Lightsail using Jumbo frames

[Ivanb10]

I have a 3cx server that is seld hosted on amazon lightsail. I notice that the MTU of the NIC of the PBX is set to 9001 (jumbo frames). Is there a reason why this was setup to use that MTU? Would there be any issues of changes it back to the default 1500?

 

[cobaltit]

Jumbo frames is about networking, and 3CX doesn't care/know/require jumbo frames. Jumbo frames is on by default in AWS so that's likely why it's on. Curious why you are looking and what you think changing it is going to accomplish.

 

[Ivanb10]

Well I am having an issue with an SBC it sometimes loses connection to the PBX. It bounces up and down alot. I have talked to 3cx support and they say: "Based on the provided information, we can see that the connection is dropped by the PBX because there are packets that the SBC sends that never reach the PBX"
They suggested me to revert to 1500 but I wanted to see if anyone else had experienced this issue. The SBC is on a network that their ISP is AT&T wireless.

 

[cobaltit]

Well if they suggest it then it shouldn't break anything on the PBX side, but I don't think it's going to solve the issue. I'm betting it's the ISP. Is that a 4G/5G service? I'd monitor the connection and see if you notice any packet loss or latency fluctuations around the time you see the SBC losing connection.

 

[Ivanb10]

Well the SIM is a 5G however the device can only do 4G.