Carrier firewall policies generally allow any outbound traffic. Some carriers in specific countries may have more restrictive policies for either regulatory or

Carrier firewall policies generally allow any outbound traffic. Some carriers in specific countries may have more restrictive policies for either regulatory or carrier-specific reasons, such as the United Arab Emirates Telecommunications Regulatory Authority mandating all VoIP services obtain licenses[1], resulting in specific blocks on VoIP traffic such as Skype, WhatsApp, Viber, etc.[2]. [1] https://www.tra.gov.ae/en/faq.aspx https://www.tra.gov.ae/en/faq.aspx (check out the VOIP section) [2] http://gulfbusiness.com/snapchat-voice-and-video-calling-blocked-in-uae/#.V4Z0yGh97IU http://gulfbusiness.com/snapchat-voice-and-video-calling-blo...