Activity light on my cable modem ...?

I have had cable service for a few years.
I leave the cable modem powered on all the time.
As I recall when I first got the unit the activity light would flash mostly
when I was using it.
Now it seems to be flashing all the time even when the computer is off.
Is the flashing light reflecting a huge volume of activity on the cable?

William Lee

"Will-Lee-Cue" <(E-Mail Removed)> wrote in message
news:1PGie.95412$(E-Mail Removed)...
>I have had cable service for a few years.
> I leave the cable modem powered on all the time.
> As I recall when I first got the unit the activity light would flash
> mostly when I was using it.
> Now it seems to be flashing all the time even when the computer is off.
> Is the flashing light reflecting a huge volume of activity on the cable?
>
> William Lee
Yea, I notice the same thing. Even with the computer off the activity light
is going crazy. I guess it means nothing now.

I wonder if it is reflecting the increased number of subscribers on the
cable system?
Ya think it can ever bog down from high traffic?

William Lee

"Nog" <(E-Mail Removed)> wrote in message
news:jLqdnWgX9dSg3BbfRVn-(E-Mail Removed)...
>
> "Will-Lee-Cue" <(E-Mail Removed)> wrote in message
> news:1PGie.95412$(E-Mail Removed)...
>>I have had cable service for a few years.
>> I leave the cable modem powered on all the time.
>> As I recall when I first got the unit the activity light would flash
>> mostly when I was using it.
>> Now it seems to be flashing all the time even when the computer is off.
>> Is the flashing light reflecting a huge volume of activity on the cable?
>>
>> William Lee
> Yea, I notice the same thing. Even with the computer off the activity
> light is going crazy. I guess it means nothing now.
>
>
>

On Wed, 18 May 2005 13:24:29 GMT, "Will-Lee-Cue" <(E-Mail Removed)>
wrote:

>I wonder if it is reflecting the increased number of subscribers on the
>cable system?
>Ya think it can ever bog down from high traffic?

Exactly. What you're seeing is all your neighbors traffic. However,
only the traffic that's destined for your cable modems MAC address,
and gets decrypted, appears at the ethernet port. Therefore, you
can't put a sniffer on the ethernet port and either decrypt the
traffic, or try to measure it. (There are other ways of measuring
traffic such as through the JTAG port).

A good clue is the netmask of your cable connection. You'll find it
on the status screen of your router or wireless router. Depending
upon your cable topology (I have a wall chart from CED magazine
hanging on my office wall with all the cable technologies), you can
guess the number of neighbors:
255.255.255.0 254
255.255.254.0 510
255.255.253.0 1022
255.255.252.0 4046
The local Comcast system runs with 1000 users per node. Incidentally,
the big CISCO CMTS boxes can handle up to 65,000 customers per box
(though up to 64 remote nodes).

The more users on your segment, the slower your cable modem will run.
The limitation is not much in the download speed, but in the return
channel (between 5-45MHz) which tends to get clogged with outgoing
traffic (servers) and polluted by ingres (RF interference). This is
why the cable modem providers don't offer symmetrical or business
class service suitable for servers.

Start reading here:
http://computer.howstuffworks.com/cable-modem.htm




--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 AE6KS 831-336-2558

Thanks Jeff, That is intresting information.
I was reading about website hosting and wondering if the cable would suport
me being the server to my website.
Looks like that is not such a good idea.

William Lee


"Jeff Liebermann" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> On Wed, 18 May 2005 13:24:29 GMT, "Will-Lee-Cue" <(E-Mail Removed)>
> wrote:
>
>>I wonder if it is reflecting the increased number of subscribers on the
>>cable system?
>>Ya think it can ever bog down from high traffic?
>
> Exactly. What you're seeing is all your neighbors traffic. However,
> only the traffic that's destined for your cable modems MAC address,
> and gets decrypted, appears at the ethernet port. Therefore, you
> can't put a sniffer on the ethernet port and either decrypt the
> traffic, or try to measure it. (There are other ways of measuring
> traffic such as through the JTAG port).
>
> A good clue is the netmask of your cable connection. You'll find it
> on the status screen of your router or wireless router. Depending
> upon your cable topology (I have a wall chart from CED magazine
> hanging on my office wall with all the cable technologies), you can
> guess the number of neighbors:
> 255.255.255.0 254
> 255.255.254.0 510
> 255.255.253.0 1022
> 255.255.252.0 4046
> The local Comcast system runs with 1000 users per node. Incidentally,
> the big CISCO CMTS boxes can handle up to 65,000 customers per box
> (though up to 64 remote nodes).
>
> The more users on your segment, the slower your cable modem will run.
> The limitation is not much in the download speed, but in the return
> channel (between 5-45MHz) which tends to get clogged with outgoing
> traffic (servers) and polluted by ingres (RF interference). This is
> why the cable modem providers don't offer symmetrical or business
> class service suitable for servers.
>
> Start reading here:
> http://computer.howstuffworks.com/cable-modem.htm
>
>
>
>
> --
> Jeff Liebermann (E-Mail Removed)
> 150 Felker St #D http://www.LearnByDestroying.com
> Santa Cruz CA 95060 AE6KS 831-336-2558

On Wed, 18 May 2005 17:16:06 GMT, "Will-Lee-Cue" <(E-Mail Removed)>
wrote:

>Thanks Jeff, That is intresting information.
>I was reading about website hosting and wondering if the cable would suport
>me being the server to my website.
>Looks like that is not such a good idea.

If home cable and DSL connections were suitable for hosting, there
would be no need for big server farms, full of web hosting servers,
and big fat pipes to the internet. I run a few weather stations on
local DSL connections. One or two users every few days is not much of
a load. That works fine. However, for the ones that are publicly
accessible, I mirror it to a hosting service.


--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 AE6KS 831-336-2558

Jeff,

Do you recall which issue of CED your chart came from?

I'm on Comcast with a netmask 255.255.252.0.
I think that means 4046 max users for a specific upstream freq?

Mike
N6DZU

"Jeff Liebermann" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> On Wed, 18 May 2005 13:24:29 GMT, "Will-Lee-Cue" <(E-Mail Removed)>
> wrote:
>
> >I wonder if it is reflecting the increased number of subscribers on the
> >cable system?
> >Ya think it can ever bog down from high traffic?
>
> Exactly. What you're seeing is all your neighbors traffic. However,
> only the traffic that's destined for your cable modems MAC address,
> and gets decrypted, appears at the ethernet port. Therefore, you
> can't put a sniffer on the ethernet port and either decrypt the
> traffic, or try to measure it. (There are other ways of measuring
> traffic such as through the JTAG port).
>
> A good clue is the netmask of your cable connection. You'll find it
> on the status screen of your router or wireless router. Depending
> upon your cable topology (I have a wall chart from CED magazine
> hanging on my office wall with all the cable technologies), you can
> guess the number of neighbors:
> 255.255.255.0 254
> 255.255.254.0 510
> 255.255.253.0 1022
> 255.255.252.0 4046
> The local Comcast system runs with 1000 users per node. Incidentally,
> the big CISCO CMTS boxes can handle up to 65,000 customers per box
> (though up to 64 remote nodes).
>
> The more users on your segment, the slower your cable modem will run.
> The limitation is not much in the download speed, but in the return
> channel (between 5-45MHz) which tends to get clogged with outgoing
> traffic (servers) and polluted by ingres (RF interference). This is
> why the cable modem providers don't offer symmetrical or business
> class service suitable for servers.
>
> Start reading here:
> http://computer.howstuffworks.com/cable-modem.htm
>
>
>
>
> --
> Jeff Liebermann (E-Mail Removed)
> 150 Felker St #D http://www.LearnByDestroying.com
> Santa Cruz CA 95060 AE6KS 831-336-2558

On Wed, 18 May 2005 09:22:53 -0700, in alt.internet.wireless , Jeff
Liebermann <(E-Mail Removed)> wrote:

>On Wed, 18 May 2005 13:24:29 GMT, "Will-Lee-Cue" <(E-Mail Removed)>
>wrote:
>
>>I wonder if it is reflecting the increased number of subscribers on the
>>cable system?
>>Ya think it can ever bog down from high traffic?
>
>Exactly. What you're seeing is all your neighbors traffic.

and any broadcast packets that your ISP does't filter.


--
Mark McIntyre
CLC FAQ <http://www.eskimo.com/~scs/C-faq/top.html>
CLC readme: <http://www.ungerhu.com/jxh/clc.welcome.txt>

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http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----

On Wed, 18 May 2005 18:46:24 GMT, "M2" <(E-Mail Removed)> wrote:

>Do you recall which issue of CED your chart came from?

Nope. There's a foldout insert in every issue. Usually it's
sponsored by some manufactory. Once a year, they include the latest
cable network topology diagrams. I save them all and have about 8
years worth. It's amazing to watch how topology changes along with
alliances and mergers. Anyway, you'll see some of the wall charts at
the bottom of:
http://www.cedmagazine.com/ced/index.htm
Ah, foundit:
http://www.cedmagazine.com/ced/2003/...fiberchart.pdf
Oops. That's from 2003 which is ancient. I won't be in the office
for a few daze, but I'll see if I can find it online.

>I'm on Comcast with a netmask 255.255.252.0.
>I think that means 4046 max users for a specific upstream freq?

Comcasts hybrid dual fiber pretzel ring star/bus topology will handle
up to about 4000 homes per node. Very reliable on the backbone and to
the main nodes. Constipated to the max on the mini-nodes and local
distribution bus.

--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 AE6KS 831-336-2558

Copied from the following URL.

http://www.cisco.com/warp/public/701/3.html




Host/Subnet Quantities Table
Class B Effective Effective
# bits Mask Subnets Hosts
------- --------------- --------- ---------
1 255.255.128.0 2 32766
2 255.255.192.0 4 16382
3 255.255.224.0 8 8190
4 255.255.240.0 16 4094
5 255.255.248.0 32 2046
6 255.255.252.0 64 1022
7 255.255.254.0 128 510
8 255.255.255.0 256 254
9 255.255.255.128 512 126
10 255.255.255.192 1024 62
11 255.255.255.224 2048 30
12 255.255.255.240 4096 14
13 255.255.255.248 8192 6
14 255.255.255.252 16384 2

Class C Effective Effective
# bits Mask Subnets Hosts
------- --------------- --------- ---------
1 255.255.255.128 2 126
2 255.255.255.192 4 62
3 255.255.255.224 8 30
4 255.255.255.240 16 14
5 255.255.255.248 32 6
6 255.255.255.252 64 2


*Subnet all zeroes and all ones included. These
might not be supported on some legacy systems.
*Host all zeroes and all ones excluded.

Lars