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Took over headend, need advice (2.0 system) Newish to this world

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newcableguy
Took over headend, need advice (2.0 system) Newish to this world

I took over for a small city owned cable system.

Details

Docsis 2.0
Cisco ubr7246 CMTS
2 channel down
4 channel up

550MHZ system

1 down channel qam 64
1 down channel qam 256

4 upstreams at 16qam

250mbps of available bandwidth
Currently utilizing 65 mbps at peak, sometimes 69

The packages they have set up are 4mbps, 2mbps, 1mbps with 1mbps up

What I understand is
64QAM @ 6MHz width = about 26Mbps. 1 channels = 26Mbps total capacity.
256QAM @ 6MHz width = about 38Mbps. 2 channels = 38Mbps total capacity.
So that maximum throughput I should see is 64Mbps

Now ideally the system needs severely upgraded, but until we get more customers we will never be able to afford the upgrades. We can always purchase more bandwidth, but getting customers at these speeds is going to be impossible.

So what I don't know, and don't have any training on, how do I add more channels? Does anyone have any tutorials or information they would like to share?

kwesibrunee
Welcome to the Cable world...

Welcome to the Cable world....? Nah it's not too bad, but will take a while to understand how it all works, it is pretty complex.

I am assuming for the purposes of this writeup, from your descriptions above, that you have a 7246Non-VXR chassis with either 2x MC16C blades or 1 x MC28C blades with a NPE-225 and are powered by AC (110v) power supplies. If this is your setup, then you are very near the capacity of this setup and to get any further capacity you will need to upgrade.

you have a few choices some better than others.... I am assuming a customer count of ~250

in no particular order: Most of these assume you have your plant segmented into at least 2 nodes/trunks Disclaimer: I work for Casa

1. upgrade to a cisco 7246VXR w/a NPE G1, with at least 1 preferably 2-4 MC28U blades ( you want a 1:1 relationship between plant segments and blades if possible, i.e. you have 4 nodes you want four blades, if you have 8 nodes you want four blades and do a 2:1 relationship). This is the cheapest and most straightforward upgrade, equipment can be found on the used market for < $1000 total even for 4 blades. The downside is the most bandwidth you can get to a particular segment is ~75 megs, which doesn't get you much room to grow. With proper segmentation (i.e. at least 4 segments) and a fully loaded chassis you could support up to 10-15 megs per subscriber before you start hitting the ceiling. Fully filled chassis would be capable of 310 megs of backbone bandwidth. (each blade would support about 75 megs of bandwidth)

2. upgrade to a cisco 7246VXR w/a NPE G2 and at least 1 MC88V blade. This solution will cost about $7-8k for a setup with 1 MC88V blade, additional blades will cost around $5k. With 1 MC88V blade even without proper segmenatation you would be able to offer 20-30 megs per customer (assuming customers switch to D3.0 modems) With Proper segmentation a fully loaded chassis ($20k) would support about 1.2 gig of backbone bandwidth (each blade about 300 megs)

3. upgrade to a cisco UBR10k with PRE2s and a MC20x20 blade. This solution requires switching from 110 ac to 220 ac or DC. A used Chassis can be found for $6-10k on the used market, MC20x20 blades are about $2k each on the used market. With this CMTS you would be able to offer speeds up to 50+ megs. A fully loaded chassis would support about 8 gigs of bandwidth ( each blade supports about 775 megs of bandwidth)

4. upgrade to an Arris C4 chassis with DCAMS and UCAMS, don't have much experience with this model but it would have similar capacity to a Cisco UBR10k and cost a similar amount on the used market.

5. upgrade to a casa C40G with 2x10G SMM and 8x96 DS card and 16x8 US card (220 AC or DC available), there is not much of these on the used market, but a CMTS like this would cost $40k+ depending on configuration. This CMTS fully populated/licensed is capable of about 30 gigs of bandwidth or half that with one of each card or redundancy.

6. Casa offers a CMTS as a service product that would be the same hardware as above (or the newer versions) for a fixed monthly cost per subscriber, Not sure of the price but it is in the $10 range. Casa would handle the configuration of the CMTS, you would provide the bandwidth and end user support, This solution gets you current CMTS without a huge upfront cost.

There are also more current solutions from Cisco, Casa and Arris, but they start at about $100k and only go up from there.

Things to keep in mind, the cisco/arris gear listed above has mostly been End-of-life / end-of-support which for small operators is not always an issue, but means you can't typically call cisco/arris with problems or get gear RMAed, meaning if it breaks you will have to replace it yourself.

If your interested in any of these solutions, let me know how many segments (nodes/trunks) you have and a customer count (a homes passed would be useful too) and I could get you a BOM (bill of materials) for each one so you could look into pricing.

newcableguy
interested

6. Casa offers a CMTS as a service product that would be the same hardware as above (or the newer versions) for a fixed monthly cost per subscriber, Not sure of the price but it is in the $10 range. Casa would handle the configuration of the CMTS, you would provide the bandwidth and end user support, This solution gets you current CMTS without a huge upfront cost.

I am absolutely interested in something like this though at the moment we only have 105 subs, but if we can get decent bandwidth we can take back from the dsl provider in town, and by my calculations and user interests, easily hit 300+ customers, so that is something that I am interested.

Could I get some contact information would love to talk with you more

kwesibrunee
What country are you in? And

What country are you in? And what state, if US? Then I will get you in touch with the right person. I work out of the Western US.

you can hit me up at jason dot patterson at casa dash systems dot com (replacing dot with ., dash with - and at with @)

docsis