[kwlug-disc] Rogers Bandwith Limit - Consequences of exceeding?

Chris Irwin chris at chrisirwin.ca
Mon Feb 9 14:08:37 EST 2009

On Mon, Feb 9, 2009 at 12:57, unsolicited <unsolicited at swiz.ca> wrote:
> Andrew Kohlsmith (lists) wrote, On 02/09/2009 10:05 AM:
>> HomePhone isn't voip -- the home phone modem uses a different "channel"
>> for its communications, so it's plain old not over the internet.

Home Phone *appears* to be VOIP (see below). But you are correct that
it is on a different channel. The term channel is particularly
suitable when discussing how cable is divided :)

Check out the How Stuff Works article on Cable Modems[1]. The article
on Cable Television[2] is interesting, but it doesn't really add too
much to this discussion.

> I haven't used it to know - where does their phone box go, assuming you have
> TV and internet:
>               incoming cable
>                      ^
>                      v
> <-> internet <-> home phone <-> tv digital terminal <->

The rogers Phone box plugs in to your cable the same as a cable modem
or tv terminal.

> Is home phone digital or analog? Is it IP?

Home Phone is a digital phone service.

A warning: Everything I'm writing here is the results of some light
reading in the past and a few quick Wikipedia searches to double-check
my memory.

According to the Rogers Telecom[3] and PacketCable[4] articles, the
"Home Phone" service is run on a separate channel, thus does not
impact Internet bandwidth (and, importantly, the opposite). The Rogers
Telecom article refers to it as VOIP, but the Cable Television
article[5] indicates the following:

"Note that in many cases, digital cable telephone service is separate
from cable modem service being offered by many cable companies and
does not rely on IP traffic or the Internet."

I read this as underscoring the separated phone/internet bandwidth
rather than saying that the technology precludes use of IP. If you are
implementing a packet-switched voice network, I would think IP would
be the logical choice to build upon, if only to allow your backbone to
run on "commodity" hardware. It also allows Rogers to piggyback on
their existing network if necessary.

> Did you use 'cable modem' above particularly? I know the suffering you're
> referring to. Does this impact (digital) TV or home phone? (Same set of
> wires.) Digital TV just being a different 'IP range' going over the same
> wires.

Different channel. There is no impact in either direction. I suppose
it is possible that too many phone users could cause bandwidth issues,
but I would imagine Rogers has this planned for better. Internet usage
is variable, whereas Phone will always be one stream per adaptor --
assuming fancy things call-waiting happen Rogers-side, which is
something I have not researched and should not be assumed.

[1] http://computer.howstuffworks.com/cable-modem.htm
[2] http://electronics.howstuffworks.com/cable-tv.htm
[3] http://en.wikipedia.org/wiki/Rogers_Telecom#Rogers_Home_Phone
[4] http://en.wikipedia.org/wiki/PacketCable
[5] http://en.wikipedia.org/wiki/Cable_television#Other_cable-based_services

Chris Irwin
<chris at chrisirwin.ca>

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