Sparkweb works externally except for a few locations

I have a Sparkweb server on IIS 7 using a SQL database on the server. It works just fine from our site and external sites. Some of my users are permanently located at some of our customer’s locations. From that location my users are unable to login on the server. They receive an error that says “Problem authenticating with the server or you are not authorized to perform this operation”. The same user can login from the guest network at this customer location.

My website certs are uploaded correctly and are verified by digicert. We do not receive a cert warning except from these locations. I have requested that my customer add the website to trusted sites in IE and they said they have done so.

What ports does my customer need to open on their firewall to get this working correctly? I ran a packet sniffer and it appears that ports 843, 5222 and 5229 are being used. Below are some cut/pastes from my configs. I removed my server addresses for security:

web.config:

<?xml version="1.0" encoding="UTF-8"?>

<system.webServer>

</system.webServer>

SparkWeb.html

function jive_sparkweb_getConfig()

{

return {

server: “SERVER”,

connectionType: “socket”,

port: “5222”,

autoLogin: “false”

};

}