Posted by Randy Kremlacek on Sep 8, 2012 10:26:00 AM
|This blog post is part 2 of a two part series on the importance of a proper network when implementing a Hosted PBX solution. Part 1 discussed the Local Area Network (LAN) and this one discusses the Wide Area Network (WAN)|
|It was the best of times, it was the worst of times. It was the spring of hope, it was the winter of despair. We were all going direct to Heaven, we were all going direct the other way - Charles Dickens|
The Best and Worst of Times for Virtual PBX
At TeleDynamic, we've seen the best and the worst of LAN networks. Some were built and configured correctly to handle Business VoIP, others were not.
This is a tale of the best and the worst that WANs can be and how to improve them to support the addition of Virtual PBX onto your network.
You WAN's Role in a Virtual PBX Solution
The wide area network consists of your Internet connection and any dedicated connections you have to other locations. Part I of the Tale of Two Networks covered the local area network requirements for a Virtual PBX implementation.
Now in part II, we get to the bigger challenge of VoIP - establishing a high-quality connection to the outside world.
Data Circuits for Virtual PBX
The Best of Times
The bottleneck of any business network is always the Wide Area Network circuits. They typically run from from 1.5MB (T1) to 100MB (rare and expensive) and it’s easy to identify the chokepoint. Local Area Networks (LANs) on the the hand, run at speeds of 100MB to 1GB.
The good news is that these Internet data circuits prices are coming down and speeds are going up. Even better news is that data circuits are starting to come with Quality of Service (QoS) rules already enable - thus prioritizing voice traffic.
If you’ve got a data circuit that has QoS and meets the happy VOIP trio of latency no more than 120 milliseconds, packet loss less than 1%, and jitter no more than 40 milliseconds, you’ve got a fine Virtual PBX data circuit.
The Worst of Times
If the data circuit does not meet the criteria as described above, your Virtual PBX system will fail.
While QoS can be implemented using customer-premise hardware, there is no fix for excessive latency, packet loss or jitter, other than replacing the circuit. While cable companies are doing a great job in delivering high bandwidth, they don't deliver business class circuits. As such, they sometimes don’t deliver the goods when it comes to consistently delivering voice quality service.
Bandwidth costs money, and business class circuits costs money. The availability of high quality, business class bandwidth depends largely upon the location of the business. Densely populated areas that are close to the central office have a multitude of affordable options, while outlying areas can only be served by expensive T1 lines.
Routers for Virtual PBX
The Best of Times
When it comes to handling voice, there are three kinds of routers in this world:
• Routers incapable of handling voice
• Routers capable of handling voice
• Routers that could be made capable
If a router is designed to handle VoIP transmission and is programmed correctly, the router does not interfere with the Virtual PBX. In fact, the router can enhance voice services by providing QoS and protecting against VoiP-related security threats. So, if you have a quality router that is voice-enabled and programmed correctly, you'll have no problems.
The Worst of Times
Bad routers are the #1 source of VoIP issues.
Older routers were not designed to transmit voice. While they function perfectly fine on data transmission, older routers can wreak havoc with voice traffic. Sometimes you can upgrade the firmware on these older routers but the majority simply need to be replaced.
The second source of router problems for Virtual PBX is a lack proper programming to support voice. There are dozens of parameters that affects the ability of a router to reliably support voice transmission. If even one of these parameters are off, it can make a real mess of VoiP transmission.
On top of all this, many IT personnel are not VoIP experts. It can be a considerable challenge to have the IT administrator deliver a thoroughly programmed router implementing VoIP best practices.
At the end of the day, VoIP quality is neither inherently good or bad. It's all about a properly engineered data network. Make sure that your provider has addressed the elements described above and you're tale of two networks will, hopefully, have a happy ending.
About the Author
President | Head Chef
Randy Kremlacek is president and Head Chef of TeleDynamic Communications and is a Digium Select Partner and 2013 Pinnacle Award winner. TeleDynamic Communications provides turnkey premises-based PBX and hosted PBX, SIP Trunking and Unified Communications. Randy Kremlacek prides himself on knowing the telecommunications industry as well as he knows his way around his own kitchen. READ MORE
Topics: Virtual PBX