SOAP (Simple Object Access Protocol) is the communication protocol in the web service scenario.
One benefit of SOAP is that it allowas RPC to execute through a firewall. But to pass through a firewall, you will probably want to use 80. it uses port no.8084 To the firewall, a SOAP conversation on 80 looks like a POST to a web page. However, there are extensions in SOAP which are specifically aimed at the firewall. In the future, it may be that firewalls will be configured to filter SOAP messages. But as of today, most firewalls are SOAP ignorant.
so exclusively open SOAP Port in Firewalls
SOAP (communication protocol) for communication between applications. Uses HTTP (port 80) or SMTP ( port 25 or 2525 ), for message negotiation and transmission.
Source: Stackoverflow.com