Hosted PBX
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@PSX_Defector said:
There's a reason Ma Bell setup the network the way she did.
Because it locked people in and made them lots of money.
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@PSX_Defector said:
PBXes fail, usually due to lazy telcom admins. I've lost all internet connections to the world over multiple pipes in a single location but the PRI was still running just fine.
Similarly remember when the middle east went offline a few years ago because the cable in Egypt was cut? All phones in Bahrain and UAE were gone... except those on SIP. I was on the phone with a country that was "offline" over SIP. No PRIs left up in the country for days. SIP users just had latency increase.
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@PSX_Defector said:
Like most things, 90% of "failures" are self inflicted, bad configs, bad equipment. I've seen loops need some changing and fixing, but never outright fail out the blue without any reason.
The self inflicted I've seen the most is in choosing PRIs with SLAs that protect the vendor from prosecution if a service is not reliably delivered. I've had PRIs out for six months at a shot with no recourse for the customer because of a strong SLA that gives them no means to do anything except pay a reduced monthly bill for a service that didn't even exist for them.
PRIs have single points of failure combined with low inherent incentive for vendors to be concerned. Connections are private and low priority.
Sure, customers can get dual PRIs, but the ability to get competing vendors to provide them for failover is extremely cost and difficult and still offers lower protect than public SIP for the same use case.
PRI is just a bundle of risk. Most of that risk is contractual, not physical, but even physically the antiquated technology carries significant risks that SIP simply does not unless you intentionally add scenarios to cause it to happen.
Like I said before... there is a reason all the big carriers stopped doing PRI and moved to SIP and lie about it being PRI now, because SIP is cheaper AND more reliable.
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Who even provisions true PRI today?
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@scottalanmiller said:
@PSX_Defector said:
Of ALL the telecom technology out there, PRI is the MOST reliable service out there for voice.
T1, which is a dependency of PRI, is simply not that dependable.
Nowadays, T1's are delivered as HSDSL circuits, since at least 2004ish. On one pair versus the two pairs of PRI. Modulation is different, but it emulates a PRI fairly well.
A PRI is an ISDN product, which delivers channels down to the location. They can be voice, data, or both. A T1 can be a PRI, but a PRI is not always a T1. Don't conflate T1's and your strange bad luck with them with PRIs which deal in trunks from central offices to a location.
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@PSX_Defector said:
A T1 can be a PRI, but a PRI is not always a T1. .
Actually the PRI specification is very clear that it IS always a T1. The moment that there is no T1, it's not a PRI. It might be PRI emulation, but even that is questionable as the T1 isn't emulated. It's VERY much tied to T1 in every way.
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@scottalanmiller said:
Who even provisions true PRI today?
Everyone. ISDN is still a legit product line.
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@PSX_Defector said:
Don't conflate T1's and your strange bad luck with them with PRIs which deal in trunks from central offices to a location.
But it is what the term PRI means. You can do things that behave like PRIs in other ways on more reliable medium, but they aren't PRIs. They have PRI termination, but that's not the same.
But even those, most of the problems still exist. Not all, the physical carrier improves. But you still have the contractual problems that plague the industry and are alone a risk so high that it makes all other risks combined into trivial background noise.
My experience with all other outage types are rare and short. None going over a period of hours. PRI routinely happens to more customers and for periods of times going into days and even into months. (None has yet topped a year outage.)
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@PSX_Defector said:
@scottalanmiller said:
Who even provisions true PRI today?
Everyone. ISDN is still a legit product line.
It's definitely not everyone. Nearly no one does a physical PRI. Most vendors don't even have the product for any region, let alone most.
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@scottalanmiller said:
PRIs have single points of failure combined with low inherent incentive for vendors to be concerned. Connections are private and low priority.
You can't eliminate every SPF. You have to entrust your network to support the product as best and effectively as they can. And as someone who's worked both for and against telecom vendors, I can say from a Tier 1 provider, a PRI is very, very stable.
And as someone who has worked in telecom, I can say a PRI is considered high priority in a outage situation. Someone cuts a trunk line, guess what the tech is gonna be doing first?
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@scottalanmiller said:
@PSX_Defector said:
@scottalanmiller said:
Who even provisions true PRI today?
Everyone. ISDN is still a legit product line.
It's definitely not everyone. Nearly no one does a physical PRI. Most vendors don't even have the product for any region, let alone most.
AT&T covers most of the US, both in their traditional regions (MOKAT, Pac/NV, Ameritech, BellSouth) and out (thank you TA96). But if you want the entirety of the US, I'm not going to find things for little co-op or one central office, but here are the big boys:
http://business.frontier.com/enterprise/pri-isdn
https://www22.verizon.com/wholesale/solutions/solution/ISDN%2BPRI.html
http://www.centurylink.com/wholesale/pcat/isdnpri.html
https://www.cincinnatibell.com/aboutus/regulatory_affairs/Tariff/CBAD/Indiana/LocalSvcs/section7.pdf
https://www.fairpoint.com/enterprise/voice/isdn-pri/
https://www.megapath.com/voice/lines-pri/I could pull regulatory pages on it on a state by state basis. Remember also that PRI, by extension ISDN, is regulated. Even in Texas, I can get someone on shit if they f[moderated] up a line, month long outages from a previously working circuit are complete and utter farces.
https://www.puc.texas.gov/agency/rulesnlaws/subrules/telecom/26.142/26.142.pdf
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@PSX_Defector said:
And as someone who has worked in telecom, I can say a PRI is considered high priority in a outage situation. Someone cuts a trunk line, guess what the tech is gonna be doing first?
As a customer advocate, I guarantee you, this isn't true. They might say this internally, but it doesn't really happen. Bring down a power line, someone's home cable will be back up days before the PRI gets fixed.
That's why their is that handy SLA saying that the customer can't get out of the contract.
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@PSX_Defector said:
I could pull regulatory pages on it on a state by state basis. Remember also that PRI, by extension ISDN, is regulated. Even in Texas, I can get someone on shit if they f[moderated] up a line, month long outages from a previously working circuit are complete and utter farces.
They are very, very real. Say all you want about regulation, it isn't keeping the phone lines working for customers.
Worst outages I've seen, of course, are in the Rochester region. Also where the worst POTS problems.
I've had months of POTS outages in Rochester as well.
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Another legacy "problem" is wrongful termination. I don't mean being fired. I mean the wrong customer getting the calls. I'm sure this risk happens on all technologies, but I've never heard of SIP calls going to the wrong customer. I've witnessed this first hand with POTS and PRI lines. Wrong trunks being delivered or even home phone lines being put directly into a corporate PBX somewhere distant.
Could happen with SIP, but does it?
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One of the most important things to remember is that nearly all risks from PRI or POTS are vendor risks, not technology ones. They might be encouraged by the technology, but it is the risk that you are under either because vendors struggle to understand how to work with these old technologies (which seems odd but really happens), or how they contractually have so much more opportunity to extort. SIP providers, if handled logically, are essentially powerless to extort and must resort to good service to make money. PRI vendors almost always have heavy extortion powers and heavy legal protections and monopolies to ensure that there is little to no means for a business to protect themselves from them. Regulation is useless in a monopoly situation where the vendor can put you out of business because the lawsuit is over.
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@scottalanmiller said:
@PSX_Defector said:
And as someone who has worked in telecom, I can say a PRI is considered high priority in a outage situation. Someone cuts a trunk line, guess what the tech is gonna be doing first?
As a customer advocate, I guarantee you, this isn't true. They might say this internally, but it doesn't really happen. Bring down a power line, someone's home cable will be back up days before the PRI gets fixed.
Obviously you know everything about AT&T and their policies, so no point explaining it. Other than you being utterly wrong about AT&T's policies and procedures for outages.
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@PSX_Defector said:
Obviously you know everything about AT&T and their policies, so no point explaining it. Other than you being utterly wrong about AT&T's policies and procedures for outages.
Did I say AT&T? All I know is real world what customers have happen to them. AT&T is just one of many, many phone providers and not one that I see very often. AT&T and the SMB are uncommon bedfellows.
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AT&T is, I will admit, the only carrier that I've had good luck with in a PRI-like space. I've never complained about AT&T circuits. But you can't use AT&T as an example, the market is large and AT&T is just one of a multitude of players. I'm explaining the risks of PRI, if AT&T doesn't leverage its position, that's great, but it doesn't change the market or the technology risks. One good vendor does not change how the market behaves. I've lost links (not PRI, can't imagine any enterprise using PRI) but "PRI like" links from AT&T and they were excellent in resolving them. Those links were outside of the US where customer support is far more important, but the service was still good.
But you are relying on a single vendor, that few people consider especially in the SMB, as why the whole approach is reasonable. That doesn't work. I never said it was AT&T, and AT&T doesn't define how PRI is approached.
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But some really critical things to keep in mind...
- Companies of any size at all do not use PRIs. A PRI is just was too small for large companies to use. This is an SMB-only product category.
- AT&T and the big service contracts both that you are using as examples both are uncommon and/or don't apply to the SMB.
PRIs are dangerous additionally because they are exclusively used by small, mostly powerless customers. Very different than a customer getting an OC-192.
