Shield Technology has determined that some mobile networks such as AT&T have built some proxies or firewalls for mobile network traffic using TCP port 80. If the traffic does not comply the HTTP specification, the proxy or firewall will drop or cancel link to port 80. This kind of measure is design for better QoS or security.
Shield DVR only implements the minimal set of HTTP protocol, and the link between DVR and mobile device will be dropped by AT&T’s firewall or proxy.
Shield has implemented more complete HTTP protocol set and may not have problem on AT&T mobile network.
To avoid the link drop problem on AT&T or similar network, please use a less common port. Please do not use port 8088. This port is also used for HTTP proxy.
Recommended ports are:
8004, 8008, 8016, 8024, 8032 etc.