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.

Cheers,

/ Jim Gast, TDS Telecom

From: VoiceOps [mailto:[email protected]] On Behalf Of Brian Knight
Sent: Wednesday, February 12, 2014 2:15 PM
To: [email protected]
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
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