IETF-89 Proceedings

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Network Virtualization Overlays (nvo3) (WG)

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Additional information is available at


Routing Area Area Director(s):

Routing Area Advisor

Technical Advisor(s)

Meeting Slides:

Blue Sheets:


No Request for Comments

Charter (as of 2012-02-23):

Support for multi-tenancy has become a core requirement of data centers
(DCs), especially in the context of data centers supporting virtualized
hosts known as virtual machines (VMs). Three key requirements needed
to support multi-tenancy are:

o Traffic isolation, so that a tenant's traffic is not visible to
any other tenant, and

o Address independence, so that one tenant's addressing scheme does
not collide with other tenant's addressing schemes or with addresses
used within the data center itself.

o Support the placement and migration of VMs anywhere within the
data center, without being limited by DC network constraints
such as the IP subnet boundaries of the underlying DC network.

An NVO3 solution (known here as a Data Center Virtual Private
Network (DCVPN)) is a VPN that is viable across a scaling
range of a few thousand VMs to several million VMs running on
greater than one hundred thousand physical servers. It thus has
good scaling properties from relatively small networks to
networks with several million DCVPN endpoints and hundreds of
thousands of DCVPNs within a single administrative domain.

A DCVPN also supports VM migration between physical servers
in a sub-second timeframe.

Note that although this charter uses the term VM throughout, NVO3 must
also support connectivity to traditional hosts e.g. hosts that do not
have hypervisors.

NVO3 will consider approaches to multi-tenancy that reside at the
network layer rather than using traditional isolation mechanisms
that rely on the underlying layer 2 technology (e.g., VLANs).
The NVO3 WG will determine which types of connectivity services
are needed by typical DC deployments (for example, IP and/or

NVO3 will document the problem statement, the applicability,
and an architectural framework for DCVPNs within a data center
environment. Within this framework, functional blocks will be
defined to allow the dynamic attachment / detachment of VMs to
their DCVPN, and the interconnection of elements of the DCVPNs
over the underlying physical network. This will support the
delivery of packets to the destination VM within the scaling
and migration limits described above.

Based on this framework, the NVO3 WG will develop requirements for both
control plane protocol(s) and data plane encapsulation format(s), and
perform a gap analysis of existing candidate mechanisms. In addition
to functional and architectural requirements, the NVO3 WG will develop
management, operational, maintenance, troubleshooting, security and
OAM protocol requirements.

The NVO3 WG will investigate the interconnection of the DCVPNs
and their tenants with non-NVO3 IP network(s) to determine if
any specific work is needed.

The NVO3 WG will write the following informational RFCs, which
must have completed Working Group Last Call before rechartering can be

Problem Statement
Framework document
Control plane requirements document
Data plane requirements document
Operational Requirements
Gap Analysis

Driven by the requirements and consistent with the gap analysis,
the NVO3 WG may request being rechartered to document solutions
consisting of one or more data plane encapsulations and
control plane protocols as applicable. Any documented solutions
will use existing IETF protocols if suitable. Otherwise,
the NVO3 WG may propose the development of new IETF protocols,
or the writing of an applicability statement for non-IETF

If the WG anticipates the adoption of the technologies of
another SDO, such as the IEEE, as part of the solution, it
will liaise with that SDO to ensure the compatibility of
the approach.