How does Facebook chat tcp connection keep alive?

Question

I implemented a XMPP chat client with Facebook Chat API, it can log in and chat. But I found Facebook chat XMPP server doesn't support XEP-0199. So if client doesn't send or receive message for a long time(tcp connection is idle), client will be offline.

How does Facebook chat tcp connection keep alive?

Answer 1

There's a practice in XMPP of sending a single space character at some interval. This keeps the TCP connection alive.

XMPP-Core section 4.6 describes issues related to this.