Open source IP PBX: Pingtel SIPxchange - Network World

Open source IP PBX: Pingtel SIPxchange - Network World: "Open source IP PBX: Pingtel SIPxchange"
Of Pingtel's three open source IP PBXs, we tested SIPxchange Enterprise Communication Server, Version 3.7. Pingtel also has the SIPxNano for fewer than 30 users, as well as a free, downloadable version of its sipX product, which is supported by the SIPfoundry open source community.

We installed SIPxchange from a single CD that included the Linux CentOS 4 and the IP PBX software. The installation requires the administrator to enter information about 15 system and network parameters using a basic GUI; the system was up and running in 15 minutes. A second system was brought online to test failover support

The core infrastructure of the Pingtel system is completely rooted in SIP, and can be installed on multiple Linux kernels or ported to Sun Solaris. No media streams pass through the SIPxchange server. RTP streams are passed directly between endpoints with just call-control messages relayed to the server.

This allows for reduced workload requirements on the IP PBX system, which gives Pingtel an architectural advantage over most. The other servers included with the product -- such as authentication, registration and presence servers -- are software stacks running on the same physical box but are isolated from the IP PBX from a software perspective. So if one of them has issues, it does not bring down the others.

The administrative Web interface allows for quick and easy setup and management. New users can be provisioned and configured separately or as a group. For large numbers of new users, the interface's support for a CSV format lets you import settings from an Excel spreadsheet. The proper format for the CSV file is included on the "add users" interface.

Because SIPxchange is exclusively SIP-based, adding gateways and other SIP devices is as easy as adding a user to the system. Outbound and inbound call route plans can then be developed from the default settings and used.

For high availability the SIPxchange system can be configured for load balancing and redundancy with multiple servers in multiple locations. When we simulated a catastrophic failover, we found that as long as the endpoint being used supported more then one DNS SRV record, it was able to fail over automatically. Because the calls handled by the Pingtel system are randomly load-balanced, service was not interrupted for some of the endpoints that were registered to the failover call controller.

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An open source group has posted free Session Initiation Protocol-based PBX software that lets businesses create their own phone switches from standard Linux servers - but drawing business customers to the technology could be an uphill effort.

Called sipX, the PBX offering is compatible with SIP phones and media gateways that can change IP voice to traditional TDM voice and vice versa so calls can be switched onto traditional phone networks.

SipX was written by SIPFoundry, whose goal is to encourage businesses to develop interoperable SIP products so end users can readily take advantage of SIP features, such as presence, without tweaking the equipment they use. The organization considers itself a developer community where members can contribute to writing open source code, similar to the Linux development community.

Development of sipX parallels similar efforts that produced Asterisk free PBX software, backed by equipment vendor Digium. Asterisk was released last September.

While free software might be attractive to some, it is unlikely to become a major force in large businesses. "It has potential for small organizations or homes, but it's unlikely to make a significant dent in the enterprise," where customers want more than just a PBX, says Paul Strauss, a research manager at IDC. "You do need support; you do want assurances of quality; you do need to see what's going on inside it; you want the vendor to sell you phones."

SIPFoundry's key founder, PingTel, says it hopes that businesses interested in the open source SIP software will buy it along with supplemental software tools and support from PingTel, using the same model Red Hat uses with Linux. PingTel sells PBX support services wrapped around a version of sipX.

Sterling National Bank in New York says it likes the idea of open source PBX software, but chose to acquire it through PingTel and hire the vendor to support the bank's phone system rather than go it alone. "We're probably not that brave," says Eliot Robinson, the bank's executive vice president. "We want somebody to call on when we need some help to configure the system or to support some users' specific requests."

He says he also likes the idea of an open source development community that he believes will innovate new features quickly. "It's good to know there's multiple developers out there enhancing the system," he says.