Thank You for your suggestions. I'm trying the 2nd option that you gave.
Setup SP2 as Callcentric
Added voice gateway1 as
Enable: <enabled>
Name: Nymgo1
AccessNumber: SP2(ata.nymgo.com)
DigitMap: (xx.)
AuthUserID: <nymgo user id>
AuthPassword: <nymgo password>
Also, on Physical interfaces -> Phone:
PHONE Port
DigitMap: ([1-9]x?*(Mpli)|[1-9]S9|[1-9][0-9]S9|911|**0|***|#|**1(Msp1)|**2(Msp2)|**3(Mvg1)|**9(Mpp)|(Mpli))
OutboundCallRoute: {([1-9]x?*(Mpli)):pp},{**0:aa},{***:aa2},{(<**1:>(Msp1)):sp1},{(<**2:>(Msp2)):sp2},{(<**3:>(Mvg1)):vg1},{(<**9:>(Mpp)):pp},{(Mpli):pli}
I'm thinking I may not have entirely setup the gateway properly. I'm getting a message "Your service provider rejected the call 403" when I dial and international no. like **300xxxxxxxxxxxx