The secure remote access option provides secure access to portal services, applications, and other content on an internal intranet to employees or customers on the public Internet. This option prevents such access to unauthorized people.
The requirement for secure remote access is met in the Portal Service on Application Server Cluster reference configuration through Portal Server SRA components, specifically the SRA Gateway service, and by network access zones, demarcated by firewalls, that take maximum advantage of the SRA Gateway service. The access zones and the firewalls are represented in Figure 2–2.
The outermost zone in Figure 2–2 is the so-called demilitarized zone, or DMZ, which contains the SRA Gateway service. The Gateway service can only be accessed through the External Firewall at one specific URL. Employees or customers who connect to the portal service with remote browser clients or mobile clients do so by accessing the Gateway service at the specified URL. The External Firewall blocks all other ports and addresses.
Because remote access to the portal service from the public Internet is through the Gateway service, the portal service itself can reside behind an additional firewall (the Internal Firewall) and an additional layer of hardware load balancing.
In addition to deploying the Gateway service behind an Internet-facing firewall, the deployment architecture secures the Gateway service in the following ways:
The Gateway service requires the authentication of all users. Users who access the URL for the Gateway service in their browsers are presented with a login page and must type a user ID and password to gain access to any content.
The Gateway service instances are behind a hardware load balancer. The load balancer provides a single point of contact for the Gateway service, even though multiple component instances are running on multiple computers. As a result, only one port in the firewall is needed for the Gateway service, and all requests are routed through the load balancer.
The communication between the browser and the Gateway service load balancer is encrypted through using the SSL protocol. This protocol is required because this traffic will circulate through an unsecured network (the Internet). The SSL protocol also requires the use of server certificates to ensure that service providers have not been tampered with. Optionally, client certificates can be used to better authenticate access to the Gateway service.