Dog Food, WAN Performance, and Hosted VoIP
by February 17, 2011

Filed under: Case Studies

My field engineering team works with customers and partners in many regions and time zones, and we often host working sessions from remote locations.  This provides great opportunities to employ our own solutions and “eat our own dog food” to monitor and troubleshoot common services we use between sites.

I hosted a virtual technology workshop a few days ago  from our Portsmouth office.  We were working with a partner to propose a hosted VoIP PBX service management offer.  I started the meeting using Citrix Online’s GoToMeeting and dialed in using my Vonage business line.

Early in the discussion I was interrupted by a brief click followed by…dead air.  Vonage has been very reliable from many locations, so I assumed this was a fluke and quickly rejoined the call.  A couple of minutes passed, and my call dropped again.  At this point I was having flashbacks to my days as a subscriper of  AT&T ‘s wireless network last year and experience with many call failures.

I rejoined and offered my apologies, this time using my Sprint-powered Evo.

Some of the team members were new to the project, so I took this opportunity to demonstrate PathView Cloud’s network performance monitoring and troubleshooting capability and used  our own experience as an example.

A PathView microAppliance in my office was monitoring my Internet connection all the way to a companion  device located in a San Francisco area hosted facility.  This shows the WAN performance from the remote office out over the Comcast cable network and out to ‘the cloud’ using a variety of protocols including ICMP, UDP, and TCP.

As you can see from the performance charts, data and voice loss were substantial, peaking at 20% several times throughout the day.  Mean Opinion Score (MOS) suffered as well.  You can see a number of red diamond-shaped event markers indicating performance violations for the path.

Troubleshooting WAN and VOIP 1

Looking at the same path in a dual-ended view, we see loss in both directions but peaking on the return leg – San Francisco to Portsmouth. You can also see a lot of transience of the route taken by the UDP packets used by PathView. Check out the yellow diamonds indicating each route change.

Troubleshooting WAN and VOIP 2

It’s no wonder I was having dropped VoIP calls! Looking at the diagnostic showed a clear issue in the Comcast network, starting with the first hop near my office. Packet loss in the range of 4-12 % was experienced when the diagnostic fired. You can also see where the ISP is retagging the QoS values in the IP headers defined for the path. This isn’t unheard of, since QoS is rarely supported over broadband networks and the best effort Public Internet.

When troubleshooting an issue with VoIP over the WAN, you don’t necessarily have to own the hosted PBX to gain meaningful insight to the performance between your handset and the service.  Often times the problem is with the WAN connection, and you can easily use PathView Cloud to monitor the performance from your LAN out to a hosted microAppliance.  If you’re an existing PathView Cloud customer or partner, check out our support site for details on targeting one of our hosted microAppliances for this purpose.

With a solid example of WAN performance affecting hosted VoIP quality as context we went on to complete a productive workshop that day.

Our own dog food: delivered easily via the cloud, and it never tested so good!

-Adam