Communications Express provides an integrated web-based communications and collaboration client. Communications Express is a common component of Messaging Server and Calendar Server, providing end users with a web interface to their calendar information and mail, as well as an address book.
This chapter contains the following sections:
Communications Express depends upon the following Sun Java System component products:
Access Manager (if you are using Sun Java System LDAP Schema Version 2)
You install Communications Express as a front-end server (in a multi-tier environment). The Messaging Server packages can then be configured to run as Webmail server, which connects to a back-end store running Webmail server. Also, both Communications Express and Messenger Express can run on different IP addresses.
In addition, you can configure Communications Express to have the Address Book on the front-end machine store its data either in the LDAP directory infrastructure or on an LDAP server other than the Communications Express machine. See the Sun Java System Communications Express 6.3 Administration Guide for more information.
Communications Express communicates with Calendar Server through the Calendar Server HTTP service, the mshttpd daemons for Messaging Server, and the LDAP service for address book. The cshttpd daemon, the mshttpd daemon can be local or remote, and the LDAP service can all be either local or remote.
When using a load balancer or port director type device, make sure to utilize “sticky” (persistent) connections such that users are continually routed to the same front-end server for the duration of their session.
Communication between mail and calendar is automatically established because both applications are deployed within a single web container. Also, you can optionally use Access Manager to provide the single sign-on mechanism.
Both calendar and mail applications share the same address book.
The Address Book Store provides horizontal scalability. See the Sun Java System Communications Express 6.3 Administration Guide for more information.
Communications Express supports virtual domains.
The Calendar and Address Book client modules are deployed as a single web application in any web container. The mail module is rendered by the Messenger Express. Messenger Express is the standalone web interface mail application that uses the HTTP service of the Messaging Server.
Figure 23–1 shows the Communications Express software architecture.
Communications Express consists of the following modules:
Calendar. The presentation layer of the Calendar module is based on JavaServer PagesTM. These JavaServer Pages pages can be customized to suit the requirements of the client. The data layer accesses a Java API for Calendar (JCAPI) to enable exchange of data with Calendar Server over HTTP-based protocol.