Ever since April, when the legal barricades on VoIP were lifted by the government, Indian communications market has been inundated by VoIP products and solutions, with vendors of all hues promising instant nirvana. While the hype surrounding IP telephony will take some more time to die down, it is time for Indian enterprises to see through the clouds and ask the most vital question —what is in it for me?

For starters, it is important to pare the fat. That, one can do by grasping the differences between all the jargons being bandied around. If you remove the veneer of technical wizardry surrounding this new technology on the block, it is easier to understand that IP telephony means much more than VoIP. The technology that allows voice to be carried over an IP network is called VoIP. To put it simply, IP telephony is an application with VoIP as the underlying technology.

Who Needs It?
Although there is no dearth of VoIP products and solutions in the communications market, all of it comes with a staggering price tag, making it beyond the reach of enterprises devoid of deep financial pockets. Then who needs it? The answer is simple: enterprises with sizeable amount of geographically spread branch offices. This is primarily due to the fact that, as any vendor would tell you, VoIP is all about saving on long-distance call costs. So if you are someone trying to find ways to cut your communications costs, VoIP is the answer. Which is not to say that this is the only benefit associated with VoIP. Other strategic and financial benefits include reduced total cost of ownership, bandwidth efficiency, and operational simplicity.

"The payoffs are clear—big savings and new revenue streams—but the cost of making the wrong choice can be very high. VoIP can transform a customer’s network from a one-service overlay infrastructure to a single, multi-service IP-based network that delivers integrated voice, data, video and multimedia services," says Ravi Chauhan, V-P (enterprise solutions), Nortel Networks.

According to him, voice over IP in the enterprise converges voice with exciting new applications. Businesses get new services such as unified messaging, follow-me mobility and Web-based call center capabilities. And the line between the voice network, internet, e-mail, and fax blurs.

Another major benefit of VoIP is that convergence helps a business to reduce infrastructure, staffing and facilities cost. "The major business impact of VoIP lies in the fact that it leads to reduced total cost of operations," opines D Dhinakaran, deputy general manager, Avaya. A converged network can reduce investment in multiple network infrastructures to a single IP-based network. An organization will no longer need to invest in a dedicated PBX or maintain a separate ISDN network for its multimedia needs. The migration to a single network will significantly reduce the complexity of enterprise’s network infrastructure, leading to easier administrations, he adds.

Then there is the ever important factor of employee productivity. VoIP means that they are no longer confined by geographical locations. IP phones would work anywhere on the network, even over a remote location. "Arguably, the most significant benefits of a converged network can be derived from the range of applications that enable organizations to increase employee productivity by streamlining administrative tasks, and allow them to focus on activities that create new revenue streams," says Anil Nair, director (sales), Tata Telecom.

Though there are a host of benefits associated with VoIP, there are issues and challenges for enterprise network convergence as well. Are Indian enterprises ready for network convergence? Yes, says Ravi Chauhan. He thinks that there is clearly a business case for deploying VoIP solutions in Indian enterprises that are geographically spread out. "Given the fact that 70 percent of a company’s communications costs are in the form of inter-office STD bills, VoIP makes economic sense."

Deployment Strategies
It is crucial that enterprises handle the convergence issue with clear goals in mind and go through careful planning and with experienced partners. There are two methods for deploying VoIP in your enterprise. One is the evolutionary approach—gradual migration by IP enabling. This implies adding IP telephony gateways to existing PBXs, which enable them to interface with IP phones and soft phones connected to local and remote LANs. This approach helps enterprises to protect much of their investment in digital and analog phones, and the corresponding line and trunk circuit cards.

A revolutionary strategy involves throwing out everything you have and starting from the scratch with pure IP products and solutions. Most of the vendors provide both these choices to a converged network and it is very unlikely that Indian enterprises will go for the IP-centric method since they have considerable investment made into existing PBXs and it makes no economic sense in eliminating those before depreciation.

There are some key consideration that one needs to take into account for a proper deployment strategy. A single network may mean lower network management costs, but it also mean a single point of failure for the enterprise. Moreover, the requirements for voice are more stringent than most data applications. High latency—the time delay on traffic—is less acceptable with voice than with data traffic. Thus, enterprises will do well to measure and characterize end-to-end latency and packet loss for IP telephony traffic class across the network. Whether the results are acceptable or not depends on the quality of voice expected and the amount of bandwidth usage. Besides, IP phones introduce the complexities of telephony and high expectations of 99.999 percent uptime. IP phones require a separate source of power, which means that if your electricity goes out, so does the communications capability for the entire enterprise. Not like the good old TDM phones on which you can count on in any time of emergency. Although 99.99 percent uptime is an acceptable target for converged network availability, it can be a challenging goal for many LAN/WAN implementations.

Choosing a vendor with both voice and data experience is another important factor, according to Dhinakaran. "When evaluating potential vendors, attention must be given to the level of experience and support (including remote monitoring capabilities) available for these new technologies from vendors and their channel partners."

To determine the ability to carry voice over long distance, one should examine WAN utilization before adding voice. According to Nortel Networks, to do this, the WAN should be running no more than 85 percent utilization at peak traffic. The acceptable percentage of voice traffic should be engineered for each transmission link in the IP network, and should be estimated based on telephony usage of the particular enterprise.

QoS—Treading on Thin Ice
One hot issue that is associated with VoIP is quality of service (QoS). Even in a well-managed IP network with adequate bandwidth and good latency characteristics, its is necessary to implement QoS strategy to prioritize traffic for voice, data and video, according to Avaya. This may require the replacement of some legacy data network elements with newer elements that implement the appropriate QoS standards. There are many QoS standards like DiffServ, RSVP, 802.1P and Q MPLS. Note that QoS monitoring and management increases in complexity as the LAN network interconnects with WAN and other public IP networks, such as the Internet.

What forms of QoS work best for VoIP? The expedited forwarding (EF) DiffServ, feels Ravi Chauhan. This provides low latency, high-priority service that is ideally suited for VoIP. The EF behavior is implemented with a high emission priority and lowest discard possibility. Basically, in order to achieve the behavior, network node must ensure that the EF traffic has the lowest possible delay, jitter and loss since is the service is attempting to emulate a virtual leased line over an IP network.

Security—Loose Ends
Other problems with VoIP as it exists today revolve around the issue of security. Currently, encryption and authentication of user access is only a recommendation by H.323. What this means is that any H.323-aware user can tap into any conversation on the system. Telephony over IP is relatively secure when it is transmitted over a switched LAN or private IP WAN, but it is open to any one with the right equipment if transmitted over public data networks such as internet or LANs configured as shared broadcast zones.

As of now, VoIP is permitted only among closed user groups, and the government is yet to lift the ban on interconnectivity with PSTN, which might prove to be major stumbling block in the adoption of VoIP. Interoperability among vendors is almost extinct, which could pose the next major hurdle as some vendors don’t follow the open standards. "Companies today have more heterogenous or mixed vendor networks and systems than ever, and that is only going to increase. Using open standards helps ensure interoperability with existing and future open standards platforms and applications," says Anil Nair, presenting the case for open standards. Open standards will allow companies to design networks and systems that support the unique communication needs of businesses.

There are great many advantages that VoIP brings to the table for enterprises, albeit with pitfalls. The packet-switched road delivers reduced capital and operational costs, and dramatic efficiency gains. On the other hand, it also throws up significant challenges. Deploying VoIP can clearly be complex and dependent on specific enterprise situation. Make sure to understand the goals for convergence, and current and future user needs before you brace yourself for VoIP. And remember that the power of IP does not lie in phone features on the IP network, but in new applications and features that do not exist in the existing phone network.

MT Jeevan