Migrating from an Avaya phone system to 3CX

When the support contract on its Avaya phone system ran out, Zehnder needed a replacement built on open standards: something that would make the company independent of a single vendor, cut running cost and stay flexible. With more than 500 employees making over 2,000 outgoing calls a day, the PBX is a lifeline. Going back to another proprietary system was not an option once the initial cost, the renewals and the running cost were added up.

The decision

Zehnder chose the 3CX phone system together with beroNet gateways. 3CX cut operating cost through simpler administration and the freedom to buy standard SIP telephones, and it fitted into the Windows infrastructure that was already there. The gateways were chosen for their modular design, their compatibility with 3CX and the fact that they need no drivers, with echo cancellation and fax support already in the device. Adding a beroNet failover switch turned the pair into a complete in-house redundancy solution.

By placing the gateway in front of our proprietary PBX we were able to run a soft migration to 3CX. It proved itself a robust, carrier grade system from day one, handling up to 5,000 calls per day — internal, incoming and outgoing. I was particularly pleased that we could keep using our familiar Windows fax system simply by adding the beroNet CAPI solution.

— Ercan Yapalak, IT department, Zehnder

Soft migration instead of a cutover night

The test infrastructure went up in January 2010. Zehnder ran the new 3CX system and the existing Avaya system in parallel, which made the old system its own fallback. Thirty users from sales, field sales and production moved first; everybody else stayed where they were. The 3CX system, the Avaya system and the external PRI trunks all met inside one beroNet gateway with three E1 ports, so nobody outside the pilot group noticed that anything had changed.

That is the part worth taking from this project. A gateway is what makes a migration gradual: both systems keep their extensions, calls between them cross the gateway, and departments move when they are ready rather than on one nerve-racking evening.

Redundancy

Telephony is business critical at Zehnder, so the installation was built with two gateways and a failover switch. Maintenance can be done on one device while the other carries the traffic. From the first day of the pilot the gateways carried the full load: every call passes through them before it is handed either to the Avaya system or to 3CX, internal calls between the two systems included.

Fax

Sixteen analogue fax machines were connected through two 8-port FXS gateways, which pass fax on to the E1 gateways over SIP using T.38. The existing soft fax solution kept working through beroCAPI, so staff carried on sending faxes from their desktops exactly as before.

Afterwards

The project had teething trouble, most of it caused by the ageing Avaya PBX.

Large infrastructure projects often have teething problems. At that point it matters how fast a vendor responds. 3CX and beroNet answered all our questions quickly and competently.

— Ercan Yapalak, IT department, Zehnder

The hardware in this project was the berofix generation. The equivalent today is the enterprise SBC platform: the same modular idea, with PRI and BRI or analogue modules, remote management through beroCloud, and the same failover switch in front of the line. Calls between ISDN and SIP need no session licence; only SIP-to-SIP traffic is licensed.