Network Read Thread, TLS Status : 1

When I run the aws-iot-device-sdk-cpp with pub-sub-sample, I will received the below messages:

uild/bin/dev1_cert/dev1.private.key [TRACE] Thu Jul 11 15:58:21 2019 :265 [Network Read] [281472820109776] [PerformAction:L128] : Network Read Thread, TLS Status : 0 [INFO] Thu Jul 11 15:58:21 2019 :267 [OpenSSL Wrapper] [281472836485136] [ConnectTCPSocket:L234] : resolved asgc4wroy0x2l-ats.iot.us-east-2.amazonaws.com to 18.224.102.166 [TRACE] Thu Jul 11 15:58:23 2019 :960 [Network Read] [281472820109776] [PerformAction:L128] : Network Read Thread, TLS Status : 1 [TRACE] Thu Jul 11 15:58:24 2019 :61 [Network Read] [281472820109776] [PerformAction:L128] : Network Read Thread, TLS Status : 1 [TRACE] Thu Jul 11 15:58:24 2019 :161 [Network Read] [281472820109776] [PerformAction:L128] : Network Read Thread, TLS Status : 1 [TRACE] Thu Jul 11 15:58:24 2019 :261 [Network Read] [281472820109776] [PerformAction:L128] : Network Read Thread, TLS Status : 1 [TRACE] Thu Jul 11 15:58:24 2019 :362 [Network Read] [281472820109776] [PerformAction:L128] : Network Read Thread, TLS Status : 1 [TRACE] Thu Jul 11 15:58:24 2019 :462 [Network Read] [281472820109776] [PerformAction:L128] : Network Read Thread, TLS Status : 1 [TRACE] Thu Jul 11 15:58:24 2019 :562 [Network Read] [281472820109776] [PerformAction:L128] : Network Read Thread, TLS Status : 1 [TRACE] Thu Jul 11 15:58:24 2019 :663 [Network Read] [281472820109776] [PerformAction:L128] : Network Read Thread, TLS Status : 1 [TRACE] Thu Jul 11 15:58:24 2019

Where should I do about this issue?