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Speak Easy

The VoIP market is set to explode once the telecom sector opens up and IP Telephony is legalized in April 2002. Some enterprises have already deployed this technology and are leveraging its benefits. by Brian Pereira

AN e-mail we recently received read:

"Save upto 90% on your ISD telephone bills, call from your Internet connected PC. Pay in Local Currency. Available all over India. Make Worldwide PC-to-Phone calls to Landlines."


Packet Switching: A network/technology in which digitized information from multiple channels is statistically multiplexed into packets and carried as and when required.

VoIP: The enabling technology for IP Telephony and Internet Telephony. It indicates that voice is digitized and converted into packets and carried over IP.

IP Telephony: Telephony application using VoIP technology over private IP network which delivers QoS.

Internet Telephony: Internet Telephony specifically refers to dependence on the public Internet to route calls, as opposed to IP telephony, which uses dedicated IP networks. QoS cannot be assured over Internet. VoIP call control Protocols: H.323 (an ITU-T standard), SGCP, IPDC, SIP (Session Initiation Protocol)

Acronyms: LEC - Local Exchange Carriers IXC - International Exchange Carriers ITSP - Internet Telephony Service Provider FSP - Fixed Service Provider ISP - Internet Service Provider PSTN - Public Switched Telephone Network PBX - Private Branch Exchange CUG - Closed User Group NLD - National Long Distance ILD - International Long Distance

A message of this kind reminds us of a not-so-new way of communicating that's about to create a maelstrom in the Telecom sector. If technology like Voice over IP (VoIP) and applications like Internet Telephony or IP Telephony (See Glossary) were just alternative ways to communicate, that wouldn't be reason enough for enterprises to embrace them. So when computer enthusiasts started making "free" calls from their PCs to other PCs or phones back in 1999, the corporate world watched in interest and thought earnestly about implementing this on their own internal networks, (imagine the cost savings on inter-branch telephone calls). Of course, the plethora of new applications also prompted many to experiment with various VoIP solutions.

Today, VoIP is used (legitimately) in close user groups (CUGs), within corporate LANs/WANs. Regulations do not permit enterprises to route IP-based calls through traditional PSTNs (See story on page 26 : VoIP - packaged voice and more), and ISPs are not allowed to offer Internet Telephony services. So for now VoIP is used in a limited way. However, the VoIP market is set to explode once the NLD/ILD space opens up and Internet Telephony is legalized in April 2002 (See story on page 24 : VoIP set to explode as Telecom opens up).

"The Indian market currently has a considerable penetration for VoIP in the Enterprise Closed User Group, with almost 70 percent of enterprises deploying the technology on their WAN backbones," says Swapan Johri, General Manager, Enterprise Solutions, HCL Comnet. "With the opening up of the NLD/ILD space, we can expect a big surge in the VoIP and the Soft switches (software switches) market. However, what needs equal consideration is the fact that the supporting technologies should also provide high QoS (Quality of Service) for voice services, as well."

Soft switches are responsible for call-control functions such as call routing, admission control and connection control. Because of their increased capacity and space saving feature, soft switches are replacing old Class 5 switches on traditional PSTN networks.

Until now, Indian enterprises have been experimenting with all kinds of solutions in an effort to upgrade data networks for voice. VoIP has been implemented on Frame Relay, ATM and Ethernet networks and there have been attempts to interface data networks with PBX systems.

"Enterprises generally deploy new products quickly. They have implemented all kinds of solutions—IP-PBX, existing PBX, traditional PBX. We see it becoming more complex for enterprises to grow their networks as Telecommuting increases and more branches are added to the network," says Enis Erkel, VP-Carrier VoIP, Asia Pacific, Nortel Networks. "Most CIOs are overloaded looking for solutions to simplify their networks and management."

But the road to VoIP hasn't been smooth.


There have been many technical (and political) barriers and growth has been slower than expected. All along the main impediments to growth have been government regulations, high-costs, vendor interoperability and lack of awareness.

As of now, enterprises need to have separate networks for data and voice communications. And those implementing VoIP need to have a separate network for internal communication (VoIP in CUGs) and external calls with the rest of the world (PSTN voice). "Since interconnection (between PSTN and data networks) isn't permitted, a dual parallel infrastructure has to be created thereby increasing costs," says HCL Comnet's Swapan Johri.

An industry consultant says VoIP was slow to take off here because of restrictions such as connecting PABXs at the endpoints as well as those on interconnection of leased lines and PSTN lines.

"Getting leased lines and high equipment costs are also a hindrance," says Ketan Sanghvi, Managing Director, WANLANd Datacom (India). "While the government has mentioned that the restrictions relating to VoIP will be relaxed, we still don't know what will be the nature of these relaxations."

The other reason for slow adoption of VoIP is the adaptation of existing networks for voice.

"The existing networks have been predominantly built for data communications and are being leveraged to provide voice in the same infrastructure. The technology per se is evolving and has stabilized to a certain extent now," says Suresh Srinivasan, GM-Enterprise Networking Solutions, Ramco Systems.

Srinivasan adds that the bandwidth required for VoIP technology is higher compared to VoFr (Voice over Frame Relay), and existing network devices need to be upgraded to accommodate QoS features. "But these technical differences are reducing as vendors come out with products that address these problems in a very effective way."

Rajeev Mehta, Head-Business Acquisition, Tata net, agrees. "Although we are in the business of providing VSAT services, we found VoFR to be quite efficient, because satellite bandwidth (for VSAT connectivity) is expensive."

Cost has been the main reason for slow adoption of VoIP in the enterprise. While the technology offers many benefits and useful applications, CIOs ponder if the investment in infrastructure is really justified. Furthermore, now that NLD/ILD costs are being slashed, does it still make sense to send voice over data networks?


With VoIP calls (on internal networks) being virtually free, enterprises just need to make a one-time investment in infrastructure (to upgrade existing data networks). Connecting two locations on the WAN would require VoIP gateways and terminals (IP phones) at both ends of the link. Tata net for example, is offering such connectivity at just under Rs 2 lakh (two gateways and two IP video phones).

Jasjit Sawhney, CEO, Net4India, says Internet Telephony can help corporates bring down costs of ILD calls by as much as 40 percent.

Says Ketan Sanghvi of WANLANd DATACOM (India), "For the enterprise, there is a significant cost-savings if VoIP is implemented between various locations within and outside the country under current tariff rates. However, the benefits may vary with the costs (which currently are difficult to predict, given the potential for intensive levels of competition between the various long-distance players). If the cost drops substantially (which seems a little unlikely in the near future), the benefits of VoIP may not appear that attractive."

Internet Telephony is currently deployed in more than 90 countries. The cost-savings and applications are appreciated by enterprises around the world, and depending on how the Telecom sector opens up, that may soon be the case here too.

"Worldwide, on average, there is a 40-50 percent differential between the toll quality call rates and Internet telephony rates and the same can be expected in India," says Amitabh Singhal, Secretary, Internet Service Providers Association of India (ISPAI).

For now, IP telephony solutions are primarily being used by small and mid-sized offices whose voice traffic is typically supported by myriad technologies. "It is when IP telephony solutions scale for use in place of conventional private branch exchanges that corporations will realize significant cost savings in their network hardware," says Jangoo Dalal, VP-Channels & Business Development, Network Support Services, Cisco India.

Return on Investment

Apart from cost-savings, CFOs and decision makers also question the ROI (return on investment).

Says Debashish Mitra, VoIP Program Director, TCS, "There is a considerable ROI upon setting up a VoIP based service. Consider this: The Capital expenditure that is required for providing 'n' new services over traditional networks is a couple of order higher than that required to provide equivalent services over an IP framework. In fact, new IP-based frameworks make it easier to create new services and then execute the same with minimal investment and re-compiling."

KVSSS Gunneswara Rao, Director-VoIP, D-Link (India), has a similar opinion. "The return on VoIP infrastructure environment derives from reduced number of networks required, easy network management, freedom from proprietary legacy switches, lower long-distance costs, and improved IP-based services for customers and employees."

Evidently, the cost savings and ROI will be realized once enterprises actually deploy the technology and begin to use IP Telephony applications in business communications. The fact that many enterprises around the world are already enjoying the benefits and savings of this technology is reason enough to deploy it. Just take a look at how other Indian enterprises are using IP Telephony, and you'll speak easy about this technology.

The QoS factor

While VoIP technology does bring forth cost-savings and new applications, IS personnel question the quality of calls and ask if it can match that of regular PSTN calls. There are several reasons why quality of calls suffer. For one, data networks were not designed for voice, and latency isn't a major issue if the packets are purely data. However, if the packets represent video or voice, latency becomes a critical issue for transmission, and the time for packet delivery should be an absolute minimum. An enterprise user says that, with adequate bandwidth, the quality of calls (on internal networks) can match that of PSTN calls. However, there have always been QoS issues with Internet Telephony (routing IP-based calls through the Internet.)

"Quality of Service is an issue with Internet telephony as one does not have control over the Internet, since it is a public platform. But with IP telephony (that is IP-based calls on internal networks), QoS is not an issue, as one has control on the network," says Jangoo Dalal, VP-Channels & Business Development, Network Support Services, Cisco India. "The issue of QoS is not specific to India but worldwide."

The problem with Internet Telephony is that sound quality and coherence of the conversation is compromised. With Phone-to-Phone IP calls, the loss of quality is almost unnoticeable. However, with Phone-to-PC calls and PC-to-PC calls, the loss of quality is noticeable, especially with slower computers and slower Internet connection speeds.

"The quality of voice is affected by the Internet telephony software used, the processor speed, the compression technique and the level of congestion in the network," says Jasjit Sawhney, CEO, Net4India. "Then there are issues of latency (delay between packets), packet loss and jitter—variation in latency between packets. Jitter morphers are used to minimize the effect."

While end-users at home may tolerate latency and jitter (due to savings in long-distance communications), corporate users transacting business deals over the phone or speaking with peers abroad won't be so forgiving.

So what can be done to ensure QoS? What tools and techniques are available?

"To improve QoS you need adequate bandwidth, decongestion of network and a break up of network to carry voice and data separately," says Net4India's Jasjit Sawhney.

Since the same network carries data as well as voice, one encounters latency during peak periods of data transfer. While proper bandwidth allocation is one workaround to the problem, better voice compression codecs also play an important role.

"Generally, QoS is handled at the intermediate routers that can implement QoS protocols like MPLS, Diffserv or Intserv and COPS. Also, use of ITU specified (G.series) codecs at the endpoints help in increasing the quality of voice communications over a limited bandwidth," says Debashish Mitra, VoIP Program Director, TCS.

Venkat Kedlaya, Managing Director, Convergent Communications India, feels there will always be problems with Internet Telephony since the Net cannot guarantee a packet delivery method. "To minimize the problem, an ISP offering VoIP should implement good traffic and bandwidth management techniques."

Implementing the right tools/algorithms/codecs can ensure QoS, asserts Ketan Sanghvi, Managing Director, WANLANd Datacom (India). "There are sophisticated voice-compression algorithms and better call management techniques built into billing and call management software."

Another expert opines that routers should be configured to assign priority to voice packets and delay the passage of data packets. "This can be done on a private network, but it will be a challenge to do this on the Internet," he says.

Then there are proprietary QoS standards developed by equipment vendors. Nortel Networks for instance has a QoS standard called Nortel Networks Service Classes.

Ashok Danole, CEO, Automation Experts feels the most important aspect about QoS is that it has to be implemented end-to-end—right from the source (phones or PCs), to boxes in transit (Ethernet switches), and routers in path. "We have implemented QoS

techniques on many sites and can guarantee that technology has taken care of QoS issues. When vendors start interoperating, all issues relating to QoS will be history."

Brian Pereira can be reached at brianp@networkmagazineindia.com