The new product is part of the Mountain View, California-based vendor’s Solution Insight range of modules that can be loaded onto the range of appliances on which it delivers the core NetSensory technology for monitoring data apps, explained Scott Safe, its VP of marketing. However, whereas its predecessors have been specific to individual vendors’ technologies (there are Solution Insight modules for F5’s WANJet optimization offering and Certeon Inc’s S-Series acceleration appliances), this is the first for a generic application, Safe went on.
This means spanning different vendor’s VoIP infrastructure and, since the module monitors both the media and the signalling, support for at least the most frequent signalling protocols. In the event, Network Physics chose to go with Session Initiation Protocol (SIP), H.323 (which was previously touted as the standard for VoIP and used by a number of vendors, but is now being superseded by SIP) and SCCP, a.k.a. Skinny, the Cisco-specific protocol.
Though Skinny appears to be on its way out in favour of full SIP at Cisco, the networking heavyweight’s sheer market clout, together with the fact that there are still a lot of its CallManager IP PBXs in the market running SCCP, makes it worthwhile to work at least with that proprietary protocol.
The semi-standard nature of the VoIP market today had another consequence for Network Physics, too. In the data world, explained Dave Trowbridge, the company’s director of marketing, Network Physics is able to derive data from the flow control protocols that are written into TCP, providing a deep understanding of network dynamics from which to derive metrics such as jitter and MOS score.
On the other hand the Real-Time Protocol (RTP) used by VoIP runs on User Datagram Protocol (UDP), and as such comes with no guarantees that a packet has been delivered and, equally, with no flow control protocols.
You need to be running another protocol on top such as the [standards-based] RTCP XR in order to get such metrics, though a lot of the IP PBX vendors still haven’t moved to support that standard, Trowbridge went on.
As such, Network Physics had to develop a way for its VoIP monitoring technology to still derive metrics from the network, and this was done by developing and extensively testing a series of models with which to achieve the same result when RTCP XR is not available.
This enables the module to be used throughout a company’s migration to an entirely standards-based VoIP implementation, said Trowbridge.
The new module, which goes on general availability in January, also comes with the ability to diagnose call set-up issues in flight, i.e. when the call is underway, Safe added. Other metrics include degradation factors (i.e. to what extent packet loss, jitter, codec, delay and so on are impacting the overall quality), which enables companies to prioritize their responses. The marketing VP also pointed out that MOS and jitter are also measured separately for the conversation and the listening side of a call.
Perhaps the most significant development vis-a -vis what competing products can do, however, is the module’s ability to be deployed in a one-arm fashion, i.e. only at one end of a conversation, such as at corporate HQ, without the need for instrumentation at the other end, so there is no need for agents or synthetic handsets to be installed for monitoring purposes.
You’ve typically had to instrument both sides of the conversation to get these metrics, said Trowbridge. This capability not only allows monitoring of calls out to remote offices across a corporate LAN, for instance, but also across VoIP calls generally, including different service providers’ networks, which in turn means the module can be used to verify how well SLAs are being met.
As a module delivered on the appliances, the entry-level version of NetSensory Solution Insight for VoIP supports up to 100 concurrent calls (which equates to an environment of around 600 handsets) and has a US list price of $4,995. As an introductory offer, through the end of March Network Physics is offering its midmarket appliance, the NetSensory NP-2000 PRO, at its normal list price of $9,995, with a free VoIP module supporting up to 50 concurrent calls bundled onto it.
As for competition, Safe said he expects this offering to meet traditional vendors of VoIP monitoring technology such as Fluke, Viola Networks and NetIQ, but against them our advantage is that, with the appliance and the module, you can monitor both voice and data.
