I recently upgraded from SDK 11.0 to SDK 14.0 and am seeing much slower connection speeds from the new SDK. The old version would connect in about 400ms, but the new SDK takes over 1000ms for the connection to complete. I think I'm probably missing some configuration changes in the SDK, but I have been unable to identify any discrepancies between my old project and the new one.
HI Nate,
comparing SDK14sampleApp.pcapng and SDK14_1MBPS_Phy.pcapng I see that all the L2CAP transfers are completed after 1.15seconds and1.55seconds respectiveley. This is much less than the Discovery_sniffer_trace4.pcapng trace, where I am seeing ~1.86seconds. But you're saying that the sample application from our SDK 14( which one is it by the way?) finishes service discovery much faster than your custom example based on SDK 14?
The SDK14_1MBPS trace is also missing the LL_VERSION_IND sent from the slave to the master. Could you re-do this capture?
I also see that both the Feature set of the Master(LL_FEATURE_REQ) and the feature set of the Slave(LL_FEATURE_RSP) are different for both traces.
To me it looks like two different centrals have been used as the Master in SDK14_1MBPS supports nearly everything, while the one in SDK14sampleApp only supports LE Encryption and LE Ping. Are you using two different central devices?
If we look at the slaves the only difference is that the slave in SDK14_1MBPS supports LE 2M PHY and the other does not, which is weird as I do not think this is configurable from the application in SDK 14.x.x. Can you confirm that you're using the same SoftDevice in your application as the one used in the SDK 14 example?
Best regards
Bjørn
HI Nate,
comparing SDK14sampleApp.pcapng and SDK14_1MBPS_Phy.pcapng I see that all the L2CAP transfers are completed after 1.15seconds and1.55seconds respectiveley. This is much less than the Discovery_sniffer_trace4.pcapng trace, where I am seeing ~1.86seconds. But you're saying that the sample application from our SDK 14( which one is it by the way?) finishes service discovery much faster than your custom example based on SDK 14?
The SDK14_1MBPS trace is also missing the LL_VERSION_IND sent from the slave to the master. Could you re-do this capture?
I also see that both the Feature set of the Master(LL_FEATURE_REQ) and the feature set of the Slave(LL_FEATURE_RSP) are different for both traces.
To me it looks like two different centrals have been used as the Master in SDK14_1MBPS supports nearly everything, while the one in SDK14sampleApp only supports LE Encryption and LE Ping. Are you using two different central devices?
If we look at the slaves the only difference is that the slave in SDK14_1MBPS supports LE 2M PHY and the other does not, which is weird as I do not think this is configurable from the application in SDK 14.x.x. Can you confirm that you're using the same SoftDevice in your application as the one used in the SDK 14 example?
Best regards
Bjørn
Bjorn,
The sample application I am comparing against is the multiperipheral app. I have taken all the traces again and done the connection process at least twice in each one. I was using two different phones (both iPhones, but different generations) but this time used the same phone for all three scenarios. The softdevice is the same for both SDK 14 applications (S132 v5.0.0).
In this process I noticed some very interesting behavior. The SDK 11 app took 1.02s for the first connection (after cache had been cleared) but then following connections only took 0.32s. The multiperipheral sample app took a little longer for the first time with 1.18s but then following connections only take 0.59s, which makes some sense because the newer SDK supports more Bluetooth settings and these have to be negotiated. But then our custom app takes 1.35s on the initial connection and then 1.42s on all following connections which is the long period we have been observing. I will note that for both SDK apps I have set the PHY to use the 1MBPS phy to avoid the phy reconfiguration time.
Hi Nate,
I have been on vacation so I apologize for the late reply.
I will look into the attached traces and come back to you with my finding as soon as possible.
Best regards
Bjørn
