Considerations for voice and video over IP

What should customers consider if they want to run voice and video over their Internet service? What are the additional issues to consider when choosing DSL or a T1?

-- Stephen Tunney

If you are looking to run some type of VoIP connectivity across your Internet connection to either augment or replace conventional phone service, you first need to determine how much bandwidth that each phone call in progress will require. Also see where your carrier has points of presence installed and what type of bandwidth that they have in place to service those remote nodes.

You will also need to look at your Internet provider's own Internet connectivity. See if they will work with you on telling you how much Internet connection they have and how much competition that you have with the ISP's other customers for bandwidth. Some VoIP providers will talk about their use of quality of service (QoS) techinques to help control bandwidth to make sure the bandwidth is available when needed for proper call quality. Keep in mind that maintaining QoS is almost impossible to do over the Internet as all the routers between you and the end point of the connection would have to agree on how to control how the bandwidth for a given service is used. It will probably be a long time, if ever, before I think we can expect this possibility to exist.

Running video over your connection can present similar challenges. You will need to carefully define what you are trying to do with the video - teleconferencing, streaming video to customer/Internet users, etc. Talk with the providers of the equipment that you are considering using for this task to see what particular recommendations that they have for getting the best quality of video for the bandwidth that you will have available.

Although running QoS over the Internet isn't a reality today based on the ISPs that I have talked to, there is another option that mighthelp. Packeteer sells a product that functions as a packet-shaping device that will give you some level of control over how your bandwidth can be used. While you can implement QOS on your local network equipment assuming that type of functionality is available with what you have, that wont help you once you reach the Internet. The network equipment that you use might have additional functionality.

As to choosing DSL or T1, I would also suggest considering a cable-modem connection. Depending on the type of Internet providers available in your area, there may be wireless options and potentially fiber connectivity that might be able to get you even faster speeds. Look at the costs for each and compare that with the ability to get increased Internet connections when your growth warrants it. In evaluating the different connectivity options, have the potential provider specify the bandwidth speed for both upload and download. When looking at services such as VoIP or video, knowing your connection speeds is very important in being able to plan out how best to use it. Although my response to your question has been broad, as you find out more information on how you want to use the services you mention and your expectations on how you want to use them, you will be able to get a better idea on what type of connection will work best for you. Put your prospective vendors to the test and have them provide suggestions and guidance on what connection will work out the best based on the equipment you will be using.

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