DTRET/EXPGRP (2009) 5 FINL 03 12.2009 EXPERTS GROUP "THE PLTFORM FOR ELECTRONIC DT RETENTION FOR THE INVESTIGTION, DETECTION ND PROSECUTION OF SERIOUS CRIME" ESTLISHED Y COMMISSION DECISION 2008/324/EC Series Information on the Transposition of Directive 2006/24/EC Position Paper No 5 Closer understanding of the term Internet Telephony in relation to its application in Directive 2006/24/EC version of 03 December 2009 Impression of technological - and business alternatives with respect to the implementation of voice services on the Internet (Voice over IP or ). Executive Summary In the EU, an increasing number of service providers offer voice services based on the Internet protocol (IP). s an element of convergence to an all internet (IP) based platform, the service providers use the possibilities of harmonizing on a multi-, multi services platform. However, introducing a new technology like Internet based services also brings with it questions about the regulatory obligations an operator has when offering a public telecommunications network or service. This annex to the industry paper explores the technology and business alternatives with respect to the implementation of voice communication services on the internet in general. Discussing the possible interpretations of Internet Telephony as it is referred to in the directive, we researched all possible voice solutions on the Internet protocol. Services can differ both in technology choices (architectures and protocols) and business models, resulting in different environments for data retention: 1. service can be implemented in many different ways, using various standards. Implementation can range from a full Managed NGN implementation to Peer-to-peer SIP. In a full Managed NGN or IMS implementation almost the same data to be retained will be available as in the PSTN world, whereas in a peer-to-peer SIP implementation most data is not stored at all. 2. n operator or service provider can offer Services using different business models. Depending on the business model more or less data to be retained will be available. For instance an operator will store more data for a post-paid minutes based offering than for a pre-paid or flat fee offering, resulting in different environments for data retention. In addition to the technological and business models the element of public available services need to be taken into account. Not all voice services are regarded as public available voice services. In Page 1 of 7
relation to the data retention directive only public electronic services are regarded in scope. The way how to determine between services which are to be regarded as public available voice services is relevant and need to be determined. This is not done in this overview, for this we refer to the European Regulatory Group and its publications on this matter. 1. Introduction The rollout of networks which is currently happening throughout Europe is a good thing considering the European objectives for the telecommunications market. does help to promote competition. This more Internet-like service model allows for faster innovation, where new services are already one of s strong points. ll in all this leads to more competition and innovation. t the end of the day this provides consumer benefits. ut introducing a new technology like also brings with it questions about the regulatory obligations an operator faces when offering a public telecommunications network or service. When considering obligations like lawful intercept, interconnection between operators, emergency services and quality reports, questions arise how to fulfil these obligations considering such a new technology as. This same question becomes relevant when considering data retention. The European Union has adopted a directive on the retention of data, directive 2006/24/EC. This directive, here called the directive contains rules on the retention of data from communication services. Member states are currently in the process of implementing this directive in national legislation. ut, many member states have already indicated that they postpone implementing rules on data retention for Internet Telephony. Still, discussion on data retention for networks should not be postponed until member states have implemented the regulation. is currently quickly becoming the de-facto technology for delivering telephony services. Most if not all operators are either exploring the use of this technology or are already actively offering services using it. number of operators have already indicated a strategy for a complete transition from old circuit-switched to this new packet-switched technology. However, is a technology quite unlike traditional TDM-based PSTN. With circuit-switched telephony, the number of technological standards is limited and so are the choices that need to be made when putting this technology into use. With, there are many more decisions to be made before applying the technology, both in a technological / architectural area and in a number of business areas. These choices influence the need for operators and service providers to retain data for their own business purposes and hence influence the environments for data retention. This will be elaborated in the next Chapters. This industry paper looks at data retention for networks and services. First, this paper explores the technological alternatives when implementing, and discusses the possible consequences for data retention. Then, the different business alternatives are discussed, also including the possible consequences for data retention. ly, conclusions and recommendations are formulated. Page 2 of 7
2. Technological alternatives lthough has been around for over a decade since the introduction of protocols like H.323 and RTP, a lot has changed since then. esides the ITU and the IETF, both ETSI and PacketCable have become involved in standardization of architectures and protocols. ecause of this, the number of technological standards for employing for offering telephony services is quite large, e.g.: - The ITU has standardised H.323, which is an umbrella recommendation containing a number of standards that can be used when implementing. - The IETF has standardised both RTP and SIP. RTP is the most used protocol for transporting the actual speech, whereas SIP is a widely used protocol. The number of extensions on SIP since it s introduction in 1999 is impressive. - The ITU and ETSI have cooperated in the standardisation of Megaco/H.248, which is another protocol based on IETF s MGCP protocol. lthough this protocol is mostly used for controlling so-called -gateways, it can also be used for delivering voice services to end s. - ETSI has standardised in TISPN and adopted the 3GPP standards, as a part of the IP Multi Subsystem. This IMS is an architectural framework for delivering multi services, and is now used for delivering services both in the fixed and in the mobile domain. - CableLabs and EuroCableLabs specify how to deliver multi services on top of DOCSIS and EuroDOCSIS over the HFC network. They specify technologies referred to as PacketCable 1.5 as also described by ITU-T standard J.162 (network call ) and more recently PacketCable 2.0 that is based on the IETF SIP standards. CableLabs has also standardised there PacketCable 2.0 with hooks to IMS as developed by 3GPP. ll these developments have consequences for the possible architectures and for the implementation options of the protocols. The focus in this industry paper will be on SIP, because this is currently the most popular protocol. Of course there is a strong relation between business choices (discussed in the next part of this paper) and architectural choices (discussed in this chapter). architectures, referred to as generic models. Figure 1 shows four different alternative architectures. These four architectures are by no means exhaustive, but they are a good representation of the different architectural options. Page 3 of 7
1) IMS or IMS-like rchitecture 2) SIP Proxy rchitecture direct 3) SIP Re-direct rchitecture 4) P2P SIP rchitecture direct direct Figure 1: Different generic models using SIP The first generic model is an IMS or Managed NGN-like architecture. In this architecture the operator is involved in handling all traffic between s, and is also involved in handling the flows between s. solution using Session order Controllers (SCs) can be part of this category. For data retention, most if not all of the current requested data can be available: It registers if a call becomes connected; It registers if and when a call is answered; It registers if and when a call is ended. The second generic model is a so-called proxy architecture. In this architecture the operator will handle the between s, and the flows will be transported directly between the s in a call. ut there is an important difference with the previous architecture. Using SIP Proxy allows for direct between s as well. For data retention, this can have the following consequences: It registers if a call becomes connected; It registers if and when a call is answered; It may not register if or when a call is ended. The third generic model is the SIP re-directs architecture. In this architecture the operator is only involved in the first part of the call setup. The operator does receive the initial call setup message, but then re-directs the directly to another. For data retention less data will be available: It does not register if a call becomes connected; It does not register if or when a call is answered; It does not register if or when a call is ended. Still, because the initial call setup is handled by the operator, it can still be known which is trying to communicate with which other. The last generic model is a so-called peer-to-peer (P2P) SIP architecture. lthough this is currently only used for Internet-based communication services like e.g. Skype and MSN, it is a development Page 4 of 7
looked at with great interest by many market players. In the P2P SIP architecture, the different s equipment together form a network. lthough the operator can or will be involved with setting up the service and installing and managing the s equipment, the operator is no longer involved during calls. For data retention this means that: It does not register if a call becomes connected; It does not register if or when a call is answered; It does not register if or when a call is ended lso, because the operator is no longer involved even during initial call setup, it will not register which is trying to communicate with which other s. Of course, architectural choices made by a operator are closely related with the business choices such an operator has. Therefore the next chapter looks at the different business implications when applying to telephony services. Protocols lthough the architectural alternatives are the most relevant technical differences when looking at, there are other implementation options as well. Looking at the SIP protocol as specified by the IETF, the number of RFC pages that are about SIP has increased substantially in the past years, as is shown in Figure 2. Figure 2: The growth of SIP protocol specifications Much of this growth has a direct relationship with the number of players involved in the specification process. This has grown significantly now that SIP has become the protocol of choice for with ETSI, ITU and PacketCable. ecause of this there will be many implementation differences between implementations, even when applying the same architecture. For data retention this means that care should be taken in translating the requested data items for retention into parameters. Page 5 of 7
Vendor specific implementations part from the many options in the protocols as stated in the standards, vendors introduce specific proprietary options to differentiate themselves from competitors. Data items for retention will probably depend on these vendor specific implementations. 3. usiness alternatives esides different technological choices, also business choices have an influence on the environments for data retention. Traditional PSTN services are mostly based on minutes based pricing. illing information is based on Call Detail Records (CDRs). These CDRs are currently also used for data retention purposes. Some based telephony services nowadays still are using minutes based pricing and will still collect and store Call Detail Records. These Call Detail Records can be used for data retention purposes. However, many telephony service providers are already moving to flat fee models. For flat fee offerings there is no need to collect and store Call Detail Records for billing purposes. This will result in less data to be available for data retention purposes. Subscriber data is still available, but call data like call duration may not be available. Internet Parties like Skype and MSN use prepaid telephony offerings to their customers. lso other telephony service providers may move to prepaid offerings (just like in the mobile world). For prepaid offerings there is no need to store CDRs for billing purposes. Call data may therefore not be available. If the prepaid offering is based on pre-paid cards, even the subscriber data may not be available. Many Telephony Service s do not have full control of the complete value chain. There will be. Virtual Telephony s, operators and ccess or s. See Figure 3. Virtual Telephony Virtual Telephony Virtual Telephony Name, address Phone number, SIP URI s ccess/ ccess/ ccess/ ccess/ IP address Figure 3: Example of vertical split in the value chain and some data elements of these parties Page 6 of 7
The Virtual Telephony s (VNO s, like warehouses) resell the offerings of operators. operators can deliver their voice services using multiple access or network providers. This may lead e.g. to international Voice operators having one voice service platform in Europe, but using various access providers in different countries. This business model stimulates competition as a customer can choose between various Telephony s using the same access line. For data retention this model will have various consequences: Full call data is not available in one company: data types need to be collected from separate companies, e.g. the name and address data from the Virtual Telephony, the phone number or SIP URI from the operator and the IP addresses from the access or network provider. If data retention requirements differ from country to country, an international might need to implement these different requirements on its single platform, which will result in huge costs. 4. Conclusions and recommendations lthough services may easily be seen as a functional look-alike of PSTN, this is not the case in all implementations. Only if a voice service is positioned as a public available service, with the capability of receiving and originating national and international calls, based on an E.164 numbering plan, it can be seen as such. So apart from technological and business alternatives building the service, each voice service offered need to be judged and determined if this is a public available service as mentioned above. There are also examples of completely different services with different capabilities, regarded as over the top services. In figure 4 we present a complete overview of choices in both architecture as in business models. amount of data available for retention most data retention items are available no data on end time of calls subscriber information may not be available no data on any activity available not known if a call becomes connected PSTN Full-scale IMS / managed NGN Flat fee offering SIP redirect architecture Prepaid offering P2P SIP architecture Figure 4 Illustration that data available for data retention depend on the architectural and business choices. Page 7 of 7