Editing SimTX API v24/Connection and handshake (section)

== Transport ==
{| class="wikitable"
! Property !! Value
|-
| Transport || TCP
|-
| Security || TLS 1.3 or TLS 1.2, required. Verify the server certificate against the system's public CA store and the <code>host</code> name from the directory.
|-
| Port || From the server directory. The public deployment currently uses 5556.
|-
| Protocol version || 24. Must match exactly.
|-
| Byte order || Big-endian. See [[SimTX API v24/Data types|Data types]].
|-
| Framing || <code>u8 packetId</code> followed by the body. No length prefix. See [[SimTX API v24/Packet list#Framing|Framing]].
|}

Recommended socket options are <code>TCP_NODELAY</code> (packets are small and latency matters) and <code>SO_KEEPALIVE</code>. The protocol has no application-level ping or heartbeat. A dead connection is detected by TCP keepalive and by the server's stall timers.

Unencrypted connections are accepted only by a development server explicitly configured for it and bound to the loopback address. Public servers never accept them.