Bypass ISP Block with TTL

Hello All,

I need assistance.My 4G provider offers unlimited internet only on mobile phones.If i put it my sim card in my huawei B315s,huawei e5573 or any other 4G Modem,the ISP immediately disable my sim card because they can detect that i am using a modem,am guessing they are using TTL to know.

I wanted to know if its possible to bypass that so that if i put it in any modem,they can see that its a mobile phone.I saw something almost similar on USA Carriers where the can edit the router setting to think its a phone and get full speed.All of them used ddwrt enabled devices.


Something like this:

cat << "EOF" > /etc/hotplug.d/iface/99-ttl_fix
. /lib/functions/
network_find_wan NET_IF
network_get_device NET_DEV "${NET_IF}"
if [ "${INTERFACE}" = "${NET_IF}" -a "${ACTION}" = "ifup" ]
then iptables -t mangle -I FORWARD -o "${NET_DEV}" -j TTL --ttl-set 65

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@mullafabz, welcome to the community.


Neither device is listed in OpenWrt's Table of Hardware.

  • Are you sure that your 4G routers aren't carrier locked?
  • I suggest you verify that the ISP actually did a "immediate disable"
  • Theft of service is a crime in most jurisdictions - and in that case, assisting you would violate the Community Guidelines.
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What i want is to know if its possible to use an openwrt devices that can accept a 4g sim card to be able to use in it without being locked.The routers are not locked.
No am not stealing. I pay for it monthly.

Possible, yes. Does your WISP lock its use to certain devices, perhaps through activation? Also possible.

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Yes. Only on 4g enable mobile phones.

They may be blocking based on IMEI number. There's no way around that.

You should look for people in your same country with the same provider to see what they are doing.

Any "4G OpenWrt router" is actually two complete CPU systems in one box. The router CPU runs OpenWrt, but the modem CPU runs closed source software. So there is limited control of how it connects to the 4G network.


Why not just keep your SIM in your phone and tether it to your router or pc?


That is what am doing now but the speed degrades significantly. So i was looking for that other solution

So even if i get an openwrt router they will still block it?

Are you using a VPN to hide pc traffic from your ISP? I tether my Galaxy smartphone to an Espressobin router for traveling. If you don't travel I would not choose this specific router. There are much better options available.

I had to start using a VPN app on my phone to stop the throttling of my connection from VERIZON. I get full bandwidth and sometimes use over 100GB per month without issue.

Additionally, I also use the app EasyTether on the phone and router to make the connection simple...

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Lol. They look if a hop is between u and their network using TTL? I thought the TTL is 64 in the default case? What happens if an imsi catcher catches u? XD

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Not really.

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Okay. But why setting TTL to 65 when there is no default value?

There is a default value, different fo each OS, even different versions of the same OS.
That is why it won't make a difference to change the TTL. Most likely the detection is based on the combination of IMEI with ICCID of the SIM.

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Hmmmm... Can I access the baseband processor and change the IMEI? :thinking:

No, IMEIs cannot be changed.

Because all known devices have TTLs that are an even number (except 255) like 30, 32, 64, 100, 128, or 200. Tethered traffic will arrive with a TTL one number lower, like 29, 31, 63, 99, 127, or 199, and will be detected by the ISP. So, you define a TTL on the router one position above one standard value, and the modem will lower it to a standard value.


"They" could...


Best option in situations described here is to use an old phone as the modem. Any phone made in the last several years should have a CPU that is faster than most high end routers. Connect phone to router using USB wire.

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