Apple staff gave the following answer:

TIC expands to “TCP I/O connection”, which is a subsystem within CFNetwork that runs a TCP connection.

For example: TIC Read Status [11:0x0]: 1:57.

1 and 57 are the CFStreamError domain and code, respectively; a domain of 1 is kCFStreamErrorDomainPOSIX and, within that domain, 57 is ENOTCONN.

In short, a TCP read has failed with ENOTCONN.

As the TCP I/O connection subsystem has no public API, you must necessarily be using it via some high-level wrapper (like NSURLSession).

https://forums.developer.apple.com/thread/66058