Let me play Devil’s Advocate for a bit. Almost everywhere you look these days, IT professionals are hawking VoIP to business and residential consumers alike. The ILECs are in, the Cable companies are in, and VoIP providers spring up almost over night to provide ever lower per minute charges on phone calls. The benefits of VoIP center around cost, extending existing infrastructure, and extending the fabric of the nebulous Internet. All of these advantages entice unsuspecting business owners and IT professionals alike to jump on the bandwagon of $avings! But this panacea for the ails of America’s aging telephony infrastructure hide a nasty side-effect – a complete and total lack of oversight and standards.

What, exactly, is VoIP? VoIP stands for Voice-over-Internet-Protocol which means I can make phone calls using my Internet connection right? Sure, this is an accurate albeit airy definition. “Internet Protocol” comes in a variety of flavors. The most popular mechanism for VoIP currently is the SIP protocol. However, VoIP can use other protocols like H.323, Skinny (SCCP), GSM, ILBC, Jabber, and a bunch of other proprietary types of VoIP like chatting on XBox Live! or using a voice chat application like Roger Wilco on your PC! All of these applications allow you to use the Internet to have a verbal conversation with another person or even a group of other people. Many chat clients have added support in recent years for audio conversations – iChat, MSN, Yahoo! Messenger, Google Talk, and many more. “VoIP” is a single term with a limitless number of accurate applications. From a business perspective, VoIP often applies to Hosted solutions from companies like Packet 8; VoIP equally applies to premise IP PBX solutions from companies like Digium with their switchvox appliance; and VoIP even applies to Hybrid offerings from companies like Fonality with their Hybrid-Hosted IP PBX offering.

In consideration of the space alloted to this no-holds-barred VoIP revelation, let’s look specifically at hosted VoIP offerings (Vonage, Skype, Cbeyond, XO, Teliax, Broadvoice, Bandwidth.com, among others, all offer ‘hosted’ VoIP services).

VoIP reminds me of the story of Doctor Jekell and Mr. Hyde. In the lab, VoIP is an incredible technology with countless potential uses far beyond those implemented by most modern Providers. In the lab, calling costs return null and quality is arguably superior to the traditional PSTN which has been long plagued by the laws of physics directing analog wave forms towards oblivion with each mile of copper traveled. In the lab, VoIP setup is so simple a child who knows how to type can enter in the authorization credentials for a new account and service commences almost instantly. VoIP is a healing technology that can redirect hundreds or even thousands of dollars a month back into the business’ coffers. In the lab.

But….VoIP on the streets is a ruffian, a hoodlum causing a ruckus in nearly every Local Area Network it touches. Problems arise when the IT department must punch yet another hole in an already teetering firewall and provide a special lane for this new special traffic. VoIP the destroyer.

Now, the position of Devil’s Advocate carries with it a measure of responsibility to own up to ones accusations. I’ve written that VoIP has its dirty side, maybe even an evil side. I didn’t write that SIP is evil, or IAX is evil, or even heaven forbid I write that Skype is evil. VoIP is evil principally because it doesn’t know what it wants to become when it grows up. VoIP is not a standard. SIP is a standard. G711 is a standard. No one controls VoIP.

Anyone over half a century old remembers when the four major Baby Belcos dominated the American telephony landscape. They each created their own standards for interoperability and charged the other major players fees to run calls on their copper. This made Long Distance a cash cow for many years for these companies. But they grew and expanded and ran into each other’s territory quickly. The complexity of making sure one network’s proprietary standards interoperated correctly with all the other networks became a nightmare. Companies consolidated and eventually single standards emerged and carriers started making money off features and services like 3-way calling and Caller ID.

VoIP is currently a youngster stretching its wings in the wide, wide world of free market. Which standard will win? SIP? IAX2? GSM? Nobody knows, and woe to the business owner who dives into a single technology headfirst without first understanding some of the basic ground rules. Luckily, I’m going to point out some of the more obvious pitfalls in order to better prepare the uninitiated for the trails of VoIP. Please don’t misunderstand; I’m an industry insider working for a leading IP PBX vendor. I live VoIP. VoIP can and will save you money, time, and trouble. But you have to know how to approach it, or it will rear back and bite you in the wallet. The first rule: VoIP is currently uncontrollable, so vett your Provider and PBX vendor carefully.

As any IT manager knows, implementing fundamental network features like QoS, CoS, VLANs, and ACLs helps the LAN operate efficiently and improve the lives of all employees. VoIP requires many of these same standards to prioritize VoIP packets above all other types of traffic. VoIP is greedy for bandwidth, pushing smaller packets through the same CAT5 at a much higher rate of speed. I always use the same analogy: “regular” Internet activity like surfing the web is comparable to a softball pitcher’s vocation. A large chunk flies from the pitcher’s hand to the catcher’s mitt, and so too are HTTP packets received by a host from a server. VoIP resembles a machine gunner standing on that same pitcher’s mound shooting at a target. The same distance is covered in the same amount of time, but the payload in terms of bullets delivered is much higher, though each bullet is many times smaller than the softball.

Modern LANs are starting to adopt this new start-up technology into their standard firmware and basic rule sets. But existing infrastructure, even a few years old, may require a complete overhaul to effectively welcome VoIP. Up until the advent of VoIP, the Internet has largely been a TCP club. But VoIP is quickly changing the landscape with its insistence on bringing UDP to the table in a big way. While a well-managed LAN can easily accommodate this UDP influx, what about the WAN? Who controls that?

The small to medium business owner doesn’t have any influence over the wilds of the WAN. Even the most airtight iptables and QoS policies don’t translate at all once packets start leaving the safety and stability of the LAN. ISPs provide no control whatsoever to standard business DSL or Cable bandwidth circuits. In perfect democratic equality, the DSL or Cable modem treats every packet in with the exact same priority. First come, first served. But voice conversations don’t work like that. There can be no delays or interruptions when a person is speaking naturally. And isn’t the conversation you’re having over the phone more important than whatever YouTube video is streaming on your monitor?

ISPs are starting to offer circuits that account for our special child VoIP. But another snare springs from the Internet – what happens when your VoIP traffic travels from one ISP to another?! What if the two ISPs don’t implement the same QoS rules for VoIP packets?

There is no control. You the consumer control your business’ LAN and that’s about it. The rest is up to the ISP, the VoIP provider, and even the phone company when you call a regular land-line or cellular phone!
So what can be done to make sure this fascinating technology has the proper environment to share its many blessings? Here are some simple rules to follow when shopping for VoIP:

Ask the provider detailed questions about their backbone.
Do they host their servers in a reputable data center? Do they get their bandwidth from a well-known provider like Level 3? A friend of mine thought it would be neat to start a VoIP company and began offering services through machines hosted in his garage. He did some good business for awhile, but his company didn’t last long.

Make sure your VoIP service requires authentication.
This point may seem like a no-brainer, but many VoIP providers do not require registration from the customer, making toll fraud incredibly easy for even amateur hackers. Authentication strings that use a hash in place of a clear-text password provide required security.

Find out what kind of VoIP architecture the provider uses.
Is their network built on a proprietary solution like Broadsoft or do they make use of Open Source VoIP solutions like Asterisk? Proprietary may turn out products with fewer initial bugs and open lines of communications to the developer via a support team, but Open Source means a much larger community of devoted followers hammering away at the application out of sheer pride and commitment to excellence. Asterisk is the most widely deployed Open Source telephony platform in the world precisely because so many people have contributed hours upon hours towards development and stability.

Figure out the DTMF type up front!
With analog lines and PRIs, DTMF was never really a consideration. VoIP companies have choices like rfc2833, inband, and info – and some companies use a different DTMF setting for inbound calls and outbound calls! If customers can reach your Auto Attendant but can’t dial an extension because key presses aren’t recognized, you might as well not have a phone system at all. This one is the Achilles Heel for almost every company I know.

Make sure your network supports QoS.
It cannot be stated enough that VoIP traffic on your network needs an all-access pass to the HOV lane. Because VoIP uses UDP instead of TCP, there are no second chances for these packets. They need to arrive in order, unchanged every time. If your network equipment does not support QoS, simple things like sending an email when someone is on the phone will have a noticeable effect to the conversation. Some customers may detect “clipping” or “clicking” on the line however briefly. A good QoS policy protecting VoIP easily soothes its greedy need for dedicated bandwidth. VoIP does not like to share.

By following these rules, you’ll find you’re much better prepared to welcome VoIP into your LAN. You cannot exercise control over every avenue VoIP travels, but taking care to provide the proper environment within your LAN goes a long way to guaranteeing quality from your phone system. Selecting your provider with care ensures that when VoIP leaves the LAN, it is treated with respect by the ISP and VoIP provider. You definitely cannot control every bit of the Internet, but you can test the waters methodically and enjoy this technology and all the powerful features it has to offer.

Written by Tyler Merritt