[VoiceOps] VoIP passive monitoring appliances or software - any recommendations?

Gast, Jim jim.gast at tdstelecom.com
Wed Feb 12 16:02:34 EST 2014

Hi, Brian -

If your VoIP endpoints can give you RTCP-XR (RFC-3611), turn it on.  You can harvest the "Statistics Summary Report Block" for Jitter and Packet Loss stats and the "VoIP Metrics Report Block" for things like MOS score.  All of these stats are from the viewpoint of that particular VoIP endpoint.   They aren't very good at helping you find the site of packet losses, but they are great at telling you whether or not you have a problem.


/ Jim Gast, TDS Telecom

From: VoiceOps [mailto:voiceops-bounces at voiceops.org] On Behalf Of Brian Knight
Sent: Wednesday, February 12, 2014 2:15 PM
To: voiceops at voiceops.org
Subject: [VoiceOps] VoIP passive monitoring appliances or software - any recommendations?

$DAY_JOB is at a national ISP/NSP where we resell VoIP services.  We do peering with the VoIP carrier at one of our remote POP's.  We are looking for a better way to be able to monitor the handoff of those calls to our carrier over that peering link.

We have quite a bit of instrumentation within our walled garden to tell us about call quality.  We can monitor our QOS policies to ensure packets aren't being dropped by intermediate routers.  If the customer uses our routers to terminate their SIP session, we can pull call quality stats from those routers as well.  We can also use our own office telephones to make and receive test telephone calls, and we can of course run Wireshark captures from the switches to which those phones are connected.

However, we can't say for certain that the customer's RTP traffic actually made it on the wire connecting us to the VoIP provider, nor can we say that the traffic is being transmitted and received properly.  The peering link is connected to a Cisco 12k router on our side, so there is no way (afaik) to mirror the port, as on a switch.

For the moment, I am envisioning that we'll need to deploy a server running Wireshark to the remote POP.  It will need two network interfaces; one connected to a management network, the other a capture interface.  The capture interface will connect to a network tap, and the network tap connected in-line between our router and the patch panel.

Wireshark is probably adequate for what we need.  But I'm wondering if there is any software or an appliance that would do the job better.  Given the usual details - calling number, called number, date and time - we want to be able to quickly inspect traffic and dig into the details of the stream.  Do we see any missing packets from the media stream?  What is the MOS score of a particular call?  Do we see any missing packets coming from us?  Any missing packets from the provider?

Alerting on bad call quality would be a nice-to-have addition.

Any recommendation would be appreciated.  Thanks in advance.

-Brian Knight
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://puck.nether.net/pipermail/voiceops/attachments/20140212/ba33cf9a/attachment.html>

More information about the VoiceOps mailing list