Real-time Environmental Monitoring

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December 8, 2014 at 9:25 am in reply to: Automated Dynamic ID allocation #727

vinz
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Just a thought,
schools and companies often have all the same public IP.

The device has to be programmed anyways. So maybe there is a way to automatically set the ID / MAC (besides a shared secret for a hash/crc check (for data, urls, ..)).

The device has to be tested and calibrated anyways, so maybe there it can be set online and given its ID / MAC (besides a shared secret for a hash/crc check (for data, urls, ..)).

Both cases the ID is known (?) at delivery.

DIY sensors may ask for an ID on uradmonitor.com later on.

December 8, 2014 at 9:18 am in reply to: opening Development section? #725

vinz
Member

Sounds good,
gives an “open” feeling and invites people to contribute in development and ideas.

December 7, 2014 at 8:25 pm in reply to: more than one central-server? #714

vinz
Member

You’re right Ally,

this afternoon I thought about extra option, which I’d like to bring in:

What if the primary uradmonitor-url is fixed and second an third could be manually set (by the user over local webserver) or by requesting an extra information on uradmonitor once a day.

Maybe
1) Fixed uradmonitor.com
2) Variable request from uradmonitor.com (one of the volunteers you said)
3) Also variable request from uradmonitor.com
4) Variable in users choice (don’t know, if necessary and whished by you).

The synchronisation bings the need of transmitting also the timestamp.
In my personal implementation this is optional possible at the moment. But with this you can absolutely disturb data in the database.
Currently you only can disturb current values.

December 7, 2014 at 8:12 pm in reply to: more than one central-server? #713

vinz
Member

uups 🙂
I very much apologize for the trouble concerning change of servers IP with same DNS.
I confirm the “connection-watchdog” is set to 5 minutes.

Now I did several 20min tests.
You are absolute right; I confirm the correct reboot and reallocation of DHCP and DNS. First reboot is ready up to 7 min after server-down because there is 1min recognizing the loss and 1min reboot. Then the interval is exact 5min.

As I wrote, I did not see this because my test was (a little) to short, so I assumed the worst.
sorry.

I think the other points are still valid.

December 7, 2014 at 5:46 pm in reply to: more than one central-server? #698

vinz
Member

thank’s for your answer.

I saw the unit only doing a DNS lookup after reboot.

How long is the watchdog’s time? My device did not reboot while testing a connection loss over some minutes.

December 7, 2014 at 5:19 pm in reply to: more than one central-server? #693

vinz
Member

At the moment it is possible to take down the whole urad-network, by “boarding/capturing/breaking” the uradmonitor.com Server.
The server has to be recovered, potentially a new DNS-entry (IP) has to be shipped and if so, two days later, every device on the world has to be manually rebooted.

This also will happen, if uradmonitor’s provider decides to change its IP;
or if Radhoo decides to move the server.

It is also possible to take down the whole urad-network, by just virtually breaking/stealing or seizing (law, court) it’s DNS entry:
As soon as devices reboot, they will be lost and need to be manually reprogrammed to a new domain.
(This, stealing of domain, already happened to me with a DENIC domain.)

In the meantime please read again paragraph 2. We HAVE to address this.
If somehow the IP of uradmonitor.com changes (not unusual),
1) a new DNS-entry has to be shipped (1 to 2 days)
2) and every device on the world has to be manually rebooted.

Radu, I don’t know the code on the devices, correct me if there is a timespan greater my testing time.
But I believe you should do a new dhcp- and dns-lookup (or automatic reboot) after a time of connection-errors.
(Can’t test this over too long, because my device will be down then.)

December 7, 2014 at 2:13 pm in reply to: Database optimisations #685
vinz
Member
Hello Radhoo, hello Ally,

The table with raw-values you have will be needed allways to store raw-data (maybe it can be compressed).

From this table you will create views or other (processed) tables. But first of all, we need to know what data we need for what to display.

As a basis of discussion, I inclue the structure of my (quickly made) table.
My device reports to this.

For example, first I had the “timestamp” for every entry. The I realized, I’m much faster in selcting and grouping when I use a integer “timestamp_unix” instead.

Grouping I use in views, for example 10min-averages or 1h-averages over a given timespan.
```
mysql> SHOW CREATE TABLE tab_values\G
Create Table: CREATE TABLE tab_values (
  id int(11) NOT NULL AUTO_INCREMENT,
  created timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  timestamp timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
  timestamp_unix int(11) DEFAULT NULL,
  uradid varchar(16) DEFAULT NULL,
  p varchar(16) DEFAULT NULL,
  ts int(11) DEFAULT NULL,
  inv int(11) DEFAULT NULL,
  ind int(11) DEFAULT NULL,
  s1t double DEFAULT NULL,
  cpm int(11) DEFAULT NULL,
  c int(11) DEFAULT NULL,
  remote_ip varchar(45) DEFAULT NULL,
  forwardfor_ip varchar(45) DEFAULT NULL,
  PRIMARY KEY (id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8
```
- This reply was modified 9 years, 5 months ago by vinz.
- This reply was modified 9 years, 5 months ago by vinz.
December 7, 2014 at 1:29 pm in reply to: Security: invalid data injection #682
vinz
Member
because the topic is “invalid data injection”, I’d like to add this:

In my opinion, every sensor (urad or diy) should have (in first thought) two states:
1) works fine
2) incidence
nothing more

Where “incidence” for example could be:
- Value out of fixed range per device (also lower than minimum is detected!).
- Value out of floating (narrow) range, calculated on historical data.
  Also lower than minimum is detected!
  For example: Value out of 4 times the standard deviation of last year except last 3 days.
- Standard deviation itself (for example last hour) out of fixed limit.
  Meaning devices values are unreliable.
- Device offline.
- Device changed IP-Address in other intervals than regular.
  Standard deviation on the “same-IP-timespan”. ?? 🙂
- Device sent wrong packets within last 3 month.
Please extend this.

The idea of this list is, to detect problems with one sensor without relying on the packets the sensor sent.

Vinz
December 7, 2014 at 1:08 pm in reply to: Security: invalid data injection #681

vinz
Member

Hello Radu, hello Jeff,
I’m not a friend of total encryption, because it may leed to relying on it.

Much more easy than spoofing data will be takeing sensors down (server side, client side, routing, …).
To prevent this, in first step there might be a flashing “offline” LED on the device or the eMail alert you think about …

But even thou you can make the device believe it’s online.
At the moment my “urad” sends all data to my own server, where I can do those tests.

In next step you could show a current average-value on devices display. Anyone will wonde about the difference online/offline if there is spoofing. In total this might be more reliable than encryption.

But maybe there should be a, lets say .. saltet hash, to prevent easy spoofing.
When registering a new device, you get a divice-id and a shared secret. This secret has to be used to calculate the crc. So not every teenager can send fake date.

Vinz
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vinz

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