but pre-calculating exactly what the CPU load would be once you implement your call-control logic is pretty much equivalent to cycle counting a Windows program.  Unnecessary.

    That being said, the CPU load meter probably wasn’t a real diagnostic tool, but rather something an engineer just killed time doing.  There are just simpler ways of tracking CPU load if you’re diagnosing a problem rather than implementing a CPU meter.  Or it could have been vendor-supplied code that the vendor used to show off how cool their platform was that they just included in their product.

  13. Marc says:

    I remember having a Windows 2000-like task manager for an old Windows Mobile phone. It had a CPU usage column. Useful for seeing why your battery was only lasting 10 minutes… that program hogging the CPU was probably to blame.

    But yes a fullscreen meter is pointless, and probably uses some fancy graphics that actually use more CPU power than it would be using otherwise.

  14. Torkell says:

    Speaking of pulse dialing, it’s been know for people to acidentally dial 112 (the Europe-wide emergency number) while working on their home phone wiring. All it takes is shorting the wires together a few times…

  15. Frymaster says:

    In fact, I managed to accidentally call 112 trying to hand-dial the time (123) :/

  16. someone else says:

    Gotta like ISDN. No annoying in-band signalling just because you got a loose cable or made the wrong sound …

  17. DEngh says:

    Maybe they put it there for *fun* because they knew geeks would enjoy it.

    >>time developing and testing

    >>quite useless

    Easter egg?  Non-critical-path and maybe just for fun.  At least for Raymond.

  18. Smart Ass says:

    100% ?

    I’m not an IP phone engineer, but I’m pretty sure that’s a fairly firm upper bound for CPU load in ANY application.


  19. Jolyon Smith says:

    Emergency calls made by the telephone network itself is the reason that the emergency number was changed from 111 to 999 (in the UK at least) – telephone wires knocking against each other in high winds resulted in 111 calls.

    999 was subsequently chosen even though it is almost the slowest 3 digit number you could dial on a rotary dial of the day (000 being the only slower one) because when dialling, it was considered the easiest to find if blind or in the dark whilst being the LEAST likely to occur as the result of a wind-storm induced false dial made by the telephone network itself.

    112, 222 etc were presumably also (more) likely to occur spontaneously/spuriously.

    Or so I seem to remember once being told.

  20. Peter says:

    Jolyon: I’ve heard the same thing. In New Zealand the dials were backwards for some reason (9 sent 1 pulse…) and hence the emergency number is 111.

    I have no explanation for where 911 comes from though…

  21. Drak says:


    Probably the 9 doesn’t occur naturally very much (hence the 999 in the UK), and if the first one doesn’t occur, then the next 2 can be the fastest possible (1).

    I think.

  22. Jared says:

    Way back when Bell Labs divided up the phone number space, x11 was reserved for system related services — 411 was information, 611 was repair, etc.  It was from this set that 911 was chosen for local emergency.

    Note also that all exchanges used to start with digits 2-9, as they all had names. 0 & 1 on the dial had no letters, so could not be used as the first two exchange digits because no name could be generated for the exchange.  

    0 was the escape number for the attendant.  1 was used as the escape to long distance direct dialing.

    Area codes were defined as x0n or x1n, (x being 2-9) as they could not be legal exchanges, and x00 & x01 were reserved for "special area codes" like the 800 & 900 service.  8nn codes (888, 877, 866, etc.) are being held for additional toll free numbers.

    I do not remember when 555 was restricted as an exchange.  A couple of other exchange values, like 947, were also never assigned.  

    555 is now a dead prefix (except for 555-1212 for information) useful for dummy phone numbers in books and TV scripts.  

    947 got picked up when a "caller pays extra" 900 type number was needed that could be easily blocked by equipment that was hard-wired to let area codes (x0x/x1x) automatically pass as legitimate long distance.

  23. Mike says:

    gotta love IP phones, no annoying in-band signaling, and you can have multiple calls on the same wire *and* you can use cheap commodity hardware!

  24. someone else says:

    @Smart Ass:

    Well … no. System load may pass 100% (e.g. two thread with a deadline of 3 cycles when you have only 4 left). Of course, this will cause (hard) real-time apps to fail.

  25. Walter says:

    The classic Bjarne Stroustrup quote is "I have always wished for a computer that would be as easy to use as my telephone. My wish came true. I no longer know how to use my telephone."

    I can never get over the fact that the phone on my desk has an IP address.  It even has a button marked LOCIP that causes it to read the IP address aloud in a mechanical monotone.

  26. zizebra says:

    Oh my god! My phone is frozen, the cpu meter isnt changing. Can you please hold on While I reboot my phone

  27. Zero says:

    I picked up a rotary phone for my mom about a year ago — with working bell ringer and everything and she loves it.

    The only problem is when she can’t get through an automated menu because it won’t even auto-connect to a human when no tones are produced.

  28. tanjayuser says:

    You might be having a phone that is running WinCE. So, it might ship with a CPU meter app just to make things easy to debug, for eg, when you are experiencing packet loss. If the CPu is pegged, it might lead to dropped audio packets, which causes audio clipping.

  29. Wince says:

    If the phone would be running windows the load would be constant 100%.

  30. Dude says:

    It would be cool with a graphical realtime spectrum analyzer in the phone’s display.

  31. johndill says:

    In high school the phones were locked with a rotary lock that prevented you turning the dial. With practice we could dial using the hook switch, but even easier was hitting it 10 times quickly. "Operator, I’ve been trying to reach 555-1212 for the past half hour and I can’t seem to get through, could you try the number for me?"

  32. 이성호 says:


    저는 한글을 잘 하죠

    안녕 잘가 사과 오랜지

    저는 한국에서태어났어요~

  33. 이성호 says:


    저는 한글을 잘 하죠

    안녕 잘가 사과 오랜지

    저는 한국에서태어났어요~

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