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
The Cable TV List (http://cabletvlist.com/) doesn't get much traffic, but
it does have some quality people on it that can answer most CATV
questions. It is heavily weighted on the TV side, so most things are
related to transport gear, IRDs, and distribution equipment. I am unaware
of any DOCSIS specific mailing lists, but if anyone out there does know of
one I would like to know about it as well.
Don't believe they have a mailing list, but this is a good source for technical issues on the modem/cmts side. Very helpful forum. Pulled me out of the weeds a couple of times. www.docsis.org.
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.
Those that are SCTE members have access to the SCTE mailing list. Like the comments about the CableTV list, it is often focused on plant/transport/RF more than Docsis but there are good DOCSIS knowledgeable people on the list too that answer questions.
Graham Johnston
Network Planner
Westman Communications Group
204.717.2829
johnstong@westmancom.com
think green; don't print this email.
In the past I was asked to create the cisco-ubr list
to cover some of these types of things.
https://puck.nether.net/pipermail/cisco-ubr/
I can create a catv or similar list easily. good name
suggestions welcome.
- jared
Colton,
It really depends on what features you are after. I've demo'd one of the small 1/2RU C-DOCSIS CMTSs, and they certainly work. For us though it was a non-starter as we needed support for DSG and it didn't have it. If all you are after is basic internet connectivity there is Pico Digital, Vecima, Sumavision, as well as others. Many of the C-DOCSIS CMTSs seem either only support, or are more often meant to support layer 2 operations where the routing happens upstream from the CMTS.
Graham Johnston
Network Planner
Westman Communications Group
204.717.2829
johnstong@westmancom.com
think green; don't print this email.
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:
Jared Mauch wrote:
I can create a catv or similar list easily. good name
suggestions welcome.
"There are only two hard things in Computer Science: cache invalidation
and naming things".
docsis-nsp?
Nick
Jared Mauch wrote:
> I can create a catv or similar list easily. good name
> suggestions welcome."There are only two hard things in Computer Science: cache invalidation
and naming things".
docsis-nsp?
Done.
https://puck.nether.net/mailman/listinfo/docsis-nsp
- Jared
Graham,
What is DSG? Yes, I am really looking for a CMTS to perform layer 2 just as
our DSLAMs and GPON do today. All layer 3 will be upstream. I would want to
handle DHCP upstream, but have the CMTS insert Option 82 if that is a
feature. Not sure what specific CMTS stuff you need.
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?
I would honestly perfer something that was hardened for outdoor use. Think
garden style apartments. What is the best for something like that?
Comparing DOCIS 3 to VDSL2, the modems and CMTS appear to be more cost
effective per customer. G.FAST I have not seen pricing on, but I expect it
to be more than VDSL2.
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?
The biggest reason to not do EuroDOCSIS is logistics and dealing with
various TAC organizations versus a pretty small increase in per channel
performance (but not per hertz). I'd pretty strongly recommend against it,
just because you're going to run into issues ranging from buying modems, to
dealing with node vendors, to finding people who can do basic stuff like
plant balancing. You wouldn't think it would matter, but it throws people
off to see that extra channel bandwidth.
My 2 cents, buy CMTS/CCAP gear that's upgradeable to D3.1, ie CBR8, E6000,
or the big Casa unit, for the time being shoot for 24 channel downstream
bonding groups (24 * ~37mbps - overhead) which yields about 740 mbps
usable. That's plenty for most nodes, especially since you're not offering
video you can have many bonding groups since channel space isn't a problem.
Scott Helms
Chief Technology Officer
ZCorum
(678) 507-5000
Colton,
You're only going to find very small, old, or not certified (usually still
very small) CMTSs that only do layer 2. All of the major vendors are doing
layer 3 because we've found out over time that not doing it is more
problematic. Having said that, if you're looking for a more ONT/DSLAM type
of install there is a new type of CMTSs that look at lot like traditional
telco DLC/BLC deployments.
https://intx15.ncta.com/wp-content/uploads/2015/05/17-Remote-PHY.pdf
The remote PHY+MAC boxes are basically mini-CMTSs and they typically rely
on something upstream handling layer 3. The remote PHY boxes are different
as they don't even do a complete layer 2 and instead forward DOCSIS frames
back to a centralized CMTS/CCAP.
Scott Helms
Chief Technology Officer
ZCorum
(678) 507-5000
In-line below.
-Daniel
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.
Scott Helms wrote:
My 2 cents, buy CMTS/CCAP gear that's upgradeable to D3.1, ie CBR8, E6000,
or the big Casa unit, for the time being shoot for 24 channel downstream
bonding groups (24 * ~37mbps - overhead) which yields about 740 mbps
usable.
the good thing about eurodocsis is that it gives you a full 1gig usable
if you're bonding over 24 channels. There's a natural residential
performance plateau at 1G because 10G NICs haven't really made it to the
consumer level yet, which means that if you want to hand off > 1gbit,
things become more expensive and/or more complicated.
Nick
Hi Colton,
For what it sounds like you’re really looking for, a remote MAC-PHY (or
pre remote MAC-PHY, ala mini CMTS) would probably be the good fit for your
application. This is certainly not an endorsement, as we haven’t used any
remote MAC-PHY devices today.
There are a couple players pouring money into products that haven’t really
been mentioned yet...
1) Huawei - which initially brought a mini CMTS to market (D3.0, 16x4.)
Some C-DOCSIS stuff, so may be feature poor but it doesn’t sound like you
really need the boatload of features that are in a classic full-size CMTS
anyway. Not sure what’s going on with their D3.1 remote MAC-PHY general
availability is either.
2) Gainspeed - D3.0/D3.1 product (not sure about where the generally
availability of their product lines are) but if you happen to be a Juniper
customer, they partner with Gainspeed so it can be easy to get engaged
with them.
Ed
On 2/2/16, 11:03 AM, "NANOG on behalf of Scott Helms"
Nick,
That very small upside for an extreme downside. Trying to hire someone to
work on your system with Euro channelization, not to mention buying
amplifiers and passives is a huge PITA. I have customers in Europe who
decided to do US DOCSIS and they universally wish they had used the local
"flavor".
Scott Helms
Chief Technology Officer
ZCorum
(678) 507-5000
Hi,
<SNIP>
I would honestly perfer something that was hardened for outdoor use. Think
garden style apartments. What is the best for something like that?
It depends where you are going to be deploying these things, northern
New York state? Arizona? There's a reason curbside cabinets exist.
Comparing DOCIS 3 to VDSL2, the modems and CMTS appear to be more cost
effective per customer. G.FAST I have not seen pricing on, but I expect it
to be more than VDSL2.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?
In the UK, half the country is using EURODOCSIS, half DOCSIS
(historical reasons - the original companies had different ideas. I
know that Liberty Global - who bought them all - can't wait for the
new 3.1 standard where there will be no difference). One problem with
using the 'wrong' one is simply around signal leakage. What happens
when some fool leaves an unterminated bit of coax lying around? What
frequencies is this new areal broadcasting on? Remember, even if the
customer is the one who unterminates the cable it's still your problem
to detect and fix.
You will need to get EURODOCSIS equipment (including CPE) that:
-Works on 110v (the EU uses 230v)
-Has an FCC sticker rather than a CE sticker
-Isn't going to break any FCC rules if used in EURODOCSIS mode
-Has support available in North America
The key differences are summarised at
https://www.excentis.com/blog/differences-between-us-docsis-and-eurodocsis-and-will-docsis-31-eliminate-them.
There a a lot more to it than the channel width!
On a separate note, remember that G.FAST is extremely sensitive to
dodgy wiring and line length. If the local loop length length gets
near 500 yards you will be lucky to hit 150Mbps down. Over 500 yards
and you will be lucky to hold sync outside of a lab.
Alex