Home Networking
charter-ietf-homenet-03

This working group focuses on the evolving networking technology
within and among relatively small "residential home" networks. For
example, an obvious trend in home networking is the proliferation of
networking technology in an increasingly broad range and number of
devices. This evolution in scale and diversity sets some requirements
on IETF protocols. Some of the relevant trends include:

o Multiple segments: While less complex L3-toplogies involving as few
subnets as possible are preferred in home networks for a variety of
reasons including simpler management and service discovery, the
introduction of more than one subnet into a home network is enough
to add complexity that needs to be addressed, and multiple
dedicated segments are necessary for some cases. For instance, a
common feature in modern home routers in the ability to support
both guest and private network segments. Also, link layer
networking technology is poised to become more heterogeneous, as
networks begin to employ both traditional Ethernet technology and
link layers designed for low-powered sensor networks. Finally,
similar needs for segmentation may occur in other cases, such as
separating building control or corporate extensions from the
Internet access network for the home. Different segments may be
associated with subnets that have different routing and security
policies.

o Service providers are deploying IPv6, and support for IPv6 is
increasingly available in home gateway devices. While IPv6 resembles
IPv4 in many ways, it changes address allocation principles and allows
direct IP addressability and routing to devices in the home from the
Internet. This is a promising area in IPv6 that has proved challenging
in IPv4 with the proliferation of NAT.

o End-to-end communication is both an opportunity and a concern as it
enables new applications but also exposes nodes in the internal
networks to receipt of unwanted traffic from the Internet. Firewalls
that restrict incoming connections may be used to prevent exposure,
however, this reduces the efficacy of end-to-end connectivity that
IPv6 has the potential to restore.

Home networks need to provide the tools to handle these situations in
a manner accessible to all users of home networks. Manual
configuration is rarely, if at all, possible, as the necessary skills
and in some cases even suitable management interfaces are missing.

The purpose of this working group is to focus on this evolution, in
particular as it addresses the introduction of IPv6, by developing an
architecture addressing this full scope of requirements:

o prefix configuration for routers
o managing routing
o name resolution
o service discovery
o network security

The task of the group is to produce an architecture document that
outlines how to construct home networks involving multiple routers and
subnets. This document is expected to apply the IPv6 addressing
architecture, prefix delegation, global and ULA addresses, source
address selection rules and other existing components of the IPv6
architecture, as appropriate. The architecture document should drive
what protocols changes, if any, are necessary. Specific protocol work
described below is expected to be within the scope of the working
group once the architecture work is complete. However, the group is
required to review its charter and milestones with the IESG and IETF
community before submitting documents that make protocol changes. It
is expected that the group has to discuss some of the below solutions,
however, in order to complete the architecture work.

The group will apply existing protocols to handle the five
requirements above. For prefix configuration, existing protocols are
likely sufficient, and at worst may need some small enhancements, such
as new options. For automatic routing, it is expected that existing
routing protocols can be used as is, however, a new mechanism may be
needed in order to turn a selected protocol on by default. For name
resolution and service discovery, extensions to existing
multicast-based name resolution protocols are needed to enable them to
work across subnets.

For network security, the group shall document the concept of
"advanced security" as a further development of "simple security" from
RFC 6092. The main goal of this work is to enable a security policy
that adapts to IPv6 threats as they emerge, taking into account not
only traffic from the Internet at large, but within and leaving the
home network itself.

It is expected that the working group will define a set of protocol
specifications to accomplish the five requirements from
above. However, it is not in the scope of the working group to define
entirely new routing protocols or address allocation protocols. As
noted, additional options or other small extensions may be necessary
to use the existing protocols in these new configuration tasks. The
working group shall also not make any changes to IPv6 protocols or
addressing architecture. Prefix configuration, routing, and security
related work shall not cause any changes that are not backwards
compatible to existing IPv6 hosts. There may be host visible changes
in the work on naming and discovery protocols, however. In its design,
the working group shall also consider security aspects and the impact
on manageability. The main focus of the working group is home
networks, but the group's results may also find applications in other
small networks. The group should assume that an IPv4 network may have
to co-exist alongside the IPv6 network and should take this into
account insofar as alignment with IPv6 is desirable. But the group
should also ensure that even IPv6-only are possible, and while
IP-version agnostic work is of course desirable, IPv4-specific work is
outside the scope of the group.

The working group will liaise with the relevant IETF working
groups. In particular, the group should work closely with the V6OPS
working group, review any use or extension of DHCP with the DHC
working group, and work with additional DNS requirements with the
DNSEXT and DNSOP working groups. If it turns out that additional
options are needed for a routing protocol, they will be developed in
the appropriate Routing Area working group, with the HOMENET working
group providing the architecture and requirements for such
enhancements. The working group will also liason with external
standards bodies where it is expected that there are normative
dependencies between the specifications of the two bodies.
It is expected that in the architecture definition stage liaising with
the Broadband Forum, DLNA, UPnP Forum, OASIS, ZigBee Alliance and
other SDOs is necessary, as is understanding existing technology from
these groups.