Re: sysadmin qualifications (Re: apt-get vs. aptitude)
On 10/15/2013 10:06 AM, berenger.morel@neutralite.org wrote:
Le 15.10.2013 15:36, Jerry Stuckle a écrit :
If you want to confuse things by getting into the OSI model, modems
are Layer 1 (Physical). Routers are Layer 3 (Network).
Thanks for precision.
I stayed away
from this because it's mainly of interest to engineers and network
programmers; the only thing most programmers have to worry about is
Layer 7 (Application).
Honestly, I think that it is often a good idea to know what is around
your domain.
Why? Do you know how a TV signal is encoded at the station? How it is
modulated onto the carrier? The operation of the RF and IF strips in
your TV? The frequencies of the local oscillator(s) being used? How
the RF signal is demodulated? How the video and audio are decoded? How
the video is displayed on the screen? How the audio ends up at the
speakers?
Or do you just turn it on and watch your favorite show?
Programmers nowadays do not have to manage computer's memory too, but it
seem that when they know how low level works they write more robust
programs.
Not necessarily. I've seen great programmers who don't know or worry
about the internals. And I've seen poor programmers who grew up
building their own hardware. There is little relationship between
knowledge of the underlying hardware and ability to program.
Sure, I am a programmer, and do not care at all about all those layers.
But knowing that they exist allows me to have a better understanding
about why something could have problems, and to speak with other people
with different interests.
By example, in my last job, I was able to speak with the sysadmins,
because I have knowledge about stuff that I do not need to know: linux,
networking, firewalls (hardware and software), active directory, and
that kind of stuff that programmers do not need. But it always helps to
have knowledge you do not need, and if I did not liked that idea when I
was younger, I now love it.
It is named general culture I think (if that translation from the French
expression is correct).
None of which has anything to do with the OSI layers or programming.
They are all sysadmin functions.
It doesn't hurt to have knowledge you don't need now. But this world is
way too complex to know everything about everything.
Personally, although I grew up with the hardware (long before the OSI
layered paradigm), I haven't worried about that end for years. Rather,
I've spent my time on more productive endeavors. Just like I don't
program in assembler (for Intel or Motorola MPUs or IBM mainframes),
although I could do any of them still.
In my opinion, programmers which only cares about their stupid languages
and paradigms are doing a big error. You can learn as much high level
stuff as you want. It you do not have a basic understanding of what
allows you to stay so high, you take the risk of falling, and the higher
you are, the more dangerous the fall is.
I would really like that teachers teach asm x86 at school. It is useless
nowadays, right. Except that thanks to that, I had no problem to
understand C pointers. Still thanks to that, I was very good in my
electronic lessons, which in turns have helps me a lot in my
programming, because I know why some operations are faster than others.
Yes, it is useless, in the end. But it makes so many things damn easier
to learn and tinker.
Pointers have nothing to do with assembler. C is not the only language
with pointers, although it makes some of the most efficient use of them.
But it doesn't require knowledge of underlying memory access to use
pointers. I've taught many C and C++ classes over the years (I used to
do corporate programmer training), and never once did we get into how
memory works. Those who never programmed in languages with pointers,
i.e. COBOL, had a little trouble getting used to them, but they caught
on fairly quickly.
Plus, here, we are not discussing about programming, but about
networking, so I think minimal knowledge of network stuff and some
electric basis can be useful ;)
Not really. When you're troubleshooting network problems in low level
code, it is important. Otherwise it's no more important than knowing
how everything in your TV works.
Calling a router which include a modem a modem, would be the same as
calling modem a computer. Because computers includes modems (it is not
mandatory, but I think that nowadays, every computer includes a sound
card able to have both input and output, right? So, to convert analog
signals to numeric ones, and vice versa, which is the work of modems).
Modems are not networking stuff, they are electrical stuff, which are
sometimes used by some networking stuff.
True. Except it's normally the other way around. Companies don't
design routers then add a modem to them; they design the modem then
decide if they need to add a router. A small, but significant
difference.
Jerry
I think that this way is strange, but conception can be made in so many
ways... The only important point in conception is, imho, that in the
end, you should have good results.
Companies can build my netbook by creating cells and putting stuff
around (random words, it is for the example. Plus, that would make sense
since the cell determine how many power you can use), but I won't name
my computer a cell.
Nope. You build a modem because you know you need a modem. You may
decide to add a router at a later time to make the modem more useful by
allowing multiple devices to be connected to the modem. You don't build
a router then later decide to add a port requiring
modulation/demodulation to it.
Jerry
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