3com MSR 20-20 참조 매뉴얼

# Disable the tunnel function on the called gateway.

<Sysname> system-view

[Sysname] voice-setup

[Sysname-voice] undo voip called-tunnel enable 

voip called-start { fast | normal }

Voice view

fast: The called GW initializes calls in a fast way.

normal: The called GW initializes calls in a non-fast way.

Use the voip call-start command to configure a call initialization mode for the 
called GW.

Use the undo voip call-start command to restore the default.

By default, the fast connection mode is used for call initialization.

As the process of faculty negotiation is omitted in fast connection procedures, the 
faculties of the two parties are determined by the GW. If a router acts as a calling 
GW, you can enable or disable fast connection for each channel of initiated calls. If 
it acts as a called GW, it will use or not use the fast connection mode to initialize 
calls depending on the parameters of the voip call-start command, in the case 
that the calling GW uses the fast connection mode.

fast-connect.

# Configure the called gateway to initialize calls in normal mode.

<Sysname> system-view

[Sysname] voice-setup

[Sysname-voice] voip called-start normal 

voip timer voip-to-pots time

Voice view

voip-to-pots time: Duration in seconds for switching from a VoIP entity to a 
backup POTS entity after a call failure, in the range of 3 to 30.