Greg Royal founded Cistera Networks six years ago to provide a convergence server platform that connects a company's enterprise applications to telephone users, using voice over IP. Greg continues at Cistera as CTO and EVP, and writes a blog We spoke to Greg to discuss his company and its embrace of Linux in his industry.

Can you tell us a bit about your business and how you embrace Linux?

Cistera Networks is a software development company based in Dallas. We build enterprise application platforms for IP Communications, specifically Cisco Call Manager and Sylantro Hosted Platforms. As with most enterprise IP PBX platforms, we make extensive use of Linux in our products. It is an extremely robust and scalable platform to deliver an application appliance strategy.

Linux forms the basis of our enterprise IT strategy along with a comprehensive Cisco network infrastructure. Linux came about five years ago as a necessity, and has subsequently turned into a strategy for us.

In the early days, Red Hat Linux was used to provide Web site capabilities, as well as email, file and print services for a small number of client machines The Internet provided us with a remarkable amount of support for the various challenges we had in building out a cost-effective infrastructure as well as with the flexibility to try different service offerings and capabilities. These included CMS systems from Joomla, Zope, and a trouble ticket system, RT. Other systems included CVS code repositories and Antfarm build management.

As our company grew larger, it was necessary that we move toward more robust commercial offerings However, we did not want to lose the flexibility that moving to a closed proprietary system would require.

For example, a key requirement was that we remain a multi-client environment, which included Mac OS X, Windows XP and Red Hat Desktop because of the various requirements of each department. The hard-and-fast rule was unless there was a very good reason, an application must run in a cross platform browser like Firefox. For this reason, we moved to Zimbra Enterprise for Groupware, Salesforce.com for CRM, and Joomla for all internal content management. The next major shift planned is the move to Oracle Financials on Red Hat Advanced Server.

How has Linux diffused into your enterprise and who do you monitor and manage your Linux boxes?

Linux touches every part of the organization The core enterprise systems number 12 servers running Red Hat Advanced Server. The IP Telephony system is Cisco Call Manager but also includes three Trixbox Servers for various services. Zimbra Enterprise on Red Hat Advanced Server provides Groupware.

User Management and Access management is provided via a Radius server which also contains the OpenLDAP server. Monitoring of the servers is done by Nagios, but we also have a VoIP QoS System from ManageEngine for our SIP servers.

Because certain groups look after their own departmental requirements (e.g. R&D owns code management and documentation), the framework of standardization is small and flexible. For example, we require LDAP support and it runs in Firefox Otherwise, all other management tools integrate into the Linux platform. This significantly reduces the overhead and cost of supporting various applications.