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 LANs can be and how to improve them to support the addition of Virtual PBX onto the network. 

LAN Cabling

The Best of Times

Many times we see very old cabling in many of the networks we work with. The good news is that old data cabling like Category 3 does support Virtual PBX. Category 3 has been around since the late 1990’s so nearly every business has adequate internal cabling for Virtual PBX

Although many vendors insist on having customers run all new category 5e cable, the reality is that VoiP works perfectly fine on Category 3 cabling.

The Worst of Times

We’ve seen some pretty shoddy cabling installations over the years. Poorly terminated wires,crimped cables and cable runs over the 100 meter limit are the leading culprits. If you add the basic wear and tear that old cabling and jacks have endured over many years, you’ve may have a problem – especially if you’re considering adding VoIP traffic to the mix.

Fortunately, bad cabling is easy to spot. Just physically inspect the cabling from the individual workstation jacks and in the data room. If it’s neat, tidy and looks like it was done professionally, you’re OK.  If it looks ugly, you may have problems and it’s probably time to upgrade your cabling to support a virtual PBX environment. As a bonus, both your voice and data will be more reliable.

Ethernet Switches

The Best of Times

Virtual PBX requires a miniscule 80 Kbps (Kilobits per second) of bandwidth per telephone. The vast majority of installed Ethernet networks can handle 100 Mbps (Megabits per second)! In other words, the amount of traffic that VoIP adds to the LAN data network is minimal.

In smaller businesses, simple 100 Mbps Ethernet switches handle voice work just fine. But for larger networks of 50 phones or more, you should install Ethernet switches that support QoS (quality of service). You’ll see a standard known as 802.11p/q when talking about QoS. 

Additionally, larger networks require the establishment of VLAN’s (virtual local area networks). This technology “virtually” separates voice and data, again prioritizing voice.

Today, both 802.11p/q and VLAN capabilities are standard on all quality Ethernet switches.

The Worst of Times

So, since Ethernet switches are fast enough to support voice, we’ve got it made, right? Not so fast there Sparky.

First, there are some very cheap and shoddy Ethernet switches on the market place that barely support data transmission, let alone quality voice transmission. When you suspect that you migh have a bad or older Ethernet switch, replace it. Technology move so fast these days that it just makes sense to get the latest and greatest. There are many choices for quality Ethernet switches. Netgear, HP, Dell, and Cisco are some of the higher quality providers.

Second, we’ve seen many instances where Ethernet switches are daisy-chained together. That’s a real no-no and results in degraded network performance and voice quality will suffer. The solution is to have individual cable runs to each device location.

Lastly, when a virtual PBX solution is deployed with 50 or more phones, the best results will be achieved by implementing a separate VLAN for voice.