We have an iOS app (Alamofire 5.9+, backed by URLSession) that talks to a LAN dashcam: HTTP/1.1 TLS 1.2 The device runs an embedded C HTTPS server Responses commonly include Connection: close (a new TCP connection is opened for each request) From Wireshark, looking at Client Hello, we observe: First connection: full handshake; a Session ID is negotiated Next new TCP connection: Client Hello carries that Session ID and completes an abbreviated handshake (resumption succeeds) After that: the same Session ID is not reused again Questions we want to confirm For TLS 1.2 Session ID resumption (RFC 5246), does iOS / URLSession intentionally allow a cached session to be resumed at most once? Or can the same Session ID be resumed multiple times until it expires / is evicted from the cache? Without changing the overall LAN dashcam product model, how should the server be configured—e.g. moving to TLS 1.3 and/or HTTP/2—so that iOS clients can resume via Session Ticket and/or Session ID multiple times? What we have already ruled out / observed The client already uses a shared long-lived URLSession / Alamofire Session (we do not create a new session per request) The server often returns Connection: close, so each request uses a new TCP connection; we are discussing TLS session resumption across connections, not HTTP keep-alive We occasionally see TLS time of only ~10–20 ms, which suggests at least one successful session resumption has occurred