diagnosing network speed bottlenecks

[Jerry Feldman]

I consistently get 30Mbps (30751 Kbps) down and 15Mbps (15649Kbps) up. I
recently went up one notch for less money. Before then sent me the
DOCSIS 3 modem, I was getting consistent tests roughly 20/8. Generally,
my bandwidth has been pretty good over the years with Comcast and
predecessors.

However, at work they have us capped at 2Mbps even through the pipe is 5
T1s (7Mbps). I am currently talking to RCN for business Internet service
because this horrible bandwidth is affecting how our FEs do work away
from the office.


On 09/30/2009 01:36 AM, Greg Rundlett (freephile) wrote:
> I'm not a network packet-sniffing blood-hound, so I need some help of
> the mere-mortal variety :-)
>
> 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.
>
> The service that I have costs $42.95 per month and advertises
> "Downloads up to 15Mbps, uploads up to 3Mbps with PowerBoost" (which
> is inflated due to the fuzzy math they use around the temporary boost
> they allow on the first xMB of a transfer, and depends on the
> equipment you have*).  Now Comcast is offering tiered services of
> Internet (the highest depending on a DOCSISv3 modem).  Their 'economy'
> service is the only service that is cheaper, while there are three
> plans that are more expensive -- up to $99/mo. for Internet service.
> http://www.comcast.com/shop/buyflow2/products.cspx (can't access page
> without giving your address)
>
> 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
>
> When I called them to inquire why my speeds don't seem to stack up to
> the service - they offered three explanations...
> a) that sites that I'm using will and do control how fast they will
> allow me to download from them and
> b) that my router could be the culprit because they generally wear out
> after two years, and I should buy a new 'draft-N' router.
> c) that my network speed is shared by all the devices on my network so
> that could affect my observed speed
>
> a) while sites do limit bandwidth allocated to a single user, I don't
> think this will be the case all the time.  Anyone know of a site that
> doesn't throttle which would allow me to eliminate a)
> b) I have a U.S. Robotics 802.11g router currently and I'm open to
> opinions on whether I should replace it, or test it's capacity.
> c) I have 6 DHCP clients on the router (none windows), and nobody is
> awake right now but me, so those clients can't possibly be hogging all
> my bandwidth.  I just installed ntop and I'm collecting some stats,
> but it doesn't look like there's too much "latent" activity on my LAN.
>  The peak load in the last 5 minutes was 8.9 Kbit/s
>
> Note too: I have a wired CAT5 connection, although other devices use wireless.
>
> * I have a DOCSISv2 modem (the Arris TM602g)
> http://www.productwiki.com/arris-tm602g/  -- a new model supplied when
> I recently signed up for their bundled service of Internet, Phone and
> Cable.  According to
> http://en.wikipedia.org/wiki/List_of_device_bandwidths#Modems.2Fbroadband_connections,
> the DOCSISv2 standard means the modem is only capable of 4,750/3,375
> kB/s speeds, which means it will never get to "15 MB/s" that they
> advertise.  According to the product data sheet, the max data rate
> down is 30 or 42 Mbps which equals 3.75 - 5.25 MB/s
>
> Greg Rundlett
>
> nbpt 978-225-8302
> m. 978-764-4424
> -skype/aim/irc/twitter freephile
> http://profiles.aim.com/freephile
> _______________________________________________
> gnhlug-discuss mailing list
> gnhlug-discuss at mail.gnhlug.org
> http://mail.gnhlug.org/mailman/listinfo/gnhlug-discuss/
>
>   


-- 
Jerry Feldman <gaf at blu.org>
Boston Linux and Unix
PGP key id: 537C5846
PGP Key fingerprint: 3D1B 8377 A3C0 A5F2 ECBB  CA3B 4607 4319 537C 5846


-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 252 bytes
Desc: OpenPGP digital signature
Url : http://mail.gnhlug.org/mailman/private/gnhlug-discuss/attachments/20090930/fef0c4cd/attachment-0001.bin