Archived from groups:  (More info?)

Question about typical company network. We are looking at going gigabit mainly
because of a perceived network slowdown in the past 6 months or so. But... some
of use are not sure that the 100 Mb T1 current network is really the fault.
Question is: We have some really speedy computers on the network and some not so
speedy. Can slow clock speed computers drag down the entire network? We have B /
G Wi-Fi on both sides of the firewall. Can they drag down overall speed of the
network? We have hubs / switches that feed other hubs / switches. How bad a
practice is that?
There are about 50 wired drops around the building and around 8 wi-fi hot spots.
Previous IT guy set the wi-fi up with all different SSIDs. We don't care about
lap top roaming so maybe that's not a big deal. Or not?
Any suggestions?

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DanR wrote:
 
> Question about typical company network. We are looking at going gigabit mainly
> because of a perceived network slowdown in the past 6 months or so. But... some
> of use are not sure that the 100 Mb T1 current network is really the fault.
> Question is: We have some really speedy computers on the network and some not so
> speedy. Can slow clock speed computers drag down the entire network? We have B /
> G Wi-Fi on both sides of the firewall. Can they drag down overall speed of the
> network? We have hubs / switches that feed other hubs / switches. How bad a
> practice is that?
> There are about 50 wired drops around the building and around 8 wi-fi hot spots.
> Previous IT guy set the wi-fi up with all different SSIDs. We don't care about
> lap top roaming so maybe that's not a big deal. Or not?
> Any suggestions?
>  
>  
Have you run a sniffer over the network to determine where the  
consumption and waste is ?

Archived from groups:  (More info?)

You must run a network traffic analysis prog to see where the bottlenecks  
are and how the bandwidth is being used/shared.
 
Consider putting high bandwidth 'power' users on their own network if  
possible... give them a fibre spine if required.
 
Someone should be managing your network - reliabilty, usability and security  
will be compromised if you let benign (?) anarchy rule ;-)
 
Have fun
 
Guy
 
 
"DanR" <dhr22@sorrynospm.com> wrote in message  
news:QVoUe.3268$6e1.1632@newssvr14.news.prodigy.com...
> Question about typical company network. We are looking at going gigabit  
> mainly
> because of a perceived network slowdown in the past 6 months or so. But...  
> some
> of use are not sure that the 100 Mb T1 current network is really the  
> fault.
> Question is: We have some really speedy computers on the network and some  
> not so
> speedy. Can slow clock speed computers drag down the entire network? We  
> have B /
> G Wi-Fi on both sides of the firewall. Can they drag down overall speed of  
> the
> network? We have hubs / switches that feed other hubs / switches. How bad  
> a
> practice is that?
> There are about 50 wired drops around the building and around 8 wi-fi hot  
> spots.
> Previous IT guy set the wi-fi up with all different SSIDs. We don't care  
> about
> lap top roaming so maybe that's not a big deal. Or not?
> Any suggestions?
>
>

Archived from groups:  (More info?)

"DanR" <dhr22@sorrynospm.com> wrote in message
news:QVoUe.3268$6e1.1632@newssvr14.news.prodigy.com...
> Question about typical company network. We are looking at going gigabit
mainly
> because of a perceived network slowdown in the past 6 months or so. But...
some
> of use are not sure that the 100 Mb T1 current network is really the
fault.
> Question is: We have some really speedy computers on the network and some
not so
> speedy. Can slow clock speed computers drag down the entire network? We
have B /
> G Wi-Fi on both sides of the firewall. Can they drag down overall speed of
the
> network? We have hubs / switches that feed other hubs / switches. How bad
a
> practice is that?
> There are about 50 wired drops around the building and around 8 wi-fi hot
spots.
> Previous IT guy set the wi-fi up with all different SSIDs. We don't care
about
> lap top roaming so maybe that's not a big deal. Or not?
> Any suggestions?
>
If you are running from the server through one switch and using one output
to feed another switch at 100 Mb, then taking the outputs of the second
switch to feed a number of workstations, then all those workstations must
share the single 100Mb feed from the first switch. Not good practice for
maintaining good throughput and response.
 
Just watching the "blinking lights" on the switches can give you some idea
of loading and in what directions the load is coming from.
 
Either you need to redistribute the workstation load more evenly or better,
take the network to gigabit so that the data moves a bit faster. Also be on
the lookout for a bad or "garbaging" NIC. Some varieties can soft fail
slowly and really start dragging a network down. Using managed switches
rather than unmanaged and setting them up properly usually makes a
significant difference.
 
You may also wish to look at adding a second (and third or fourth) ethernet
port on your server and feeding a switch directly rather than using a point
of an existing earlier switch. Four ethernet ports on the server, each
feeding a single 16 port switch and then directly to the clients will share
out the load significantly but be absolutely sure you use good NICs such as
the genuine Intel Pro series rather than many of the cheap aftermarket types
that generally cannot stand very high consistent traffic error free.
 
Remember also the cascading guidelines for switches, 10Mb - 3 cascaded,
100Mb - 2 cascaded, gigabit - no cascading.
 
Peter

Archived from groups:  (More info?)

Pierre wrote:
> "DanR" <dhr22@sorrynospm.com> wrote in message
> news:QVoUe.3268$6e1.1632@newssvr14.news.prodigy.com...
>> Question about typical company network. We are looking at going gigabit
>> mainly because of a perceived network slowdown in the past 6 months or so.
>> But... some of use are not sure that the 100 Mb T1 current network is really
>> the fault. Question is: We have some really speedy computers on the network
>> and some not so speedy. Can slow clock speed computers drag down the entire
>> network? We have B / G Wi-Fi on both sides of the firewall. Can they drag
>> down overall speed of the network? We have hubs / switches that feed other
>> hubs / switches. How bad a practice is that?
>> There are about 50 wired drops around the building and around 8 wi-fi hot
>> spots. Previous IT guy set the wi-fi up with all different SSIDs. We don't
>> care about lap top roaming so maybe that's not a big deal. Or not?
>> Any suggestions?
>>
> If you are running from the server through one switch and using one output
> to feed another switch at 100 Mb, then taking the outputs of the second
> switch to feed a number of workstations, then all those workstations must
> share the single 100Mb feed from the first switch. Not good practice for
> maintaining good throughput and response.
>
> Just watching the "blinking lights" on the switches can give you some idea
> of loading and in what directions the load is coming from.
>
> Either you need to redistribute the workstation load more evenly or better,
> take the network to gigabit so that the data moves a bit faster. Also be on
> the lookout for a bad or "garbaging" NIC. Some varieties can soft fail
 
What are the symptoms of a bad or "garbaging" NIC? Would it be constant traffic
even when the user is not doing anything network related? Would "watching the
"blinking lights" help find one of these NICs? Would a managed switch make a
"garbaging" NIC a non issue?
 
> slowly and really start dragging a network down. Using managed switches
> rather than unmanaged and setting them up properly usually makes a
> significant difference.
>
> You may also wish to look at adding a second (and third or fourth) ethernet
> port on your server and feeding a switch directly rather than using a point
> of an existing earlier switch. Four ethernet ports on the server, each
> feeding a single 16 port switch and then directly to the clients will share
> out the load significantly but be absolutely sure you use good NICs such as
> the genuine Intel Pro series rather than many of the cheap aftermarket types
> that generally cannot stand very high consistent traffic error free.
>
> Remember also the cascading guidelines for switches, 10Mb - 3 cascaded,
> 100Mb - 2 cascaded, gigabit - no cascading.
>
> Peter

Archived from groups:  (More info?)

Hi Dan,
 
A garbaging NIC can often be found by watching the lights. Network software
analysis tools very rarely find it as the data it is sending is invariably a
load of rubbish and may not even be valid bytes. All it seems to do is use
bandwidth. The user may even be otherwise totally inactive but the NIC keeps
chattering. A final usual proof is to unplug the ethernet cable at the
suspect machine and see if there is an improvement.
 
Putting in a managed switch is not the way to fix that problem. You have to
find the bad NIC and replace it. It is a bit like using a bucket to drain a
flooded area when in fact the drain should be unblocked!
 
As others have said, a good audit and mapping of the complete network is
mandatory if you are going to approach the issues in any sort of logical
manner. The scatter gun approach generally leads to more confusion.
 
With a good map of your network, you can isolate sections logically and see
if the isolated section was that hogging the network and then break that
section into smaller sections until the culprit is found. There could well
be other issues which have affected the network loading and performance too
such as a new application installed, the server databases not responding
quickly enough because of server performance issues and so on. Again. draw
up in detail what the network has and step through it first.
 
As an example, a client of mine runs some 50-60 workstations to two separate
servers on a single network. The primary server is also running a moderately
heavy SQL database and file storage of some 2 terabytes of image files
averaging 1.5 Mb each. In any one minute period, it is usual to have some 20
workstations up and down some 10-15 image files each, apart from referencing
the SQL database and a medium accounting job. It used to run at 100 Mb with
unmanaged switches on two segments and was a bit slow. Once a garbaging NIC
dropped performance by some 25% overall. The same system is now upgraded
with two managed switches and gigabit,  it flies!
Peter
"DanR" <dhr22@sorrynospm.com> wrote in message
news:RHJUe.2760$7D1.1746@newssvr12.news.prodigy.com...
>
>
> Pierre wrote:
> > "DanR" <dhr22@sorrynospm.com> wrote in message
> > news:QVoUe.3268$6e1.1632@newssvr14.news.prodigy.com...
> >> Question about typical company network. We are looking at going gigabit
> >> mainly because of a perceived network slowdown in the past 6 months or
so.
> >> But... some of use are not sure that the 100 Mb T1 current network is
really
> >> the fault. Question is: We have some really speedy computers on the
network
> >> and some not so speedy. Can slow clock speed computers drag down the
entire
> >> network? We have B / G Wi-Fi on both sides of the firewall. Can they
drag
> >> down overall speed of the network? We have hubs / switches that feed
other
> >> hubs / switches. How bad a practice is that?
> >> There are about 50 wired drops around the building and around 8 wi-fi
hot
> >> spots. Previous IT guy set the wi-fi up with all different SSIDs. We
don't
> >> care about lap top roaming so maybe that's not a big deal. Or not?
> >> Any suggestions?
> >>
> > If you are running from the server through one switch and using one
output
> > to feed another switch at 100 Mb, then taking the outputs of the second
> > switch to feed a number of workstations, then all those workstations
must
> > share the single 100Mb feed from the first switch. Not good practice for
> > maintaining good throughput and response.
> >
> > Just watching the "blinking lights" on the switches can give you some
idea
> > of loading and in what directions the load is coming from.
> >
> > Either you need to redistribute the workstation load more evenly or
better,
> > take the network to gigabit so that the data moves a bit faster. Also be
on
> > the lookout for a bad or "garbaging" NIC. Some varieties can soft fail
>
> What are the symptoms of a bad or "garbaging" NIC? Would it be constant
traffic
> even when the user is not doing anything network related? Would "watching
the
> "blinking lights" help find one of these NICs? Would a managed switch make
a
> "garbaging" NIC a non issue?
>
> > slowly and really start dragging a network down. Using managed switches
> > rather than unmanaged and setting them up properly usually makes a
> > significant difference.
> >
> > You may also wish to look at adding a second (and third or fourth)
ethernet
> > port on your server and feeding a switch directly rather than using a
point
> > of an existing earlier switch. Four ethernet ports on the server, each
> > feeding a single 16 port switch and then directly to the clients will
share
> > out the load significantly but be absolutely sure you use good NICs such
as
> > the genuine Intel Pro series rather than many of the cheap aftermarket
types
> > that generally cannot stand very high consistent traffic error free.
> >
> > Remember also the cascading guidelines for switches, 10Mb - 3 cascaded,
> > 100Mb - 2 cascaded, gigabit - no cascading.
> >
> > Peter
>
>

Archived from groups:  (More info?)

On Sat, 10 Sep 2005 23:08:32 GMT, "DanR" <dhr22@sorrynospm.com> wrote:
 
>Yes, I should have provided more information about our network hardware. Problem
>is I don't really know.
 
Fine.  However you should have some clue who's got performance
problems.
 
>We are a production company with 6 Avid sweets, 2 audio
>sweets, one online editing room and an interactive department.
 
That's Suite's, not sweets.
 
>We don't have any
>IT people per se... but have designated one of our coders to be responsible for
>the network.
 
I can't tell for sure but if you have 50 boxes, you really should get
someone qualified to do the troubleshooting.  It's easy enough to plan
and setup a new network.  It's requires experience to troubleshoot an
existing network.
 
>He's a sharp guy and seems to know his network jargon. And he is
>new on the job having taken over the network from someone who left. Because I'm
>fairly handy with computers in general  
 
Well, ok.
 
>I'm helping the boss think through our
>move to giga-bit and the coincidental network / Internet slowdown we have been
>experiencing.
 
Ok, so it's an *INTERNET* slowdown, not a server to client or render
farm slowdown.  That's not going to change at all by going to gigabit.
You're bottlenecked at 1.5Mbits/sec at the T1 and that's your limit.
Do the traffic monitoring to see what and how much is moving in and
out of the T1.  Don't be surprised if you see worms, file sharing, and
garbage.
 
>The main reason to go giga-bit is to move very large files around
>on the network. (video files in the giga-Bytes) And because of the Internet
>slowdown of late we are talking and wondering if that will improve Internet
>throughput.  
 
That's very different from an *INTERNET* slowdown.  Most render farms
are interconnected with gigabit ethernet.  The big boxes have multiple
gigabit cards to distribute the load.  I got to play with one RAID
server with 4 cards and a load balancer.  Yeah, for in house traffic,
gigabit is great.
 
However, you still have to know if you're making an improvement.  For
that you need numbers, measurements, calculations, and pretty graphs
to impress the boss.  I suggest MRTG for traffic monitoring.
 
>Obviously it will be a fairly expensive endeavor to run all new
>cable throughout the building and get new NICs.
 
Baloney.  CAT5e will do gigabit just fine.  You don't really need
CAT6.  Keep the cable lengths down to less than 300ft.  Avoid long
flexible ethernet CAT5 jumpers.  Borrow a cable certifier and test
your wiring.  New gigabit NIC's are cheap.  Netgear GA311 is about
$20.  I recently upgraded a law office with gigabit everything.  It
was a barely noticeable improvement.  You only notice an improvement
if your existing 100baseTX system is saturated.  Do the measurements
and you'll know for sure.  If lazy, use Windoze XP Perfmon to check
client network utilization.  
 
>So we're also thinking about
>only doing new giga-drops at some work stations and not the entire network.
 
Fine.  Draw the topology map as I suggested and see how many boxes in
between the gigabit NIC's need to be upgraded.
 
>All
>new drops will be home runs and if we do the entire building that means all home
>runs.
 
Home runs to what?  I smell a big building with cable lengths more
than 300ft which will require some intermediate boxes.  Home runs
aren't always best.
 
>But there's a but and that is that we are considering fiber to the upper
>floor because of long runs.
 
How long?  If you don't know, guess.
 
>So that is a bit of background and I'm just trying to learn what I can so I can
>ask intelligent questions and better understand what the heck is going on.
 
Well, ok.  I think I've given you a good start on the buzzwords.  So
far, you've made the decision to spend some money, considerable time,
and a bit of guesswork, in order to upgrade a network that you don't
have a clue where it's running slow, why it's running slow, or whether
you have a traffic problem.  Also, this has nothing to do with
wireless so you're asking in the wrong newsgroup.  To insure that
you'll get no useful answers, you've supplied not one single name,
number, model number, distance, or accurate description.
 
>I'm
>basically a home network guy and that is the extent of my network hardware
>knowledge.
 
Well, you're learning.  Business LAN's are very similar except that
reliability is a much bigger issue than performance or features.  Your
real task will be to fix whatever problem you can't seem to describe
accurately, and do it without breaking anything else or having 50
irate graphic artists screaming at you.  That's quite different from
home networking.
 
>I appreciate the help so far provided. Thank you all.
>Jeff... when you say "A T1 (DS1) is 1.544Mbits/sec.  You'll get about
>1.3Mbits/sec thruput in both directions." Does that mean that just one
>workstation at a time will see that throughput?
 
No.  The bandwidth is distributed roughly equally among the
workstations.
 
>If 10 computers / workstations
>are at the same time doing a Microsoft update for example... are they sharing
>that 1.3Mbit bandwidth?
 
Yes.  In theory, each workstation will get 1/10th the incoming
bandwidth.  MS Update is a bad example because of the way they do
bandwidth limiting, but that's a diversion and not part of this
discussion.
 
>Are they each then downloading at 130Kb. Does it work
>that way?
 
Yes.
 
>Also curious about one of our people who constantly listens to
>Internet radio streams. Any harm there?
 
No.  I do that in the office.  Screaming audio is from 24Kbits/sec to
about 128Kbits/sec.  Compared to your 1500Kbit/sec, the screaming
audio listener only eats about 8% of your incoming bandwidth.
However, if you're saturating the T1 with other traffic (do the
sniffing), then that last 8% might be fatal.
 
 
--  
Jeff Liebermann     jeffl@comix.santa-cruz.ca.us
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558

Archived from groups:  (More info?)

Jeff has it right again except for one part. Gigabit NICs are cheap and you
get what you pay for. having been intimately associated with a similar type
of installation, we ended up throwing out 23 Netgear GA311 NICs and a
variety of other breeds. The majority of them just cannot reliably stand
intense high volume traffic as occasioned by hundred megabyte file transfers
running 24/7. They randomly and intermittently buckle resulting in a few
more retries which takes precious bandwidth. Commercial installations
usually run at sub 5 or 10% network utilisation. Graphics and imaging sites
often run at 80%+ utilisation for minutes on end.
 
After a lot of experimentation and testing of various NICs, we replaced all
the NICs on the network with genuine Intel Pro series NICs which were a bit
dearer and have never had a problem in the three years since and it flies.
And no, I am an independent contractor with no interest or shares in Intel!
 
Peter
"Jeff Liebermann" <jeffl@comix.santa-cruz.ca.us> wrote in message
news:0r07i1t243545j0jur8971jroso4usvkl3@4ax.com...
> On Sat, 10 Sep 2005 23:08:32 GMT, "DanR" <dhr22@sorrynospm.com> wrote:
>
> >Yes, I should have provided more information about our network hardware.
Problem
> >is I don't really know.
>
> Fine.  However you should have some clue who's got performance
> problems.
>
> >We are a production company with 6 Avid sweets, 2 audio
> >sweets, one online editing room and an interactive department.
>
> That's Suite's, not sweets.
>
> >We don't have any
> >IT people per se... but have designated one of our coders to be
responsible for
> >the network.
>
> I can't tell for sure but if you have 50 boxes, you really should get
> someone qualified to do the troubleshooting.  It's easy enough to plan
> and setup a new network.  It's requires experience to troubleshoot an
> existing network.
>
> >He's a sharp guy and seems to know his network jargon. And he is
> >new on the job having taken over the network from someone who left.
Because I'm
> >fairly handy with computers in general
>
> Well, ok.
>
> >I'm helping the boss think through our
> >move to giga-bit and the coincidental network / Internet slowdown we have
been
> >experiencing.
>
> Ok, so it's an *INTERNET* slowdown, not a server to client or render
> farm slowdown.  That's not going to change at all by going to gigabit.
> You're bottlenecked at 1.5Mbits/sec at the T1 and that's your limit.
> Do the traffic monitoring to see what and how much is moving in and
> out of the T1.  Don't be surprised if you see worms, file sharing, and
> garbage.
>
> >The main reason to go giga-bit is to move very large files around
> >on the network. (video files in the giga-Bytes) And because of the
Internet
> >slowdown of late we are talking and wondering if that will improve
Internet
> >throughput.
>
> That's very different from an *INTERNET* slowdown.  Most render farms
> are interconnected with gigabit ethernet.  The big boxes have multiple
> gigabit cards to distribute the load.  I got to play with one RAID
> server with 4 cards and a load balancer.  Yeah, for in house traffic,
> gigabit is great.
>
> However, you still have to know if you're making an improvement.  For
> that you need numbers, measurements, calculations, and pretty graphs
> to impress the boss.  I suggest MRTG for traffic monitoring.
>
> >Obviously it will be a fairly expensive endeavor to run all new
> >cable throughout the building and get new NICs.
>
> Baloney.  CAT5e will do gigabit just fine.  You don't really need
> CAT6.  Keep the cable lengths down to less than 300ft.  Avoid long
> flexible ethernet CAT5 jumpers.  Borrow a cable certifier and test
> your wiring.  New gigabit NIC's are cheap.  Netgear GA311 is about
> $20.  I recently upgraded a law office with gigabit everything.  It
> was a barely noticeable improvement.  You only notice an improvement
> if your existing 100baseTX system is saturated.  Do the measurements
> and you'll know for sure.  If lazy, use Windoze XP Perfmon to check
> client network utilization.
>
> >So we're also thinking about
> >only doing new giga-drops at some work stations and not the entire
network.
>
> Fine.  Draw the topology map as I suggested and see how many boxes in
> between the gigabit NIC's need to be upgraded.
>
> >All
> >new drops will be home runs and if we do the entire building that means
all home
> >runs.
>
> Home runs to what?  I smell a big building with cable lengths more
> than 300ft which will require some intermediate boxes.  Home runs
> aren't always best.
>
> >But there's a but and that is that we are considering fiber to the upper
> >floor because of long runs.
>
> How long?  If you don't know, guess.
>
> >So that is a bit of background and I'm just trying to learn what I can so
I can
> >ask intelligent questions and better understand what the heck is going
on.
>
> Well, ok.  I think I've given you a good start on the buzzwords.  So
> far, you've made the decision to spend some money, considerable time,
> and a bit of guesswork, in order to upgrade a network that you don't
> have a clue where it's running slow, why it's running slow, or whether
> you have a traffic problem.  Also, this has nothing to do with
> wireless so you're asking in the wrong newsgroup.  To insure that
> you'll get no useful answers, you've supplied not one single name,
> number, model number, distance, or accurate description.
>
> >I'm
> >basically a home network guy and that is the extent of my network
hardware
> >knowledge.
>
> Well, you're learning.  Business LAN's are very similar except that
> reliability is a much bigger issue than performance or features.  Your
> real task will be to fix whatever problem you can't seem to describe
> accurately, and do it without breaking anything else or having 50
> irate graphic artists screaming at you.  That's quite different from
> home networking.
>
> >I appreciate the help so far provided. Thank you all.
> >Jeff... when you say "A T1 (DS1) is 1.544Mbits/sec.  You'll get about
> >1.3Mbits/sec thruput in both directions." Does that mean that just one
> >workstation at a time will see that throughput?
>
> No.  The bandwidth is distributed roughly equally among the
> workstations.
>
> >If 10 computers / workstations
> >are at the same time doing a Microsoft update for example... are they
sharing
> >that 1.3Mbit bandwidth?
>
> Yes.  In theory, each workstation will get 1/10th the incoming
> bandwidth.  MS Update is a bad example because of the way they do
> bandwidth limiting, but that's a diversion and not part of this
> discussion.
>
> >Are they each then downloading at 130Kb. Does it work
> >that way?
>
> Yes.
>
> >Also curious about one of our people who constantly listens to
> >Internet radio streams. Any harm there?
>
> No.  I do that in the office.  Screaming audio is from 24Kbits/sec to
> about 128Kbits/sec.  Compared to your 1500Kbit/sec, the screaming
> audio listener only eats about 8% of your incoming bandwidth.
> However, if you're saturating the T1 with other traffic (do the
> sniffing), then that last 8% might be fatal.
>
>
> --
> Jeff Liebermann     jeffl@comix.santa-cruz.ca.us
> 150 Felker St #D    http://www.LearnByDestroying.com
> Santa Cruz CA 95060 http://802.11junk.com
> Skype: JeffLiebermann     AE6KS    831-336-2558

Archived from groups:  (More info?)

On Sun, 11 Sep 2005 14:09:00 +1000, "Pierre" <rainsford@ihug.com.au>
wrote:
 
>Jeff has it right again except for one part. Gigabit NICs are cheap and you
>get what you pay for. having been intimately associated with a similar type
>of installation, we ended up throwing out 23 Netgear GA311 NICs and a
>variety of other breeds. The majority of them just cannot reliably stand
>intense high volume traffic as occasioned by hundred megabyte file transfers
>running 24/7. They randomly and intermittently buckle resulting in a few
>more retries which takes precious bandwidth. Commercial installations
>usually run at sub 5 or 10% network utilisation. Graphics and imaging sites
>often run at 80%+ utilisation for minutes on end.
>
>After a lot of experimentation and testing of various NICs, we replaced all
>the NICs on the network with genuine Intel Pro series NICs which were a bit
>dearer and have never had a problem in the three years since and it flies.
>And no, I am an independent contractor with no interest or shares in Intel!
>
>Peter
 
Oops.  I just mean't the GA311 as an example of a cheap gigabit NIC.
I have to confess that I don't have experience with the GA311 NIC
under heavy continuous load.  I guess I'll avoid the GA311 as the
Intel card is only about $30 each.
|  http://www.tigerdirect.com/applica [...] 62&CatId=0
My only point was that a gigabit conversion is no longer very
expensive at the client end.  
 
Looking at Gigabit switches, the prices seem to hover around $10-$20
per port for unmanaged and $25 to $40 per port for managed switches.
I would go with the managed switch as I'm a big fan of SNMP monitoring
and management.  Knowing what's happening and being able to turn
things on and off remotely is worth the extra dollars.
|  http://www.tigerdirect.com/applica [...] 201|c:596|
94 gigabit switches to chose from, some of which are fairly cheap.
 
Incidentally, you're largely proving my point, that gigabit is only
effective when the network segment is heavily loaded.  With light
loads, I can do quite well with 100baseTX-FDX.
 
 
--  
Jeff Liebermann     jeffl@comix.santa-cruz.ca.us
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558

Archived from groups:  (More info?)

First of all i suggest updating drivers on all of your network card.
The I suggest removing hubs and replacing them with switches
Then run a traffic analyzer on the hosts (pc) where you see more traffic.

Archived from groups:  (More info?)

Jeff, I want to make sure I understand your comments.
>> Jeff... when you say "A T1 (DS1) is 1.544Mbits/sec.  You'll get about
>> 1.3Mbits/sec thruput in both directions." Does that mean that just one
>> workstation at a time will see that throughput?
>
> No.  The bandwidth is distributed roughly equally among the
> workstations.
>
Could the above sentence read "No.  The bandwidth is distributed roughly equally
among the  workstations" that are at that moment sending / receiving on the
Internet.
In other words... the active workstations share the bandwidth. True? I think
that is what you said below.
 
> If 10 computers / workstations
>> are at the same time doing a Microsoft update for example... are they sharing
>> that 1.3Mbit bandwidth?
>
> Yes.  In theory, each workstation will get 1/10th the incoming
> bandwidth.  MS Update is a bad example because of the way they do
> bandwidth limiting, but that's a diversion and not part of this
> discussion.
>
>> Are they each then downloading at 130Kb. Does it work
>> that way?
>
> Yes.
>
I'm really surprised to learn that a T1 Internet connection has these
limitations. Seems then that (except for upload) it's like having 50 or so
computers on a home DSL Internet connection. I would have thought that this
would have been un-acceptable. My "thought" is not based on technical knowledge
but I always assumed that a T1 was the ultimate way to go.
One more thing. At any given time during the work day we have about 20
computers using instant messaging. Most of the time there is not traffic but the
apps are always listening. Is that much of a load?
I am extremely grateful for the time you've spent providing all this good
information. If we don't have to run all new cable your tip will save our
company a lot of money and labor.

Archived from groups:  (More info?)

On Mon, 12 Sep 2005 13:07:11 GMT, "DanR" <dhr22@sorrynospm.com> wrote:
 
>Jeff, I want to make sure I understand your comments.
>>> Jeff... when you say "A T1 (DS1) is 1.544Mbits/sec.  You'll get about
>>> 1.3Mbits/sec thruput in both directions." Does that mean that just one
>>> workstation at a time will see that throughput?
>>
>> No.  The bandwidth is distributed roughly equally among the
>> workstations.
 
>Could the above sentence read "No.  The bandwidth is distributed roughly equally
>among the  workstations" that are at that moment sending / receiving on the
>Internet.
>In other words... the active workstations share the bandwidth. True? I think
>that is what you said below.
 
Yes, the active workstations share the bandwidth roughly equally.
Note that this is NOT true with wireless where the distribution varies
with the connection speed.
 
No, this does NOT mean that one workstation at a time will that
thruput as you previously stated.
 
>I'm really surprised to learn that a T1 Internet connection has these
>limitations.
 
You get what you pay for.  In the past, it was assumed that a T1(DS1)
came with a superior level of support from the telcos.  I still
remember one hour service from Pacific Bell.  Now daze, T1 is just
another service and may just be a muxed channel off some telco fiber.
I actually get better service from my DSL lines than I do from the
T1's.  The only real benefit of a T1 is the 1.5Mbits/sec outgoing
bandwidth, which cannot be easily supplied via DSL.
 
>Seems then that (except for upload) it's like having 50 or so
>computers on a home DSL Internet connection.
 
The conventional rule of thumb for loading is:
  100 users doing light web browsing and email.
   10 business users doing whatever business users do.
    1 file sharing user.
 
>I would have thought that this
>would have been un-acceptable.
 
What is unacceptable?  Only having 50 computers on a single T1?
Again, it depends on what those users are doing.  By todays standards
of bloated and bandwidth hungry applications, a T1 is a small pipe.
If you would kindly dig out the sniffer and see what's moving on your
T1, you might have a better idea of whether you're dealing with a
capacity problem or an abuse problem.
 
For example, a customer calls me on Sunday morning (yawn) to ask why
their T1 is moving large amounts of traffic when there's nobody in the
office.  This is a good question.  I expected to find a virus, worm,
or hacker.  Instead, I found that a clever user had found a program
that "synchronized" his files between his home computer and his office
machine.  He had set it up incorrectly and it was "synchronizing" much
of the corporate server farm as well as gigabytes of junk on his
desktop.  Eventually, it would have killed his home computer, but I
didn't want to wait.  So, I dived into the managed ethernet switch,
pulled the virtual plug on his machine, and left a nasty voicemail
message.  This type of nonsense happens all the time.
 
Another example.  A while back, I noticed that the MRTG traffic graphs
showed that someone was downloading about 25Mbytes of something every
5 minutes.  It was causing problems with VoIP traffic and streaming
content.  It turned out to be Symantec Live Update trying to update
Norton Antivirus.  One problem.  Norton AntiVirus had been removed
from that machine, but not Live Update.  It would merrily try to
update NAV, fail, and then try again in 5 minutes by downloading
everything over and over and over, etc.  
 
Moral:  You need to know what's moving on your network or you can't do
anything useful in the way of troubleshooting and capacity planning.
 
>My "thought" is not based on technical knowledge
 
Got it.  Your thinking is based on emotion.  I have a ladyfriend that
sometimes operates that way.  The scarey part is that it often works.
There are books and classes to optimized intuition, crystal ball
gazing, Ouigi Boards, and pseudo science that may help with this way
to non-technical troubleshooting.  I've often suspected that the
government also uses this method in their technical ventures.
 
>but I always assumed that a T1 was the ultimate way to go.
 
You can't afford the ultimate.  At this time, an OC-192 at
9.6Gbits/sec symmetrical is about as fast as commonly available.
Korea has 10Mbit/sec consumer service.  Most cable modems and some DSL
vendros will do 6Mbits/sec download and 512Kbits/sec upload.  Desktops
will soon have 10Gigabit ethernet cards.  Some crude numbers:
  http://www.infobahn.com/research-information.htm
 
Incidentally, if *ONLY* incoming bandwidth is an issue, you might
wanna consider distributing the load.  Get several DSL connections and
use one of these to manage the load:
  http://www.edimax.com/html/english [...] router.htm
The DSL lines are MUCH cheaper than the T1.  However, if your problem
is outgoing bandwidth, a load balancing router will do nothing.
 
>One more thing. At any given time during the work day we have about 20
>computers using instant messaging. Most of the time there is not traffic but the
>apps are always listening. Is that much of a load?
 
No load at all.  Some IM clients (i.e. AIM) deliver advertising and
stupid videos which grab a small amount of bandwidth, but nothing
disgusting and nothing that's running all the time.  However, if
people are using IM for file transfers, the bandwidth use might be
momentarily quite high.
 
>I am extremely grateful for the time you've spent providing all this good
>information. If we don't have to run all new cable your tip will save our
>company a lot of money and labor.
 
I still think you need someone with network troubleshooting experience
to impliment monitoring and traffic analysis.  Render farms use LOTS
of bandwidth.  My guess(tm) is that you're speed problem may be in an
unexpected area.
 
 
--  
Jeff Liebermann     jeffl@comix.santa-cruz.ca.us
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558