www.tatacommunications.com                                      www.capacitymedia.com

VoIP Interconnect
A guide for se...
Rich VoIP
A reputation you
can rely on

Choose the right partner

_ The world’s leading TDM/VoIP hybrid

The voice of
the future is here
The bridge to the IP future is grounded in strong relationships and leading ne...
Our VoIP

   Innovative and
   reliable solutions
   for today’s


_ NGN network access w...

The need to
     interconnect voice over IP
     An all-IP infrastructure allows operators to benefit from growth in IP se...


access to each other, regardless of whether they have     no control over how VoIP packets are routed. This
     VoIP or T...

interconnects allow carriers to maintain the various        them. Native VoIP interconnects make even more
The challenges of
     VoIP interconnection
     What are the factors holding back carrier progress towards the interchang...


  Source: Tata Communications

they still think of portal players and other best-...
interconnect, carriers will need to understand each        INTEROPERABILITY
     other’s security infrastructure and how t...

The migration of
TDM bilaterals to VoIP
There are a number of options and factors to consider for carriers w...

       Source: Tata Communications


process of translating between codecs, or voice             As the VoIP market becomes more demanding of
The NGN evolution
     Traditional carriers need to engage with the new breed of VoIP providers or risk becoming uncompeti...


addressing (ENUM) need to be resolved (see box
       Number portability presents carriers                   below). In th...

Choosing a VoIP
interconnect partner
It’s clear that VoIP is the future, so picking the right company to wor...
voice operator, Tata Communications has the               80% of its traffic, while carrying out the remaining


As markets deregulated, new market entrants built      selected, or the entire range of, operational functions
     up nat...

                                           Source: Tata Communications
One IP World

                    Building the pathway
What will the
future look like?   _ IP interconnection
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VoIP Interconnect

  1. 1. www.tatacommunications.com www.capacitymedia.com VoIP Interconnect A guide for service providers making the transition to an all-IP world Published in association with: Published by: publishing
  2. 2. Rich VoIP experience A reputation you can rely on Choose the right partner _ The world’s leading TDM/VoIP hybrid wholesale voice network _ Relationships with over 1500 voice providers _ VoIP solutions since 1997 _ Guaranteed interoperability and codec support Take your VoIP business farther with industry and technical expertise. www.tatacommunications.com
  3. 3. FORWARD The voice of the future is here The bridge to the IP future is grounded in strong relationships and leading network expertise Since the potential of the IP protocol to carry wide VoIP evolution, choosing the right partner to drive your IP ranges of traffic types was first recognised, well over 15 transition is integral to your success strategy. The right years ago, carriers have been viewing voice over IP (VoIP) partner can bring hands-on experience to configuring in one of two ways – as an industry threat or a business native VoIP interconnects, improved reach to suppliers, opportunity. However, despite the decade that has high quality of service, and transparent management of passed since the first pioneering deployment of conversion requirements. commercial VoIP, the fundamental structure of the As the world’s leading international wholesale voice industry has not significantly been altered. operator, Tata Communications can provide the network Until now, that is. Across the voice industry, providers reach that operators look for in a VoIP interconnect are investing in next-generation networks (NGNs) that partner. Our extensive network of supplier relationships leverage the efficiencies of an all-IP transport core to and our industry-leading BestValue RoutingTM engine drive new business opportunities. helps our VoIP customers balance price and quality as We are in the midst of a burst of industry activity – as per their business needs. carriers begin to execute on convergence, it has become Our twin heritage of VoIP and TDM networks, and the quite clear how VoIP can deliver true benefits to investment we have made in migrating our TDM core transform the industry as a whole. The rising demand for network and interconnects to VoIP, put us in an excellent services like video conferencing forecasts new revenue position to help other carriers do the same, using the streams that can result from converged communications. best practices we have distilled from our 12-year Video, messaging, content, IPTV and more can all be VoIP heritage. delivered seamlessly over a unified platform to enrich the We at Tata Communications look back with pride on subscriber experience and increase opportunities for our extensive history of VoIP innovation, but what matters revenue generation. most for us is that we continue to be a leader in a dynamic Meanwhile, the efficiency gains that result from IP have industry. By sharing our knowledge and expertise, we look been quantified, revealing tremendous potential for a forward to speeding a transformation to IP that will open transformational-scale effect. Besides offering cost a pathway for future industry prosperity. savings, IP promises to decrease the time required to roll We have written the guide for our colleagues and peers out new services and increase resource utilisation. across the voice industry, with whom we have been Nevertheless, significant challenges remain for new building relationships for the past 50 years. This guide is a entrants into the IP world, including managing part of our commitment to work with you as a supportive interoperability and conversion challenges, and dealing and innovative partner as we move into an IP future. ■ with the lack of native IP interconnects. During the process of transition to an all-IP world, protocol conversion and codec transcoding are significant mandates for managing the seamless integration and Michel Guyot interoperability of both TDM and VoIP networks. President, Global Voice Solutions For service providers looking to move forward with a Tata Communications VoIP Guide 2009 01
  4. 4. Our VoIP advantage Innovative and reliable solutions for today’s market Outsourcing _ NGN network access without investments _ Improve scale and reach while reducing cost of non-core business _ Streamlined, best-in-class traffic management and network expertise VTS Prime _ One-stop-shop voice termination service _ Assured high-quality terminations _ Leading global coverage Take your VoIP business farther with industry-leading solutions. www.tatacommunications.com
  5. 5. CONTENTS Contents Page CHAPTER 1 4 As operators invest in next-generation networks there’s a need to interconnect natively over IP: but the migration of TDM interconnects to VoIP is a barrier to growth CHAPTER 2 8 What are the challenges of VoIP interconnection, and how can they be overcome? CHAPTER 3 11 How should carriers undertake the migration of TDM bilaterals to VoIP? CHAPTER 4 14 The NGN evolution: traditional carriers must engage with the new breed of VoIP providers CHAPTER 5 17 The future lies in native VoIP, so choosing the right VoIP interconnect partner is critical NETWORK MAP IBC Tata Communications’ global IP footprint CONTACT DETAILS For more information about Tata Communications please contact: For more information about Capacity magazine © Telcap Ltd. please contact: Marcelle Ferland Communications Manager Tel: +44 (0) 20 8549 2449 Tel: +1 514 868 7272 Fax: +1 514 868 7168 Fax: +44 (0) 20 8549 1249 Email: marcelle.ferland@tatacommunications.com Email: info@capacitymedia.com www.tatacommunications.com www.capacitymedia.com VoIP Guide 2009 03
  6. 6. The need to interconnect voice over IP An all-IP infrastructure allows operators to benefit from growth in IP services, but the migration of interconnects from TDM to VoIP remains a key challenge Networks are moving inexorably to an all-IP future as VOIP INTERCONNECTS growing numbers of telecoms operators invest in Many carriers are convinced by the VoIP business next-generation networks. An all-IP core that can case and the move to VoIP is gaining momentum. efficiently carry multiple types of service, including Ovum reports that between 2007 and 2012, VoIP voice, data, video, content and messaging, makes international wholesale minutes will have more than economic sense, since carriers reduce operational quadrupled going from 75B in 2007 to a projected and capital costs by running a single network and a 279B in 2012. VoIP which represented 37% of the single set of operational and business systems overall international voice wholesale traffic in 2007 is (BSS/OSS). An all-IP infrastructure makes strategic expected to rise to 87% in 2012. This statistic shows sense, too. It enables operators to capitalise on the that the VoIP market is growing up, with an increasing revolution taking place in IP services, helping them number of carriers able to carry VoIP across their core acquire and implement the higher margin, enhanced networks. There is, however, one large barrier that services that customers are beginning to look for. prevents operators from fully realising the potential In the future, service providers will offer voice as an and cost efficiencies of VoIP: the very small number enhanced IP service. In a next-generation, all-IP of VoIP interconnects that currently exist between network, voice will easily be able to be combined carriers. Tata Communications, for example in 2008, with other communications services, such as video transported about 24 billion of international wholesale conferencing, with content services, from IPTV to voice minutes of which 50% is VoIP. In common with other carriers in today’s market, Tata Communications has to maintain TDM infrastructure in parallel with The quicker the market as a whole VoIP infrastructure. It can provide voice services adopts native VoIP interconnection, equally to VoIP providers, carriers that haven’t yet the faster all carriers can benefit migrated their core network away from TDM and to from VoIP economics and service carriers that transport VoIP across an all-IP core but flexibility haven’t yet migrated their interconnects from TDM to VoIP. In an evolving market, carriers must expect social networking applications, and with business to support a hybrid infrastructure, despite the applications, such as click-to-call. Of course, there costs involved. However, the quicker the market will continue to be huge demand, worldwide, for voice as a whole adopts VoIP interconnection, the faster all as a standalone service. In most cases, the capital carriers can benefit from VoIP economics and cost of VoIP infrastructure can represent a significant service flexibility. saving as compared to legacy TDM-based networks, There are considerable benefits to a VoIP which will allow for more competitive voice service interconnection. IP interconnections are more cost- offerings in a low margin environment. effective and quicker to roll out than TDM-based 04 Capacity publishing
  7. 7. CHAPTER 1 INTERNATIONAL VoIP MINUTES (millions) Source: Ovum – David James and Mark Giles, October 2008 interconnections, which require more expensive equipment, local loop access lines and longer set-up Because of the investments and testing times. Capacity can be turned up or Tata Communications is making in its down over an IP interconnect almost immediately, so next-generation network (NGN) and carriers can be more responsive to their customers BestValue RoutingTM system, it is one of and gain greater control over their business. And a the few international wholesale voice carrier can use the same IP interconnection for players that can give its customers and multiple services. This reduces operational cost suppliers direct access to each other, and gives operators business flexibility and quicker regardless of whether they have “time to margin”. VoIP interconnection eliminates the VoIP or TDM interconnects quality degradation that occurs when calls are converted from VoIP to TDM and possibly even partner which can offer an extensive range of back again. interconnects and a dynamic routing capability. Certainly, carriers with TDM interconnects may find ROUTING CAPABILITIES their termination costs rising as the world moves to IP. As the retail voice market continues to fragment and They will need to use partners to get them to the the number of VoIP providers proliferates, the ability rising tide of VoIP providers and this will add cost and to support IP interconnection will enable a carrier to delay to the termination. Tata Communications has reach many more suppliers directly. This gives it more anticipated this problem and has been working hard choice over the price it pays for capacity and quality to address it. Because of the investments Tata to any required destination. However, the carrier will Communications is making in its next-generation need to weigh up the economics of setting up network (NGN) and BestValue RoutingTM system, it is individual commercial agreements with large numbers one of the few international wholesale voice players of suppliers itself, against working with a VoIP peering that can give its customers and suppliers direct VoIP Guide 2009 05
  8. 8. access to each other, regardless of whether they have no control over how VoIP packets are routed. This VoIP or TDM interconnects. However, not many can have a considerable impact on latency and carriers have the scale in their voice and IP quality of service. Serious carriers must make businesses to justify them in following Tata significant investments if they are to provide an Communications’ lead. acceptable level of latency, quality and security in a The long-term goal of the industry must be VoIP VoIP service. interconnections. Carriers can exchange VoIP traffic by either using the public internet or a private IP/MPLS-based NGNs are more dedicated connection. Each of these interconnect flexible than TDM networks as they types has their benefits and drawbacks and it is can support multiple business models up to the carrier to decide which connection type simultaneously for different types best meets their requirements. The public internet and levels of service supports best-effort packet delivery and this may not be compatible with the latency requirements of some carriers for the delivery of voice and video services. VoIP interconnects that are as secure, reliable and Nor is the public internet as secure as using a private high quality as existing TDM interconnects are not IP connection. There is no routing transparency only highly desirable, they are achievable today over the public internet, which means a carrier has over private IP connections using MPLS. Such INDUSTRY INITIATIVES ADDRESSING VOIP INTERCONNECTION Three industry bodies are working on the problem of VoIP interconnection from slightly different perspectives. Tata Communications is a member of all three organisations and is actively contributing to the interconnect and interoperability recommendations and specifications standards that they are variously working towards. I3 FORUM The International Interconnect Forum for services over IP (i3 Forum) is the youngest industry initiative to tackle the problem of IP interconnection but they have already developed a set of technical and commercial guidelines that will help carriers migrate from traditional TDM bilaterals to VoIP-based interconnects. i3 Forum is also looking at providing interconnection recommendations for other voice bilateral services such as access services and ISDN. The i3 Forum was set up in 2008 by eight global carriers and already has more than 20 members, including Tata Communications. This fast-moving group will draw on the best practices of its members. Tata Communications is playing a leading role in the Forum because of its unmatched experience in the VoIP market and its technical and commercial expertise in interconnect migration, which it has distilled in its VoIPLinkTM product. IP INTERNETWORKING ALLIANCE (IPIA) The IP Internetworking Alliance has its roots in the GSMA’s IPX (IP eXchange) programme, which originally set out to specify an IP interconnect network for mobile operators selling high-value 3G services. IPX was conceived as a managed, private network that would deliver IP services securely, with agreed levels of quality and differentiated classes of service, and with a revenue model closely aligned 06 Capacity publishing
  9. 9. CHAPTER 1 interconnects allow carriers to maintain the various them. Native VoIP interconnects make even more existing business models they engage in today while sense for service providers that have already built ensuring that security, reliability and quality translate out an IP core or which have started to build into value that someone will pay for. At the same a next-generation network. There are plenty of time, IP/MPLS-based NGNs are more flexible organisational and technical challenges to overcome: than TDM networks as they can support multiple putting VoIP interconnects in place is not a trivial business models simultaneously for different types task, as the next chapter of this Handbook explains. and levels of service. Migrating to VoIP interconnects However, technologies, solutions and approaches has a revenue impact but carriers are likely to are now available that can significantly reduce the improve net margins because of the efficiency gain. cost and risk of migration. Three key industry They could even gain incremental revenue from bodies (see box) are also undertaking welcome enhanced services. developments that will give the market confidence in the future of VoIP interconnection. In this handbook, MIGRATION STRATEGIES Tata Communications distills 12 years experience The voice industry urgently needs operators not only of delivering VoIP services, implementing VoIP to take a hard look at VoIP economics and the interconnects and building NGNs to show how significant advantages of native VoIP interconnects, carriers can successfully manage the transition to the but also to put in place a strategy for migrating to next-generation VoIP world. ■ with network interconnect models in traditional networks. In the IPX hubbing model, an IPX provider uses its large, global footprint to provide high quality interconnections between multiple operators and their IP services, including VoIP, as well as commercial billing and settlement facilities – “cascading payments”, in IPX-speak – for participating operators. The industry has recognised IPX’s potential to become a more generic standard for high quality, secure IP service interconnection, applicable beyond the mobile domain. Tata Communications has participated successfully in the first “real world” technical and commercial GSMA IPX trial with a CDMA partner, Telus, and a GSM partner, Telekom Austria. IPSPHERE Like IPX, IPSphere Forum has been working for some time to specify the commercial and technical framework for IP service interconnection. The IPSphere Forum looks at a range of IP services that may need to be interconnected across networks, including content services, such as gaming services and video downloads, and Telco/Web 2.0 “mash-up” services. IPSphere Forum also aims to support any type of commercial arrangement between service providers, beyond traditional business models, and is proposing an open, SOA-based framework to facilitate new ways of creating service value between parties. It has proposed a carrier interconnection mechanism, the IPSphere Inter-Carrier Interface (IICI), which has quality and security mechanisms as well as a means of transporting payment information between carriers. The IPSphere Forum is most applicable to retail operators with large numbers of end users to whom they wish to offer a range of services, in competition with internet-based portals. Tata Communications participates in the IPSphere Forum and maintains a close watch on its developments. ■ VoIP Guide 2009 07
  10. 10. The challenges of VoIP interconnection What are the factors holding back carrier progress towards the interchange of VoIP traffic? Although there is growing demand for interchange of interconnect and its bilateral partner then translates high-quality VoIP traffic, service providers are at very the traffic back into VoIP to carry it across its network. different stages on the road to VoIP interconnection. A key weapon of persuasion here will be the Five key challenges are holding back carrier business case for removing TDM networks and progress. Each challenge can be overcome, but this interconnects. The operational costs of TDM, in terms will require carrier commitment and help from a VoIP of power consumption, equipment footprint, leased interconnect partner. line connections, personnel and field operation staff are significantly higher than IP costs, while equipment ORGANISATIONAL supplier investment in TDM is decreasing and their READINESS FOR CHANGE maintenance charges are likely to rise. At the same One of the most serious challenges the voice industry time, TDM networks and interconnects will not needs to address is its TDM legacy. Many carriers support the enhanced voice services that are have not yet decided to invest in a next-generation IP beginning to arrive on IP networks. This will begin network, so IP is not a core competency for them. to make TDM-based carriers less attractive for voice Such companies are a long way from being able to termination. There are also ways of inexpensively replace their TDM interconnects. Where a body of IP acquiring the necessary expertise to implement experience does exist in an operator’s organisation, it VoIP interconnects, by working with a partner is likely that it is very much smaller than the operator’s experienced in building them. Such partners have pool of TDM expertise. Even if carriers have started guidelines and templates that simplify the process TM migrating their networks to an all-IP core, not all of – Tata Communications’ VoIPLink interconnect them will migrate their TDM interconnects at the same service, for example, draws on the carrier’s experience time. Some carriers are choosing to keep legacy of building hundreds of VoIP interconnects. Guidelines interconnects because the processes and systems for VoIP interconnection are now being drawn up by the i3 Forum, IPIA and IPSphere Forum, Many carriers have not yet decided to and these promise to make VoIP interconnection invest in a next-generation IP network, as straightforward and standardised as TDM so IP is not a core competency. They interconnection. Although many carriers are clinging are a long way from being able to onto their TDM interconnects, there is less and less replace their TDM interconnects reason for them to do so. that support them, such as network monitoring PERCEPTION OF VOIP systems, are well understood. There is considerable AS A LOW QUALITY SERVICE organisational resistance to replacing TDM intercon- Ten years ago, when VoIP was in its infancy, it did nects, even if this means an operator translates calls have a reputation for delivering a poor customer from VoIP in the core network to TDM through the experience. When many service providers think of VoIP, 08 Capacity publishing
  11. 11. CHAPTER 2 BESTVALUE ROUTINGTM Source: Tata Communications they still think of portal players and other best-effort from and correlated between the IP session layer, services. However, VoIP technology has now matured where the VoIP application runs and the network to the point that it is possible to achieve a higher transport layer. Tata Communications feeds these quality of service by using VoIP than with TDM. VoIP metrics into its BestValue RoutingTM Engine (see box carriers can also support finer-grained levels of QoS. p10) to ensure that customers get the quality of voice The industry now needs to catch up with advances termination they need and also into its performance in VoIP technology. Carriers need to engineer management tools, enabling it to drill down into areas next-generation networks and VoIP interconnects affecting QoS and carry out root-cause fixes. to deliver high-quality VoIP services. For example, Tata Communications’ NGN incorporates innovations PERCEPTION OF VOIP that ensures that carriers who pay for high quality AS AN INSECURE SERVICE – including the delivery of caller ID – get it. It Again, it is true that IP networks can be less secure has built in the ability to collect multiple layers of than TDM networks if they are not properly managed quality metrics from each of its supplier connections, and configured. Fortunately, IP network security including IP bandwidth, data flow, packet loss, technology is also mature and many carriers have, or delay/jitter, round-trip timings and capacity utilisation. are acquiring, considerable experience in this area. IP Excellent visibility into the network is imperative if networks should have appropriate authentication, Tata Communications is to avoid connections authorisation and access control capabilities in becoming over-subscribed, affecting performance place, protective equipment, including firewalls and and SLA contracts. Such metrics need to be collected support for secure protocols. When building a VoIP VoIP Guide 2009 09
  12. 12. interconnect, carriers will need to understand each INTEROPERABILITY other’s security infrastructure and how to configure the By far the greatest challenge facing carriers that want interconnect so that the same level of security is sup- to implement VoIP interconnects is the lack ported end-to-end. Changes to network equipment of settled VoIP standards. VoIP is heavily influenced must not compromise security. The internal topology by the internet world where continuous innovation of a carrier’s IP network addresses must be hidden tends to win out over standardisation. Internet-based from its partner(s) with a vital piece of VoIP network signalling protocol standards, for example SIP, are still equipment: the session border controller (SBC). evolving and vendors implement the SIP standards that do exist slightly differently to gain competitive THE RIGHT BACK-OFFICE SUPPORT advantage. Operators have adopted or created distinct IP networks and VoIP interconnects mean changes to flavours of VoIP and there are no settled approaches to back-office provisioning, billing and service assurance the compression or otherwise of VoIP traffic. systems and processes. If carriers run hybrid IP/TDM As enterprises move to VoIP, interoperability issues networks, they will need operational systems that will only become more challenging given the large bridge between the two and treat both as though number of suppliers in the IP/PBX market, compared they are a single pool of capacity. Carriers will need to relatively few (but still incompatible) equipment to consolidate CDRs from both networks in order vendors in the carrier-grade VoIP market. To to bill and report on traffic accurately. IP networks simplify VoIP interconnection, carriers should not have generate more data which can be used for business to worry about the vendors, equipment versions, advantage: operators must decide how to collect protocols and codecs their partner(s) are using and and handle this data. Working with an interconnect Tata Communications is on a mission to remove all partner that has already transformed back-office the complexity associated with VoIP interoperability systems can help carriers understand what they from its customers and suppliers. can keep and where they will need to make changes, Because interoperability has such a large effect on minimising the expense and effort involved in the building of VoIP interconnects, it will be migrating to VoIP. discussed in more depth in the following chapter. ■ TATA COMMUNICATIONS’ BESTVALUE ROUTINGTM ENGINE Tata Communications’ BestValue RoutingTM Engine handles TDM as well as VoIP connections so that Tata Communications can take traffic from any customer and route efficiently to any supplier regardless of the technology either uses to connect. Every hour the BestValue RoutingTM Engine looks at the quality and cost/margin on every route – for over 1,500 suppliers connected to Tata Communications – and it carries out tens of thousands of routing changes. It uses historical information to predict demand in the next hour and assesses the capacity and quality of available supply at code level in order to update its routing tables. The engine takes in price and quality information from customers and matches this with the level of service suppliers can offer, then determines the best way to route customer traffic. The BestValue RoutingTM Engine is a core competency for Tata Communications, enabling it to meet customers’ price and quality requirements profitably, ensuring that Tata Communications remains a viable player in the highly competitive voice market. The fact that the BestValue RoutingTM Engine is technology-agnostic means that customers and suppliers get the widest possible choice of routes and both can migrate to VoIP interconnects at their own pace. ■ 10 Capacity publishing
  13. 13. CHAPTER 3 The migration of TDM bilaterals to VoIP There are a number of options and factors to consider for carriers when they migrate their TDM bilaterals to VoIP Carriers moving to all-IP networks will want, at the there are new standards and updates to the protocol very least, to migrate their most important TDM being developed all the time. bilaterals, which handle the majority of their voice Because SIP grew out of the internet community, it traffic, to VoIP interconnects. They can approach this is more flexible than traditional communications migration as an evolution, choosing to add VoIP as an protocols, so it holds out the promise that new alternative gateway to an existing TDM site when they SIP-based communications services can be need a capacity upgrade, for example. This means developed more quickly than has been possible in the that they don’t have to invest in expensive and past. It will also be easier to build services that inflexible TDM capacity and they can gradually combine SIP-based communications with web-based migrate away from the legacy TDM interconnect. function, leading to greater innovation in the Or, if a carrier is expanding its network footprint, it can communications market and greater service revenue opt to set up a new site with a VoIP interconnect opportunities for operators. Retail service providers from the start, even if existing sites still use TDM are already looking at services that combine voice interconnects. Carriers will need to plan their own with email, for example, as well as with video, roadmaps for TDM to VoIP interconnect migration, voice over IM, collaboration services and enterprise based on their capital cycles, which will determine applications. how fast they can acquire new technology and build up their IP knowledge base. Given Tata Communications’ history Carriers also need to take into account their quality as one of the earliest carrier-grade requirements when setting up a VoIP interconnect. VoIP providers, its core network The public internet can deliver the expected quality supports SIP and the legacy for a large segment of wholesale voice customers. TDM-inspired protocol H.323 However, mobile operators, and retail service providers that demand high quality will want to Service providers will need to decide which variant interconnect in one of two ways: either using a private of SIP their VoIP application should support – SIP-I is network environment with dedicated capacity for currently gaining most traction in the carrier market – voice traffic; or using IP/MPLS with its built-in classes and whether their VoIP interconnects should be based of service and security mechanisms. solely on this protocol or whether they need a more The choices do not end here. VoIP services speak generic facility that will allow it to translate between using different signalling protocols. Given Tata SIP variants, between SIP and H.323 and even Communications’ history as one of the earliest carrier- between VoIP protocol(s) and TDM. A session grade VoIP providers, its core network supports SIP border controller (SBC) supports protocol conversion and the legacy TDM-inspired protocol, H.323. Since (see box p12) and is key to overcoming many of SIP is newer and more active in the VoIP community, the interoperability issues delaying TDM to VoIP VoIP Guide 2009 11
  14. 14. VoIPLINKTM INTERCONNECT VIA SESSION BORDER CONTROLLER Source: Tata Communications of best practices based on Tata Communications’ An SBC is key to the security and extensive experience of building VoIP interconnects, interoperability of VoIP interconnects. including best-practice guidelines for selecting It sits at the edge of a network as and configuring vendor equipment, and by its a demarcation point for security VoIPLinkTM interconnect product. Tata Communications and billing is contributing its guidelines to the work the i3 Forum is carrying out, developing industry-standard migration. Large international carriers like Tata recommendations for TDM to VoIP bilateral migration. Communications use SBCs to allow them to handle VoIP traffic regardless of the protocol it speaks THE ROLE OF THE SBC so customers and suppliers do not have to worry An SBC is key to the security and interoperability of about the protocol they have implemented in VoIP networks and VoIP interconnects. It sits at the their networks. edge of a carrier’s network as a demarcation point for Tata Communications’ knowledge of both protocols security and billing purposes, authenticating and puts it in a good position to advise customers, whether authorising traffic passing through the network they are migrating from TDM or older VoIP protocols and carrying out any conversions needed between to SIP, on the best way to implement VoIP VoIP signalling protocols. The new generation interconnects. Its advice is supported both by a set of SBCs also handles transcoding which is the 12 Capacity publishing
  15. 15. CHAPTER 3 process of translating between codecs, or voice As the VoIP market becomes more demanding of compression algorithms from one to another. quality, Tata Communications reports that growing The most important function of an SBC however, is numbers of customers want their bilateral VoIP that it masks a carrier’s internal IP addresses, used interconnects to support G.711, an uncompressed for routing and media, from public view. When the codec which provides a high level of voice quality VoIP market was in its infancy, carriers started off across an IP/MPLS network. However, few VoIP using media gateways at the edge of the network, suppliers have supported G.711 because it requires with gatekeepers or proxy servers to handle routing. up to three times the bandwidth of other codecs. When two carriers set up an interconnect, they would As a result, they prefer not to terminate G.711 exchange all their media gateway access lists and IP calls and they either need to be supplied with addresses which could grow quickly and become unmanageable. Not only did this exchange represent Tata Communications, as a a security risk, it also made routing to large numbers carrier, can ensure that a customer of partners very unwieldy, especially when media sending any codec can properly gateways were moved/added/changed and their IP terminate that phone call to any addresses needed to be updated. With an SBC, all supplier in the world this complexity is hidden. Customers and suppliers use one or two interfaces to the SBC which then takes care of any translations needed to route transcoding devices, introducing cost and a between them. potential point of failure, or calls need to be routed through an SBC which carries out the TRANSCODING CHOICES transcoding for them. By interconnecting to a Not only do VoIP carriers and vendors have options carrier such as Tata Communications that for signalling protocols they can use, they also need supports this capability, the supplier can be to decide on the voice codecs (encoding algorithms) assured they will receive all the potential minutes. that are used for packet transmission. In the VoIP However, Tata Communications expects that world there are many codecs for carriers to choose as the number of carriers able to support from, but none have become the defacto standard G.711 increases, customers will start asking that all networks use. Tata Communications for native end-to-end G.711 termination. IPIA’s currently requires its suppliers to support one of IPX initiative also requires that carriers engineer three codecs which it believes have the greatest into their network the ability to handle calls industry momentum at present: G.711, G.729 and end-to-end without adding latency through G.723. However, Tata Communications is building unnecessary transcoding. the ability to transcode from one codec to another This means that with its NGN network, Tata into its NGN. This will allow for network support Communications is keeping track of which codecs of other codecs that are gaining popularity are being used on a call-by-call basis, using this data in the industry, including GSM AMR, favoured by to inform its routing decisions. The carrier already mobile operators, and iLBC which is used by has a static view of which codecs its suppliers software application developers. Since it doesn’t support. But it will also need to be able to route see the codec incompatibility problem being calls dynamically, based on their codecs, to avoid resolved by the market any time in the near compromising call quality through transcoding. future, Tata Communications, as a carrier, can ensure This is not a trivial exercise given that that a customer sending any codec can properly Tata Communications has over 1,000 suppliers terminate that phone call to any supplier in each typically supporting the three codecs the world. it mandates. ■ VoIP Guide 2009 13
  16. 16. The NGN evolution Traditional carriers need to engage with the new breed of VoIP providers or risk becoming uncompetitive VoIP will not kill the traditional bilateral model but it is bilateral agreements. Some operators see the rise of extending the number of partners with which opera- such providers as a threat, believing that they spell the tors will need to exchange traffic. New types of VoIP end of voice revenues. In fact, end users will continue providers (portals) account for an increasing share of to want voice delivered with a guaranteed level of the voice market. Telegeography reports that in the quality and security, so it is highly unlikely that “free” first quarter of 2008, the US had 16.3 million consumer voice services will displace completely current VoIP lines, representing nearly 14% of all US house- revenue models. However, traditional operators will holds and more than a quarter of US broadband need to engage with new VoIP providers directly or households. risk becoming uncompetitive because they will pay Many of the VoIP providers that operators will need more than they need to for voice termination and to connect to have been in existence for less than five deliver a higher latency, lower quality service using years and are far outside the scope of a carrier's multiple intermediaries. End users will continue to want voice VOIP PEERING HUBS delivered with a guaranteed level of VoIP peering is the rising model for interconnection quality and security, so it is highly between multiple carriers that don’t have established unlikely that “free” voice services relationships with one another. VoIP peering is sup- will displace completely current ported by a peering hub, an interconnect platform revenue models operated by a VoIP peering provider. Carriers connect to the hub through a native VoIP interconnect and gain TATA COMMUNICATIONS’ NGN Tata Communications already has a global, private IP backbone across which it can ensure high quality VoIP connectivity. However, it expects its cost efficiency and performance to improve even further when its next-generation network (NGN), an MPLS-based overlay network supported by Sonus and ZTE softswitches is fully deployed. Tata Communications' new all-IP network is using multi-function Sonus and ZTE equipment to replace its current mix of legacy TDM switches, media gateways and session border controllers. By consolidating its network onto a single NGN infrastructure, Tata Communications expects to achieve cost and performance advantages enabling it to deliver the best quality and value to its customers. The carrier has currently deployed Sonus equipment in a number of sites across the USA, Europe and Asia as well as ZTE equipment in India and has an aggressive timescale for completing its transition to an all-NGN network by mid 2010. Tata Communications' NGN will, from edge to edge, be one managed IP network, engineered to support high-quality voice services. Voice will be transported in dedicated pipes with QoS guaranteed so that Tata Communications can meet the market's highest quality and lowest latency requirements. However, even though the NGN is an all-IP network, it will continue to support Tata Communications TDM 14 Capacity publishing
  17. 17. CHAPTER 4 TATA COMMUNICATIONS’ NGN Source: Tata Communications access to hundreds of other carriers similarly billing and settlement are completed directly by the connected to the hub. There are different business origination and termination parties. A provider like models related to peering, one of which details the Tata Communications supports VoIP peering with a peering provider taking care of billing and settlement next-generation network that is capable of resolving between carriers when they exchange VoIP traffic any interoperability problems between partner across the hub. Other models allow for the carrier to networks. A VoIP peering hub thus connects many of handle transport only and charge accordingly, and all the islands of VoIP that currently exist in the market, customers. The equipment that Tata Communications is installing is capable of supporting both TDM and VoIP protocols, including all the variants of SIP and H.323 signalling protocols, in the case of VoIP, as well as multiple VoIP codecs. Any carrier connected to Tata Communications today, as a TDM or VoIP bilateral or a VoIP peering partner, can continue with their existing interconnects and, when desired, migrate their TDM interconnects to VoIP over time. Using both Sonus and ZTE, Tata Communications is readying itself to handle any enhanced VoIP service a customer will ask it to carry in the future. Migrating to an NGN is a large undertaking and Tata Communications understands the growing pains and challenges that must be addressed, from retraining staff on new equipment to deploying new hardware and accompanying OSS/BSS systems across a very large global footprint. As a result, Tata Communications is building up invaluable experience it can share with its VoIP partners as they put their own migration plans in place. Partners can also elect to outsource their international network management complexities to Tata Communications thereby enabling them to focus on their core business. Tata Communications is closely monitoring the return on its NGN investment and the benefits it expects to achieve in terms of quality improve- ments, management efficiency and lower cost, so it can help others understand the business case. ■ VoIP Guide 2009 15
  18. 18. addressing (ENUM) need to be resolved (see box Number portability presents carriers below). In the internet, voice end-points are identified with a large headache. How do they by IP addresses and in order to reach them directly, keep track of all end-customer moves VoIP operators may need to map PSTN numbers to and daily number changes within IP addresses using an ENUM database. Routing peered operators’ organisations? and addressing of voice traffic is quickly increasing in complexity with the need to query the required enabling any VoIP provider to pass traffic directly to routing information from various private and any other VoIP-enabled operator. public databases before making routing decisions. There are a number of challenges associated with Only a handful of carriers are likely to have implementing a VoIP peering hub, especially in the the experience, technical capabilities, network current market where industry standards for VoIP architecture, geographic reach and large numbers interconnection have yet to be established. Issues of connected suppliers to become credible VoIP such as number portability (NP) and routing and peering providers. ■ NUMBER PORTABILITY AND ENUM CHALLENGES Retail Service Providers (MNOs, fixed, broadband) daily lose and gain large numbers of customers. Many of these customers will keep their numbers when they change providers, thanks to number portability regulation. As a result, carriers can no longer assume that any number in a range once assigned to a particular operator will still belong to a customer of that operator. The customer may have changed provider several times since s/he originally acquired the number. If the carrier routes a call based on a number range, it may find it is paying a high price for termination as the call is passed on from provider to provider until it reaches the customer – and of course, quality is also compromised. Number portability presents carriers with a large headache. How do they keep track of all the end-customer moves and daily number changes within peered operators’ organisations so that they can route calls direct to the right destination? They now need to be able to route on individual phone numbers rather on number ranges, which, in Tata Communications’ case, means being able to store over a billion phone numbers and having the ability to update this database daily so that numbers are correctly assigned to operators. The number portability database then has to be linked to their BestValue RoutingTM Engine. Before taking each routing decision the sophisticated routing engine has first to dip into the database to understand which operator owns the number being called, so that it can calculate the best route according to a customer’s quality and price criteria. Since Tata Communications handles hundreds of thousands of calls a second, supporting such a volume of database look-ups is no small task. Tata Communications already has the ability to support number portability-based routing in a number of countries round the world and is working to extend this capability to others. This is part of its commitment to deliver best value to its voice customers. In a VoIP peering context, ENUM adds an extra dimension to the number portability problem. Many VoIP providers hold customer numbers in an ENUM database, making customers addressable across the internet. VoIP peering providers need to gain access to those databases in order to deliver VoIP calls over the public internet and increasingly over private IP networks. A number of models for ENUM access are emerging here. Tata Communications is working on the ENUM evolution and is actively participating in several industry discussions on this topic. Tata Communications is building a routing architecture and the solutions that will handle ENUM-based routing. ■ 16 Capacity publishing
  19. 19. CHAPTER 5 Choosing a VoIP interconnect partner It’s clear that VoIP is the future, so picking the right company to work with is critical Migrating to IP and VoIP delivers a wide range of QUESTIONS TO ASK benefits, from cost savings and the ability to offer As operators consider how best to migrate away from enhanced services to provisioning flexibility and their TDM comfort zone to VoIP interconnection, they the convenience of having a single connection should ask the following questions about potential supporting multiple services and connectivity to VoIP interconnect partners: multiple suppliers. > How many VoIP interconnects has this carrier Operators can significantly reduce the time and set up? effort involved in moving to IP/VoIP interconnections > How many suppliers can this partner connect me if they work with an experienced partner that can to – how extensive a choice can it offer me of provide the right expertise and support. This partner termination quality? should have a thorough understanding of the > How does it ensure that its suppliers deliver challenges facing operators as they migrate to the quality of service I need? Does it have a IP/VoIP interconnects and convincing solutions state-of-the-art sophisticated routing engine that to these problems. And operators will want the guarantees the best routes for my calls according reassurance that they are working with a carrier to my price and quality criteria? partner that is leading the industry in the > Does it support retail quality call completion, development of standards for IP/VoIP interconnects, with Calling Line Identification delivery assurance so that the next-generation interconnects they are and support for the high quality G.711 codec? putting in place will be future-proof. > Does it have well-established processes, For those carriers that have strong TDM back- templates and guidelines to help me configure my grounds and little experience with VoIP, there are native VoIP interconnection? solutions in the market that will allow them to bridge > How much work will I need to do to interconnect into the VoIP world with minimal investment. The with this partner – do I need to invest in SNARC product from Tata Communications is a transcoding and protocol translation function complete turnkey solution that provides a VoIP gate- or will the partner handle this for me? way for the customer to interconnect into their legacy > Can I go to this partner for advice about what I TDM switch. Tata Communications will manage and need to change in my organisation and back-office maintain the VoIP gateway and the customer is systems to support the new VoIP interconnect? responsible for the cross connect into the TDM switch > If I choose to retain legacy TDM interconnects for and must provide Tier 1 IP bandwidth. The solution will the time being will my business be treated with the enable the carrier to have direct access to all voice same level of priority and professionalism? services and suppliers in the Tata Communications > Has partner got the appropriate provisioning network. The carrier can use this experience to learn staff who can walk us through the interconnect about the VoIP interworkings and allow their staff to process and test to ensure full compatibility? become comfortable with the technology. As the world’s leading international wholesale VoIP Guide 2009 17
  20. 20. voice operator, Tata Communications has the 80% of its traffic, while carrying out the remaining network reach that operators need in a VoIP 20% of its voice business with a multitude of interconnect partner. It can connect TDM and partners through a high quality VoIP provider like VoIP customers to over 1,000 suppliers, using its Tata Communications. industry-leading BestValue RoutingTM Engine to meet VoIP interconnection is the future of the voice both types of customers’ price and quality criteria industry. Operators can benefit from a VoIP equally. Tata Communications’ knowledge and future more quickly and with least pain if they experience of VoIP interconnection is unsurpassed choose the right IP/VoIP interconnection partner to in the market, thanks to 12 years of engagement help them. with the technology. Our twin heritage of VoIP In a next-generation all-IP converged network, and TDM networks and the investment it has voice can easily be combined with other end-users' made in migrating its TDM interconnects to VoIP, services such as video conferencing and video share puts it in an excellent position to help other as well as with service providers’ mission critical carriers do the same, using the best practices inter-working and roaming IP-based traffic such as that Tata Communications has distilled from its Sigtran. Beyond voice, Tata Communications’ portfo- own experience. lio of wholesale services includes a comprehensive Tata Communications can offer a set of solutions range of mobile services: from signalling connectivity to support customers in all aspects of IP/VoIP services, such as SCCP and Wireless Global migration and the implementation of VoIP Roaming, to enhanced roaming services, such as interconnects. Its global NGN, with its dedicated, Managed Roaming and Intelligent CAMEL eXchange high-quality voice transport capability, will continue (ICX), operators are able to reduce costs, maximise to support TDM customers so that they can revenue and improve call services delivery, by migrat- migrate to VoIP at a pace that suits their business. ing to a converged IP-based interconnect supporting Tata Communications’ global voice solutions, such their voice, signalling and data requirements. as VTS Prime, provide reliable, high-quality call REASONS FOR OUTSOURCING Tata Communications’ knowledge VOIP CONNECTIVITY and experience of VoIP Over the past five years, a combination of market interconnection is unsurpassed in deregulation and the arrival of VoIP has changed the the market, thanks to 12 years of economics of wholesale voice dramatically. Retail engagement with the technology operators that used surplus network capacity to build a wholesale business when termination rates completion with Calling Line Identification delivery were high are finding their margins dwindling now assurance for mobile operators and other retail that competition and new technology have driven service providers. It is playing a significant role in prices down. Wholesale voice has become a industry organisations that are trying to structure the low-margin, high-volume business. IP/VoIP interconnects model while making it easy for At the same time, the voice market is becoming partners to connect to its network whatever variant more complex. New retail voice providers have of VoIP they use. And Tata Communications opened for business, so carriers must make finer can support next-generation VoIP peering and grained routing decisions. The larger the number of outsourcing models, enabling customers to choose providers, the greater the variance in price and whatever mix of VoIP peering and bilateral quality, and this can change on an hourly basis, interconnects they need. For example, an operator depending on the time of day. Numbers have may set up high-quality, VoIP bilateral interconnects become portable or have moved to the IP cloud in with its top five to 10 partners, which account for many markets across the world, so carriers now have 18 Capacity publishing
  21. 21. CHAPTER 5 HIGH LEVEL TATA COMMUNICATIONS NETWORK Source: Tata Communications to keep track of how customers are moving between operators in order to route calls to the right operators In order to remain cost competitive efficiently. In order to remain cost competitive, carriers need to make significant carriers need to make significant changes to changes to their operational systems, their operational systems, requiring considerable requiring considerable investment for investment for relatively small returns. relatively small returns Large carriers, where international voice is a relatively small component of their overall revenue, networks that need to focus their resources on their are now considering outsourcing this business to a core business and do not have the desire or the partner with the scale, focus and ongoing investment capital to extend their geographic reach or physical programme to keep them at the top of the market. By connections to large numbers of international allowing a carrier specialising in wholesale voice to suppliers. Such service providers nevertheless want manage their international voice business for them, to grow their business and this means extending, large carriers reduce their capital and operational through an outsourcing partner, their ability to expenditures while being able to improve their handle international termination as cost-effectively service to customers. Efficiency gain and direct cost as possible for their customers. Examples of service reduction is a large spur to outsourcing for this providers in this category include pre-pay/calling segment of the market. card companies, voice over broadband providers A second group evaluating the benefits of and portal companies. Outsourcing represents a outsourcing are retail service providers with limited revenue growth opportunity for this set of operators. VoIP Guide 2009 19
  22. 22. As markets deregulated, new market entrants built selected, or the entire range of, operational functions up national or international VoIP businesses to on behalf of the carrier, including SLA management, compete with incumbents’ wholesale voice dispute resolution, settlement and reporting. Large businesses based on legacy technology. A number carriers are then free to redeploy their international of new entrants successfully gained a significant voice termination staff in another capacity market share of voice traffic and for a while within their organisation. The carrier can also benefit have been profitable, benefitting from the lower oper- from a reduced need for staff in other areas of ational costs achievable with VoIP. As wholesale its business, including network operations, voice is more and more a commodity trading engineering and finance, since instead of maintaining business, however, this group of carriers is facing relationships with hundreds of supplier partners, pricing pressures and threats from incumbents, these departments only deal with one: Tata which are reasserting themselves in the voice market Communications. with next-generation, all-IP networks and VoIP Retail operators can take advantage of Tata services of their own. New entrants are therefore Communications’ extensive network footprint, looking at moving up the value chain and developing gaining a virtual presence in new markets round the retail operations. By outsourcing their wholesale globe without the need to invest in PoPs. VoIP operations, they can focus on building their operators moving into the retail market can retail business. similarly take advantage of Tata Communications’ international network and large number of partner Retail operators can take advantage relationships. Tata Communications aggregates of Tata Communications’ extensive traffic from all round the world and sends it to its network footprint, gaining a virtual partners’ networks, resulting in interesting retail presence in markets round the globe opportunities for carriers prepared to outsource to without the need to invest in PoPs the company. Tata Communications is also able to help such carriers design and implement further Tata Communications’ network reach, large network build-outs and to co-invest in new network number of commercial relationships, advanced voice deployments so that carriers can establish a management platform, network design and build presence in a particular market much faster than capability and willingness to make joint investments they could on their own. with its customers are all strengths it can bring Finally, carriers can use Tata Communications’ to an outsourcing arrangement. The carrier can experience with building NGNs, to migrate their manage routing for a large carrier, calibrating its business onto a next- generation platform. As part of BestValue RoutingTM Engine with the carrier’s an outsourcing deal, they can work with customers customers’ cost and quality requirements and to upgrade their network infrastructure with the matching these against the capabilities of the cutting-edge technology that Tata Communications carrier’s set of suppliers. deploys in its own network, reducing the cost and Tata Communications can further carry out risk of migrating to IP and VoIP. ■ CONTACT DETAILS For more information about Tata Communications please contact: Marcelle Ferland Communications Manager Tel: +1 514 868 7272 Fax: +1 514 868 7168 Email: marcelle.ferland@tatacommunications.com www.tatacommunications.com 20 Capacity publishing
  23. 23. TATA COMMUNICATIONS’ GLOBAL IP FOOTPRINT Source: Tata Communications
  24. 24. One IP World Building the pathway What will the future look like? _ IP interconnection _ Converging communications _ Mobile traffic over IP Give your opinion. Drive Change. Build a future-perfect IP world Join the conversation that will shape the future at OneIPWorld.net www.tatacommunications.com