nanog mailing list archives

Re: alternative to voip gateways


From: Nick Edwards <nick.z.edwards () gmail com>
Date: Mon, 25 May 2020 23:30:39 +1000

We opted for Adtran TA5000's with 48 port VDSL2 vectoring combo cards,
going by expected losses we expect to have more than 50mbps d/l at all
cabins, we are going to lock them at 50 anyway sincve we reply on RF
to get data in first place. and use a central splitter to separate
vdsl and POTS at each cabin, must like everybody did adsl, apparently
this is largely how they do it in Europe vdsl and pots on same line
(just on a much bigger scale than us). This gives them their high
speed data and reliable POTS - since if the residential areas loses
power, not relying on end user SIP, their voice will still work when
their modems (and area) is without power.

We were advised that having an inline microfilter - like adsl, would
be more problematic at vdsl since it is essentially a bridge tap -
something we all know is bad, it would be much greater issue, and the
central splitter unit we looking at using allegedly avoids this
problem.

The cost of the cards (and chassis) would be not justified for small
operations, but at our numbers its actually a cost saving over the
dual devices path, as well as the metallic line testing ability.

Thanks to all for advice.

On 5/12/20, Michael Thomas <mike () mtcc com> wrote:

On 5/11/20 1:31 PM, Mark Delany wrote:
We need to keep battery backup requirements, and expand them to all last
mile IP bits. The need to call 911 has not gone away.
For sure. I was merely observing that the conversion of POTS to VOIP
in Australia didn't create a nation-wide disaster as the
pearl-clutchers once predicted.

In fact, if anything, the same folk who complained about the so-called
largesse of a nationwide IP last-mile are strangely silent now that
WFH is de rigueur.

To your point, the original plan was 90+% passive optical back to
major exchanges so the infrastructure was largely invulnerable to
wide-scale power shutdowns/failures. All a residence has to do is feed
a 7W NTD to stay connected.

Is this expecting ftth? Obviously things like DSLAM's and CMTS's require
power. But all of this doesn't perfectly emulate the POTS requirements
since it is my responsibility to feed power to the CPE my wifi routers,
etc. What we saw last fall is that going long on gas/propane power
generator companies is a pretty good bet and works fine in my neck of
woods (in the boonies and the gold country) , but I don't see how that
scales when you turn off the power to, oh say, Oakland or San Jose (or
at least parts of them), which they did and will keep doing for the
foreseeable future.

Mike




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