 Implementing VoIP - Important SMB Considerations
Written by: Curtis S. Burnside, CCNA, CIW - Jul 23, 2008
Many small and midsize business owners have heard about voice over IP or VoIP as a great way to save money on both local calling and long distance charges as well.
There are a number of issues to consider when looking at implementing VoIP, not the least of which is network reliability and assuring that telephone calls are close to "toll quality" and not being dropped or callers being cut off.
Because VoIP calls utilize a data connection or Internet connection rather than the public switched telephone network (PSTN) these calls are at the mercy of what many times is a best effort network. Business owners and customers alike who have become used to toll quality calls utilizing the PSTN are many times gravely disappointed with dropped calls, perhaps sounding like Darth Vader from time to time, as well as unconnected or misdirected calls.
The major migration issues for a small to midsize business then surround:
1. A quality network or Internet connection assuring not only uptime reliability but also voice clarity.
2. Service level agreements (SLA) that assure the service provider selected will deliver on their promise.
3. Coordinating existing telephone equipment into the VoIP initiative.
4. Assuring a clear migration or integration path for remote workers and additional branch offices.
Let's take these items one and a time.
A quality network or Internet connection -- although a small office of five handsets or less might well be served utilizing an ADSL or cable modem Internet connection, these types of small, best effort connections will be ill-suited for a larger deployment, primarily due to network congestion, half duplex and ISP oversubscription issues.
Many people don't realize that just because you have an advertised "massive bandwidth" downstream bit rate like 3, 6 or 10 Mbps, this doesn't necessarily mean that the quality of the connection is adequate to support real-time upstream requirements for protocols such as VoIP.
In a general sense what's generally needed is an adequate sized Internet pipe from a quality service provider that provides for either an SLA or at least an end to end QOS metric. This then assures the voice packets arrive in order and as close to real time as possible. It should be noted that even with a quality provider with its own Tier 1 IP backbone such as AT&T, Sprint or Qwest that the Internet is a public place rife with latency and delay.
Service provider selection in VoIP network design are of tantamount importance when implementing Voice Over IP.
So what's generally needed for larger offices is to select a quality 4 wire, full-duplex T1 or better class of service preferably from a tier 1 provider or a resale of such.
In the event the business has multiple branch locations and is hoping to the erase long-distance toll for intra-company calling, and might also require a high-speed IP backbone for its own intra-company data initiatives, then a telecommunications broker or service provider should be approached to design a private IP backbone, which are surprisingly affordable in this day and age. The customer business can then leverage this backbone for other high speed data traffic such as SQL applications, e-mail, Internet browsing and file transfers etc.
SLAs Service-Level Agreements generally have four major components with regard to voice over IP initiatives. Unfortunately many service providers do not provide a "jitter" SLA metric which can be of increasing importance depending on the class of service desired and the number of users and business locations.
Let's then look at the acceptable tolerances for measuring the SLAs required for an SMB VoIP initiative.
Latency -- measures the time it takes for IP packets to travel one way between points in the service providers network, generally measured in milliseconds, this metric should be less than 50ms, with superior service being less than 40ms.
Jitter -- measures the difference in time it takes for two IP packets to travel between points in the network. If provided, this metric should be less than 5ms – 10ms, with superior service being less than 2ms.
Packet loss -- measures the number of IP packets dropped as they traverse the service provider's network. This metric should be less than 1% with superior service being less than .5% of the total packets.
Meantime to repair (MTR) -- this is the time period the service provider commits to repairing a downed or impaired circuit. Obviously extremely important when the majority of your voice traffic is being carried via VoIP. Most quality service providers should be able to commit to a four hour or less MTR. Additionally, provisioning options which allow for a “fully managed router” or VoIP gateway on your T1 connection are very affordable and allow the service provider to constantly monitor the status of the connection, this allows the provider to initiate repairs even when you as a customer may not be aware of a downed or impaired circuit condition.
Coordinating Existing Equipment & Assuring a Clear Migration --
Depending on your current equipment configuration you may or may not desire to keep your equipment. The choice of whether to use your existing equipment, purchase IP enabled equipment or perhaps utilize a "Hosted PBX" solution will be a major determining factor in your ongoing migration plan and quality of service.
Suffice it to say that almost all quality service providers can deliver the required network access component and managed customer premise equipment (CPE) to allow most businesses to utilize their existing telephone equipment. Unfortunately this many times includes digital to analog conversion which if done often enough within the network provides for decreased efficiency and voice clarity.
What many business owners don't realize are the tremendous advantages surrounding utilizing a fully managed or hosted PBX service. From disaster recovery and redirecting calls on-the-fly to allowing for rapid deployment of remote workers or the ability for traveling workers to take their phone with them, this option should be looked at by any business considering VoIP.
In the long run, as with any business decision it is always best to consult a professional. Especially if professional services can be had with no additional cost and will result in the most cost-effective and best in class solution being implemented.
Firms such as ours provide professional Certified telecom consultancy services everyday and deal with complex offerings on regular basis. In a market space where service offerings and service providers come and go, we keep track of service providers, the offerings and pricing to assure a knowledgeable business decision. Feel free to give us a call any time at 1-877-566-5600 or visit us on the Web at www.TheTelecomBroker.com
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