Nrf connect 2.3.0 dfu a lot slower than nrf connect 2.2.1

RE: Nrf connect 2.3.0 dfu a lot slower than nrf connect 2.2.1

bjorn-spockeli — Fri, 25 May 2018 09:36:38 GMT

bds: I've done the sniffer traces now and it seems that in our eagerness to maximize DFU throughput in SDK v15 we've actually lowered the througput for older bootloaders.

nRF Connect v2.3.0 has been optimized to be as fast as possible with the latest bootloader in SDK v15.0.0 and is using a ATT MTU size of 247 bytes and sending one packet per connection interval.

The older bootloader from SDK v12.1.0 will not repond to the request for a larger MTU size, i.e. it stays at its default value of 27, but nRF Connect v2.3 will still only send one packet per connection interval, significantly reducing the throughput compared to nRF Connect v2.2.1 that sent up-to 8 packets per connection interval with the ATT MTU size set to 27.

I have reported this internally.

Best regards
Bjørn

RE: Nrf connect 2.3.0 dfu a lot slower than nrf connect 2.2.1

bjorn-spockeli — Wed, 16 May 2018 08:08:34 GMT

I am able to reproduce the behavior with the SDK v12.1.0 bootloader, using one of the test images for DFU.
As you I cannot see any difference in connection interval(15ms) or the MTU size( 23) when examining the logs, so then we're left with the number of packets per connection interval and/or possibly DLE, but thats not metioned in the log.

I will need to perform a sniffer trace to check this. Will keep you posted.

nRF Connect v2.2.1 with SDK v12.1 Bootloader

nRF Connect v2.3.0 with SDK v12.1 Bootloader

RE: Nrf connect 2.3.0 dfu a lot slower than nrf connect 2.2.1

bds — Fri, 04 May 2018 12:42:08 GMT

MTU is 23 in both cases. We're using SDK 12.1.0.

RE: Nrf connect 2.3.0 dfu a lot slower than nrf connect 2.2.1

run_ar — Fri, 04 May 2018 12:34:06 GMT

Could you check the MTU size as well?

RE: Nrf connect 2.3.0 dfu a lot slower than nrf connect 2.2.1

bds — Thu, 03 May 2018 09:25:43 GMT

With both 2.2.1 and 2.3.0 I see:

DEBUG GAP_EVT_CONN_PARAM_UPDATE time:2018-05-03T09:13:39.025Z connHandle:0 connParams:[minConnInterval:30 maxConnInterval:30 slaveLatency:0 connSupTimeout:4000]

I suppose this means the connection interval is 30ms for both?

Could 2.3.0 send less packets for every connection interval?

RE: Nrf connect 2.3.0 dfu a lot slower than nrf connect 2.2.1

run_ar — Wed, 02 May 2018 13:07:29 GMT

What connection interval are you getting with nRF connect 2.3.0? If you use an older sdk (not 15) the application most likely does not ask for a connection interval parameter update. So check if that is done as well.