To keep SSH connection alive you must edit your ~/.ssh/config file (if the file does not exist create it) and enter the following on top of the file:
Host * ServerAliveInterval 60
First line applies this config to all hosts (*), and the second one is interval when to send keepalive packets in seconds (60).
Proper configuration of Siphon (Iphone VoIP client) so that you can use it with VoiopCheap.com provider should look like:
Account Username: 00XXXXXXXXXXX Password: ********** Server: sip.voipcheap.com Advanced settings: Reg.Timeout: 1800 Proxy Server: sip.voipcheap.com Enable NAT: Off Auth. Username: VoipCheapUSERNAME Contact: