Speaking of VoIP - the key issues

Russ Shaw, technology journalist, author and blogger extraordinaire, speaks his mind about VoIP.


Guest Blogger: Russ Shaw
SearchVoIP.com welcomes Russ Shaw -- technology journalist, author and blogger extraordinaire -- to speak his mind about VoIP.
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   10 important questions to ask your potential VoIP provider
   How to prevent and fix jitter, packet loss and latency
   QoS and The Unholy Three: Latency, jitter and packet loss
   The five most common reasons businesses deploy VoIP
   First person: My ongoing Vonage experience systems
   Using VoIP from your existing phone
   Everything you need to know about 'hooking up' (VoIP, that is)
   Choosing a VoIP provider
   So tell me: What is VoIP, anyway?

10 important questions to ask your potential VoIP provider

19 MAY 2006 18:26 EDT (22:26, GMT)

On the VoIP-News Web site, veteran technology author, journalist and editor Owen Linderholm suggests 10 questions you should ask your VoIP service provider before you sign that contract for enterprise VoIP services.

Let's go over each of Owen's suggestions. I will add my comments about each.

  1. What is the contract termination policy? Can I get out early and what penalty is there? Are there other termination costs?

    I've heard many tales of overaggressive sales types of providers and systems integrators who will try to sweet talk potential clients into long-term contracts. While there is some virtue of stability to such contracts, technology, your business conditions and even business within the VoIP industry can change during the length of a long-term contract. OK, you can sign this contract, but you have some leverage of your own. Ask about specific early termination penalties, and if that sales type starts hesitating, then you are the one with the pen in your hand.

  2. What startup costs are there beyond setup and equipment fees? Besides advertised and quoted basic equipment, what else will I REALLY need? Do I need to buy phones? Will extra servers/cards/add-ons be needed beyond the base cost to actually meet my usage requirements?

    I've bought many cars in my time and have learned to not accept just the bare minimum price. Once, I did so, and my car came without a radio. Don't make the same mistake in VoIP. There's likely to be extra server cards and phones. Get specifics on how much equipment you'll need, and what the real cost is -- not just some idyllic blue sky minimum.

  3. What day-to-day usage costs are NOT covered by my service plan? What are the rates for international calls for example?

    You don't want to find out after the fact that you are grist for the "fee monster." I am talking about additional fees for conference calling, long-distance calling to certain nations, and so forth. Insist on this info ahead of time.

  4. Can the system as it comes handle outbound and inbound faxes easily? Can I just plug a fax machine in or do I need special equipment?

    I hear lots of tales of woe in this area. Whether we are talking about standalone faxes, combination multipurpose fax machines or even internal fax modems, not all faxes work with all VoIP technologies. Get this spec'ed out in advance.

  5. Do I need add-ons or extras to handle old-style analog phones I already have or those that remote or branch offices already have installed?

    Many VoIP deployments I have witnessed and covered have been stage-by-stage in which some company offices are fully VoIP deployed while others are being eased in. If this is the way you want to go about doing things, make sure that the VoIP system you are signing on to will be able to handle your legacy analog phone equipment.

  6. How does the system handle remote and mobile workers -- whether temporary or permanent? Will the experience be the same for a telecommuter in a rural area as it is for someone at head office? How about when I'm on the road? Are there any services or features to handle that?

    This might come as a surprise, but not all VoIP providers can handle mobile or remote phones as an extension to the main phone system. The most practical workaround is getting those remote employees a single line and using your VoIP system's call forwarding feature to bring them into your VoIP network. That shouldn't be a problem, but neither should having to do so be a surprise.

  7. If I estimate my requirements wrongly and need a major upgrade, what will that cost me extra above if I had made the estimate correctly to begin with? In other words, what are the additional costs for upgrading?

    In technology deployments -- as well as other things in life -- best to acknowledge the "what ifs" up front. But sometimes there is the matter of the unforeseen. Just make sure that you have wiggle room for adjusting the unforeseen, without having to fend off an unanticipated fee regimen on the part of your VoIP provider. Otherwise, you will feel like you are being punished for not visualizing every possible circumstance ahead of time.

  8. How do you guarantee your quality of service? If I have issues how do I get support, who do I contact and how fast will it happen? When there is a complex issue and my network equipment supplier, my broadband supplier and you are all pointing the finger at each other. Will you step up to solve my problem?

    Oh, that's a tricky one. Your service-level agreement needs to be both specific in terms of call quality standards (latency, jitter, packet loss), as well as in service obligations on the part of your VoIP provider. 24/7/365 is a must.

  9. What about emergency services -- do you provide full 911 or E911 services? Will dispatchers know my location automatically? How about remote workers?

    This technology is still evolving, but is essential to the safety of your office and remote workers. Ask as specific questions as you can with regard to how your prospective VoIP service provider routes "911" calls made over their system. How directly or indirectly do those calls travel to the nearest E911 emergency response center?

  10. How do I know you are going to be around in two years, let alone three?

    That's a tricky one. Make sure your service contract survives any merger, acquisition or sell-off your VoIP services provider may be planning. I'd also do a business credit check, as well as check technology Web sites, blogs and Internet discussion forums for any rumors about the VoIP company you are signing up with.

Posted by Russ Shaw
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How to prevent and fix jitter, packet loss and latency

18 MAY 2006 16:27 EDT (20:27, GMT)

In my previous post, I wrote about the three potential technological curses of VoIP -- latency, jitter and packet loss. But how should you work with your VoIP provider to avoid their onset and to fix them if they are detected by packet-measuring software such as the one your VoIP carrier uses?

There are several such solutions, including:

  • Resource reservation is a policy in place to ensure that the VoIP call has the bandwidth needed allocated from point to point before the conversation takes place. This cannot work on the Internet due to external factors, but can work on a private network where prioritization policies can be enforced where bandwidth is reserved for sending and reception points.

  • There are also network traffic tuning boxes that can be added to a network. These can manage bandwidth uses and create QoS even if other network devices don't support it.

  • Some enterprise VoIP users opt for a hosted QoS solution from a vendor capable of 24/7/365, real-time diagnosis, monitoring and service.

  • Other users deploy software that can automate, configure, deploy and manage QoS in real time.
Of the three VoIP gremlins I've written about, jitter buffers have the most specialized use. To understand why jitter buffers are necessary, let us explore not only exactly what jitter is, but why jitter occurs.

On the strangely named but high-quality U.K. based Web site 0xDECAFBAD.com, site owned Bret McDanel offers an explanation of jitter.

VoIP packets are comprised of various bits of data. Generally they have voice data, a RTP header (Real time protocol), which has a UDP (User Datagram Protocol) header which has an IP (Internet Protocol) header. The IP header is used to get the packet to the remote machine. The UDP header tells that machine which application to send the packet to (by way of port numbers), the RTP header tells that application the timing interval for that packet, and finally the voice data is used to reconstruct the analog waveform for playback in a speaker of some sort.

All of these bits add up. An IP header with no options has 20 bytes, a UDP header has 8 bytes and an RTP (Real Time Protocol) packet will have 12 bytes. Then there are the bytes for the actual voice data, which varies based on which codec is used and the settings for that codec. Each codec will take a certain amount of voice data and compress that, typical amounts are 10-20ms of voice per packet.

But sometimes, the system goes awry and packets fall out of rhythm. Time for some corrective action with jitter buffers.

In a highly allegorical sense, jitter buffers are like medicine for a snake bite -- a bit of the venom can lead to a cure.

A jitter buffer functions by isolating a small amount of the voice data in, well, a buffer. If an errant packet arrives too late, the jitter buffer tool will automatically discard the packet to prevent the gap between the callers from growing. If it arrives too quickly, it will be held for a small duration of time so that the buffer is played to the other party at a constant rate.

Jitter buffers can, by their nature, add to the end-to-end delay. That's why they are usually only effective on delay variations of less than 100 milliseconds (1/10 of a second). Jitter must therefore be minimized, ideally to 50 milliseconds or less. There are adaptive jitter buffers that can go as high as 200 milliseconds (1/5 of a second), but that's asking a lot of the solution.

As packets are received by the person you are speaking with, these packets will be queued into the jitter buffer. If they are 20-millisecond samples, every 20 milliseconds the jitter buffer will pull one packet out and play that audio data. This will continue until the buffer is exhausted.

In this way, packets containing your voice can be reordered in the way you sent them.

In my final post, I'll tell you how to put this all together, and what questions you should ask your VoIP provider to ensure you have the best quality VoIP service you can.

Posted by Russ Shaw
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QoS and The Unholy Three: Latency, jitter and packet loss

17 MAY 2006 19:08 EDT (23:08, GMT)

QoS, or quality of service, is a VoIP performance metric any enterprise considering VoIP should insist on. It is also a standard that many enterprise VoIP service providers offer as part of a service-level agreement that is part and parcel of most any VoIP services contract.

The goal of QoS is to ensure that packet traffic for a data or voice connection will not be delayed or dropped due to interference from either lower priority traffic or connection degradation.

There are three main standards involved in QoS. These are latency, jitter and packet loss. Let us take a good look at each.

Latency is the time delay between when you say something over a VoIP connection and when those packets are actually delivered over the network. This is usually expressed in milliseconds (1000 milliseconds=1 second).Too much latency and your conversation partners -- as well as you -- are likely to hear bad echoes.

Latency's handiwork can also be expressed in delays between when something is said and when what is said is heard. Too many delays, and you'll either wind up interrupting each other, asking each other to repeat what they just said, or both.

The way in which the human ear and brain react to sound has a lot to do with when the degree of latency becomes noticeable. Neurological research has pointed to around 250 milliseconds (1/4 of a second) as the not-so-sweet spot at which roundtrip voice delays become noticeable.

But since you don't want to cut things too closely, you should never accept 250 milliseconds. The International Telecommunications Union standard is 150 milliseconds, but that's one-way latency. Yet since VoIP involves conversation back and forth -- and the possibility that some of this conversation will be on the public Internet rather than via private, leased lines -- you should insist on transit latencies of much less than 150 milliseconds.

The specific latency standards often are part of service-level agreement between you and your VoIP provider. A maximum latency of around 50 milliseconds (about 1/20 of a second) is common.

Now, let us take a look at jitter, which is expressed in variations in the time delay of packet delivery. Variety may be the spice of life, but too much jitter inconsistency, and you may hear some weird sound effects.

In their service-level agreements, many VoIP providers now specify maximum jitter in their SLAs. The outer range is around 2 milliseconds -- or a 1/500th of second -- variation between the transit times of a successive series of packets containing the digital information in a VoIP calls. Some newer SLAs have slashed the expected performance to around 0.5 milliseconds, or 1/2000th of a second.

Packet loss
Packet loss, as you might expect, is the failure of small groups of digitized VoIP data to make it through the delivery process between you and those you are speaking to over your VoIP connection. Too much traffic in the network can cause the network to drop packets. Packet loss of around 1% or more can be perceived during conversation. Service-level agreements are far less tolerant of packet loss, generally allowing for a maximum of 0.1% to 0.3% of packets to not make it through. In other words, an SLA with, say, 0.2% packet loss means you are ensured that for every 1,000 packets, only two will fail at most.

Beyond just their good word, and your trust, how do VoIP service providers ensure these levels of performance? What are some tools used to measure for these metrics? If problems develop, how can they be fixed? We'll explore these issues in our next post.

Posted by Russ Shaw
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The five most common reasons businesses deploy VoIP

16 MAY 2006 20:48 EDT (00:48, GMT)

During my guest stint here, I have fielded a number of questions about enterprise VoIP deployment. I've even seen a couple of inquiries about how to make the best case for VoIP to senior managers or execs.

Well, now I have some information for you -- direct from an objective survey of those organizations that have made the decision to deploy VoIP.

Last week, Infonetics Research released a study entitled "Drivers For VoIP Deployment." To determine these drivers, Infonetics conducted in-depth interviews with 240 small, medium and large organizations that use VoIP products and/or services now or will by 2007, as well as 450 shorter interviews to determine VoIP adoption rates.

Most respondents use in-house VoIP, some use managed VoIP services and others use a combination of the two.

Infonetics quizzed respondents on 12 possible reasons for deploying VoIP. Of these 12 reasons, five received more than 50% scores on the question as to whether the reason was "definitely a driver" to deploying VoIP.

Here are the five reasons, the percentage each of them garnered in the survey, plus my commentary about each.

  1. Integrated phone system across multiple locations: 64%. VoIP equipment and management software makes it possible to distribute phone systems, virtual switchboards and related call management and administrative functions pretty much anywhere regardless of location. This integration bridges geographical separation so efficiently that best practices VoIP installations are geographically transparent.

  2. Scalability: 58:%. Because little if any extra wiring is necessary, unlike traditional telephony, it is relatively easy to add additional phones to your VoIP setup or even additional nodes to your network. Frequent user scenarios for this would be adding additional employees who need to be on the VoIP network, or even adding additional branch offices to your existing VoIP offering as you open or expand those remote facilities.

  3. Operational costs: 57%. Plainly put, VoIP saves you a bundle over traditional phone toll charges. In the case histories I write for a leading VoIP industry trade magazine about VoIP deployments, I hear tales of phone bills being cut by as much as 80%.

  4. Consolidate voice and data networks: 56%. In VoIP, voice and data travel across networks as bits. This commonality promotes ease of systems administration.

  5. Flexibility: 55%. That relates to the ability of VoIP to be retrofitted to new, as well as existing, office and mobile communications environments. Mobile users can easily be outfitted with VoIP that they can use through a secure Wi-Fi connection or over their laptop through the company's virtual private network.
Here are the other seven reasons cited in the "Drivers For VoIP Deployment" survey results, all of which are useful to make the case for VoIP:
  1. Ease of use/manageability: 50%
  2. Cost per user: 47%
  3. Applications and features: 45%
  4. (Previous phone) system has reached end-of-life: 44%
  5. Disaster recovery: 40%
  6. Employee mobility/flexibility: 40%
  7. Open standards-based: 29%
Our next column is going to be about a fairly unglamorous but absolutely essential regimen of enterprise VoIP: testing and measurement.

Posted by Russ Shaw
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First person: My ongoing Vonage experience

15 MAY 2006 15:26 EDT (19:26, GMT)

Rather than simply rattle off a list of VoIP providers and their services, I thought I would write about the service that is both the largest and the one I use directly.

Vonage is the largest North American VoIP provider by subscriber count. I have been a Vonage customer for years, and use both their standard and "softphone," software-based service.

Of their four phone-based (as opposed to PC-based) services, I'd recommend checking out either the $24.99 Premium Unlimited Plan, for home use, or the $49.99 a month Vonage Small Business Unlimited Plan -- a good plan for SMBs.

With Vonage Premium Unlimited, (my plan, incidentally) you get unlimited local and long distance calls anywhere in the US, Canada, Puerto Rico and select European countries, as well as features including Voicemail Plus, 3-way calling, call waiting and call forwarding caller ID with name and 911 dialing.

Additionally, if you sign up directly from the Vonage Web site (as opposed to a third-party distributor), you'll get a free phone adapter.

Small Business Unlimited gives you all that, plus a dedicated fax line thrown in.

The SoftPhone plan is $9.99 a month. For that, you get 500 included minutes, but there's a catch. Since this is an add-on plan, you have to already have a Vonage account, with a phone number. And you'll get a second Vonage phone number exclusively for the SoftPhone.

In my 18 months or so as a Vonage user, I have found many things to like and a few characteristics of the service that could stand a bit of improvement.

Installation, which I described in an earlier post, was easy and straightforward. Recapping:

  1. Connect one end of your Ethernet network cable to one of the numbered ports on the back of the router. Connected the other end of your Ethernet cable to the Ethernet port on the back of your PC.

  2. Hook up one end of your phone cable to the back of your phone, and the other end to the phone port on the back of your router.

  3. Power your cable modem back on, leaving your PC powered off (for the moment).

  4. Connect your power adapter to your broadband router's power port.

  5. Plug the other end of the power adapter into a nearby electrical outlet. When you made the connection, the Power LED (Light Emitting Diode) will light up.

  6. Turn your PC back on.
As for my phone number, I opted to let Vonage assign me a new one. That's because I only have a cell and not a landline -- the latter of which could be more easily replaced by a Vonage account. But that solution is not for everyone.

The smart part of simply moving your phone number from your existing carrier to your new VoIP carrier (in this case, Vonage) is that it's likely lots of folks have your existing number. Do you really want to call everyone up and say, "Here's my new phone number"? It can be a pain, and because you are changing carriers, it is unlikely your "jilted," former carrier will happily program a number change announcement complete with your new number.

The number-reassignment process can take a while, too. I have heard tales of an existing number transfer between an existing carrier (such as Verizon) to Vonage taking several weeks. Usually, the fault is red tape and paperwork. Fortunately, I hear of more instances where it takes just a week or less.

As one who likes to keep a detailed record of all my phone calls, I find that Vonage's Dashboard -- accessible via password-protected login from the Vonage site -- is an excellent way to do this. I can see a record of all my calls, to what number they were placed or from where they originated, and how long they lasted. I often cut and paste results from my Dashboard into an Excel file I keep with detailed records and commentary about all my calls.

The info you can extract from the Dashboard is not as complete as some third-party VoIP calling record utilities, but should suffice for most business and home users. I'll get into some of these products in a future post.

When we get down to call quality, I have to tell you, though, that on average, my Vonage calls sound just a little less robust than traditional land-line calling does. On about one out of four calls, I hear my caller or the person I am calling mention about some sort of an echo. Infrequently, I experience garble when I use my Vonage SoftPhone. I have diagnosed the problem and it seems to be one of a lack of system resources. I often have a dozen or so software programs open at a given time -- and frequently several instances of Word and Internet Explorer. That's a memory drain. Time for a new computer soon.

As to Vonage customer service, I have not had to deal with them in quite some time. I have heard complaints that at least the initial service level of Vonage support is of varying quality and varying understandability. Fortunately, for Vonage users, there's a viable alternative -- the non-Vonage affiliated, Vonage Forum. With some 27,000 registered users including some real brainy ones, you can almost always get your question answered there. And answered for free, without having to remain on hold like you do with Vonage's customer support.

Next column, we'll explore the appeal of VoIP to the enterprise. We'll parse the results of a just-released study that treats the issue in depth.

Posted by Russ Shaw
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Using VoIP from your existing phone

12 MAY 2006 16:48 EDT (20:48, GMT)

In today's post, we will talk about some of the basics you need to know before you sign up for the type of VoIP service that, with some additional equipment, lets you make and receive VoIP calls over your existing service.

In VoIP, phone calls are routed over your high-speed cable or DSL (Digital Subscriber Line) Internet connection. With few exceptions (such as "soft phone" services I will describe in a subsequent post later this week) you talk over your regular phone, which is hooked up to a PC. A broadband router, most of which cost less than $100, is attached to your PC as well.

As you may already know, the "Internet protocol" reference in "VoIP" describes the way in which packets (small groups of bits and bytes) are sent and received over the Internet. This packet transfer happens when you download a Web page or send and receive e-mails. The process also occurs with calls you make over the Internet, which are translated into packets of data and then re-interpreted back to sounds (and in some cases, video as well) at your recipient's PC.

There are a couple of drawbacks, however. If your cable modem or DSL service goes down, so will your VoIP connection. And although the technology is improving, VoIP services do not work well for emergency "911" calls.

Sounds expensive, but it isn't. In fact, most of the more than 400 or so VoIP-service providers in North America (which include some traditional phone companies such as Verizon and AT&T) charge either a flat monthly $19.95 to $29.95 fee for unlimited national and some international calling, or assess just a few cents per minute for each call.

The signup and setup processes for these services follow a common -- if not identical -- model. Before you get started, you'll want broadband Internet access. VoIP calls won't work over dial-up, because dial-up doesn't involve the exchange of Internet packets directly via the Internet, but through a phone line that connects to it. To put it another way, VoIP requires your phone to talk. If you are on dial-up, your phone modem will already be chattering away, making conversation just about impossible.

OK, so you have broadband. Now you are ready to get started.

First you, the prospective customer, should perform your due diligence by researching the various VoIP service providers and plans available in your area. Listings and reviews of these services appear regularly in the consumer technology press, as well as in the mainstream media.

If you identify a service you would like to sign up with, you can either call them directly or, in most cases, sign up via their Web site. There, you will be asked to input your zip code. If service is available in your city, you'll be taken through a series of screens where you enter your basic contact info, credit card data and preferred billing plan.

In my next post, I will describe the process involved in hooking up VoIP service. Then, in the post after that, I'll compare several of the leading VoIP services -- most of which I have tested extensively.

Posted by Russ Shaw
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Everything you need to know about 'hooking up' (VoIP, that is)

11 MAY 2006 18:38 EDT (22:38, GMT)

In today's post, we'll discuss the general procedure involved in hooking up VoIP service from the point after you complete your order on the VoIP service provider's Web site.

When you complete the sign-up process, you will be given a new phone number. This number will not replace your existing number given to you by your local phone company. It will simply be the one offered by your new VoIP provider. Your new number will work with your existing phone just as your old number does. For example, when someone calls you at your new VoIP connection, your phone will ring just as if your caller dialed your existing phone number. It's just that when the call travels to your phone, it will come to that same phone over the Internet, not that copper wire connection.

Most service providers will offer you a broadband router. If you already have a router provided to you by your cable company, you are probably OK. Still, some newer routers come with enhanced functionalities. If your router is two years old or more, consider replacing it with a router sold or provided by your new VoIP phone company.

A few days or at most a week after you complete your order, your VoIP equipment will arrive at your home or office. In the box, you'll find a broadband router, a power adapter for the router, along with a phone cable and Ethernet cable. Of course, you'll also see a standard welcome kit. The kit usually comes with an installation manual for your router and cable, an installation CD that helps you configure your VoIP setup, as well as cards that illustrate how to sign up for extra services such as voice mail, caller ID, call waiting, call forwarding and enhanced "911" emergency services. Unlike more familiar phone companies, most VoIP providers offer these provisions for free or for a very inexpensive price.

Now is time for the installation process. For most VoIP services, the setup procedure is fairly standard and involves the following steps:

  1. Connect one end of your Ethernet network cable to one of the numbered ports on the back of the router. Connected the other end of your Ethernet cable to the Ethernet port on the back of your PC.

  2. Hook up one end of your phone cable to the back of your phone and the other end to the phone port on the back of your router.

  3. Power your cable modem back on, leaving your PC powered off (for the moment).

  4. Connect your power adapter to your broadband router's power port.

  5. Plug the other end of the power adapter into a nearby electrical outlet. When you made the connection, the power LED (Light Emitting Diode) will light up.

  6. Turn your PC back on.
For each service I tried (and will review in the next post), my next step was to go to their Web site and complete the signup process I started when I first ordered my equipment. This meant configuring the router I had just installed to work with the service I was signing up for. The procedure involved entering a default local IP address (such as, for the Linksys router Vonage sent me), and then parading through several screens where I entered a username and password, and then selected an IP address automatically through my current Internet Service Provider -- in my case, Comcast.

Posted by Russ Shaw
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Choosing a VoIP provider

10 MAY 2006 16:09 EDT (20:09, GMT)

Business users who are considering signing up with VoIP services essentially have three general classes of options. These options are:
  • Contracting with an enterprise-class VoIP service (such as Level 3, Global Crossing and Voxeo). These are carriers that often work in partnership with providers of VoIP equipment you will be using at your office or in your network, such as those of Cisco and Avaya.

  • Signing up with a business-class flavor of VoIP service offered by brands more familiar to the consumer VoIP space. Examples include Vonage, SunRocket and 8x8 (more commonly referred to as Packet 8), as well as VoIP offerings from broadband access providers such as Comcast, Verizon, AT&T and Earthlink.

  • Working with newly enhanced PC to PSTN (public switched telephone network) offerings from companies whose voice transmission roots were in the computer-to-computer space but have recently expanded to allow calls to and from their users to standard phone numbers. Examples of these include Skype, Yahoo Messenger with Voice and Google Talk.
I will be writing detailed entries on each of these options. Since the purpose of today's column is to provide an overview, though, let us briefly go over the advantages and disadvantages of each VoIP provider option.

Enterprise VoIP carrier -- This is the most expensive option, but by far the most scalable as you grow your business. In most cases, these VoIP calls travel over proprietary networks rather than the public Internet. Networks are configured to be compatible with sophisticated VoIP analysis and measuring tools. Most of the VoIP services carried over these networks are also compatible with IP PBX solutions that provide an unsurpassed level of call-control, call tracking and caller management. Service agreements with this level of provider almost always have QoS (Quality of Service) written into these contracts. Plus, you get a level of direct, on-premise expertise that few of the consumer grade carriers offer.

Business-class consumer carrier -- These calls are highly likely to travel over the public Internet, and as such are limited by the degree and speed of Internet connectivity at any one time. Because of this, ironclad, true QoS support is uncommon. Tech support is often limited to help desks, often situated thousands of miles away from your premises. Although tech support offered by such providers has been improving due to enhanced remote diagnostics, you don't get the same degree of hand-holding an enterprise VoIP carrier offers. The advantages are transportability -- such as when you move your office -- and, of course, price.

PC-to-PSTN carrier -- Great for consumers, these products are most certainly the least robust and dependable of options available to the enterprise. Nevertheless there are a definite advantages besides price. Some of the software used in these networks has been architected to offer video or audio conference calling for dozens of participants at rates dramatically lower than a standard conference bridge. These calls can be set up with virtually no lead time. Since these carriers are PC-based, they require far less hardware, an advantage for crowded or under-powered office environments. The software that powers these offerings can easily be loaded onto notebook computers, allowing for your mobile workforce to be integrated into your VoIP setup.

Posted by Russ Shaw
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So tell me: What is VoIP, anyway?

09 MAY 2006 20:28 EDT (00:28, GMT)

Today, let's discuss what VoIP (Voice over Internet Protocol) is, and how the equipment you use in a VoIP call helps the technology work for you.

The basic concept of VoIP involves sending and receiving calls over the Internet or any Internet Protocol (IP) network. This is accomplished by converting voice traffic, such as the words you say, into data packets.

These data packets are then routed over the Internet in the same way as other data- -- such as this article -- are. When these data packets arrive at their intended destination (such as the person you are calling), the communications equipment at the other end of the call takes these data packages, reassembles them and then converts them back into your voice.

There are basic types of ways to make and receive VoIP calls.

An Analog Terminal Adapter (ATA) performs the data packet translation I have just mentioned. With an ATA you connect your existing phone to your computer or even to your Internet connection. You then sign up with a service that is ATA-based. You usually also get software you install on your PC that enables you to control various functions of your call setup (such as number of rings callers get before voicemail kicks in). Setup is quick and generally quite uncomplicated.

An IP phone physically resembles a regular phone with buttons, a cradle and a receiver/handset. But there's more here under the hook. Your standard phone comes with RJ-11 phone connectors, but your IP phones have an RJ-45 Ethernet connector. This is used to connect your phone directly to your router. Now, we are even seeing Wi-Fi IP phones that can pick up a Wi-Fi service signal and use that to connect.

Computer-to-computer VoIP services involve software from a VoIP provider, an account with that provider, as well as gear such as a microphone, speakers and in most cases, a headset. Many of these services are integrated with instant messaging utilities, enabling you to send and receive IMs at the same time you are talking over your VoIP connection. These calls are either free to other subscribers of the same computer-to-computer service, or are just two to three cents a minute to many nations.

Posted by Russ Shaw
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This blog originally appeared on TechTarget's Expert Answer Center as a post in Russ Shaw's VoIP blog. Russ served as the on-demand expert on the Expert Answer Center for two weeks in May, during which he was available to quickly answer questions on Voice over IP as well as to write daily blog entries. Keep an eye on the Expert Answer Center for topics that could help your IT shop.

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