On Fri, 11 Oct 2019, Michael Thomas wrote:
So I knew that telcos are required to battery backup pots, but are isp's
too? I have a dinky little provider who also provides pots, but i have never
been clear whether dsl stays up too in a blackout.
Of course generalizing all service providers isn't fair... From my
experience tracking telecommunication during disasters for the last 20-30
years... Let me generalize (ignoring special goverment priority systems).
Generally, during natural (and man-made) disasters:
Telecommunication service providers historically failed in this order
1. VSAT/DTH/satellite (during weather events)
2. Cable
3. Cellular/wireless
4. Telco/Wireline
5. Broadcast radio/TV (less than 20% over-the-air stations operating)
6. Network backbone systems (inter-city and toll offices)
There are too few WISPs for reliable predictions. I'd guess WISPs
reliability is similar to cellular/wireless systems.
Restoration order is a bit different. Telecommunications network service
historically recovers in this order, assuming customer premise isn't
damaged:
1. VSAT/DTH/satellite (after weather clears)
2. Network backbone (inter-city and toll offices)
3. Cellular/wireless (COWs and COLTs deployed)
4. Broadcast radio/TV (20% over-the-air stations operating)
5. Telco/Wireline
5. Cable
Cable systems tend to be the first to fail, and the last to be restored.
Telco systems tend to fail later, but take a long time to be restored.
Network backbones can take a while to repair, but generally nothing else
works until they are repaired, so they get repaired first or second.
Note: During even the worst catastrophes, there is almost always one or
two broadcast radio stations still operating. I set 20% radio/TV
stations operating as an arbitrary minimum level. Likewise, COWs and
COLTs don't provide full cellular service, but do provide minimumal cell
services.
In the last 10 years, cellular/wireless system resiliance has been
improving while telco/wireline system resiliance has been getting
noticablly worse. I assume this a flywheel affect as telco companies
have been shifting infrastructure investement to wireless networks and
away from wireline networks for the last 20 years.