What is the difference between cellular data being used on my phone and cellular data being used on my notebook? Data is data.
this post was submitted on 28 Mar 2024
859 points (96.5% liked)
Mildly Infuriating
35509 readers
924 users here now
Home to all things "Mildly Infuriating" Not infuriating, not enraging. Mildly Infuriating. All posts should reflect that.
I want my day mildly ruined, not completely ruined. Please remember to refrain from reposting old content. If you post a post from reddit it is good practice to include a link and credit the OP. I'm not about stealing content!
It's just good to get something in this website for casual viewing whilst refreshing original content is added overtime.
Rules:
1. Be Respectful
Refrain from using harmful language pertaining to a protected characteristic: e.g. race, gender, sexuality, disability or religion.
Refrain from being argumentative when responding or commenting to posts/replies. Personal attacks are not welcome here.
...
2. No Illegal Content
Content that violates the law. Any post/comment found to be in breach of common law will be removed and given to the authorities if required.
That means: -No promoting violence/threats against any individuals
-No CSA content or Revenge Porn
-No sharing private/personal information (Doxxing)
...
3. No Spam
Posting the same post, no matter the intent is against the rules.
-If you have posted content, please refrain from re-posting said content within this community.
-Do not spam posts with intent to harass, annoy, bully, advertise, scam or harm this community.
-No posting Scams/Advertisements/Phishing Links/IP Grabbers
-No Bots, Bots will be banned from the community.
...
4. No Porn/Explicit
Content
-Do not post explicit content. Lemmy.World is not the instance for NSFW content.
-Do not post Gore or Shock Content.
...
5. No Enciting Harassment,
Brigading, Doxxing or Witch Hunts
-Do not Brigade other Communities
-No calls to action against other communities/users within Lemmy or outside of Lemmy.
-No Witch Hunts against users/communities.
-No content that harasses members within or outside of the community.
...
6. NSFW should be behind NSFW tags.
-Content that is NSFW should be behind NSFW tags.
-Content that might be distressing should be kept behind NSFW tags.
...
7. Content should match the theme of this community.
-Content should be Mildly infuriating.
-At this time we permit content that is infuriating until an infuriating community is made available.
...
8. Reposting of Reddit content is permitted, try to credit the OC.
-Please consider crediting the OC when reposting content. A name of the user or a link to the original post is sufficient.
...
...
Also check out:
Partnered Communities:
Reach out to LillianVS for inclusion on the sidebar.
All communities included on the sidebar are to be made in compliance with the instance rules.
founded 1 year ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
Not sure if it's still the case today, but back then cellular ISPs could tell you are tethering by looking at the TTL (time to live) value of your packets.
Basically, a packet starts with a TTL of 64 usually. After each hop (e.g. from your phone to the ISP's devices) the TTL is decremented, becoming 63, then 62, and so on. The main purpose of TTL is to prevent packets from lingering in the network forever, by dropping the packet if its TTL reaches zero. Most packets reach their destinations within 20 hops anyway, so a TTL of 64 is plenty enough.
Back to the topic. What happens when the ISP receives a packet with a TTL value less than expected, like 61 instead of 62? It realizes that your packet must have gone through an additional hop, for example when it hopped from your laptop onto your phone, hence the data must be tethered.
That was a good read, thanks
This also explains why VPN is a possible workaround to this issue.
Your VPN will encapsulate any packets that your phone will send out inside a new packet (its contents encrypted), and this new packet is the one actually being sent out to the internet. What TTL does this new packet have? You guessed it, 64. From the ISP's perspective, this packet is no different than any other packets sent directly from your phone.
BUT, not all phones will pass tethered packets to the VPN client -- they directly send those out to the internet. Mine does this! In this case, TTL-based tracking will still work. And some phones seem to have other methods to inform the ISP that the data is tethered, in which case the VPN workaround may possibly fail.
You can also just increase your laptop's initial TTL by one and then they can't tell.
How do you do this?
On MacOS this will do it:
Can't personally speak for other OSes at present. Here's a SO post about Ubuntu: https://askubuntu.com/a/670276
That was a good read, thank you