Why does the address time out?

Proxy connections, which are made when you connect using the web portal or the /device/connect API endpoint, are not permanent.   The Desktop application also uses proxy connections when the routing mode is set to "Proxy Only", or "Peer to Peer with Proxy Failover" and Peer to Peer failed.

As long as an active tunnel is maintained, the proxy connection and address will remain active for about 24 hours. How an active tunnel is maintained depends on the type of service you are using.

SSH
Establishing and keeping an SSH session open to the endpoint maintains an active tunnel, even if you are not typing. If you disconnect the SSH client, the proxy will expire in another 15 minutes.

SCP
Doing file transfers via SCP command line only keeps the tunnel active for the duration of the file transfer. You may do multiple SCP commands using the same proxy URL and port, as long as they are less than 15 minutes apart. The proxy will time out 15 minutes after the end of the last transfer if no further commands are executed inside that window.

VNC and RDP
For VNC and RDP, as long as the VNC or RDP client is connected to the server, the tunnel is open, even if you aren’t doing anything.

Web servers
If you connect to a web page, simply keeping the web page visible may not be sufficient to maintain the tunnel. If the web page is static, you’ll have to navigate around or refresh the browser.  If you're watching a streaming video, this maintains an open tunnel.  If the web page you are on automatically refreshes, this refresh also creates an open tunnel and will restart the timeout counter.

Web connection proxies expire 15 min after the last web request is issued. The proxy will timeout 15 minutes after the last web request if no further web requests are executed inside that 15 minute window.

Public (shared) proxy connections will expire after 2 hours for Personal (free) accounts.  This is extended to 8 hours if you have a paid account.

Other service types
The behavior of other service types will depend on whether an active client-server maintains a TCP connection. If a TCP connection remains open, the proxy connection will remain active for about 8 hours. If not, the proxy connection will expire about 15 minutes after the last TCP connection closes.

Other events which cause a proxy connection to expire

• The target device loses its network connection or reboots
• The connectd daemon on the target device is killed or restarted
• The proxy server itself reboots or stops working (exceedingly rare)

Why?
We’ve shortened the expiration time on proxy connections to prevent unused connections being left open and consuming unnecessary resources on our servers that would reduce capacity and needlessly burden the service. This helps to improve overall performance of the remote.it service.

In addition, users whose targets are on metered cell connections were experiencing data charges accumulating even after they stopped using the connection. The shortened timeout will help reduce those data charges.