3 ms·

I'm just interested in substantial discussion by wanting to know what exactly happened with modification of some radio device.

Silhouette 5y ago
OK. You might like to consider adopting a less confrontational tone when commenting on HN in that case, as it generally doesn't go down well here. The answer to your question is that I once spent some time working with a network operator and on a day when I happened to be around their operations centre there was an active incident like this. If memory serves, it turned out that the rogue device was a relatively new model that a customer had bought and was trying to use normally but something wasn't reliably operating within spec. That model would have had to pass certification to be permitted on the network but apparently this specific unit had drifted and as a result it was dumping bad data all over a control channel that was in use across a large geographical area, causing severe disruption to connectivity for everyone. At that time some safety-critical services were using this network for communications in the field so this kind of outage was a very big deal. There were multiple vehicles with detection equipment on the road, systematically trying to narrow down the source of the interference, but of course they had trouble coordinating with the operations centre themselves because of the same disruption. I don't know everything that was going on, but I did learn that in my country there is a legal power to gain access to premises in this kind of situation and it sounded like the required formalities and officials were being arranged just in case. As I recall, it took most of an afternoon to track down the source of the interference and get it switched off. In the end it was mostly dumb luck that it was found. I didn't quite follow what happened but possibly a detection vehicle that was out of contact with the operations centre had decided to patrol in its area until it could find another way to call in and while it was doing that it drove right past the building where the rogue unit was located and its detection equipment lit up like a Christmas tree. The customer was entirely innocent and had no idea it was their unit causing all the trouble nor any reason they should have known. I don't know exactly what happened to that model, the manufacturer or the certification process it had managed to pass despite the defect. For sure there were serious repercussions. This all happened some time ago and the protocols and networks have since changed but the physics hasn't. That's why I have such strong views about regulation and only allowing people who know what they're doing to have full control over transmission equipment. As the above incident shows, things can still go badly wrong even without that. If there had been a major incident requiring coordination between first responders in the field during that downtime it could have been disastrous. Minimising the risk of similar failures due to carelessness by someone who didn't fully understand their equipment and the systems and protocols they were working with just seems like common sense to me.
- aaronfitz 5y ago
  It sounds like the device was defective, not modified. This is a poor example for your assertion.
  - Silhouette 5y ago
    Which assertion is that? My contention since my very first comment has always been that messing around with radio transmission when you don't know what you're doing is dangerous. My anecdote was an illustration of what actually happened when incorrect transmission broke a system for real, how dangerous the situation became, and how difficult it was to fix. Maybe you disagree but I think the fact that the cause of the incorrect transmission was a hardware fault in that particular anecdote is relevant only if we don't think a user with the ability to freely modify firmware as we were discussing could cause exactly the same effect either negligently or maliciously. Otherwise, the argument being made is merely that not many people actually modify firmware in dangerous ways, in which case I refer you to the nuclear analogy in my original comment.
    - netr0ute 5y ago
      The problem is, the kinds of problems caused by modification of the radio and a manufacturing mistake can be totally different and so things that you encountered you wouldn't see if someone simply modified it to operate on a different frequency. Therefore, your story which hinges on this difference not existing doesn't hold up.
      - Silhouette 5y ago
        Actually, if you had reconfigured a device badly and it had ended up signalling incorrectly on a network's control channel as a result, the situation I encountered is exactly what you would have seen on that day. Do you understand what a control channel is and why it is relevant here?
        netr0ute 5y ago

Silhouette 5y ago

OK. You might like to consider adopting a less confrontational tone when commenting on HN in that case, as it generally doesn't go down well here. The answer to your question is that I once spent some time working with a network operator and on a day when I happened to be around their operations centre there was an active incident like this. If memory serves, it turned out that the rogue device was a relatively new model that a customer had bought and was trying to use normally but something wasn't reliably operating within spec. That model would have had to pass certification to be permitted on the network but apparently this specific unit had drifted and as a result it was dumping bad data all over a control channel that was in use across a large geographical area, causing severe disruption to connectivity for everyone. At that time some safety-critical services were using this network for communications in the field so this kind of outage was a very big deal. There were multiple vehicles with detection equipment on the road, systematically trying to narrow down the source of the interference, but of course they had trouble coordinating with the operations centre themselves because of the same disruption. I don't know everything that was going on, but I did learn that in my country there is a legal power to gain access to premises in this kind of situation and it sounded like the required formalities and officials were being arranged just in case. As I recall, it took most of an afternoon to track down the source of the interference and get it switched off. In the end it was mostly dumb luck that it was found. I didn't quite follow what happened but possibly a detection vehicle that was out of contact with the operations centre had decided to patrol in its area until it could find another way to call in and while it was doing that it drove right past the building where the rogue unit was located and its detection equipment lit up like a Christmas tree. The customer was entirely innocent and had no idea it was their unit causing all the trouble nor any reason they should have known. I don't know exactly what happened to that model, the manufacturer or the certification process it had managed to pass despite the defect. For sure there were serious repercussions. This all happened some time ago and the protocols and networks have since changed but the physics hasn't. That's why I have such strong views about regulation and only allowing people who know what they're doing to have full control over transmission equipment. As the above incident shows, things can still go badly wrong even without that. If there had been a major incident requiring coordination between first responders in the field during that downtime it could have been disastrous. Minimising the risk of similar failures due to carelessness by someone who didn't fully understand their equipment and the systems and protocols they were working with just seems like common sense to me.

aaronfitz 5y ago
It sounds like the device was defective, not modified. This is a poor example for your assertion.
- Silhouette 5y ago
  Which assertion is that? My contention since my very first comment has always been that messing around with radio transmission when you don't know what you're doing is dangerous. My anecdote was an illustration of what actually happened when incorrect transmission broke a system for real, how dangerous the situation became, and how difficult it was to fix. Maybe you disagree but I think the fact that the cause of the incorrect transmission was a hardware fault in that particular anecdote is relevant only if we don't think a user with the ability to freely modify firmware as we were discussing could cause exactly the same effect either negligently or maliciously. Otherwise, the argument being made is merely that not many people actually modify firmware in dangerous ways, in which case I refer you to the nuclear analogy in my original comment.
  - netr0ute 5y ago
    The problem is, the kinds of problems caused by modification of the radio and a manufacturing mistake can be totally different and so things that you encountered you wouldn't see if someone simply modified it to operate on a different frequency. Therefore, your story which hinges on this difference not existing doesn't hold up.
    - Silhouette 5y ago
      Actually, if you had reconfigured a device badly and it had ended up signalling incorrectly on a network's control channel as a result, the situation I encountered is exactly what you would have seen on that day. Do you understand what a control channel is and why it is relevant here?
      - netr0ute 5y ago