IPDVB Working Group M. Stiemerling Internet-Draft NEC Expires: January 1, 2006 June 30, 2005 Problem Statement: IP Address Configuration for IPDVB draft-stiemerling-ipdvb-config-01 Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on January 1, 2006. Copyright Notice Copyright (C) The Internet Society (2005). Abstract Future IPDVB networks will require a more powerful IP address configuration management as it is currently provided in such networks. Current discussions within the IPDVB working group have shown that the future usage scenarios and requirements for dynamic configuration of IP addresses are not yet clear defined. This memo identifies the problem space for dynamic IP address configuration in IPDVB networks. Stiemerling Expires January 1, 2006 [Page 1] Internet-Draft IPDVB Address Configuration June 2005 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Network Configuration Scenarios . . . . . . . . . . . . . . . 4 3. Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3.1 IP configuration available . . . . . . . . . . . . . . . . 7 3.2 Complete Bootstrap . . . . . . . . . . . . . . . . . . . . 7 4. Related Work . . . . . . . . . . . . . . . . . . . . . . . . . 8 5. Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . 9 6. Security Considerations . . . . . . . . . . . . . . . . . . . 10 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 11 7.1 Normative References . . . . . . . . . . . . . . . . . . . 11 7.2 Informative References . . . . . . . . . . . . . . . . . . 11 Author's Address . . . . . . . . . . . . . . . . . . . . . . . 11 A. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 12 Intellectual Property and Copyright Statements . . . . . . . . 13 Stiemerling Expires January 1, 2006 [Page 2] Internet-Draft IPDVB Address Configuration June 2005 1. Introduction Future IPDVB networks will require a more powerful IP address configuration management as it is currently provided in such networks. Current discussions within the IPDVB working group have shown that the future usage scenarios and requirements for dynamic configuration of IP addresses are not yet clear defined. This memo identifies the problem space, sketches possible future scenarios, and gives an outlook into related areas. The IP address mapping to Layer 2 identifier, known as IP address resolution, and the reverse way are out of scope of this memo. This topic is discussed in [5]. The IPDVB working group has defined a new encapsulation scheme to transport IP over DVB (MPEG2 based) networks, the so-called Ultra- lightweight Encapsulation [1]. This protocol assumes that IP addresses have been already assignment to hosts, DVB receivers, and that hosts are already aware about other networking related parameters, such as IP gateway, DNS server, etc. Whereas today IP addresses are statically to those receivers, future deployments may require a more flexible IP address assignment as known from today's LAN, for instance, via DHCP [3] [4]. Assigning IP addresses dynamically opens the space for further auto-configuration of DVB receivers. information. This memo is a problem statement only and is intended to start discussions within the IPDVB working group on how IP addresses and additional related information can be dynamically configured. Comments and discussions should be sent to the IPDVB's mailing list at ipdvb@erg.abdn.ac.uk. The working group charter is available here: http://www.ietf.org/html.charters/ipdvb-charter.html. Section 2 introduces the network configuration for IPDVB networks. Section 3 describe two scenarios in detail. The document concludes with Section 4 listing similar areas of interest. The terminology used throughout this memo is defined in [2] Stiemerling Expires January 1, 2006 [Page 3] Internet-Draft IPDVB Address Configuration June 2005 2. Network Configuration Scenarios The basic assumption for IPDVB networks with respect to IP address configuration is the number of possible receivers (hosts) within a single IP subnetwork. It is assumed that future IPDVB networks may extend to 1*10E5 receivers per subnetwork but also may be limited to 10 or less receivers per subnetwork. This possible number of hosts should be consider when describing scenarios and later the solution. However, the remainder of this section discusses different network scenarios with respect to their topology in the Internet and DVB network. Figure 1 sketches a typical configuration of DVB receivers with an additional uplink, separated from DVB. This uplink can be, but is not limited to, ISDN, DSL, or cellular networks based. ,-----. DVB uplink / DVB \ *########>>#########( Network ) # \ / +----*------+ `--.--' | Network | | | Provider +-<->+ v DVB downlink +-----------+ | | | +-----v------+ +-<->--+ DVB | uplink | Receiver | +------------+ Figure 1: Basic configuration scenario The network provider is connected to the DVB network and IP network. Data from the IP network towards the DVB receiver is transmitted either over the DVB uplink or the uplink connecting them directly. Data transmitted via the DVB uplink is transported of the DVB network and broadcasted to the DVB receivers. The uplink connecting network provider and DVB receiver can be unidirectional. The scenario depicted in this figure is well-known for DVB-S based high speed Internet access with modem or ISDN uplink. This type of installation is used to replace or substitute DSL deployments in geographical areas where DSL cannot be provided, for instance. Figure 2 shows a scenario where the DVB receiver is connected via a DVB link only and this link is used in a bidirectional way. Such a Stiemerling Expires January 1, 2006 [Page 4] Internet-Draft IPDVB Address Configuration June 2005 configuration will be used, for instance, on ships while being at sea and DVB-S is available only. In this configuration all information, including IP addresses, must be transmitted via the DVB link. ,-----. DVB link / DVB \ *#######<###>######( Network ) # \ / +----*------+ `--.--' | Network | | | Provider | ^ DVB link +-----------+ | v | +-----+------+ | DVB | | Receiver | +------------+ Figure 2: DVB only configuration scenario A scenario similar to a today's common usage is the DVB broadcast as it is shown in Figure 3. The DVB part is an unicast link and all data is broadcasted to all receivers. This configuration is mainly used today for TV broadcasts (based on MPEG-2) but can be used to broadcast IP data to the DVB receivers too. In such case, DVB receivers do not have the ability to interact with any other entity to be configured. Address information can be delivered from a network provider to the receivers by a push mechanism only. However, a fine-grained IP address configuration per receiver seems to be out of scope in this case, since configuration of broadcast or multicast groups is appropriate only. Stiemerling Expires January 1, 2006 [Page 5] Internet-Draft IPDVB Address Configuration June 2005 ,-----. DVB link / DVB \ *########>>########( Network ) # \ / +----*------+ `--.--' | Network | | | Provider | v DVB link +-----------+ v | +-----+------+ | DVB | | Receiver | +------------+ Figure 3: DVB based IP broadcast Stiemerling Expires January 1, 2006 [Page 6] Internet-Draft IPDVB Address Configuration June 2005 3. Scenarios 3.1 IP configuration available This section considers scenarios where DVB receivers have IP addresses already configured, or can obtain these through another way such as the ISDN uplink in Figure 1, and only configuration of additional information is required. This address configuration of DVB receivers, for example, may be either pre-configured by the service provider or be configured by users. Figure 1 shows such a configuration example. The DVB receiver will obtain its basic IP address configuration via the non-DVB uplink (most likely via ISDN and PPP). This scenario requires additional configuration to be loaded at the DVB receivers. Possible things to configure: o IP service information, such as DNS server, proxies, etc o multicast configuration and routing information o broadcast configuration ("open bitstream" without any registration, DVB receivers just receive IP streams) o security configuration, e.g., keys, policies. 3.2 Complete Bootstrap Future scenarios can require a complete bootstrap of DVB receivers without any pre-configuration available on the IP level. Those DVB receivers may be pre-configured to known a basic DVB configuration, such as PID assignment for system information tables (SI tables). Such a receiver would need to retrieve first an IP address and learn about its IP environment (netmask, IP next hop, ...). Figure 2 shows such a scenario where a DVB receiver (and transmitter) is installed aboard a ship and is a gateway between the ship's network and the DVB network. The complete bootstrap scenario includes the one shown in Figure 3 too. Stiemerling Expires January 1, 2006 [Page 7] Internet-Draft IPDVB Address Configuration June 2005 4. Related Work Configuration of DVB, or more general MPEG2 based, networks is tackled in several other environments with different prerequisites. The IP over Cable Data Networks (IPDCN) working group is working in this area and is specifying several MIB modules with respect to MPEG2 network configuration. DVB itself has defined several mechanism to configure receivers, such as system information tables (SI tables), or within MHP. Configuration of IP hosts is focus of the Network Configuration (NETCONF) working group, Dynamic Host Configuration (DHC) working group, and defined in several RFC documents (IPV6 neighbor discovery, IPv4 Address Resolution Protocol (ARP)). Stiemerling Expires January 1, 2006 [Page 8] Internet-Draft IPDVB Address Configuration June 2005 5. Conclusions This memo is first attempt to solve the questions on how future IPDVB networks can deal with dynamic IP address configuration. Open questions are: o What are the configuration scenarios? o What exactly should be configured? o How to configure? o Who is in control of the receiver? The operator is in control of the receiver in the case of MHP. Users running a DVB PC adaptor have full control over their receiver and network operators running their routers on DVB network a likely not to give away control over their equipment. o Is it right to assume that the network provider and DVB network operator are the same entity. During the first discussions at the 61st IETF some differences between IPDVB and other network configuration techniques have been noted. The NETCONF approach is made for single router configuration and is not intended to configure thousands of host at the same time. IPCDN on the other hand considers 1*10e3 hosts per cable head end to be configured. IPDVB must consider up to 1*10e5 hosts per segment, see Section 2. This must be definitely taken into account when designing a solution. This memo is neither accurate nor complete at this point of time and should trigger the discussions within the IPDVB working group. Feedback about this memo is welcome. Stiemerling Expires January 1, 2006 [Page 9] Internet-Draft IPDVB Address Configuration June 2005 6. Security Considerations Security considerations are to be done in future revisions of this document. Stiemerling Expires January 1, 2006 [Page 10] Internet-Draft IPDVB Address Configuration June 2005 7. References 7.1 Normative References [1] Fairhurst, G. and B. Collini-Nocker, "Ultra Lightweight Encapsulation (ULE) for transmission of IP datagrams over MPEG- 2/DVB networks", draft-fair-ipdvb-ule-02 (work in progress), November 2003. [2] Montpetit, M., "A Framework for transmission of IP datagrams over MPEG-2 Networks", draft-ietf-ipdvb-arch-04 (work in progress), May 2005. 7.2 Informative References [3] Droms, R., "Dynamic Host Configuration Protocol", RFC 2131, March 1997. [4] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C., and M. Carney, "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)", RFC 3315, July 2003. [5] Fairhurst, G., "Address Resolution for IP datagrams over MPEG-2 networks", draft-fair-ipdvb-ar-04 (work in progress), April 2005. Author's Address Martin Stiemerling Network Laboratories, NEC Europe Ltd. Kurfuersten-Anlage 36 Heidelberg 69115 Germany Phone: +49 (0) 6221 905 11 13 Email: stiemerling@netlab.nec.de URI: http://www.stiemerling.org/ipdvb Stiemerling Expires January 1, 2006 [Page 11] Internet-Draft IPDVB Address Configuration June 2005 Appendix A. Acknowledgments Parts of this work are a product of the Enthrone project supported in part by the European Commission under its Sixth Framework Programme. It is provided as is and without any express or implied warranties, including, without limitation, the implied warranties of fitness for a particular purpose. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the Enthrone project or the European Commission. 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Acknowledgment Funding for the RFC Editor function is currently provided by the Internet Society. Stiemerling Expires January 1, 2006 [Page 13]