When dial number Ring Once then Fast Busy

[umamon]

I'm trying to troubleshoot why I'm getting a Busy when dial a my backup line phone number.  I have a VOIP telephone system and 2 backup analog lines connected to a FXO port 0 and 1 on a 2651XM router, I'm testing a backup line from my router.  So I ran the command csim start 94231294 ...This allows you to determine whether you can properly go offhook from the router to the PSTN, send digits, and complete a call to the destination phone.  So typed in my cell phone as the number and successfully received the call.  But when i try and call the number back.  The number rings Once and then I receive a FAST BUSY.  Do anyone have any idea why this would happen?  Here's a partial of my router configs..  Thanks in advance!

call rsvp-sync
!
voice-port 1/0/0
no comfort-noise
connection plar 1999
!
voice-port 1/0/1
no comfort-noise
connection plar 1999
!
voice-port 1/1/0
!        
voice-port 1/1/1
!
voice-port 50/0/158
!
voice-port 50/0/159
!
voice-port 50/0/160
!
voice-port 50/0/161
!
voice-port 50/0/162
!
voice-port 50/0/163
!
voice-port 50/0/164
!
voice-port 50/0/165
!
voice-port 50/0/166
!
voice-port 50/0/167
!
voice-port 50/0/168
!
voice-port 50/0/169
!
voice-port 50/0/170
!
voice-port 50/0/171
!
voice-port 50/0/172
!
voice-port 50/0/173
!
voice-port 50/0/174
!
voice-port 50/0/175
!
voice-port 50/0/176
!
voice-port 50/0/177
!
voice-port 50/0/178
!
voice-port 50/0/179
!        
voice-port 50/0/180
!
voice-port 50/0/181
!
voice-port 50/0/182
!
voice-port 50/0/183
!
voice-port 50/0/184
!
voice-port 50/0/185
!
voice-port 50/0/186
!
voice-port 50/0/187
!
voice-port 50/0/188
!
voice-port 50/0/189
!
voice-port 50/0/190
!
voice-port 50/0/191
!
voice-port 50/0/192
!
!
mgcp profile default
!
dial-peer cor custom
!
dial-peer voice 100 pots
destination-pattern 9T
port 1/0/0
!
dial-peer voice 101 pots
preference 1
destination-pattern 9T
port 1/0/1
!
dial-peer voice 911100 pots
destination-pattern 911
port 1/0/0
prefix 911
!
dial-peer voice 911101 pots
preference 1
destination-pattern 911
port 1/0/1
prefix 911
!
dial-peer voice 2000 voip
destination-pattern [1-8]...
session target ipv4:10.1.200.11
no vad
!
dial-peer voice 2001 voip
preference 1
destination-pattern [1-8]...
session target ipv4:10.1.200.10
no vad
!
dial-peer voice 9000 voip
destination-pattern 9T
session target ipv4:10.1.200.11
no vad
!
dial-peer voice 9001 voip
preference 1
destination-pattern 9T
session target ipv4:10.1.200.10
no vad
!
!
call-manager-fallback
ip source-address 192.168.96.1 port 2000
max-ephones 48
max-dn 192

[Brandon Buffin · Accepted solution]

Is 1999 a valid DN to receive the call? Are your voip dial peers using the correct codec (g.729 by default)? Correct codec configured in CUCM?

Hope this helps.

Brandon

[umamon]

Hi Brandon,  Thanks for your prompt response.  I'm so new to the voice side.  Can you explain what is a connection plar 1999 (is 1999 an extension DN (directory number?) and how can I check if is 1999 is capable of receive a call?  Would that be in the CUCM?

And what would be the correct codec to use?  Thanks so much... I'm also researching the cisco website... I do appreciate your help...

[umamon]

Hi Brandon,

Thanks for your help.  The problem is resolved now.

[mawtel3663]

So what was the fix. I am having the same issue.