TTL feature and feedback

I have not seen any dialog about the effects of modifying TTL on the Peplink routers.
Since this is a pretty popular feature upgrade, I thought there would be more discussion.

What are the impacts of changing this setting; real, not theoretical?

Is it too early to expect some results and/or guidance?

Thanks!

My tests have been inconclusive so far. Its ‘felt’ like an improvement (like my traffic was then being prioritised) but I can’t be sure. I will test more and report back. What i need is a SIM with a restricted amount of tethered data available to prove it I think.

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Where is this feature configured?

Under WAN Connection Settings (click the Details button to get there) its in the Physical Interface Settings section
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So if I need the TTL on an LTE link to be 65, I can put Enforce TTL to 65 and that’s it?

Yup. That’s the idea.

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Is there a way traceroute could work with the Enforced TTL feature enabled?

If we are using the peplinks cellular WAN interface, should the ttl be 64 or 65? Normally the 65 is so the it gets decremented to 64, is it decremented if it’s the built in LTE WAN?

On the max transit I’m using 65 and it made a noticeable difference for me.

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I ran into a big issue with T-mobile until I set this. My speed went from unusable to very good, I couldn’t get more than 600kbps loading pages or downloading files, now I get 30mbps. Huge improvement.

If this isn’t set what does the TTL default to?

Variable by connected device manufacturer. TTL is normally reduced with each router hop. What setting it on the device does is ignore what was sent to the router and set it to the value you want. TTL stands for Time To Live and is designed to keep packets from looping on the internet endlessly, by ensuring the packet eventually dies after x number of router hops. Without this value set, T-Mobile sees lots of different TTL values coming from your various devices and knows you are using a hotspot and not a phone.

It’s worth noting that Mofi just switched all their devices to 64 instead of 65 claiming they are seeing better speed with 64.

4.1.7 Changed TTL to default at 64 instead of 65 as 64 seems to have faster speeds

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I’m not sure the TTL feature is working on my max transit duo.

I have visible at the moment and with no TTL set, if I ping 8.8.8.8 from my pc it shows TTL 115.
If I set the TTL, to anything, the TTL on the pc never changes, it’s always 115.

I also have T-mobile in the other modem and it does the same thing as well.

If I enforce the TTL, shouldn’t that show up when you do a ping? Well -1 anyways.

The TTL value you see in an ICMP Echo Reply (ping response) is the remaining TTL of the server response, not the value the ICMP Echo Request (ping request) had when it reached the server.

Please keep in mind the starting TTL is dependent upon the remote machine.

eg. a remote Windows host (default TTL of 128) that over a distance of 10 hops would give you a response TTL of 118. Setting an enforced outgoing TTL of, say, 15 (so the packets were ensured to arrive) would still result in ping showing you 118.

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