Improving business VoIP with edge devices

June 11, 2009 by Garrett Smith

Voice quality and reliability are the two things that every business should be concerned about.

As VoIP technology has continued to improve and evolve the traditional myth that all VoIP is of low quality and reliability has died down some. But it is still true that if you don’t take the proper steps, like proper network infrastructure and bandwidth availability, your VoIP quality and reliability will suffer.

And sometimes that isn’t enough. That’s were edge devices, or more commonly known as network monitoring devices, come into play.

Over at the newly minted blog, Luke Reynolds offered up an excellent post on the benefits of utilizing a network monitoring device. They include:

  • Voice Quality – These VoIP specific devices act as Quality of Service routers that actually shape traffic on your IP network to optimize voice quality. Most VoIP quality issues are due to bad IP traffic patterns on your network (someone watching a YouTube video is making you sound like a robot on the phone!). A VoIP edge device solves this problem.
  • Disaster Recovery – VoIP specific routers, like the EdgeMarc, support something called DNS-SRV records, which store paths to multiple gateways for automatic failover. If your data network experiences any issues or outages, a VoIP edge device can look for alternate network paths to maintain your voice service.
  • PBX Security – Your phone system (PBX) is simply an application running on a server… and it can be hacked (please use good password practices and change it frequently). While your network may have great security, VoIP edge devices add an extra layer by acting as an ALG (Application Layer Gateway) which aids in NAT traversal and will allow you to keep your PBX on a private IP. Additionally, the edge device dynamically opens and closes ports needed for voice traffic, so that nothing is left open when it’s not needed. That means your PBX and your network are less likely to be hacked.
  • Better Support Experience – [Your provider] support is great, but it helps when we have good data. Voice-specific edge devices provide real-time quality scores of Voice traffic on your network (using MOS scoring). This, along with the traffic data inside the box, allows our support team to better diagnose problems and get resolutions faster.

Now even though network monitoring devices deliver all of the benefits Luke discusses (and even more in certain deployments), these devices are often a difficult sell to customers.


It really comes down to price.

No, network monitoring devices are not that expensive, but it does represent an additional cost. One that customer’s almost never plan for.

Today some hosted VoIP and SIP trunking providers (like mandate that a customer most have a network monitoring device, but a great many do not. A missed opportunity for the service provider and a potential nightmare in the waiting for the end customer.

In the end, what both businesses and service providers should consider when it comes to network monitoring devices (or edge devices) is whether the increased initial up-front cost is greater than the potential problems one will avoid by using one.

To me, at least, spending $600 to $3,000 (for a small to mid size deployment) is a small price to pay to prevent problems and improve VoIP service performance.

Do you agree?


  • db

    help is more fitting.

    I would like to see that device prevent problem when users are download torrents or massive UDP streaming.

  • Garrett, great points. Thanks for the post. Do you feel the points you made are as well known as they should be?

  • Sam

    Garrett & Rich,

    Consumer VoIP can cut corners, and deliver a “cheap” solution that works most of the time.

    Business VoIP cannot afford to cut corners, because a) we have SLAs b) we pay our people well to support our service and c) downtime hurts the $$$ bottom line of our customers.

    Those are a few of the reasons that we’ve made it a priority to include edge devices on our business VoIP deployments if at all possible. It’s not a magic fix-it-all, by any means, but our analysis indicated that the devices help enough to justify the additional cost.

  • Garrett Smith

    @ db

    I guess I used the term “prevent” loosely.

    An edge device won’t prevent the user from downloading torrents (the first time), but it can prevent it from happening in the future (through the insight the edge device gives customers/service providers).

  • Garrett Smith

    @ Rich

    The points are actually Luke’s (no need to reinvent the wheel). But I agree with them.

    To address your question, I don’t think that the benefits of edge devices or network monitoring are very well known or fully understood by small to medium sized businesses.

    Hate it or love it, many customers are arriving at our door and those of service providers everywhere with the “VoIP is cheap” mentality still. This causes many to simply try and deliver the low cost solution, rather than the proper solution (and taking the right steps along the way).

    In order to reverse this the industry as a whole will need to continue to educate the general public as to the benefits of edge devices, network monitoring, proper infrastructure and bandwidth.

    It’s a big effort, but the upside of more well informed customers is a huge win for all.

  • I’m a product manager for Network Instruments. Based upon my experience with customers, I would agree with most of what Garrett Smith has written. VoIP over the years has made great strides in quality, but many organizations I deal with are implementing monitoring tools after the fact.

    Companies should be implementing network analyzers before rolling out VoIP or any unified communications application to understand their current network performance, identify and eliminate potential obstacles, determine performance benchmarks, and to monitor performance post deployment.

    Beyond avoiding upfront obstacles to success, the insights gained from pre-deployment testing and continual monitoring of the added VoIP traffic will help you to intelligently configure alarms on the monitoring tool to alert you when VoIP performance deviates from the norm.

    Charles Thompson

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