In Reply to message #369569 by Lightmaster
Member Member windwaterwaves is not online, or is invisible.
4/3/2016 11:26:23 AM
windwaterwaves Member #: 86349 Registered: 2/22/2012
Posted: 37 View all posts by windwaterwaves
Company: San Juan cable Occupation: Computer Network Engineer Location: Bellingham Washington
Re: Internet
First don't bother with e-mail = NIGHTMARE they all use gmail, yahoo mail, aol mail or their own domains.  You don't want to be a ISP (i am one, believe me).

If you have forward and reverse working on the cable system you are ready for the next steps.

Find an IP provider you will need 100-200mb for that many subs, minimum burst to 1gb.  ISP's will price by utilization so you could order a 1gb ethernet/fiber link with 50mb to start that will get the IP side rolling.  Depending on your city ISP availability will be hard to get, it's the duopoly thing, either the telephone or cable company.  If there are quite a few cell towers there may be a way to get that.  Look for a local ISP that does wireless.  We actually feed an island with wireless and support 230 subs.

PM me where you are located and I can do a quick search.

Next you will need a CMTS, Pick up a Cisco UBR7246VXR ~$2k (make sure vxr) with NPE-G1 and a couple of MC28u (2 downstream, 8 upstream, docsis 2.0) max speed you can offer customers will be 10mb average, 20mb business, upstream 1mb, to 3mb depending on the SNR and the quality of your return plant equipment.  You can upgrade this unit with MC88's that do docsis 3.0 later.  For that size you may need two depending on how your plant is split.  I would say no more than 150 subs per split running 4 downstreams and 8 up.  Figure 1mb/s/subscriber, ya it has gotten insane lately..  Don't bother with a nortel 1000 you will grow out of it immediately.

Then you need a linux or windows box.  You create a modem config file (lots of samples out there).  Set up dhcp services, time service, and tftp. 

You have to decide/plan what downstream and upstream frequencies you will use especially if you are using physical filters.  We use (ugly) the fm band.. for downstream it's pretty clean though.

Here is the process, a modem listens for a digital signal and locks onto a downstream frequency.  (down light locks)  Once that happens it learns from that signal what upstream frequency to try, it sends and the cmts picks it up (up light locks).  At that point the modem sends a dhcp request to the server.  The dhcp server supplies the details, the name of the config file for that mac address (authorization), and other server info.  The modem downloads the file (noaccess.bin or basic10-1-20.bin) are our non access and 10/1 plan file names.   Once the config is loaded the online light locks, or if no access they flash (a few different types depending on model).  We use motorola modems sb5100 and sbg941 (wireless).

Voila.  The trick is to either buy, lease or write your auth software (I wrote mine) it just writes out a dhcp config file to the server the modems query.  The auth services are complete thieves!  Last I checked they wanted $5 or $6 a subscriber PER MONTH.  If you can't find anything these guys are pretty cheap, but again, monthly look up DOXcontrol on ebay. 

Pm me and check out docsis.org
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2 Replies
4/3/2016 3:40:16 PM
Lightmaster
4/4/2016 6:46:43 PM
jmiller