Internet DRAFT - draft-arkko-homenet-physical-standard
draft-arkko-homenet-physical-standard
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]