Frequently Asked Questions (FAQ’s) about Deploying IP Voice Telephony in the Customer Premise What needs to done and what sort of assessments should be made on the LAN (local area network) and WAN (wide area network) to know if VoIP is feasible? What has to be done to prepare for it?
Most companies will say that their network will support VoIP, but few of them are actually capable of running it as it sits today. Even though they have built it for VoIP, there has been no voice traffic on it, so most companies should run a “network-analysis” to determine the MOS (mean opinion score), or other tests that measure the amount of data traffic can be handled, in order to ensure successful implementation. The LAN infrastructure may need upgrading from standard data hubs to more sophisticated L2SW (Layer 2 switch) technology. The network must include end to end QoS (quality of service) which ensures voice traffic has priority over data traffic. Special consideration must be given when deploying VOIP over a WAN to ensure that all network hops provide QoS. Learn about CAT 6 Data Cable!
My current networks are a mix of PBXs, routers, and data switches from multiple vendors, do I need to migrate to a single vendor solution to get end-to-end voice QoS?
No, not necessarily. Disparate vendor infrastructures are pretty standard. The requirement to migrate to a single solution at this time is not completely required, as the standards for IP telephony are in place and being readily adopted by most manufacturers. There may be a limitation with the complete transparency of features between sites using multiple products, but basic station to station dialing across a disparate network is standard.
What needs to be known about power and “power over Ethernet (POE)” options?
There are two types of POE. The layer 2 switch can provide power or the power unit sits mid-span between the switch and the phones. The first is a logical choice allowing centralized battery backup in case of loss of power. The mid-span power unit would be used if a customer has a large investment in the current switches and does not want to replace them. Providing local power to the station telephone is an alternative. In case of power failure, stations will cease operation unless a universal power supply (UPS) is deployed to each station.
Convergence of voice and data networks can make communications more vulnerable (single point of failure - SPF, opens “voice” to data network security issues); what can be done about that?
Allowing voice on the data network will subject voice packets to the same vulnerability that data packets are subject to. Regarding system security, non-Microsoft Windows® operating systems like VxWorks® reduces the potential for email bourn viruses and random hacker attacks. Microsoft Windows® based systems face a greater potential for viral attacks and proper safeguards should be taken to protect the voice infrastructure. Additionally, by utilizing a converged platform, a customer has the best of both worlds in that some phones can be delivered via LAN and others delivered via TDM dedicated cable runs. In this case, should any attack breach the network, TDM phones will continue to operate.
Can a voice/data IP network be as reliable as traditional circuit-switched voice networks?
PBX Time Division Multiplexed (TDM) technology has advantages in single point of failure environments because the dedicated operating system (OS) is on static RAM, ROM and compact flash memory. Pure IP solutions require additional or multiple pieces of equipment to make them as reliable, i.e. redundant servers and processors which drive up cost. In many cases, however, converged IP solutions prove to be the most reliable IP communications alternative. The hybrid or converged IP-PBX’s using TDM and IP architecture is the best of both worlds.
What are the implications of adding other IP applications and media (video, wireless, etc.) to VoIP and IP telephony architectures?
If adequate network resources are available (bandwidth, processing power, memory), these are welcome additions to your network. This is especially true in LAN environments where bandwidth is plentiful. However, in WAN applications, the availability of proper bandwidth is a major consideration and proper WAN testing should be done before deploying these applications.
Are there third-party applications that can be used with VoIP architectures and platforms?
Like any traditional TDM PBX, VoIP systems can be integrated with many third party applications. However, the premise that Microsoft Windows® based VoIP systems are “plug and play” with any Microsoft Windows® based application is not true. Because VoIP systems have different features and the underlying technology is varied, integrating third party applications may require some customization by either the VoIP manufacturer and/or the application provider.
What tools (APIs, XML, et. al.) are available to allow IT staff to add or integrate custom applications to an IP telephony architecture?
The number of integration options available will vary by manufacturer. Some common industry protocols used are TAPI, CSTA and Active X. Often the tightest level of integration is the raw event code information from the VoIP PBX. As in the case of application integration, some modification may be required to successfully integrate third party applications. The VoIP manufacturer or value added reseller may offer services that could perform this integration.
What is the identifiable compelling or “killer” application(s) for VoIP for my environment, both now and in the future?
The most compelling “killer application” is the one that solves an acute need for an end user. The most common applications are reduction in network costs to connect sites, better utilization of existing data network infrastructure (the potential to eliminate the separate voice network), managing moves and changes internally, connecting remote teleworkers and connecting businesses more efficiently with their customers.
How does one get a handle on identifying and understanding the factors that comprise the Total Cost of Ownership (TCO) of VoIP?
First and most commonly are the costs associated with preparing your data network for voice traffic. Additionally, other factors such as maintenance contracts, cost of time and material maintenance, software upgrades and equipment warranty should be considered. These factors are then compared to the productivity gains and operational expense reductions achieved by using VoIP.
IP telephony is a dynamic area with frequent changes in technology; if we go to it now, what assurances are there that our investments won’t be lost or stranded in a couple of years?
Vendors have different approaches to IP telephony. The best way to guard against premature obsolescence is to make sure the equipment provider has a history of supporting and upgrading their products in lieu of abandoning them for different technologies. Users should look to the established telephony vendors who have traditionally approached the implementation of telephony services to last 7 years or more. By bringing that knowledge into the data arena, they will be the ones who make sure the investment is long lasting. By utilizing traditional telephony manufacturing and design processes, rather than using PC’s or servers for call processing, end-users can expect to avoid the need of replacing server infrastructure every 3 to 4 years.
Many IP telephones, although presumably very functional, are very expensive; what suggestions or alternatives are there?
In many cases the prices of IP telephones will continue to fall. Lower cost SIP endpoints are making an impact into the market as well. It is also possible to use a “soft-phone” which could provide all of the standard desktop phone capabilities on your personal computer, and forgo the need for an IP telephone, for a fraction of the cost. Additionally, lower cost TDM phones can be used on converged systems for applications that do not require IP technology.
Migration to VoIP could be accompanied by losses in traditional PBX functions/features; we’re not prepared to compromise our processes and operations, what can be done about that?
Some IP Telephony technology is capable of delivering the same feature functionality being used in traditional TDM systems. This is especially true with regard to converged or hybrid systems. These hybrid systems typically port over all or most of their TDM features to the new system.
Given the lack of sufficient rationale we’re considering not migrating to VoIP, how long will legacy PBXs be supported and maintained?
Most industry forecasts indicate the sale of IP based systems will surpass TDM systems by 2007. If the decision not to migrate is based on keeping an existing TDM solution in place, then the manufacturer should provide support for the life of the product. If you must invest in a new TDM system today, then your best hedge against obsolescence is to ensure the manufacturer has a migration path to VoIP that will utilize your current equipment investment.
Is a pilot site or “proof-of-concept” recommended for organizations first migrating to VoIP?
Provided your network has been fully tested to ensure that the infrastructure will support VOIP, converged IP products may offer a similar level of reliability and feature functionality as TDM products. The real question becomes, how does VoIP meet my application needs? With converged products customers have a choice of IP only, TDM only, or both. If it makes sense from an application standpoint to “go all IP,” there is no reason to fear provided the proper due diligence has been performed.
Key benefits of convergence are economies and simplifications due to one multipurpose IP network (ease of moves, adds, changes, staff reduction, etc.), how can this be demonstrated?
Historically, voice and data networks have existed as separate infrastructures within a company. Typically, each of these networks also had dedicated staff managing the day-to-day operation of the network. Adding voice to the data network has allowed many companies to completely eliminate the dedicated voice network. This in turn has eliminated the requirement for specialized staff whose sole purpose was the management of the independent voice network. In a converged network, IT staff is typically trained to administer both the voice and data applications, as well as the network infrastructure. Since the converged network is standards based, moves and changes of phone equipment has been simplified to the point where a network administrator simply has to plug a phone into a wall jack when moving equipment from one cubicle to another. In a traditional TDM system, this same move may require complicated programming and cross connections that would likely involve an expensive service call.
How can the capabilities (and dial plan) of HQ be extended to branch offices and work-at-home employees? What is needed at the sites?
Solutions vary, ranging from extending single or multiple IP handsets to remote individuals or small branches. In that case, it’s typically just the cost of the IP telephone, an IP connection and a VPN router to facilitate the same IP-PBX features as those in the main office. When larger solutions are needed “campus” type applications allow systems to be connected and operate transparently. In this case a virtual private network (VPN) is required as well as compatible VPN routers. In either case end-users get to share the same voice mail, use the same outside lines and in some cases see real cost savings in reduced central office line charges.
What sort of training in convergence/VoIP is recommended for my organization? How do vendors/suppliers train and certify their sales/support people?
The feature functionality on VoIP phones may be similar to traditional PBX phones. Specified VoIP training is required in most cases for vendors and suppliers. If the vendor is a traditional TDM reseller they will need training on data networks. If the vendor is from the IP space, then their training would center on voice applications. Look for manufactures that require their dealers to be sales certified and technically certified on the product. Products that say no technical training required should raise a “red flag” in your decision process.
Voice server operating systems range from Microsoft Windows ® to more real-time capable UNIX and Linux variants, and others such as Sun Solaris, what are the implications to users? How often are software releases updated?
Although most operating systems are deemed reliable you should look for one that is designed as an operating system for telephony applications verses a “general purpose” operating system. Microsoft Windows® is designed to operate with “every” application and therefore has lots of overhead and code added that has nothing to do with telephony applications. In the case of Microsoft Windows®, major updates can be expected every 12-18 months. UNIX, Linux, Solaris and others may extend 2 years or more before major updates.
SIP appears to be growing in importance; is support of SIP important in selection of potential VoIP solutions? How are vendors/suppliers handling evolving VoIP standards in their product/service rollouts and support policies?
SIP is open-ended and was created to be dynamic. The vendor you are choosing today should be supporting SIP in their product today. SIP capabilities will allow features and functions to happen more easily and efficiently. SIP is also an evolving standard which means many new capabilities will be supported in the future. Many telephone companies are offering dial tone via SIP trunks, as an example.
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