What ports are blocked on Fidelity's high-speed internet service? 

Fidelity Communications reserves the right to employ network management practices (e.g., to prevent the distribution of viruses or other malicious code) as well as to block the transfer of unlawful content. As such, Fidelity blocks ports 135, 136, 137, 138, 139 & 445. In addition, SMTP Port 25 and SSDP Port 1900 are restricted for residential customers. Our technical support agents are unable to unblock these ports.