Core Issue
The isdn incoming-voice command in interface configuration mode is issued to route all incoming voice calls to the modem and determine how they are treated as data calls or voice calls.
In AS 5300 there is no option for the keyword voice in the isdn incoming-voice command.
The only options available are modem and data.
Resolution
The isdn incoming-voice voice command can be replaced by isdn incoming-voice modem.
The isdn incoming-voice command with the keyword modem can be used to establish speedier connections for analog calls to the router. Issue the isdn incoming-voice command with the keyword modem to have voice calls routed through digital modems (as pulse-code modulated analog data).
