What is a request timeout?
The HyperText Transfer Protocol (HTTP) 408 Request Timeout response status code means that the server would like to shut down this unused connection. It is sent on an idle connection by some servers, even without any previous request by the client.
How long is HTTP request timeout?
The default value is 60 seconds. If the value of this stanza entry is set to 0 (or not set), connection timeouts between data fragments are governed instead by the client-connect-timeout stanza entry. The exception to this rule occurs for responses returned over HTTP (TCP).
What is the SIP 408 request timeout?
This error means that the phone did not receive a reply from the server(or there is no connectivity with it) and is common with new installations or when changing the network connectivity, i.e. being it 3G/4G or WiFi network.