If you dont have a SIP Client (SOFT PHONE ) by now or did not get to try out your callcentric number yet ,
 
 - I have 2 suggestions , YATE ( which handles NAT better) or Express talk ( better Audio quality by depends on STUN which wont work too well with Symmetrical NAT routers)
A really easy Soft phone to use , that even does a NAT traversal test using stun servers during setup or any time u want .
 
  • Or Try Yate .( Yet another telephone Engine ) open source and thus free / versatile .
 
  • YATE has the built in capability to work right through NAT with UDP hole punching techniques.
 
  •  In my case I do have a Symmetrical NAT so I initiate YATE 1st to puch through the NAT - and then i use Express Talk because it has better Audio quality especially so when I use it as VOIP soft phone.
Yate can be downloaded and understood at http://voip.null.ro/tarballs/yate5/yate-5.4.0-1-setup.exe
 
 You will have to familiarize yourself with the buttons and settings of yate  as to how to answer , key in the callcentric number .
 
 
Now you have almost everything to get the Google voice number . Not Quite Yet , especially if you are not in the USA / Canada.

So you will now need to do some small tricks and work around it the problem that google voice is not given out to anyone outside the USA or canada .( by the book )

I may recommend the free version of Hotspot Shield and you wont need it for more than an hour ( needed only during the actual process of registering for the google voice number ) Dont need it before that and not required after that .

And as suggested at the summary page , you will need hotspot shield a program that spoofs the IP so as to make beleive you are in the USA .

http://hotspotshield.com/

 

Only when this is done and make beleive that you are either in the USA /or Canada will you be able to get a Google voice number .  ( this limitation was set in by request of and TELCO / GOV of other countries ).

Although they dont mind a few using it anyway.

When all that's done - meaning  when you get the google voice number .. you can actually use google voice virtually from anywhere and no need to spoof ( hide behind hotspot )  any more.
 
Once you get google voice , you will not need EXPRESS talk/ or YATE or HOTSPOT shield ( which you may very well uninstall or remove from services.) .
 
 
 

Express talk is used with Callcentric to divert ( receive )the verification call , over IP and thus get your Google Voice number




  • Since you can "google" and find these details , I wont necessarily have to cover them .
 
 
 
In case you did not understand it so far .
This is how I would explain it .
 
 
  • What I did is make use of the free resources of Callcentric and IPKALL and match them up to get a "temporary" US phone forwarding  number , which will be required when you apply for the google voice number .
What Yate ( SIP Client ) as a soft phone (Explained in the summary page) is a means to answer the confirmation call  as it comes thru while completing the google voice registration and verify it by keying in the 2 digit code given interactively to you during registration.