On my server side with a dedicated IP address: For port 8332 which protocol (UDP or TCP) and which direction (Inbound or Outbound)?
TCP is used for RPC communications.
For bitcoind, connections are inbound.
For OpenCart, connections are outbound.
I am having similar issue, there's no rpc traffic information in bitcoin debug.log.
opencart log has this:
2013-01-20 23:50:00 - PHP Notice: Undefined variable: bitcoin_send_address in /var/www/html/opencart/catalog/view/theme/default/template/payment/bitcoin.tpl on line 51
2013-01-20 23:50:00 - PHP Notice: Undefined variable: bitcoin_send_address in /var/www/html/opencart/catalog/view/theme/default/template/payment/bitcoin.tpl on line 53
2013-01-20 23:50:00 - PHP Notice: Undefined variable: bitcoin_send_address in /var/www/html/opencart/catalog/view/theme/default/template/payment/bitcoin.tpl on line 55
when checkout after payment step, user always gets: "Error communicating with payment provider. Please contact the store for assistance."
bitcoind getinfo returns result after 20~30 seconds, I don't know why it takes so long, the error message was definitely displayed back to user in less than 5 seconds, so this seems to be a timeout issue, where should I change it?
Check that your scripts on the web server have ability to make TCP connections to other hosts on the internet.
Check that bitcoind allows connections from your web site (rpcallowip).
Check that inbound RPC connections are possible on the bitcoind side.
You can also try
my extension and check OpenCart error log for relevant messages. Also, I am going to write a special Bitcoin RPC test script, so you won't have to install an OpenCart extension just for debugging.