3 ms·
what protects a HFT microwave line from a targeted (perhaps even legal) attack of drones that get between line of site? or is the wave length larger than this?
by cyphunk 12y ago
what protects a HFT microwave line from a targeted (perhaps even legal) attack of drones that get between line of site? or is the wave length larger than this?
- minimax 12y agoI have not heard of anyone intentionally interfering with microwave links, but generally speaking these RF lines are not reliable and you get gaps from time to time due to weather and whatnot. There are a couple of ways to deal with this. In the market data case, the data only flows in one direction and usually consists of sequenced messages, so you just send the data down both the microwave and a fiber path simultaneously. You can do simple line arbitration (throw away duplicates) at the receiving end.
- Maxious 12y agoThere are easier ways to annoy HFT: "Every day for up to ten minutes near the London Stock Exchange, someone blocks signals from the global positioning system (GPS) network of satellites ... timestamps on trades made in financial institutions can be affected. " http://www.economist.com/news/international/21582288-satellite-positioning-data-are-vitalbut-signal-surprisingly-easy-disrupt-out http://www.economist.com/news/international/21582288-satelli...
- minimax 12y agoThrowing off the exchange generated timestamps doesn't mess with any HFTs. The exchanges themselves don't synchronize against one another so the timestamps are basically useless to begin with.
- kasey_junk 12y agoIf you are timestamping in a data center and they throw off the timestamp source for the entire data center that could theoretically cause you issues.
- easytiger 12y agoAnyone serious will have their own oscillator with enough Holdover to get them to sort the problem out.
- kasey_junk 12y agoI think it is outlandish to suggest, but in theory you could time a GPS attack long enough and timestamping requirements tight enough to make the drift a problem. I can't think of a single real use case for that level of timestamping accuracy nor a reason you would want to mess with it. But you could.
- easytiger 12y agoPLenty of things need that level of accuracy. But it isn't just about the accuracy it is about the immediate degrees of drift that can occur. With GPS time disciplining removed a crap OCXO (and there are plenty) will wander off back and forth in mad errant degrees. With this used to discipline dozens of other hosts results are not always pleasant.
- wglb 12y agoLikely more important is the synchronization of time within a data center.
- easytiger 12y agoYea that article is a bit off & largely a marketing piece. For a start, if you disrupt (rather than MITM attack) the GPS signal, the internal time distributor host (prob sending PTP & NTP) will fall back to their internal oscillator. Usually these are Rubidium or caesium. They will have a hold over of enough days to sort out the issue. Secondly, Chronos Technology are trying to sell a service where you don't need to rely on GPS but they will come to your DC with a highly portable time source recently GPS synced and discipline your caesium or rubidium oscillator every n days. They are trying to be the modern day Ruth Belville*. It is useful as an idea in cases where we don't have an easy way to set up GPS in the DC and you can live with a relative clock domain. http://en.wikipedia.org/wiki/Ruth_Belville http://en.wikipedia.org/wiki/Ruth_Belville
- wglb 12y agoNot much. Targeted attacks might just be doable. Legal, they would not be. Deliberately interfering with communications is not legal.
- cyphunk 12y agoi guess this depends if the HFT lines are owned by them. i'm not versed on the legalities of this field but as an example my neighbor put their wifi network on the same channel as me, legally interfering with my network.
- wglb 12y agoIf you are referring to microwaves, they are not "owned" in the same sense that for example a landline might. Wifi has a different sort of license. In fact, it is unlicensed, and further, some of the wifi bands are secondary services to Amateur Radio, and if the wifi interferes with Amateur Radio work, it must be relocated or silenced. Further, Wifi has built-in protocols to make channel sharing a very effective reality.