3 ms·

Interesting, but isn’t lightning over in an instant? How long would the actual disruption period be?

mmmBacon 6y ago
From the link I provided it shows the time scales. When the fiber transmission rate is 10-25Tb/s, these timescales represent non-trivial service disruptions. From the page 4 of the link below you can see that Africa has the highest density of lightning strikes. https://www.ofcconference.org/getattachment/d0ec1565-ce81-4897-82c1-e18cb9546c79/Lightning-Strikes-and-100G-Transport.aspx https://www.ofcconference.org/getattachment/d0ec1565-ce81-48...
- tinco 6y ago
  What does the transmission rate have to do with whether the disruption periods are non-trivial? If I read it correctly, the disruptions are on the order of milliseconds (why did you make us read through a powerpoint slideshow?). That means not noticeable for most fiber use cases. The only use case I can imagine that would suffer from this a bit, is telerobotics (i.e. remote surgery). Unless the fiber path is so long, and the lightning storms so large that there is a continuous stream of those disruptions.
  - mmmBacon 6y ago
    Actually the events themselves are only part of the outage. There has to be time for the link to come back up (not instantaneous). If the disruption is minor this might be a few hundred ms. However this is still long enough on OTN networks to trigger protection switching (scale is 100us). This causes traffic to be rerouted (disruptive). Additionally during a storm, it’s not uncommon for there to multiple lightning strikes in the same region. When I say same region, think the length of the state of Florida. BTW, Florida was where this phenomenon was first observed; every summer there would be multiple outages. The large amount of traffic on the fiber can be an issue and cause congestion and other problems (25T is a lot of traffic). Furthermore service and equipment providers have SLAs and outages can cost each money. Sorry to hear that you felt forced to read a set of slides on the matter.
    - tinco 6y ago
      Thanks, interesting! I will recover ;)

From the link I provided it shows the time scales. When the fiber transmission rate is 10-25Tb/s, these timescales represent non-trivial service disruptions. From the page 4 of the link below you can see that Africa has the highest density of lightning strikes. https://www.ofcconference.org/getattachment/d0ec1565-ce81-4897-82c1-e18cb9546c79/Lightning-Strikes-and-100G-Transport.aspx https://www.ofcconference.org/getattachment/d0ec1565-ce81-48...

tinco 6y ago
What does the transmission rate have to do with whether the disruption periods are non-trivial? If I read it correctly, the disruptions are on the order of milliseconds (why did you make us read through a powerpoint slideshow?). That means not noticeable for most fiber use cases. The only use case I can imagine that would suffer from this a bit, is telerobotics (i.e. remote surgery). Unless the fiber path is so long, and the lightning storms so large that there is a continuous stream of those disruptions.
- mmmBacon 6y ago
  Actually the events themselves are only part of the outage. There has to be time for the link to come back up (not instantaneous). If the disruption is minor this might be a few hundred ms. However this is still long enough on OTN networks to trigger protection switching (scale is 100us). This causes traffic to be rerouted (disruptive). Additionally during a storm, it’s not uncommon for there to multiple lightning strikes in the same region. When I say same region, think the length of the state of Florida. BTW, Florida was where this phenomenon was first observed; every summer there would be multiple outages. The large amount of traffic on the fiber can be an issue and cause congestion and other problems (25T is a lot of traffic). Furthermore service and equipment providers have SLAs and outages can cost each money. Sorry to hear that you felt forced to read a set of slides on the matter.
  - tinco 6y ago
    Thanks, interesting! I will recover ;)