[kwlug-disc] Cable internet providers

[Andrew Kohlsmith (mailing lists account)]

On Jun 4, 2014, at 10:37 PM, Khalid Baheyeldin <kb at 2bits.com> wrote:
>  I understand that. If you look at specs for modems they list the maximum up/down theoretical speed using N bonded channels.
> 
> But my question is if you have two modems at home, on the same cable, one from each provider, then how would one modem know not to use the channels that the other modem uses?
> 
> For example: Does each modem pick certain unique channels at link negotiation time, that are unused by anyone else on the segment?

It doesn’t work like that to my knowledge. Think of the old 10base2 networks; DOCSIS isn’t far off from that. All the modems on a segment share the same channels (although there are likely multiple bonding groups which are automatically negotiated between the head end and your modem). Your neighbours probably use the same channel bonding that you have. I don’t believe that different providers get different cable data channels; the head end is the same physical device and you’re on the same physical segment no matter who your provider is.

I’m afraid you’ve quickly hit the limit of my DOCSIS knowledge. I was mildly interested in this a number of years back but age and other information pushing what I did know out have left me with what I’ve now shared with you.

-A.