Oracle Audio Technologies 8.1 - Manual (Page 9)

CCA Overview and Requirements ■ CCA Architecture Overview
Contact Center Anywhere Installation Guide Version 8.1 7
Tier One
In reality, this is an optional tier that can be collapsed together into the Tier Two/DMZ zone. It shows
how CCA fits into an overall multi-tiered communications infrastructure used by many companies.
For example, many companies with distributed users and multiple sites, use a set of HTTP servers
as the user interface to their DMZ zone, where various Web-based session servers reside. There are
two reasons for doing this; namely load balancing and HTTP caching.
The interface handling and caching is typically managed by Reverse Proxy Servers and Basic HTTP
Servers. HTTP servers can cache static information (such as images) and provide segmentation for
additional tiers of security. This layer of HTTP servers is not part of the traditional CCA
implementation, but usually exists in larger corporate environments.
Load balancers are an essential part of any architecture using multiple HTTP/J2EE servers. There are
three functions load balancers perform:
■ Balancing the HTTP stream traffic amongst multiple HTTP.J2EE servers,
■ Off-loading of HTTPS-to-HTTP de-encryption (SSL encryption), and
■ Failover functions of re-directing HTTPS sessions from one HTTP/J2EE server to another.
CCA works with the Cisco CSS11500 content switch, which offers these three load balancing
functions. Other gear may work as long as a persistent or sticky session from the Load Balancer can
be maintained for each HTTP/J2EE server, but these are not certified.
Tier Two
This is where CCA's J2EE-based session servers live. A traditional firewall implementation in most
corporate networks includes a DMZ zone to provide maximum security. DMZ access is based on rules
set up by a security administrator, who dictates what communications are allowed through the DMZ
zone to the internal Network Zone. CCA is engineered to work properly within this structure.
Client applications access the J2EE Web Session Server(s) supporting CCA using the standard port
80 for HTTP or port 443 for HTTPS. The J2EE Web Session Servers then request data and services
from the application servers (in Tier Three/Network Zone) using port 9001 on the Company LAN. This
traffic can be limited, using a firewall, to only accept traffic on that port from the specific Web server.
No traffic is ever given the ability to directly reach the corporate data or application servers directly.
One of the most critical components of the CCA application is the J2EE Web Session Server. Located
in the Tier Two/DMZ Zone, the J2EE Web Session Server handles all requests from all users and
customers located in the Tier Zero/Internet & User Zone. These J2EE Web Session Servers handle
dynamic information and act as the main entry to the system.
J2EE Web Session Servers are hosted in a standard computer. These standard computers run four
types of software:
■ Off-the-shelf Web Server software, such as Oracle Web Session Server or BEA Systems WebLogic
■ CCA Application JSP pages
■ Servlets and other connectivity software, such as FTP and JDBC software