Stepping up to the IP telephony management table

A converged IP PBX system brings with it new and expanded management responsibilities for things such as voice quality, quality of service, bandwidth consumption, security, voice-over-IP parameter settings, IP call routing and softphone deployment.

In this round of testing, we set out to determine how well IP PBX vendors are making those extra management tasks easier to bear.

We tested products from four vendors and found that in some areas - configuration, for example - the tools were adequate across the board (for details on the IP PBX configurations submitted and pricing click here). However, for real-time monitoring, generating user-settable alarms and traps, and long-term trend reporting of IP-telephony activity - clear winners and losers are emerging.

All the leading IP PBX vendors were invited to participate in our test. Alcatel, Avaya, Siemens and Vertical Networks accepted. Shoreline Communications and Nortel declined without explanation. 3Com and Mitel Networks said they were in the middle of product upgrades. Cisco originally had agreed to be in the test but then declined saying new pieces of its IP-telephony management toolbox weren't ready for testing.

Vendors could submit any of the management tools they offer to monitor or control an IP-telephony-only environment, and third-party packages that augmented their own products. Except for Vertical, all vendors provided a mixed bag of tools. Vertical based all its management on the native Java-based browser interface that comes free with its system.

Because vendors submitted a mix of their own plus third-party tools, we decided not to render a scorecard for this review. However, there are several areas in which vendors differentiate themselves and which could be factors in your buying decision.

Different strokes

Real-time monitoring : Only Avaya and Alcatel offer users a straightforward way to see what QoS conditions - in terms of jitter and packet loss - current VoIP calls are experiencing (see graphic). Other factors include:

Phone configuration: Siemens embraces phone-side configuration of IP-telephony parameters. For example, setting the jitter-buffer size, a key parameter affecting VoIP voice quality, can be modified only on each individual IP phone; there is no centralized, systemwide jitter-buffer control in the Siemens environment.

Vertical's approach, by comparison, is weighted more heavily with the system administrator. IP PBX management should be centralized when possible. Implementing settings on a per-phone basis breeds inefficiency. Also with access to their own VoIP parameters, some users inevitably will experiment with their phone configuration. Also, centrally monitoring a whole network or subnet of IP phones yields a much better view of what's happening - in terms of bandwidth consumption or QoS performance, for example - than you get by querying individual phones.

Reboot time: Another key issue is how long it takes an IP phone to reboot. Siemens was best at 20 seconds. At the other end of the scale, Vertical's IP phones didn't come back up for 2 minutes, 15 seconds. Almost all IP-phone configuration changes require a reboot. The difference between 20 seconds and two-plus minutes certainly affects end-user disruption and downtime, and whether changes best are applied in real time or after-hours.