4 ms·
If I shined a laser pointer through the fiber in my house, would I DOS my neighbors?
by RockRobotRock 2y ago
If I shined a laser pointer through the fiber in my house, would I DOS my neighbors?
- Faaak 2y agoNo
- simonjgreen 2y agoYes, this can happen with cheap/poor splitters upstream and/or high power lasers of the correct frequency. Sending a regular red laser up the fibre will likely do nothing, however I have encountered ONUs that do not have particularly selective receive optics. Sending a laser at 1310nm or 1490nm can cause havoc.
- bcrl 2y agoOn GPON or XGSPON, sending 1490nm on the upstream will have no effect unless you get to incredibly high power levels where they cause damage to the transmit laser on the OLT's optics for GPON (many dB higher for XGSPON). Fibre optic cables and PLC splitters don't reflect signals at significant levels (directivity is typically >= 55dB). I have unintentionally tested this by accidentally connecting 2 different GPON segments together in a splitter cabinet; nothing broke. On GPON, 1310nm light launched at 2-8dB and 1270nm light at similar power levels on XGSPON is enough to blind the OLT from being able to receive signals from other ONUs. Risk-wise, it's the same as cable modems that can spray noise over the upstream channel. But most people aren't interested in launching DoS attacks that take themselves offline.