Load Testing VoIP Networks

[Brian Carscadden]

Looking for recommendations for a tool to effectively test a VoIP (or routed IP Telephony/QOS-enabled) network. NetTach is useful for h.323 videoconferencing, though I'm not sure if it's sufficient for VoIP. Right now testing is largely limited to flooding the network with traffic and testing calls.

[wdrootz]

I don’t think Cisco offers a package but your SE might have a recommendation for you.

[rberke]

Check out NetIQ's VoIP Assessor product.

It uses synthetic traffic between 'end points' which install on PC's and Unix and other platforms. The Assessor calculates call quality and maps to a MOS value using ITU G.107. You get to design a test-set with a GUI tool, designating the pairs of end points to engage in calls, and the number of calls, and the codec. The tests can be set to run for hours or days, with configurable lags between sets of calls (15 min minimum.)

My only minor gripes:

1. No implementation of RTP header compression.

2. The endpoints don't set TOS / DSCP. You have to use routers/ACLs/route-maps to mark the traffic of interest. Then again, I generally prefer to not trust end-systems QOS settings. Cisco IP phones do set their packets' QOS, though.

Richard Berke

T. Rowe Price Investment Techologies