Is it possible to order a ISDN BRI line from the LEC and have them
look at the design of a DS1 and have them if possible design the ISDN
BRI lineon a devurse path or at lest different equipment within the

I suspect that, particularly for something as small (in terms of revenue to the LEC) as a BRI circuit, you won't have much leverage to ask for anything 'off the menu', like diverse physical routing through the CO.

When you get to the point of dealing with the copper in the ground/on the pole, your options for route diversity are usually extremely limited (read: nonexistent). Telco copper plant is usually based on large multipair cables from the CO on a specific route, so even if you managed to get them to commit to diverse routeing in the CO, the copper pairs will still be in the same cable bundle, entering your building and the CO at the same points.


Off hand, I wouldn't expect a carrier to do any special engineering on
a BRI -- can you even *order* a BRI these days? :slight_smile:

As old NANOG hands know, though, it doesn't matter *what* you ask for,
few-to-no carriers properly manage physical diversity requests properly
over the long haul, anyway, and the only way to do it yourself often
requires that you ask the carrier for records they won't give you.

Regularly. Like, monthly.

Even if you're paying them extra for the diversity.

-- jra

Is it possible to order a ISDN BRI line from the LEC and have them
look at the design of a DS1 and have them if possible design the ISDN
BRI lineon a devurse path or at lest different equipment within the

Effectively: No. You might find a salescritter willing to *sell* you
such a thing, but it's not likely to have any basis in reality, at
least long-term.

In the general case, telcos try *not* to have diverse paths for end-
user lines; for them, it's simpler to have one big mondo cable hauling
lots of connections into an area than it is to have three or four that
are running in separate directions. You can certainly find
counterexamples where some level of diversity might be available (such
as a different cable hanging on the same poles), but actual diversity
from start to finish is tough.

You would be slightly better off with a DS1 and a connection from the
cable company; they may share a bunch of poles, but at some point it
will diverge and you're largely guaranteed to be on somewhat different
equipment in the CO/headend, heh.

... JG

What you can do is (if you are important enough) apply for TSP ( in conjunction with provisioning of a circuit to actually have this type of engineering happen and persist, including emergency restoration. If your local carrier doesn't offer the redundancy you want, your only other choice is to build it yourself. Considering the cost of lighting a 10G or 1G strand of fiber for 10km or 20km, working with a BRI isn't that important anymore.

- Jared
(who has a BRI line for his "POTS" at home to get clean dial tone at his distance from the CO)

Unfortunate but very true.... seen that many of times where a "special engineering" fee has been charged specifically to carry a circuit in a diverse manner (or even reasonably diverse). Then it breaks and the excuses start as to why it was never done as promised - then a couple of years later it breaks and nobody has paperwork that shows it was *ever* supposed to be diverse in the first place....



This may be a great options because the network will be going into air ports.

Seems to still be in NECA Tariff5, at least the last copy I looked at. So the rurals still are tariffed for it.

As I understand the question, you want the BRI to be path diverse to the DS1's path, correct?

It would depend upon how well you know the tech folk at the telco, and whether there is existing or planned transport in multiple directions from your site.

Even if you order bona fide protected circuits, you're not likely to be guaranteed physical path diversity.

Having said that, lots of telcos will work with you if you know the people to work with, and some will quote you a term agreement for the physical plant provisioning as an additional cost, and probably for three to five years terms.

Yes that is my goal. I guess I will be dealing with Verizon and AT&T
mostly as the LEC