nanog mailing list archives

Re: Cable Operator List


From: Daniel Corbe <dcorbe () hammerfiber com>
Date: Tue, 2 Feb 2016 11:08:45 -0500

In-line below.

-Daniel

On Feb 2, 2016, at 10:47 AM, Colton Conor <colton.conor () gmail com> wrote:

Daniel,

Thanks for the wealth of information. What kind of speeds are you offering? How many customers are you putting on one 
of these boxes? What modems are you using?

We’re using Arris modems because we have the least amount of signal-related issues with them.  We’ve had to drop to 
64qam because portions of our network runs over the air and we run into SNR issues at 256qam on the downstream.  This 
is important because it basically halves our available bandwidth.  I quoted some figures below based strictly on 
channel width but the reality of our situation is we see about half those numbers.

We don’t cap our users.  Every modem on the network can bond all 16 channels if it’s capable and it wants to.  We’ve 
got one plan.  Which means they can burst as high as they want within reason.  Every month we’re in contact with the 
top talkers in each sector and we ask them to curb their bandwidth usage.  

With this model we get about 50 to 75 users to every 16 channel CMTS we deploy.  In a 200 unit apartment building, we’d 
deploy 4 to 6 boxes.   On a 2000 user airbox station, we’d deploy about 20 of them.  

There’s also one more consideration.  Our TV service is IPTV.  Since we’re not pumping DVB-C or DVB-S signal down the 
cable, we’ve got nearly a full Ghz of spectrum with which to use for DOCSIS channels.  This gives us a lot of 
flexibility to just add additional CMTS when we begin to run into capacity issues.


I would honestly perfer something that was hardened for outdoor use. Think garden style apartments. What is the best 
for something like that? 

I’m sure someone somewhere makes an environmentally hardened CMTS but I’m not currently aware of any at the moment.  
Most of my equipment sits in wiring closets. 

Any reasons not to use EURO DOCSIS in the USA? Looks like it offers more speeds by using fatter channels. We don't 
plan on offering TV, but even if we did couldn't we just start the channels at a higher range, and still use EURO 
DOCSIS? 

EuroDOCSIS would be a better option if you’re looking to maximize bits per hertz and have enough spectrum to play with. 
 You get 8Mhz channels for 6Mhz channels which means at 16 channels you’ll get 800Mbit/sec to a modem instead of 
640Mbit.


On Tue, Feb 2, 2016 at 8:17 AM, Daniel Corbe <dcorbe () hammerfiber com> wrote:
Hey Colton,

We’re using small 16 channel CMTS systems for residential MDUs and colocating them directly on premise inside of 
wiring closets and then connecting them by metro ethernet.  We’ve had great successes so far with this model.

There’s lots of CMTS vendors.

There’s tons of used Motorola BSR 64Ks on the market, but be aware of the lack of useful IPv6 features (like prefix 
delegation) in older software releases.  If you buy a box and want to run 7.x or 8.x, you’ll need to relicense your 
downstream and upstream channels at some additional arbitrary fixed cost.

I’m personally fond of these things:

http://picodigital.com/product-details.php?ID=miniCMTS200a

You can only bond 16 channels together max though because that’s all the box supports and you can’t bond across 
boxes; however, these things are less than 4 grand if you buy them in bulk so they’re really fucking easy to just 
spam everywhere.

Blonder Tongue makes a pizza-box style CMTS too:

http://www.blondertongue.com/shop-by-department/catv/ip-over-coax/docsis/euro-docsis/

As does Harmonics:

http://harmonicinc.com/product/cable-edge/nsg-exo

All three are based on the same chipset, so the real differentiation is price and firmware features.

Then there’s Cisco.

The UBR is a popular platform.  And pretty soon there’s going to be a glut of UBR10Ks on the Market because Comcast 
is busy ripping their UBRs out of production because they’re upgrading their cable plant to the CBR platform.

Then the Arris C4, if you have deep pockets, is a modern version of the BSR:

http://www.arris.com/products/c4-cmts/


On Feb 2, 2016, at 9:00 AM, Colton Conor <colton.conor () gmail com> wrote:

Well, maybe NANOG's not a bad place for this post then! I would like to know more about the data-only side of CMTS 
systems, and who the main vendors are.

We have MDU properties where there is either old inside CAT3 phone wire, or coaxial cable. We have looked and are 
very familiar with the multiple technologies that work over phone lines namely VDSL2 and G.FAST. However, using the 
coaxial cable seems to be a much better solution than using the phone wires.

So I am looking for compacts, low cost CMTS systems. Based on the specs, I am looking for something at least DOCSIS 
3.0 capable, with at least 16X4 output. Something with the ability to upgrade to software upgrade to DOCSIS 3.1 
would be nice, but I doubt that would be a low cost solution.

Whats out there for small operators that don't want a large chassis based system to feed an entire town with.

So far I have found the http://picodigital.com/product-details.php?ID=miniCMTS200a which seems to retail for under 
$5000.


On Tue, Feb 2, 2016 at 7:48 AM, Daniel Corbe <dcorbe () hammerfiber com> wrote:

On Feb 2, 2016, at 8:42 AM, Colton Conor <colton.conor () gmail com> wrote:

Are there any mailing lists out there dedicated for cable/MSO type
operators?


I'm curious about this too.

I’m not a cable operator (in that I haven’t successfully registered for a cable franchise yet) but I do operate a 
docsis network and I’ve successfully negotiated the treacherous waters of obtaining and providing content to my 
users.

I’m still a bit green behind the ears but I could probably offer some measure of assistance if you have a specific 
question.

-Daniel






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