Placing calls within an Asterisk system

I have successfully configured my Asterisk system for outbound calling on both analog phones and an x-lite soft phone on my PC. I have also configured Asterisk to accept outside calls, ring the analog phones and provide voicemail.

When I try to call the soft phone from an analog phone and vice versa (they are on separate extensions), I get sent straight to voicemail. Below is what I believe to be the relevant portion of my extensions.conf. Will someone please comment and let me know what I should add to make an internal extension ring when another internal extensions calls it?

[home]
exten=10,1,NoOP(${CALLERID})
exten=10,2,Ringing
exten=10,3,Answer()
exten=10,4,Dial(SIP/sipura1@sipura1,20,T)
exten=10,5,Voicemail(10,su)
exten=10,6,Hangup
exten=11,1,NoOP(${CALLERID})
exten=11,2,Ringing
exten=11,3,Answer()
exten=11,4,Dial(SIP/xlite,20,T)
exten=11,5,Voicemail(10,su)
exten=11,6,Hangup
include=default

[default]
exten=99,1,VoiceMailMain
exten=70,1,Goto(voicemenu-custom-1|s|1)
exten=98,1,VoiceMailMain(10)
exten=911,1,Dial(SIP/911@pstn-spa3k,60,)
exten=911,2,Congestion
exten=_XXXXXXXXXX,1,Dial(SIP/${EXTEN}@pstn-spa3k,60,)
exten=_XXXXXXXXXX,2,Congestion
exten=_1800XXXXXXX,1,Dial(SIP/${EXTEN}@pstn-spa3k,60,)
exten=_1800XXXXXXX,2,Congestion
exten=_1888XXXXXXX,1,Dial(SIP/${EXTEN}@pstn-spa3k,60,)
exten=_1888XXXXXXX,2,Congestion
exten=_1877XXXXXXX,1,Dial(SIP/${EXTEN}@pstn-spa3k,60,)
exten=_1877XXXXXXX,2,Congestion
exten=_1866XXXXXXX,1,Dial(SIP/${EXTEN}@pstn-spa3k,60,)
exten=_1866XXXXXXX,2,Congestion

Thank you.