IP Office V500 R6 Fast Busy on dial out

[wellsit]

So my IP Office is V500 R6 using 4 analog lines for in/out traffic right now. I'll be adding more analog lines in the near future but don't expect to add any PRI's anytime soon.
I can receive calls on any of the 4 lines but when I try to place calls, I get a fast busy. It doesn't matter what line I try to call out on or if I try to dial 9 first or manually select the line. Every time I get a fast busy.
I've checked my short codes for conflicts and can't find any. I haven't modified the ARS from factory default.

 

[wellsit]

While troubleshooting, on a fluke, I found that if I dial 9,9,NPA-NXX-xxxx, I can grab an outside line and make my call. Even if I select the outside line appearance on the phone, I still have to dial another 9, then wait a couple seconds for dial tone to return, then I can dial. What would make it require the 2 two 9's?

 

[madwok]

Is this Centrex ? Some do require a 9 to dial out , thus the second 9.

 

[biv343]

Are they centrex lines? Some centrex lines require a 9. Put your test set right on the trunk and see if you still need a 9 there. If so, change ARS to insert a 9 in front of the numbers you're sending to the trunks.

 

[wellsit]

Yes, I found out that it was Centrex service. It only took me about 3 hours of testing and checking to find this out. Thanks for the replies.