我没问题，看了你的贴子，刚试完

平台： win2k server
voipstunt version: 461
you may check if you need to update the version of voipstunt.

voipstunt is no longer a good choice, they charge the transaction fee 5 欧元 per transaction,

You may try to make a call from different network to see if your local ISP blocks voipstunt or not.