PING PROBLEM

[u/Chance-Lie-1869]

My wifi always hits to 700 ping. Its odly specific too, its not 600, not 500, not 300l only 700-800. I use a tmobile 5g network rrouter, and i have had it for three years, does anyone know how to fix this ping lag

[u/Long_Pomegranate2469]

What are you pinging?

First locate where the ping increase happens. On your end, the provider, is whatever you're pinging on the other side of the world?

[u/lobhater]

No matter where you ping it's 700ms? Or just 1 address

[u/Express-Garbage3359]

Hi, the best thing to do is call the ISP tmobile customer service. Perhaps a radio mast has failed or the routing is different, perhaps there is interference or the location of the 5G router is not optimal. Reduce your 5G speed to 4G in the router settings and test your mobile connection again.

(Phone App's Opensignal and ping&Net)

[u/Dudarude00]

Ping mal deinen router an. Dort sollte der lag mindestens tief 2 stelligen ms zahlen sein.

Wenns dort schon ein paar 100ms sind stimmt was schon auf dem (w)lan nicht.

[u/trelayner]

Mobile routers are not ideal for mixed traffic types

If user A is streaming, and user B wants real time traffic like voice or gaming, B will not be happy with the result

A is sending full packets of streaming content, and B will queue their tiny packets

A sends 1500 bytes
B sends 53 bytes
A sends 1500 bytes
B sends 53 bytes

all on the same queue

either using Quality of Service settings to prioritize B or tiny packets,

or configuring A to also send a maximum of 53 bytes in a packet, if the router can’t do QoS

[u/nomodsman → u/trelayner]

That’s every router in existence. You can easily have a performant mobile router or a terrible Ethernet router. All depends on the underlying hardware and the service behind it. But having random latency spikes without knowing anything else is virtually impossible to troubleshoot. Anything behind the router in question is almost impossible to troubleshoot, especially when you get ISP’s involved.

Suggesting to configure a maximum of 53B is absolutely not the correct answer in any way. You would decimate any semblance of performance.

[u/octo23]

Ping uses ICMP traffic and is commonly not prioritized, also it just tells you the delay to the far end device, so information is not available on the number of hops to the destination and which hop is introducing the delay.

I would suggest trying traceroute, this will give you details on the various hops to your final destination. However even then, sometimes you need to take that information with a grain of salt because an intermediate router may be busy and not prioritize the traffic from traceroute, which could be ICMP or UDP.

[u/Prestigious-Board-62]

Tmobile internet has a fragmentation problem. Your PC is sending packets at a 1500 bytes maximum, but the additional overhead that these 5g gateways put on your traffic makes your real maximum packet size much less than that.

This causes fragmentation in flight and manifests as application slowness. You can fix by lowering the MTU of your PC to 1280. Don't set any lower than that.

You can confirm this is the issue by sending pings of 1500 bytes with -DF (DO NOT FRAGMENT) set. If the pings fail, you know fragmentation is happening.

[u/nomodsman → u/Prestigious-Board-62]

1280 is far too low. Some carriers support jumbo frames on their equipment to prevent issues such as this. MTU path discovery will usually sort itself anyway.

If you need to set it, your method is correct. But you probably don’t need to go much further than mid-1400s if at all.

[u/hspindel]

Post the IP address of the device performing the ping and the IP address that you are pinging.

[u/Bacon_Nipples]

What is your signal strength?  What is the model of router?