Docsis Help

This post was made after docsisdude spent some time doing a password recovery on a BSR and could not find any documentation for the BSR online.... Sound familiar???

One of the best things about Cisco is how well they document things.   I don't know how many times I've gone to www.cisco.com and found exactly what I was looking for.   Sometimes it can take a little longer than I had hoped, but that's only because they have so much documentation to sift through.   You often have to be pretty specific when doing the search, and when you find something good…. Bookmark it.   Stuff like load balancing configs, RFSW setup, CWDM SFPs, the list is endless.   Like all websites Cisco moves things around, so don't get angry when you get dead linked to the apologetic Cisco page not found error.   This brings up an interesting point.   On one hand Cisco has gone to the infinite degree to document EVERYTHING.   This has pros and cons as having all that info often makes finding things difficult.   The other side of the coin is that the other vendors often have very little as far as public documentation.   I know you can't really expect that from everyone, but it can slow you down when you don't have that PDF you need or are learning on a new box.   Either way it would be helpful if the other vendors could put more info up.   It also wouldn't hurt if Cisco trimmed some of the documentation, or removed that eight year doc about DOCSIS1.0 ;)

docsisdude

So your a DOCSIS Engineer and you compete with AT&T's U-Verse VDSL service. They're taking some of your single play subs and turning them into triple play subs, but hey you've been turning their single play subs into triple plays subs for years. The problem begins after they take the subs, but before those subs disconnect (or if those subs keep your service). What is the problem? HPNA On the HPNA wiki they brush over the topic and state some of the disadvantages of HPNA3.x are "Doesn't coexist with DOCSIS". Well I'll expand on that a little further. This has gotten some news as Comcast outside Chicago has been battling with AT&T and complained to them. This has for the most part been ignored but I'm sure AT&T is burning the midnight oil trying to come up with a solution to allow HPNA to work without disrupting DOCSIS. (right) HPNA works in the frequencies above DSL and voice, but below broadcast television. Sound familiar? Well it should because that's your DOCSIS return path. When somebody hooks up a 2Wire HPNA router/gateway to a coax line still connected to active cable plant, that HPNA signal leaves the house and gets into our return plant. I saw this first hand, and it forced me in at my previous job to vacate my preferred frequency of 35MHz. I had to use 25MHz which isn't a bad frequency, but again this is a competitors product that actively interferes with your product. The HPNA signal looks like a static "haystack" its not bursty like a TDMA based DOCSIS carrier. It can and will destroy your return path and make large swathes of said spectrum completely unusable. Is the solution for the us to high pass filter subs that switch to Uverse? Or should Uverse use the 43-50MHz range we can't use? This is barring strange mid-split systems and assuming standard diplex filters of 5-45 which roll off at @43Mhz. Everything past ~40MHz has pretty hardcore group delay issues anyway so I'd be happy to give them 40-50MHz. If that was the case they could work, we could work and we could go back to competing fairly...... Or I could just drive around with an unlicensed AM transmitter, or go pee on a VRAD.... something makes me think Harry Potter... err Kevin Martin wouldn't like that, let alone MaBell (or the Engineers at AT&T that would have to fix it).

Till next time

docsisdude