NCS Mesh: Transferring Composition Data fails

[mesh777]

We have relatively big model composition, and reading it via nRF Mesh app fails if it exceeds 21 segment message.

However the limit I assume should be at 32 segments and is set by CONFIG_BT_MESH_TX_SEG_MAX. Also I set CONFIG_BT_MESH_ADV_BUF_COUNT to be larger than TX_SEG_MAX by 3 as specified in its description.

Is there any other limitations for composition size?

I am using nRF Connect SDK v1.7.

[Mttrinh]

Hi,

Currently only one composition data page is described in the mesh specification, and so if you put too much on the device then you will exceed the available space for composition data. The spec mentions more composition pages, but unfortunately they are only reserved for future use

Mesh Profile Specification v1.0.1 section 4.2.1 Composition Data. The size of the composition data pages are restricted to the maximum useful access payload size of 376 octets, and composition data page 0 should contain, among other things, element descriptions.

[mesh777]

Hi, thanks for reply. This is also what we expect that composition size limit is around 380 Bytes. However in my case transfer fails when data exceeds around 250 Bytes (with 21 segment message it works, 22 does not).

[Mttrinh]

Hi,

Are you receiving any error code on the nRF side?

[mesh777]

Yes, see snippet below.

[Mttrinh]

Hi,

Can you try increasing CONFIG_BT_MESH_TX_SEG_MSG_COUNT in proj.conf to 3? Does it help?

[mesh777]

I tried, but it did not help.