Blog :: Network Operations

VoIP DSCP Prioritization : NetFlow Reporting

Today I’ll cover the importance of VoIP DSCP prioritization when NetFlow reporting.  We have 3 employees that work remotely in Central Maine, Pennsylvania, and Florida.  They all have Cisco routers and are exporting VoIP data to our NetFlow Analyzer server.  Read the Cisco Medianet Deployment Guide to learn more about setting this up.

Jim works in Florida, which is 13 hops from our PBX here in Southern Maine.

VoIP router hops

He has a business class internet account and, because of this, we believe they prioritize his VoIP traffic.  The quality of his calls is very good, ~7ms of jitter.

VoIP Jitter monitoring

You want to make sure you prioritize the traffic coming from your desk phone, or configure your soft phone to send prioritized traffic.

VoIP DSCP settings

We use Cisco performance reporting for Medianet’s functionality to verify QoS as well as traffic volumes caused by the G.729 vs. G.711u codecs.  My point here is that these new exports are very helpful and I’m sure you’ll appreciate them.  BTW: We are running IOS v15.2(2)T and the above required Flexible NetFlow Configuration to get the additional fields exported.

On that note, with NetFlow v9 and Flexible NetFlow so prevalent now, how often is ip route-cache flow used?