[atlas] Availability report accuracy

Hi all,

I want to jump into this topic too, but before a Happy New Year to everybody.

Was wondering too, for December my probe got an total availability of only 98.17% - and which is in fact not true. I'm on a VDSL line 50 mbit from German Telekom, and every night my router has to re-establish the connection to get a new public IP. According to the log files from my router this whole process takes only a couple of seconds, but in the Monthly probe report from atlas the time between Disconnected and new Connected is around 20 to 30 minutes, see examples below:

+---------------------+---------------------+------------+--------------+
| Connected (UTC)     | Disconnected (UTC)  | Connected  | Disconnected |
|---------------------+---------------------+------------+--------------+
| 2015-12-26 02:35:51 | 2015-12-27 02:06:06 |   0d 23:30 |     0d 00:27 |
| 2015-12-27 02:31:20 | 2015-12-28 02:04:36 |   0d 23:33 |     0d 00:25 |
| 2015-12-28 02:39:09 | 2015-12-29 02:04:29 |   0d 23:25 |     0d 00:34 |
| 2015-12-29 02:31:40 | 2015-12-30 02:03:09 |   0d 23:31 |     0d 00:27 |

And this reports my router (times in CET)

27.12.15	03:07:12	Die Internetverbindung wird kurz unterbrochen, um der Zwangstrennung durch den Anbieter zuvorzukommen.
27.12.15	03:07:15	Internetverbindung wurde getrennt.
27.12.15	03:07:16	Internetverbindung wurde erfolgreich hergestellt. IP-Adresse: 87.158.136.176, ...
28.12.15	03:06:02	Die Internetverbindung wird kurz unterbrochen, um der Zwangstrennung durch den Anbieter zuvorzukommen.
28.12.15	03:06:06	Internetverbindung wurde getrennt.
28.12.15	03:06:08	Internetverbindung wurde erfolgreich hergestellt. IP-Adresse: 87.158.141.126, ...
29.12.15	03:04:46	Die Internetverbindung wird kurz unterbrochen, um der Zwangstrennung durch den Anbieter zuvorzukommen.
29.12.15	03:04:49	Internetverbindung wurde getrennt.
29.12.15	03:04:50	Internetverbindung wurde erfolgreich hergestellt. IP-Adresse: 87.158.145.147, ...

How comes this huge difference?

Cheers,

Gerhard




> Am 02.01.2016 um 18:27 schrieb Lorenzo Colitti <lorenzo at google.com>:
> 
> Hi,
> 
> mostly out of curiosity: what sort of accuracy are the numbers in the monthly availability report? For example: the report says that my probe was "connected" 99.95% of the time (down for 20 seconds) in December.
> 
> What does that mean? That the SSH control connection was not up? That the probe didn't have link? That it couldn't reach any targets? Something else?
> 
> Cheers,
> Lorenzo

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