3 ms·

Why build 4 sets of lines when you can build 1? Isn’t this literally the reason why broad swaths of the US have zero competition?

mhb 2y ago
Resilience? Exactly the thing which is being optimized out of much critical infrastructure.
- Dylan16807 2y ago
  Laying down competing bundles along the same path gains you very little resilience. For the smallest issues, you can expect a single bundle to already have spare connections. For bigger issues, almost anything that takes out one bundle will take out the neighbors too.
- matt-p 2y ago
  It's easier to build resilience as a single network or organization than by "hoping" to have that with two different ISPs (who will obviously both of taken the cheapest route dig wise between A and B). If I need two diverse fiber paths between points X and Y, I can go to one provider who can contractually guarantee diversity. For example, they can ensure that maintenance work on Circuit 1 is not scheduled at the same time as Circuit 2, and that the paths are never less than X metres between them, as they are fully aware of the two paths.
  - AnthonyMouse 2y ago
    The one ISP is not going to do that automatically, because it costs more. Then only banks and others willing to pay a massive premium get it. And sometimes even they don't, because they run completely redundant fiber paths along different streets and then use the same OEM's equipment on both of them and a bad software update takes them both out at once, or their union goes on strike and cuts power to the whole operation before they walk out. Meanwhile diverse ISPs wouldn't be using the same A and B. ISP A has a central office in a high rise downtown, ISP B primarily targets single family homes and has their switching equipment on a piece of land next to a substation in suburbia, so if you subscribe to both you not only have links coming from opposite directions, they're each operated by independent organizations instead of a monoculture.
    - matt-p 2y ago
      That might be your perception, but let me give you real life state of affairs in the UK. In the last decade a number of ISPs have popped up and decided to fibre up areas. They are invariably buying OLTs from Nokia or Adtran (the same two vendors as BT OR) putting them in a BT OR exchange because that is cheap and very convenient, good access to backhaul etc and then renting BT OR ducts and poles to install the fibre in/on (PIA). To top it off they often are using the same fibre vendor as BT and sometimes even the same contractors to install it. Worked example of this; netomia/youfibre (though there are dozens). What resilience are we really gaining here? Organisational, and that's pretty much it.
      - AnthonyMouse 2y ago
        You've created an environment where there is a single large incumbent and the ability and incentive for anyone else to piggyback on their existing infrastructure. Now suppose that anyone could run an ISP out of their house. They wire up a few of their neighbors and then make a single long-distance run to one of many backhaul providers, none of which has a dominant market position like BT. The backhaul providers connect to their customers and each other in telco hotels, but they're smaller and more numerous because each of the largest providers has their own, so the city has three or four instead of one. Meanwhile even if you have a BT, organizational independence in itself is better than nothing.
        matt-p 2y ago
        Are there western countries with no incumbent telecom provider? It is a fine concept but you'd have to actually ban infrastructure sharing between ISPs and be building a completely Greenfield network. Quite theoretical. I'm aware of former eastern bloc countries that have dynamics somewhat reminiscent of what you describe though.
        AnthonyMouse 2y ago
        It's not that you have to prohibit it, it's that you have to somehow break their existing monopoly if it already exists, and it's easy to choose rules that don't actually break it but instead cause it to be a de facto utility again. So for example, if the incumbent has a monopoly on transit or interconnection, you have a problem because they could just charge prohibitive rates and bankrupt all their competitors. And prohibitive rates are same thing as banning them from using it, aren't they? It's what happens by default. But then the competitors can't get off the ground because the incumbent has a vertically integrated monopoly. You could require them to provide those services for their competitors at regulated rates, but then you're not actually breaking that monopoly, you're just regulating it while cementing it in place. If you have an existing monopolist then first you have to thoroughly break them up, not just mitigate the continued existence of the monopoly.
  - icehawk 2y ago
    And then Circuit 1 and Circuit 2 are taken down at the same time because even though they have diverse paths they're part of the same underlying DWDM system which has just encountered a fault. Ensuring there isn't a single point of failure is not just as simple as 'putting it in the contract.' Carriers can and have groomed their primary and backup circuit on to the same L1 path without realizing it.
    - matt-p 2y ago
      That should only happen if your protection is at the optical layer which hasn't been common for a decade or more, partly for that reason. I've never seen it happen in 20 years. Although of course small parts of the path change over time and sometimes that means bits get put in the same duct for a short run but that also happens when you buy from different providers to be honest. With some carriers you can insist they send you updated route kmls when they change either path and you can detect the change as you'll see different losses/otdr traces before and after a maintenance/fix.
matt-p 2y ago
In london I used to have 4 different physical fibre providers available plus one which is fibre to the building and cat5e to the prem. At a retail level there were hundreds of providers to choose from. Most of the country has more than one physical fibre (or FTTB/FTTC/CATV) provider available.

mhb 2y ago

Resilience? Exactly the thing which is being optimized out of much critical infrastructure.

Dylan16807 2y ago
Laying down competing bundles along the same path gains you very little resilience. For the smallest issues, you can expect a single bundle to already have spare connections. For bigger issues, almost anything that takes out one bundle will take out the neighbors too.
matt-p 2y ago
It's easier to build resilience as a single network or organization than by "hoping" to have that with two different ISPs (who will obviously both of taken the cheapest route dig wise between A and B). If I need two diverse fiber paths between points X and Y, I can go to one provider who can contractually guarantee diversity. For example, they can ensure that maintenance work on Circuit 1 is not scheduled at the same time as Circuit 2, and that the paths are never less than X metres between them, as they are fully aware of the two paths.
- AnthonyMouse 2y ago
  The one ISP is not going to do that automatically, because it costs more. Then only banks and others willing to pay a massive premium get it. And sometimes even they don't, because they run completely redundant fiber paths along different streets and then use the same OEM's equipment on both of them and a bad software update takes them both out at once, or their union goes on strike and cuts power to the whole operation before they walk out. Meanwhile diverse ISPs wouldn't be using the same A and B. ISP A has a central office in a high rise downtown, ISP B primarily targets single family homes and has their switching equipment on a piece of land next to a substation in suburbia, so if you subscribe to both you not only have links coming from opposite directions, they're each operated by independent organizations instead of a monoculture.
  - matt-p 2y ago
    That might be your perception, but let me give you real life state of affairs in the UK. In the last decade a number of ISPs have popped up and decided to fibre up areas. They are invariably buying OLTs from Nokia or Adtran (the same two vendors as BT OR) putting them in a BT OR exchange because that is cheap and very convenient, good access to backhaul etc and then renting BT OR ducts and poles to install the fibre in/on (PIA). To top it off they often are using the same fibre vendor as BT and sometimes even the same contractors to install it. Worked example of this; netomia/youfibre (though there are dozens). What resilience are we really gaining here? Organisational, and that's pretty much it.
    - AnthonyMouse 2y ago
      You've created an environment where there is a single large incumbent and the ability and incentive for anyone else to piggyback on their existing infrastructure. Now suppose that anyone could run an ISP out of their house. They wire up a few of their neighbors and then make a single long-distance run to one of many backhaul providers, none of which has a dominant market position like BT. The backhaul providers connect to their customers and each other in telco hotels, but they're smaller and more numerous because each of the largest providers has their own, so the city has three or four instead of one. Meanwhile even if you have a BT, organizational independence in itself is better than nothing.
      - matt-p 2y ago
        Are there western countries with no incumbent telecom provider? It is a fine concept but you'd have to actually ban infrastructure sharing between ISPs and be building a completely Greenfield network. Quite theoretical. I'm aware of former eastern bloc countries that have dynamics somewhat reminiscent of what you describe though.
        AnthonyMouse 2y ago
        It's not that you have to prohibit it, it's that you have to somehow break their existing monopoly if it already exists, and it's easy to choose rules that don't actually break it but instead cause it to be a de facto utility again. So for example, if the incumbent has a monopoly on transit or interconnection, you have a problem because they could just charge prohibitive rates and bankrupt all their competitors. And prohibitive rates are same thing as banning them from using it, aren't they? It's what happens by default. But then the competitors can't get off the ground because the incumbent has a vertically integrated monopoly. You could require them to provide those services for their competitors at regulated rates, but then you're not actually breaking that monopoly, you're just regulating it while cementing it in place. If you have an existing monopolist then first you have to thoroughly break them up, not just mitigate the continued existence of the monopoly.
- icehawk 2y ago
  And then Circuit 1 and Circuit 2 are taken down at the same time because even though they have diverse paths they're part of the same underlying DWDM system which has just encountered a fault. Ensuring there isn't a single point of failure is not just as simple as 'putting it in the contract.' Carriers can and have groomed their primary and backup circuit on to the same L1 path without realizing it.
  - matt-p 2y ago
    That should only happen if your protection is at the optical layer which hasn't been common for a decade or more, partly for that reason. I've never seen it happen in 20 years. Although of course small parts of the path change over time and sometimes that means bits get put in the same duct for a short run but that also happens when you buy from different providers to be honest. With some carriers you can insist they send you updated route kmls when they change either path and you can detect the change as you'll see different losses/otdr traces before and after a maintenance/fix.

matt-p 2y ago

In london I used to have 4 different physical fibre providers available plus one which is fibre to the building and cat5e to the prem. At a retail level there were hundreds of providers to choose from. Most of the country has more than one physical fibre (or FTTB/FTTC/CATV) provider available.