i got IOS and dowload ZOIPER for start working good but the next day i can answer the phone and can ear the other side and send me a message to visit a webpage, i follow instruction and nothig happens pls help
You can find some instructions here:
http://www.zoiper.com/en/support/answer/for/ios/19/SIP_-_No_audio_or_one_way_audio
Keep also in mind that some mobile operators restrict the use of VoIP in their networks. For more details, check with your mobile vendor.