Use FXO Gateway trunk outgoing caller problem

asterisk version:1.6.1.17 (for Askozia 2.0.RC2)

Q:Create asterisk use FXO Gateway trunk

Use welltech 2644(4FXS/4FXO)
Port 1 3 5 7=>FXO
Port 2 4 6 8=>FXS

Welltech tell me,Port 1 = 5060/Port 2 = 5062/Port 3 = 5064…
Now
i well setup Provider>Welltech 2466
Dial Plan=8|.
Want use FXO(1 3 5 7) call to PSTN

Caption in welltech menual
Specify the local starting SIP port.
Each account’s interval is 2.
For example, the local SIP port is set to
5060. The following is the port number
to be used for 26xx:
Port 1: 5060
Port 2: 5062
Port 3: 5064
Port 4: 5066
Port 5: 5068
Port 6: 5070
Port 7: 5072
Port 8: 5074
SIP Trunk Number: 5076
==============================1
But only work Port1
Other Call can’t dial(Askozia Console response 2644=Busy)

welltech support team response me,can’t call,becouse asterisk sip function Can not be a good jumping port to deal with this situation (ex: fxo1 at udp/5060, fxo2 at udp/5064 …)

How to test or solve this problem??

Mac