As we discussed, the server software stack consists of the operating system, a distributed file system and terminal services. On the applications side, there are three layers of systems applications: messaging and security, identity management, and desktop computing.
The messaging and security layer consists of a Mail Server, Instant Messaging Server, Proxy Server, Firewall, Anti-Virus, Anti-Spam, VPN Support. The identity management layer provides support for the access control layer for user administration. The desktop computing layer provides support for file and print services, and the various desktop applications that the thin client users need to run. Let us start by looking at the messaging and security applications.
The Mail Server ensures that emails are available locally via IMAP accounts for users. If the enterprise has dedicated connectivity to the Internet, the same mailbox can also be accessed from the outside, thus providing a single store for mails. The mail server also ensures that users have their own, personalised email IDs of the form name@companyName.com. Every person should be given access to email in the organization email is something that does not work if half the people in the organisation have it, and the other half does not. It is the most basic of applications that needs to be used by everyone in the organization. Over time, email will become the organisations lifeline for conducting business, hence it is a mission critical application and needs to be treated as such.
The Instant Messaging Server provides a local platform for chat. They are the equivalent of Yahoo and Hotmails Messenger services with the difference being that there is no need to connect to the Internet to chat with others on the same network. Jabber provides an excellent platform for IM services.
The Proxy Server ensures that multiple users can use the same Internet connection for browsing. A caching capability can speed up browsing by keeping a local copy of frequently accessed content. This is important because bandwidth in most emerging markets is still very expensive. The Firewall secures the enterprise, preventing unauthorised intrusions. It is a mandatory requirement for businesses now, given the automated programs which look for vulnerabilities on machines connected to the Net.
Viruses and spam are the scourge of todays email communications. The Anti-Virus software scans all incoming and outgoing email for viruses. Since most viruses come via email, this is a significant step in ensuring a virus-free operating environment. The Anti-Spam software marks spam as it comes in, thus ensuring a cleaner mailbox. Together, these two applications ensure that the small- and medium-sized enterprise (SME) does not have to worry about viruses destroying critical files and spam reducing productivity.
VPN stands for Virtual Private Network. It provides for a LAN-like single network environment between different offices. This way, users can share files and communicate much more easily with others, even though they may be in different geographical locations.
Taken together, these applications provide the complete infrastructure for communications and connectivity in a secure environment.
Tomorrow: Systems Software Architecture (continued)
TECH TALK SMEs and Technology+T