The Natural Philosopher wrote:
Pete Verdon wrote:
Appin wrote:

Beats me why one should go to all the trouble to install a decent
network setup and yet fail to install even a simple PABX for the
landline/s.

Because noone ever phones on the landline and I never phone out on it.

Beacause you live in a faraday cage.

No I don't.

Because phones plugged into wall sockets don't get lost,stolen, or run
out of charge.

My mobile never runs out of charge (I put it in a cradle in the car in
order to listen to the music that's on it, and it gets charged at the
same time). I guess it's possible that I could lose it or have it
stolen, and then I could conceivably use the landline that I do have
(after looking up the number I need in the backup on my computer), but
it's hardly an argument for installing a PABX.

Because you need a landline for ADSL so why not use it?

I also need a mobile for when I'm not at home, so why not use it?

===

I'm not for a moment suggesting that my situation applies to everyone. I
wasn't trying to argue that people in general shouldn't use landlines. I
was just making a good-faith attempt to answer "Appin"'s original
question - why would someone install a decent network setup and yet not
add a PABX for landlines? I have installed a decent network setup, but
don't find any need for a landline for the reasons I gave. Seemed like a
reasonable answer to me.

Pete

Dave Liquorice wrote:
On Tue, 27 Jan 2009 21:02:29 +0000, Pete Verdon wrote:

If I want to talk to Fred I press his name on the phone in my pocket, if
Bob wants to talk to me he presses my name on the phone in his pocket.
This is simple and works everywhere.

I would almost put money on it not working particulary reliably here.

But if I was there, wherever "there" is, my landline in Southampton
would be no use to me at all.

Pete

Andrew Gabriel wrote:
In article ,
Andy Champ writes:
Andrew Gabriel wrote:
I wouldn't bother with cat 6 for home use. My home network
is 1Gb, which is pretty well matched to the data rate I can
get from a pair of 7200RPM mirrored SATA drives. (Drives
are about 75Mbyte/sec sustained, and mirroring gets me to
something over 100Mbytes/sec sustained read rate, which is
similar speed to 1Gbit network. To make good use of 10Gb,
you'd need a filesystem striped across many disks, even
when using Enterprise class 15k RPM disks, or to wait for
solid state disks to replace spinning rust.)

Moore's Law (doubling every 18 months) does apply to disk transfer
rates.

Unfortunately not. Disk capacities don't lag too far 18 month doubling
now, but all other disk performance parameters lag way behind this,
which is why disk performance has steadily become a more and more
limiting factor in performance of many computing applications.
A quick calculation shows disk transfer rates have doubled about
every 45 months over the last 25 years. That's one reason
applications often require complex disk array infrastructures, to
make up for the serious [relative] lag of disk performance behind
the progress made in CPU performance.

Out of interest, here's a table of relative performance changes
I use in a presentation I give on filesystem performance from time
to time...

25 years ago Today Improvement

Rotational speed 3,600 15,000 4x
I/O's per sec 30 300 10x
Transfer rates 1 MB/s 100 MB/s 100x
Capacity 150 MB 1.5 TB 10,000x

CPU performance 4 MIPS 400,000 MIPS 100,000x

The CPU performance improvement is pretty much spot on for doubling
every 18 months. All the disk performance parameters lag behind,
mostly _way_ behind. The exponential increase in disk capacity is
not linear over the period, being faster in more recent years, which
is why it's nearly on doubling every 18 months now. When SSD's become
mainstream, there will be a giant discontinuity in disk performance.
They're still too expensive and too small to use other than in some
specialist situations, but that's changing fast.

(Note that Moore's Law is really a doubling of transistor counts on
a chip every 2 years, although it's often used to refer to any
exponential gain scheme.)

Nicely summarised, mate.

The temptation these days is uber RAM caching of disks, so that many
reads, and all writes, take place to RAM only, with the disk subsystem
trailing behind actually writing out the data in between times so to speak.

I had a shock untarring a 360Mbyte file yesterday...CPU at 3%, but 80%
of all the RAM beig used by the program to dismantle chunks of data, and
about half a minute in total to do it..during which time all the disk IO
buffering was 'stolen' for use by the program ...

Defintely 4x RAM would have helped.

Rod wrote:
Andrew Gabriel wrote:

Unfortunately not. Disk capacities don't lag too far 18 month doubling
now, but all other disk performance parameters lag way behind this,
which is why disk performance has steadily become a more and more
limiting factor in performance of many computing applications.
A quick calculation shows disk transfer rates have doubled about
every 45 months over the last 25 years. That's one reason
applications often require complex disk array infrastructures, to
make up for the serious [relative] lag of disk performance behind
the progress made in CPU performance.

Out of interest, here's a table of relative performance changes
I use in a presentation I give on filesystem performance from time
to time...

25 years ago Today Improvement

Rotational speed 3,600 15,000 4x
I/O's per sec 30 300 10x
Transfer rates 1 MB/s 100 MB/s 100x
Capacity 150 MB 1.5 TB 10,000x

CPU performance 4 MIPS 400,000 MIPS 100,000x

The CPU performance improvement is pretty much spot on for doubling
every 18 months. All the disk performance parameters lag behind,
mostly _way_ behind. The exponential increase in disk capacity is
not linear over the period, being faster in more recent years, which
is why it's nearly on doubling every 18 months now. When SSD's become
mainstream, there will be a giant discontinuity in disk performance.
They're still too expensive and too small to use other than in some
specialist situations, but that's changing fast.

(Note that Moore's Law is really a doubling of transistor counts on
a chip every 2 years, although it's often used to refer to any
exponential gain scheme.)


Maybe the new faster flash memory devices will be able to provide the
performance jumps required to feed 10Gb? :-)

Bwahaha!

Flash is even slower on writes..

The Natural Philosopher wrote:
Rod wrote:
Andrew Gabriel wrote:

Unfortunately not. Disk capacities don't lag too far 18 month doubling
now, but all other disk performance parameters lag way behind this,
which is why disk performance has steadily become a more and more
limiting factor in performance of many computing applications.
A quick calculation shows disk transfer rates have doubled about
every 45 months over the last 25 years. That's one reason
applications often require complex disk array infrastructures, to
make up for the serious [relative] lag of disk performance behind
the progress made in CPU performance.

Out of interest, here's a table of relative performance changes
I use in a presentation I give on filesystem performance from time
to time...

25 years ago Today Improvement

Rotational speed 3,600 15,000 4x
I/O's per sec 30 300 10x
Transfer rates 1 MB/s 100 MB/s 100x
Capacity 150 MB 1.5 TB 10,000x

CPU performance 4 MIPS 400,000 MIPS 100,000x

The CPU performance improvement is pretty much spot on for doubling
every 18 months. All the disk performance parameters lag behind,
mostly _way_ behind. The exponential increase in disk capacity is
not linear over the period, being faster in more recent years, which
is why it's nearly on doubling every 18 months now. When SSD's become
mainstream, there will be a giant discontinuity in disk performance.
They're still too expensive and too small to use other than in some
specialist situations, but that's changing fast.

(Note that Moore's Law is really a doubling of transistor counts on
a chip every 2 years, although it's often used to refer to any
exponential gain scheme.)


Maybe the new faster flash memory devices will be able to provide the
performance jumps required to feed 10Gb? :-)

Bwahaha!

Flash is even slower on writes..

I mentioned flash being announced with a read speed of 220 MB/s. That
story said a write speed of 200 MB/s. Which I think is pretty impressive.

--
Rod

Hypothyroidism is a seriously debilitating condition with an insidious
onset.
Although common it frequently goes undiagnosed.
www.thyromind.info www.thyroiduk.org www.altsupportthyroid.org

Rod wrote:
The Natural Philosopher wrote:
Rod wrote:
Andrew Gabriel wrote:

Unfortunately not. Disk capacities don't lag too far 18 month doubling
now, but all other disk performance parameters lag way behind this,
which is why disk performance has steadily become a more and more
limiting factor in performance of many computing applications.
A quick calculation shows disk transfer rates have doubled about
every 45 months over the last 25 years. That's one reason
applications often require complex disk array infrastructures, to
make up for the serious [relative] lag of disk performance behind
the progress made in CPU performance.

Out of interest, here's a table of relative performance changes
I use in a presentation I give on filesystem performance from time
to time...

25 years ago Today Improvement

Rotational speed 3,600 15,000 4x
I/O's per sec 30 300 10x
Transfer rates 1 MB/s 100 MB/s 100x
Capacity 150 MB 1.5 TB 10,000x

CPU performance 4 MIPS 400,000 MIPS 100,000x

The CPU performance improvement is pretty much spot on for doubling
every 18 months. All the disk performance parameters lag behind,
mostly _way_ behind. The exponential increase in disk capacity is
not linear over the period, being faster in more recent years, which
is why it's nearly on doubling every 18 months now. When SSD's become
mainstream, there will be a giant discontinuity in disk performance.
They're still too expensive and too small to use other than in some
specialist situations, but that's changing fast.

(Note that Moore's Law is really a doubling of transistor counts on
a chip every 2 years, although it's often used to refer to any
exponential gain scheme.)


Maybe the new faster flash memory devices will be able to provide the
performance jumps required to feed 10Gb? :-)

Bwahaha!

Flash is even slower on writes..

I mentioned flash being announced with a read speed of 220 MB/s. That
story said a write speed of 200 MB/s. Which I think is pretty impressive.


However, flash has to write ENORMOUS areas all at once. You write it in
whole pages. So changing one bit is like changing one bit in a disk with
a half gigabyte sector..

It may indeed do 200Mbps writes, but if you have to do thee whole 200Mb
to change one byte, it still takes a second..

In article ,
The Natural Philosopher writes:
Rod wrote:

Maybe the new faster flash memory devices will be able to provide the
performance jumps required to feed 10Gb? :-)

Bwahaha!

Flash is even slower on writes..

Write-biased enterprise flash drives are fronted by DRAM caches,
which then enable the flash controller to de-stage to the flash
memory in a more optimal way. That claws back a lot of the
performance. The flash controller can do quite clever things
to remap logical to physical blocks to minimise the number of
flash blocks which need updating (it's playing this game in
any case for wear leveling and bad block remapping). I'm not
familiar with the extent to which consumer grade flash products
deploy such techniques but I would guess much less so as they
have much shorter lives and lower performance.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

Pete Verdon wrote:
Appin wrote:

Beats me why one should go to all the trouble to install a decent
network setup and yet fail to install even a simple PABX for the
landline/s.

Because noone ever phones on the landline and I never phone out on it.
If I want to talk to Fred I press his name on the phone in my pocket, if
Bob wants to talk to me he presses my name on the phone in his pocket.
This is simple and works everywhere. Why would I want to use a different
and more clunky system just because I happen to be at home?

Different folks different strokes...

I personally go for a PABX because mobiles are on the fringe of
reception here - so depending where you are in the house as to if you
can get a signal, and when you do get one you get dropouts etc.

I prefer the voice quality (and more importantly) lack of latency on a
landline phone.

Its cheaper when SWMBO phones from bed to say bring a cup of tea up with
you ;-)

easier to transfer calls about the house, and I can do conference calls
when someone wants to talk to more than one person.

It probably ****es off the telemarketers when you put them on hold. ;-)


--
Cheers,

John.

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The Natural Philosopher wrote:
wrote:
The Natural Philosopher wrote:
D.M. Procida wrote:
I have an opportunity to get some Cat 5 cable run while we have
building/rewiring work going on.

Just to cover future possible needs, I'd like to get a socket or two
into most of the rooms in the house, but I don't to end up with a great
patchbay downstairs.
--
Run at least two cables everywhere, and LABEL them! Leave a spare one
coiled inside the backing box.


I also would like to avoid being obliged to have the hub of the network
at one fixed point, ruling out having it somewhere else in the future,
but I don't see a way around that.

That is a bit silly: cat 5 is a star network..needs a central
distribution point UNLESS you know exactly what its to be used for. I.e.
point to point happens by going back to the rack and cross linking.

The BEST place for that is possibly your loft. Run cables including
power to there.

Also run satellite TV cable everywhere as well. And put a distribution
amp in the loft as well.



Are there any domestic-friendly network cabling products or systems
that
can help manage this, being reasonably unobtrusive and offering some
degree of flexibility?

Not really. Use proper stuff - 19" rack mount panels. No need for a rack
though. Just a couple of wood rails will do.

Daniele


if Daniele is looking for a cheaper option, its possible to just buy a
handful of plugs & couplers, and fit those to the cables you want to
use now.

Crimping cat 5 structured solid core cable into plugs never really
produces reliability.

If you use the right sort of plug, and you are not forever moving the
cable, then cat5 solid is quite reliable IME when used like this. (its
not bad using the wrong plugs either for static applications)

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

John Rumm wrote:
The Natural Philosopher wrote:
wrote:
The Natural Philosopher wrote:
D.M. Procida wrote:
I have an opportunity to get some Cat 5 cable run while we have
building/rewiring work going on.

Just to cover future possible needs, I'd like to get a socket or two
into most of the rooms in the house, but I don't to end up with a
great
patchbay downstairs.
--
Run at least two cables everywhere, and LABEL them! Leave a spare one
coiled inside the backing box.


I also would like to avoid being obliged to have the hub of the
network
at one fixed point, ruling out having it somewhere else in the future,
but I don't see a way around that.

That is a bit silly: cat 5 is a star network..needs a central
distribution point UNLESS you know exactly what its to be used for.
I.e.
point to point happens by going back to the rack and cross linking.

The BEST place for that is possibly your loft. Run cables including
power to there.

Also run satellite TV cable everywhere as well. And put a distribution
amp in the loft as well.



Are there any domestic-friendly network cabling products or systems
that
can help manage this, being reasonably unobtrusive and offering some
degree of flexibility?

Not really. Use proper stuff - 19" rack mount panels. No need for a
rack
though. Just a couple of wood rails will do.

Daniele


if Daniele is looking for a cheaper option, its possible to just buy a
handful of plugs & couplers, and fit those to the cables you want to
use now.

Crimping cat 5 structured solid core cable into plugs never really
produces reliability.

If you use the right sort of plug, and you are not forever moving the
cable, then cat5 solid is quite reliable IME when used like this. (its
not bad using the wrong plugs either for static applications)

I know. I did it a few times..and then after crawling under a filthy
set of racking and behind a dusty rack, to discover that one strand had
broken,decided to give it up for Lent,.

Dave Liquorice wrote:
On Mon, 26 Jan 2009 09:46:56 -0000, TheScullster wrote:

Also worth considering running telephone and co-ax from central location

Cat5 will do analogue phone no problem and audio and baseband SD video
(with suitable baluns). Not sure if you could squeeze HD down Cat5 but
then there is no need you'd have a media PC at the display end connected
over the network.

Do you know anywhere to get suitable baluns at a reasonable price? (most
seem to cost more than that of laying in a dedicated cable!)

--
Cheers,

John.

/================================================== ===============\
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|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

John Rumm wrote:
Dave Liquorice wrote:
On Mon, 26 Jan 2009 09:46:56 -0000, TheScullster wrote:

Also worth considering running telephone and co-ax from central location

Cat5 will do analogue phone no problem and audio and baseband SD video
(with suitable baluns). Not sure if you could squeeze HD down Cat5 but
then there is no need you'd have a media PC at the display end
connected over the network.

Do you know anywhere to get suitable baluns at a reasonable price? (most
seem to cost more than that of laying in a dedicated cable!)

Try black box.. used to get all teh odds and ends from them.

What baluns do you need.

The Natural Philosopher wrote:
John Rumm wrote:
Dave Liquorice wrote:
On Mon, 26 Jan 2009 09:46:56 -0000, TheScullster wrote:

Also worth considering running telephone and co-ax from central
location

Cat5 will do analogue phone no problem and audio and baseband SD
video (with suitable baluns). Not sure if you could squeeze HD down
Cat5 but then there is no need you'd have a media PC at the display
end connected over the network.

Do you know anywhere to get suitable baluns at a reasonable price?
(most seem to cost more than that of laying in a dedicated cable!)

Try black box.. used to get all teh odds and ends from them.

What baluns do you need.

None right now... but each time I have looked in the past they were
typically £50 - £100+ per end, which usually makes running a co-ax or
long VGA lead cheaper.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

John Rumm wrote:
The Natural Philosopher wrote:
John Rumm wrote:
Dave Liquorice wrote:

Cat5 will do analogue phone no problem and audio and baseband SD
video (with suitable baluns).

Do you know anywhere to get suitable baluns at a reasonable price?

What baluns do you need.

None right now... but each time I have looked in the past they were
typically £50 - £100+ per end, which usually makes running a co-ax or
long VGA lead cheaper.

I've helped set up a CCTV system which sent composite video over maybe
75m of cat5 using baluns. They were IIRC about a fiver (not sure per
pair or per end) from ebay, and I didn't think they'd work at all.
Actually, they work a treat - no significant difference locally vs
remotely. (The picture was poor either way because the cameras were
crap, but that's a different matter.)

Pete

Pete Verdon wrote:
John Rumm wrote:
The Natural Philosopher wrote:
John Rumm wrote:
Dave Liquorice wrote:

Cat5 will do analogue phone no problem and audio and baseband SD
video (with suitable baluns).

Do you know anywhere to get suitable baluns at a reasonable price?

What baluns do you need.

None right now... but each time I have looked in the past they were
typically £50 - £100+ per end, which usually makes running a co-ax or
long VGA lead cheaper.

I've helped set up a CCTV system which sent composite video over maybe
75m of cat5 using baluns. They were IIRC about a fiver (not sure per
pair or per end) from ebay, and I didn't think they'd work at all.
Actually, they work a treat - no significant difference locally vs
remotely. (The picture was poor either way because the cameras were
crap, but that's a different matter.)

That sort of money would make it quite an attractive option...


--
Cheers,

John.

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| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

In article , John Rumm
scribeth thus
The Natural Philosopher wrote:
John Rumm wrote:
Dave Liquorice wrote:
On Mon, 26 Jan 2009 09:46:56 -0000, TheScullster wrote:

Also worth considering running telephone and co-ax from central
location

Cat5 will do analogue phone no problem and audio and baseband SD
video (with suitable baluns). Not sure if you could squeeze HD down
Cat5 but then there is no need you'd have a media PC at the display
end connected over the network.

Do you know anywhere to get suitable baluns at a reasonable price?
(most seem to cost more than that of laying in a dedicated cable!)

Try black box.. used to get all teh odds and ends from them.

What baluns do you need.

None right now... but each time I have looked in the past they were
typically £50 - £100+ per end, which usually makes running a co-ax or
long VGA lead cheaper.

I'm sure they'll be cheaper around than from Black Box !. Good outfit
but rather expensive IMHO..

Theres a CCTV company New Concepts or RF concepts in Northern Ireland
who do these .. not too expensive IIRC..

CPC I think have them too ....
--
Tony Sayer

In article ,
tony sayer writes:
I'm sure they'll be cheaper around than from Black Box !. Good outfit
but rather expensive IMHO..

Theres a CCTV company New Concepts or RF concepts in Northern Ireland
who do these .. not too expensive IIRC..

CPC I think have them too ....

Often in CPC's special offer leaflets.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

Andrew Gabriel wrote:
In article ,
tony sayer writes:
I'm sure they'll be cheaper around than from Black Box !. Good outfit
but rather expensive IMHO..

Theres a CCTV company New Concepts or RF concepts in Northern Ireland
who do these .. not too expensive IIRC..

CPC I think have them too ....

Often in CPC's special offer leaflets.

last ones they had were VGA versions at about £50 IIRC...

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
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| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/