Greg Rundlett (freephile | 1 Oct 03:47 2009

Re: diagnosing network speed bottlenecks [SOLVED]

On Wed, Sep 30, 2009 at 1:36 AM, Greg Rundlett (freephile)
<greg@...> wrote:
[snip]
> I'm generally dis-satisfied with the speed of my Comcast "High Speed"
> Internet connection.  It's touted on the tele as being some
> ambiguously huge amount faster than light travels in a vacuum.
[snip]
> Speed tests like http://www.dslreports.com/speedtest?flash=1 report my
> performance as...
> 4,909 Kb/s Download
> 3,055 Kb/s Upload
>
> But, in my experience downloading files, I rarely get anything like
> that.   In fact, while the DSL Reports Speed Test is checking my
> system, I'm watching the "Network History" graph on the "Resources"
> tab of System Monitor (v2.26.0.1) aka gnome-system-monitor and it's
> not breaking 800Kbps.  I then used wget to download MySQL Workbench
> and it reports 33,373,104 downloaded in ~42 seconds at a rate of 783
> KB/s

Ah, thanks to those who pointed out that 783KBs = 6.26Mbps (or ~2.82GB/hr.)

Sorry, I was misreading Comcast service as being measured in megaBytes
(big B) while it's actually stated in megabits (little b).   Comcast
didn't catch the simple arithmetic / language mistake I was making --
which put me onto the trail of a non-existant problem.  Thanks all for
pointing out that I'm actually getting "standard" bandwidth.

The upshot is that I know more about how various network devices (e.g.
wireless routers) and standards (e.g. DOCSISv2 and DOCSISv3) affect
(Continue reading)

Greg Rundlett (freephile | 1 Oct 03:49 2009

Re: diagnosing network speed bottlenecks

On Wed, Sep 30, 2009 at 1:01 PM, H. Kurth Bemis <kurth@...> wrote:
> Seriously now.
>
> Comcast provides nothing but stellar service.  Let's not be hard on them
> or suspect them of incorrectly representing their service offerings.
>
> Greg, it's obviously your Ethernet cables.  I bet they're no name.  I
> suggest you give the Denon AK-DL1's
> (http://www.usa.denon.com/ProductDetails/3429.asp) a try.  Also, you'll
> have to locate your computer no more then 59inches from your router
> (shorter distance for the data to travel = faster speeds).
>
> Finally, I've heard that waxing your modem will make it go faster.
>
> Good Luck.
> ~k

That's funny.  /me shakes head incredulously at people with money to burn.
Greg Rundlett (freephile | 1 Oct 04:01 2009

Re: diagnosing network speed bottlenecks

[snip]
>
> Note that some ISP's are known to cheat on well-known speed tests.  If
> you have access to a fast offsite server, try your own network speed test:
>
>
> http://blog.bfccomputing.com/articles/2007/06/09/your-network-speed-testing-made-easy
>
> That should tease out whether you're being unfairly shaped or not.
>

Thanks Bill, that's a handy tool to have.  It shows that I'm getting
close to 10Mbps on my local network.  I'll test it wider when i get a
chance

~ Greg
Lloyd Kvam | 1 Oct 06:01 2009

Re: Enabling Virtual Machine support


Thank you very much for your advice and interest.  HP sales support has
yet to get back to me with a list of models that support virtualization.
I assume the T9550 model at nearly $2K would do the trick, but that's
beyond my budget.  I'm simply going to stick with what I bought.

My old winXp (to handle payroll) partition could not be booted with my
SATA drive.  Rather than struggle with drivers, I'm using virtualbox and
things seem to be working well.

Virtualbox was a great recommendation.

--

-- 
Lloyd Kvam
Venix Corp
DLSLUG/GNHLUG library
http://dlslug.org/library.html
http://www.librarything.com/catalog/dlslug
http://www.librarything.com/rsshtml/recent/dlslug
http://www.librarything.com/rss/recent/dlslug
Ben Scott | 1 Oct 15:40 2009
Picon

Re: diagnosing network speed bottlenecks [SOLVED]

On Wed, Sep 30, 2009 at 9:47 PM, Greg Rundlett (freephile)
<greg@...> wrote:
> Sorry, I was misreading Comcast service as being measured in megaBytes
> (big B) while it's actually stated in megabits (little b).

  Be aware there's no standard symbol for bytes, bits, or octets.  The
"B = byte, b = bit" convention used by some is by no means universal.
When dealing with communications, I always spell out "byte" or "bit",
for this reason.

  In communications technology, speeds are almost always given in bits
per second.  Further, prefixes like "mega" and "kilo" are almost
always the actual SI prefixes, not the "binary prefixes".  In other
words, one kilobit/sec is 1000 bits per second, not 1024 bits per
second.

  For those interested in history, there is a technical reason for
this difference:

  Computers don't process bits, they process machine words (e.g., on
i386, a word is 32 bits).  Storage devices generally store blocks.
For example, IDE and SATA hard disks work with blocks of 512 octets.
So the machine is actual incapable of working with "10 bytes" or "1000
bytes" as unit quantities.  If you want 1000 octets of SATA disk, the
computer had to work with two blocks totaling 1024 octets.  So working
in bytes, with unit quantities based on multiples of 2, makes sense.

  (Which is why computer scientists adopted a bastardized version of
the SI prefixes: They needed prefixes.  SI already had a system of
prefixes, in base ten.  The base ten multiples weren't useful, but the
(Continue reading)

Jerry Feldman | 1 Oct 18:28 2009

Re: diagnosing network speed bottlenecks [SOLVED]

Basically, (as you did mention in the last paragraph) data
communications are almost always serial. However dialup modems are
capable of transmitting synchronized signals. Normally, when dealing
with dialup modems, you are dealing with a byte oriented protocol where
each 8-bit byte is framed with a stop and start bit (actually I don't
recall whether it is an extra stop of start such that an 8-bit byte
becomes 10 bits on the line). But modems are also capable of doing
synchronized traffic that does not require a stop and start bit. And, at
speeds above 1200 bits per second, the actual line protocol between the
2 modems is quite different to achieve the compression and higher
effective bit rates, but the computer itself sends the bits to the modem
in serial fashion.  Actually, it really does not matter because very few
of us actually use a phone modem any longer.

On 10/01/2009 09:40 AM, Ben Scott wrote:
> On Wed, Sep 30, 2009 at 9:47 PM, Greg Rundlett (freephile)
> <greg@...> wrote:
>   
>> Sorry, I was misreading Comcast service as being measured in megaBytes
>> (big B) while it's actually stated in megabits (little b).
>>     
>   Be aware there's no standard symbol for bytes, bits, or octets.  The
> "B = byte, b = bit" convention used by some is by no means universal.
> When dealing with communications, I always spell out "byte" or "bit",
> for this reason.
>
>   In communications technology, speeds are almost always given in bits
> per second.  Further, prefixes like "mega" and "kilo" are almost
> always the actual SI prefixes, not the "binary prefixes".  In other
> words, one kilobit/sec is 1000 bits per second, not 1024 bits per
(Continue reading)

Jerry Feldman | 1 Oct 19:04 2009

RCN business services reliability and bandwidth

My company is in a Regus office and after a communications "upgrade" we
are now on a shared LAN with a maximum bandwidth of 2Mbps (symetrical).
Previous to the "upgrade" the office had something like 3 T1s and we all
shared the available bandwidth. Not only that, we are paying about
$800+/Mo for that service and 6 static IPs (1 dedicated to our VPN the
other largely unused by requested by our IT people).  To add to this,
when we got the new connections, I was able to run some tests, to
compare the old and the new. As an example, under the old (AT&T
backbone) I could ping blu.org in under 20ms, and under the new carrier
(Level3) it is rarely under 70ms. A traceroute shows a lot of latency in
the level 3 centers in Cincinnati and Chicago. This affects how people
work at home. Our products are Linux based financial risk analysis
programs. So when one of our financial or integration engineers logs in
from home, they have to log in through a Toronto based Citrix server
then connect to the Boston servers. So when they run our product it is X
over IP, which is very slow (and considerably slower since the upgrade).
We have been offered a dedicated 1.5 dedicated (for the same price) or a
3.0 dedicated (by fiddling with some other figures it would be slightly
higher ~120/Mo).  Additionally, we do a number of Webex presentations.

RCN's service is assymetric 20Mbps/2Mbps for a savings of several
hundred bucks a month. They will also be increasing the upload side
supposedly by the end of the year. They are also giving us 8 static IPs.
at a significantly lower price than Regus. My question to this list is
basically what your RECENT experience is with RCN. has there been any
network outage where the Internet has been down for any significant time
period, or have there been many short outages. For instance, in our
case, even a momentary outage could knock a Citrix session offline. In
addition to outages, what has your experience been with bandwidth. Are
you seeing their advertised bandwidth, or a much lower bandwidth.
(Continue reading)

Bill McGonigle | 1 Oct 21:33 2009

[GNHLUG] [DLSLUG-Announce] DLSLUG: next meeting November 5th

Just a quick note so everybody knows the next meeting will be November
5th.  We'll be in Haldeman 041 (with desktop power), so we'll do the
encryption / key-signing meeting then.

-Bill

--

-- 
Bill McGonigle, Owner
BFC Computing, LLC
http://bfccomputing.com/
Telephone: +1.603.448.4440
Email, IM, VOIP: bill@...
VCard: http://bfccomputing.com/vcard/bill.vcf
Social networks: bill_mcgonigle/bill.mcgonigle
_______________________________________________
DLSLUG-Announce mailing list
DLSLUG-Announce@...
http://dlslug.org/mailman/listinfo/dlslug-announce
_______________________________________________
gnhlug-announce mailing list
gnhlug-announce@...
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Ben Scott | 1 Oct 22:53 2009
Picon

Re: diagnosing network speed bottlenecks [SOLVED]

On Thu, Oct 1, 2009 at 12:28 PM, Jerry Feldman <gaf@...> wrote:
> Basically, (as you did mention in the last paragraph) data
> communications are almost always serial. However dialup modems are
> capable of transmitting synchronized signals.

  I didn't think this was the case, but I just checked the V.32
standard, and it does indeed say that the signaling on the telephone
line is synchronous.  Now, I think every modem I've encountered only
implemented the RS-232 lines needed for async.  So the modem must be
buffering synchronous data to/from the telephone line internally, so
it can go back and forth to the host asynchronously.  The host then
has to buffer the UART for the same reasons.  How's that for
backwards?  :)

  But it's still serial, and still bit oriented.  Synchronous
transmission doesn't necessarily mean you have to have only one
particular framing discipline.

-- Ben
Alex Hewitt | 1 Oct 22:59 2009
Picon
Picon

VPN problem...

I recently was relating on the list how a client was having a problem 
with their Linksys BEFSX41 router and the solution was that Linksys 
RMA'd the router. They apparently have removed the BEFSX41 model from 
their active product list so they sent me a BEFVP41 v2 model. I received 
it yesterday, configured it and tested it from my office network. The 
router was set to obtain it's WAN address dynamically from it's WAN 
connection. It connected fine to a wireless bridge that I use for this 
purpose and I could surf the web from behind it with a PC. I then 
configured the VPN tunnel exactly as the old router was set up and it 
immediately connected to the customer's end point and I could ping 
systems located at the end point LAN. I tore down the setup and put the 
router in a container to set up at my client's location this morning.

I got to the client site and thought that all that was going to be 
necessary was to set the WAN address of the Linksys router to match the 
static address being provided by Comcast at the customer location. As 
soon as I did that I was able to connect to the internet from behind the 
router. But I then noticed that the VPN was not connected. Since the VPN 
settings were identical to the previous router there shouldn't have been 
a problem. For the fun of it I set the router to obtain it's WAN address 
dynamically and immediately the VPN tunnel connected. I checked the logs 
but didn't see anything obviously wrong. I did notice that when the 
router is setup to use a dynamic address, it has the correct date and 
time. When it's set up with a static address the status page says "time 
unavailable". I think this might be part of the problem. If the router 
doesn't know the time (perhaps the clock can't be used?) then the VPN 
connection might not work. I'm also puzzled as to what server it's 
requesting date/time data from. It has the ability to manually set the 
time zone but doesn't give any choices as to which ntp server to use.

(Continue reading)


Gmane