A YANG Data Model for Fabric Topology in Data Center NetworkHuawei101 Software Avenue, Yuhua DistrictNanjingJiangsu210012Chinazhuangyan.zhuang@huawei.comHuawei101 Software Avenue, Yuhua DistrictNanjingJiangsu210012Chinashidanian@huawei.com
RTG Area
I2RS Working GroupRFCRequest for CommentsI-DInternet-DraftThis document defines a YANG data model for fabric topology in Data Center Network.Currently, a data center network is composed of single or multiple
fabrics which are also known as PODs (a Point Of Delivery), which may
be heterogeneous due to implementation of different technologies within
these fabrics. For example, within a DC network, Fabric A may use VXLAN
while Fabric B may use VLAN. The management of the entire heterogeneous
network will be sophisticated and complex especially when the DC network
scales.However, in this heterogeneous DC network, fabric can be considered
to be an atomic structure to provide network management and services, as
well as capacity scaling. From this point, the management of the entire
DC network can be broken down into management of these fabrics as to
provide easier management and flexibility and scalability.With this purpose, this document defines a YANG data model for the
Fabric topology of Data Center Networks by using YANG [6020][
I-D.draft-ietf-netmod-rfc6020bis-09]. To do so, it augments the generic
network and network topology data models defined in [I-D.ietf-i2rs-yang
-network-topo] with information specific to a DC fabric. This model defines the generic configuration and operational state for
the DC fabric common to all vendor implementation, which can be extended
by vendors with specific information. This model can be used by the
network elements to expose to a network controller and capture their
understanding of the overall network topology. Also, it can be used by a
network controller to represent its view of the fabric topology that it
controls and expose it to applications for network management for
Data-center networks.Moreover, in the context of topology architecture defined in [I-D.ietf
-i2rs-yang-network-topo] and [I.D. draft-ietf-i2rs-usecase-reqs-summary],
this model can act as a service topology in conjunction with the existing
I2RS topologies. As a service topology, this DC fabric topology can be
further connected with network elements in the underlay topologies, such
as L3 topology defined in [I.D. draft-ietf-i2rs-yang-l3-topology-01]. By
using the DC fabric topology, people can describe characteristics of a DC
fabric (such as encapsulation, spine/leaf node, and gateway type, etc.).
Also, clients can consume the topology information at fabric level, while
no need to parse entire set of links and nodes in underlay networks.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 [RFC2119].
DC Fabric: also known as POD, is a module of network, compute,
storage, and application components that work together to deliver
networking services. It is a repeatable design pattern, and its
components maximize the modularity, scalability, and manageability of
data centers.The following notations are used within the data tree and carry the
meaning as below.In this document, these words will appear with that interpretation only
when in ALL CAPS. Lower case uses of these words are not to be interpreted
as carrying RFC-2119 significance.
This section provides an overview of the DC Fabric topology model and
its relationship with other topology models.The relationship of the DC fabric topology model and other topology
models is shown in the following figure (dotted lines in the figure
denote augmentations).From the perspective of resource management and service provisioning,
the fabric topology model augments the basic network topology model with
definitions and features specific to a DC fabric, to provide common
configuration and operations for heterogeneous fabrics.The fabric topology model is designed to be generic and can be
applied to data center fabrics built with different technologies, such
as VLAN, VXLAN etc al.The structure of "ietf-fabric-topology" data model is depicted in the
following diagram.The fabric-topology augments the generic ietf-network and
ietf-network-topology modules as follows: A new topology type "ietf-fabric-topology" is introduced
and added under the "network-types" container of the
ietf-network module.Additional topology attributes are introduced, defined in
a grouping, which augments the "network" list of the network
module. The attributes include a Fabric name, fabric-id, type
of the underlay network, descriptions of the fabric as well as
a set of options defined in a container. The options container
includes leaves of the gateway-mode (centralized or distributed)
and traffic-behavior (whether acl needed for the traffic).Additional data objects for nodes are introduced by augmenting
the "node" list of the network module. New objects include node
id of a node in the topology and its role, such as "SPINE" node
or "LEAF" node, which should work together with gateway-mode.Termination points (in network topology module) are augmented
with logical port attributes defined in a container. It contains
common information of name, id, role of the port (such as port
connected to endpoint, or port connected to intra-fabric
communication, etc al). Besides, it also carries layering
information for a port with containers of layer 1, 2 and 3
information. A set of acl for the fabric is also defined. At last,
it provides a set of underlay ports that the logical fabric port
can be mapped to.In addition, we also define several rpc operations for fabric
managements within data center networks to get and configure fabrics
and obtain a response. The YANG module defines 7 rpc commands for this
management, including getting all fabric information, composing a fabric,
decomposing a fabric, adding a node to a fabric, removing a node from a
fabric, adding a link to a fabric and removing a link from a fabric.TBDA YANG Data Model for Network TopologiesA YANG Data Model for Layer 3 TopologiesThe YANG 1.1 Data Modeling LanguageYANG - A Data Modeling Language for the Network Configuration
Protocol (NETCONF)Key words for use in RFCs to Indicate Requirement LevelsCommon YANG Data TypesSummary of I2RS Use Case Requirements