Network Working Group J. Arkko Internet-Draft A. Keranen Intended status: Informational Ericsson Expires: September 6, 2012 March 5, 2012 Minimum Requirements for Physical Layout of Home Networks draft-arkko-homenet-physical-standard-00 Abstract Support for network technology in buildings varies greatly depending on the age of the building, but the ease of building a home network is also highly dependent on the chosen wiring, power, and equipment space designs. As networking technology evolves at a fast pace, it is important to choose designs that are expected to be useful for a long time. While there are many cabling, equipment, and protocol standards, only limited standards exist for the physical network layout for new buildings. This memo sets a baseline requirements that new, single-family dwellings must at least satisfy in order to benefit from advances in networking technology. Standardizing network technology for buildings is a challenging task, however. This memo has been submitted for the home networking working group at the IETF as one forum that the authors were able to find that cares about the home network as a system. However, in general the IETF has expertise only on protocols, not on the physical medium. Advice is sought on what existing standards already address this problem, what standardization efforts may be under way in the world, and if work remains, what the right forum to discuss these matters might be. Status of this Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. 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." This Internet-Draft will expire on September 6, 2012. Arkko & Keranen Expires September 6, 2012 [Page 1] Internet-Draft Home networking layout March 2012 Copyright Notice Copyright (c) 2012 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Requirements language . . . . . . . . . . . . . . . . . . . . . 4 3. Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . 4 4. Network Layout . . . . . . . . . . . . . . . . . . . . . . . . 5 5. Cabling . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 6. Space and Power . . . . . . . . . . . . . . . . . . . . . . . . 7 7. Security Considerations . . . . . . . . . . . . . . . . . . . . 8 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 8 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 8 9.1. Normative References . . . . . . . . . . . . . . . . . . . 8 9.2. Informative References . . . . . . . . . . . . . . . . . . 9 Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . . 9 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 9 Arkko & Keranen Expires September 6, 2012 [Page 2] Internet-Draft Home networking layout March 2012 1. Introduction Support for network technology in buildings varies greatly depending on the age of the building. Older buildings may have no wiring to support any network infrastructure, power may be available only at select places, and so on. Newer buildings can generally support some wired networking mechanisms and provide space and power for the necessary equipment. But the ease of building a home network is also highly dependent on the chosen wiring, power, and equipment space designs. As networking technology evolves at a fast pace, it is important to choose designs that are expected to be useful for a long time. A well-designed network architecture at the physical, cabling, power, and equipment space level could support anything from plain old telephone systems to broadband IP networks, IP-based TV systems, and home automation. The underlying physical infrastructure should not be impacted by technology evolution such as moving from traditional telephony to transporting voice over IP networks, variations in employing either Ethernet switching, routing, and network address translation, moving from IPv4 to IPv6, and so on. While there are many cabling, equipment, and protocol standards, to date there has been no standard for the physical network layout for new buildings. This memo sets a baseline requirements that new, single-family residences must satisfy in order to benefit from advances in networking technology. The basic requirements call for using general purpose cabling in a star topology and providing space for equipment in an equipment rack, and sufficient power supply. Standardizing network technology for buildings is a challenging task, however. This memo has been submitted for the home networking working group at the IETF as one forum that the authors were able to find that appears to care about the home network as a system. However, in general the IETF has expertise only on protocols, not on the physical medium, equipment racks, power supplies, or civil engineering and building requirements. Similarly, cabling standards bodies have experience only on the physical medium but not its application in a specific context, civil engineering standards bodies have only experience on buildings and not on networking requirements, equipment form factor and rack specifications are not specified for a particular home network context, and so on. As a result, it is unclear what forum would have the right expertise to discuss this. Advice is sought on what existing standards already address this problem, what standardization efforts may be under way, Arkko & Keranen Expires September 6, 2012 [Page 3] Internet-Draft Home networking layout March 2012 and if work remains, what the right forum to discuss these matters might be. The rest of this memo is organized as follows. Section 2 defines the requirements language. Section 3 discusses the motivation for needing any physical infrastructure beyond wireless in houses. Section 4 specifies the required network layout and minimum capacity, Section 5 specifies the use of Category 6 cabling, and Section 6 specifies the requirements for equipment space and power. Finally, Section 7 outlines brief security requirements for house networks. Buildings that satisfy the minimum requirements are said to be compliant with this specification. Many buildings may support additional facilities, however, and some of the optional requirements are discussed throughout the memo. Note that requirements for commercial buildings, apartment buildings, and special purpose residences such as summer homes are slightly different, and not covered in this specification. 2. Requirements language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119]. 3. Motivation A frequently asked question is whether a wired infrastructure is needed at all, given the existence of fast and inexpensive wireless networking. End user computing equipment such as laptops employ largely wireless networking today, and the trend is expected to continue, and even accelerate, with other types of devices as well. However, there are several reasons why the existence of a base wired infrastructure within a building is still essential complement to wireless technology: o The need to support applications such as video surveillance, IP- based TV, or network-connected backup storage that may exceed the capacity of at least the current generation of wireless technology. o The need to support applications that benefit from Power-over- Ethernet (PoE) and other similar technologies that can be implemented only over wired infrastructure. Arkko & Keranen Expires September 6, 2012 [Page 4] Internet-Draft Home networking layout March 2012 o The need to support legacy technologies, such as plain old telephones and other devices that can benefit from wired connectivity. o Reconnecting parts from different areas of the house. For instance, the Internet connection, the best place for a wireless LAN access point, and the desired place for an IP-based TV device may all be in different areas of the house. Connecting these different locations is possible over wireless as well, but it is typically more efficient to use a wired infrastructure. o A wireless access point infrastructure is often easiest built on top of a wired infrastructure that connects to the access points. While typical homes today cope with a much simpler architecture that needs no infrastructure or multiple access points, evolving wireless technology generally tends to decrease cell size while increasing bandwidth. Future local area wireless technology or even light-based communication mechanisms may make use of multiple access points in a far more aggressive manner than today's 802.11 wireless LANs. o Ability to employ future networking technology innovations that may also require wired connectivity. As an example, one of the authors has deployed sensor network on top of wired infrastructure in his home. Another frequent question is whether there is a need for a dedicated space to place equipment in. While technology evolves at a fast pace and is also being embedded in all of our devices, it is expected that some central equipment, such as routers, ADSL modems, or Power-over- Ethernet feeds will also be needed in the future. It is easier to place these devices in a dedicated space that can be engineered to provide the necessary power and connectivity. In addition, a dedicated space can be designed to prevent the equipment from causing a visual or aural distraction to the occupants of the building. 4. Network Layout The network MUST use a structured cabling model and a star topology. Note that single-family homes are typically well within the maximum cable length limits even in this configuration. Exceptional situations, such as secondary buildings MAY be handled through the addition of extra local star configurations for the other buildings. Arkko & Keranen Expires September 6, 2012 [Page 5] Internet-Draft Home networking layout March 2012 All external wired connectivity to the building MUST be brought to the same space that holds the center of the star. For instance, fiber-optic cables and phone cables are brought here so that they can be easily connected to the routers, switches and other devices in the central equipment space. This model ensures that individual devices can be connected despite changes in networking technology, merely by reconfiguring the central cable cross connect panel appropriately. For instance, individual devices within the house get to have full-speed connectivity to the central equipment and the technology used to communicate to one device is not dependent on another device. At least one wired connection MUST be provided in this topology for every primary room. This includes the living room, kitchen, bedrooms, libraries, offices, media rooms, and other rooms where the occupants may spend significant amount of time. These rooms are likely to have a computer or a media device that needs connectivity either directly or via a wireless access point device placed nearby. Connections MUST also be provided in rooms dedicated to technology, such as as heating or technology rooms or closets. It is expected that these rooms employ technology that benefits from smart energy or safety applications that may benefit from connectivity. Connections MUST also be provided in hallways or entrance rooms associated with the primary entrance, as those areas may employ movement sensors, surveillance cameras, home automation panels or other technology that again may benefit from connectivity. Connections MAY also be provided in additional areas such as storage rooms, hallways, bathrooms, basement, attic, and so on, but it is not strictly required. The expected applications in these areas typically relate to safety and building health monitoring. 5. Cabling The network MUST use cables manufactured and installed according to the Category 6 specifications [TIA.568-B.2]. This allows high-speed networking applications such as Gigabit or even 10 Gigabit Ethernet [IEEE.802-3ab.1999], as well as many other uses (including legacy voice services and surveillance applications). Note that a more stringent cabling standard MAY be used for all the cabling, as long as it is compatible with Category 6. In addition, the network MAY use other types of cables as seen appropriate. For instance, the installation of fiber optic cabling within the building Arkko & Keranen Expires September 6, 2012 [Page 6] Internet-Draft Home networking layout March 2012 may be useful, even if it is not something that should be recommended today as the only cabling model. Cabling SHOULD be installed in manner that makes it possible to replace or upgrade the cables to future standards. For instance, cables can be installed in tubes, cabling shafts, or other conduits where they can be replaced without affecting the structures around them. In general, the expected lifetime of buildings should be from 30 to 100 years or even beyond. While current installations are likely to be useful in 20 years time, it is also likely that either the physical lifetime of the cabling or the suitability of today's cables to future applications demands replacement after some number of decades. 6. Space and Power The house needs to provide sufficient space and power for placing equipment, such as modems, routers, and file servers. Each star center point in the network topology MUST employ a 19 inch rack system [IEC.60297-3-100]. The rack system MUST be at least 22U (97.9 centimeters) high and at least 600 millimeters deep. There are no mandatory requirements on the configuration of the rack, but it is RECOMMENDED that space in the rack be provided for Category 6 cable termination panels, a power panel, shelves for freestanding equipment, as well as some free space for rack-attached equipment. For instance, a 22U system could be used to accommodate a 2U termination panel for 32 cables, a 24-port 1U Ethernet Switch, 1U power panel, 2 shelves both taking up 4U space, and 10U remaining space for rack-attached equipment. It is useful to reserve a free shelf at the top of the rack with enough free space above it so that larger equipment, such as standalone PCs can be accommodated. Common industry standard of 900 millimeters deep racks may be unnecessarily space-consuming for home environments, however. The depth of 600 millimeters is sufficient for many types of equipment (small switches are typically 200 to 300 millimeters deep, for instance), even if it may not be sufficient for high end servers and other full-size equipment. A smaller form factor rack standard might be useful for home environments. The placement of the rack shall be according to the relevant building codes and practices. Often the rack is placed in a technology room that houses other equipment as well such as electrical cabinets. In addition, mains power MUST be provided for the equipment space. Arkko & Keranen Expires September 6, 2012 [Page 7] Internet-Draft Home networking layout March 2012 This power MUST be fed from an dedicated circuit breaker and SHOULD be filtered to prevent equipment damage from thunderstorms and similar phenomena. 7. Security Considerations While communications equipment does not have the same electrical safety concerns as electricity cabinets, it is still RECOMMENDED that the equipment cabinets are protected from children and accidental tampering. This can be accomplished with a lockable door, for instance. Safety critical applications SHOULD employ connectivity that matches the security requirements. For instance, fire and burglary alarms, and medical applications should use either strong cryptographic security over the wireless medium, or cabling that is not easily tampered with by outsiders. For instance, burglary alarm systems should not rely on cabling that is routed unprotected outside the building. 8. IANA Considerations This document has no IANA implications. 9. References 9.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [IEEE.802-3ab.1999] "IEEE Standard Standard for Local and Metropolitan Area Networks - Part 3: Carrier Sense Multiple Access with Collision Detection (CSMA/CD) Access Method and Physical Layer Specifications - Physical Layer Parameters and Specifications for 1000 Mb/s Operation over 4 pair of Category 5 Balanced Copper Cabling, Type 1000BASE-T", IEEE Standard 802.3ab-1999, 1999. [TIA.568-B.2] "Commercial Building Telecommunications Cabling Standard - Part 2 - Balanced Twisted Pair Components", TIA/ EIA 568-B.2. Arkko & Keranen Expires September 6, 2012 [Page 8] Internet-Draft Home networking layout March 2012 [IEC.60297-3-100] "Mechanical structures for electronic equipment - Dimensions of mechanical structures of the 482,6 mm (19 in) series Part 3-100: Basic dimensions of front panels, subracks, chassis, racks and cabinets", IEC 60297-3- 100:2008. 9.2. Informative References Appendix A. Acknowledgments The authors would like to thank Marc Blanchet for the inspiration to write about this. The authors would also like to thank all the active members of the HOMENET working group for interesting discussions about home networking, Ericsson for supporting Jari's home networking experiments, Joel Halpern for excellent feedback, the TEKES/TIVIT programs for future Internet and Internet of Things research for funding, and Jari's family for endurance and for the permission to use the kitchen table as a soldering platform. Authors' Addresses Jari Arkko Ericsson Jorvas 02420 Finland Email: jari.arkko@piuha.net Ari Keranen Ericsson Jorvas 02420 Finland Email: ari.keranen@ericsson.com Arkko & Keranen Expires September 6, 2012 [Page 9]