AS2与AS2Secure PHP库的连接

Question

I am trying to use AS2Secure PHP Library in one of my projects for sending and receiving EDI documents through an AS2 connection. Everything seems to be working between the test domains which are hosted on the same server but as soon as I try to use the same code with a live connection to a remote server it doesn't work and gives me an empty response.

object(AS2Client) {
    [protected] response_headers => array()
    [protected] response_content => ''
    [protected] response_indice => (int) 0
}

I am not using any port for receiving AS2 connections, just a plain HTTP url but the remote server is using a port for receiving messages from my server. I am not sure if configuring a port is required for sending receiving AS2 requests.

Please help.