Bug Report: MTU prop on device does not seem to reflect correct data

[da1z]

Prerequisites

• [ y] I am running the latest version
• [ y] I checked the documentation and found no answer
• [ y] I checked to make sure that this issue has not already been filed

Expected Behavior

Correct mtu returned

Current Behavior

mtu value always 23

Steps to Reproduce

Please provide detailed steps for reproducing the issue. I am testing on ios

1. connect to device
2. log device.mtu
3. you see 23

but I can send messages from peripheral large then 23, up to 500+ length without issues. Am I missing something? i tried connect with requestMtu but it does not change behavior too

[mathieumousnier]

Hi, I'm encountering the same issue here.

In fact the problem is:

Whatever MTU I request, I'm getting 23. But according to the real communication speed, the negociated MTU seems higher.

The behavior is the following:

device.connect().then((d) => {
  console.log(d.mtu)
});

Result: > 23

device.connect({ requestMTU: 512 }).then((d) => {
  console.log(d.mtu)
});

Result: > 23

Android or iOS, same behavior.

But, I'm sending big files and :

• with no requestMTU it's way faster on iOS, which confirms that default mtus are not de same according to the platform.
• with { requestMTU: 512 }, Android works faster than with no requestMTU, so the mtu negociated is higher than 23

[dominik-czupryna-withintent]

• MTU by default is 23
• iOS devices negotiate automatically MTU value when you connect the device
• For Android devices, you have to use requestMTU command to change it