[conspire] Comcast jamboree, day deux

[Rick Moen]

For years, we've noticed sometimes the Cisco DPC3941B DOCSIS 3.0 24x4
Wireless Business Gateway box goes through multiple reboots during the
middle of the night, which we alway guesstimated to mean a remotely
triggered maintenance regime right out of 'The Office' ('Have you tried
turning it off and back on again?').  Like, maybe Comcast Corporate was
aware of these SOHO gateways being a foetid pile of dingo's kidneys
prone to RAM exhaustion and becoming unable to maintain their state
tables, and so just had a cron job to force-reboot them frequently.

And basically our attitude was:  Oh-kay, it suggests a downbeat
assessment of their technical adequacy from our outsider perspective,
but:  You do you. Comcast.

At the end of yesterday's exhausting day, Deirdre and I had gone to bed
just before midnight, and, suspiciously right _at_ midnight, we suddenly
had no bandwidth across our uplink.  I observed to Deirdre that, during
the immediately-past day's Comcast festivities, Comcast's voice-response
system had advised me that our address would have a maintenance interval
(for unexplained reasons) that night starting at 2am, so maybe they
started early.  We were so tired, we just gave up and nodded off.

At 8:20am, I was woken by an incoming call on my cellular, and it was a
Comcast rep informing me that the requested rDNS entry for the IPv6
address was now live.  'Great, thanks', said I, briefly considering
checking but deciding I needed more sleep more than I needed
confirmation of a fix that was currently no longer urgently needed --
because I'd applied the "Facebook remedy" to the IPv6 problem.  That is, 
"No Facebook; no Facebook problems".  (I'd somewhat savagely shot IPv6
in the foot at the stack level.  And yes, Michael, I will move to a
less brutal solution, and thank you kindly for the tip obout how to 
selectively disable _only_ IPv6 autoconfiguration.) 

So, I got back to sleep -- to be woken up an hour or so later by Duncan
Mackinnon saying something like "Rick, the uplink is still down, and
I've already power-cycled the Cisco."  Without getting out of bed and
possibly without even opening my eyes, I grabbed my cellular and
re-dialed Comcast Business's main number (800-391-3000) and went through
the now-familiar voicemail-tree gauntlet.  Eventually, I reached a
live-human rep who asked screening questions and checked remotely, 
noting that the router was back but had only (IIRC) "20% signal", so
eventually after a few checks that everyone agreed connectivity was
back, we ended the trouble-ticket case.  The rep observed sagely that
the gateway had rather a long service life and it would be wise to 
have it replaced if it acted up again.  I agreed to this, and didn't 
press to have it happen immediately.

I _think_ it was at exactly 1pm that the uplink failed again.  This
time, a cold restart resulted in the 'online' light for the uplink not 
lighting, so I went through the voice-tree gauntlet again, reaching a
nice, sympathetic rep who attempted basic diagnosis but then, concurring
with her prior colleague, said it was time to have a Comcast Business
on-site tech visit to do hardware-level debugging that would likely
include swapping out the Cisco DPC3941B for something that might suck
less or suck differently.  She predicted a 4-hour (at max.) arrival
window, which, fair enough.  

While waiting for their guy to arrive, I caught up on sysadminly
housekeeping including making sure all cables and electronic units were
labeled, plus removing temporarily from the diagnostic picture a couple
of pieces of gear that didn't strictly need to be there -- and then
reverifying that the problem persisted.  At first, the uplink worked, 
which was briefly worrying in a way I lacked a good gameplan for, but
then the uplink went down and even the gateway box's two WiFi ESSIDs 
became dysfunctional.  Which on balance was A Good Thing:  It's not a
good outcome if you are obliged to tell the visiting tech that it turns
out to be a Heisenbug that they cannot now observe but you swear was
real a while ago.

Around 4:30pm, the Comcast Business guy arrived: top-notch fellow for 
that job role, IMO.  Because of the dismal experience in 2015 with
Comcast's outsourced installer who, among other things, severed the
household's ADSL, voiced landline, and TV antenna connections in the
process of cabling up the Comcast Business connection for Cheryl -- as a
reminder, said asshat gratuitously severed all the coax cables at the
roofline, and then lied about having done that -- Duncan and I politely
inquired if he (today's tech) worked for Comcast's Business division and
not for a subcontractor (and not for Comcast Residential/Xfinity).  Yes,
he was the real deal, he said.

After a couple of basic checks, he yanked the Cisco DPC3941B out with my
blessing -- and brought in from his van a Technicolor model CGA4131COM
replacement gateway, did basic configuration, and then politely invited
me to complete the configuration from my careful notes about the Cisco's
configuration.  (I just now put the finishing touches onto that.)

So far:  The new gateway box performs rather a lot better than the old
one, but I'll skip details for length's sake.  

However:  Cheryl is paying $18.45 per month ($221.40/year) to _rent_ the
damned gateway box (an underpowered and overfeatured thing where Comcast
has root remotely), which seems frankly stupid.  I gather that the
'modem' (terminal adapter) portion must comply with the DOCSIS 3.0 (or
3.1?) (Data Over Cable Service Interface Specification) spec, but
otherwise could be anyone's hardware (and I'm not interested in
integrated telephony, which complicates things).  

Something like a Motorola MB7621 ($78 online) would suffice.  That's
_just_ a 'modem', not providing a firewall, a DHCPd, or a WAP.  Nor does
it have eight ethernet ports like the Technicolor model CGA4131COM, but
rather one ethernet port -- because, frankly, that's what you have an
ethernet switch for.  And we already have a bunch of WAPs, separately.
They connect to ethernet switches just fine.  ($221.40/year in rent,
wow.  Sucker bait.)

In the category of actual progress, with Duncan's good offices, we got
all new ethernet cabling strung across the subflooring and passed up
into the living room adjoining the Technicolor model CGA4131COM -- such
that, perhaps tomorrow, I can finally re-unify the shambles that was
left when Raw Bandwidth cut off ADSLv1 service and left about half the
computing devices in my house with no uplink.

Whew, what a day.  Again.