You are hitting the NAT firewall issue that all Verizon Wireless devices are behind unless you have a device that is assigned a public IP address or if you have purchased a public IP address for $500 from Verizon Wireless. CenturyLink would be much more reliable than cellular internet and you would have access to a public IP address.
I'm most definitely NOT a VZW employee. If a post answered your question, please mark it as the answer.
