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draft-ietf-ccamp-network-inventory-yang.txt
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CCAMP Working Group C. Yu
Internet-Draft Huawei Technologies
Intended status: Standards Track S. Belotti
Expires: 8 January 2024 Nokia
J.-F. Bouquier
Vodafone
F. Peruzzini
TIM
P. Bedard
Cisco
7 July 2023
A YANG Data Model for Network Hardware Inventory
draft-ietf-ccamp-network-inventory-yang-02
Abstract
This document defines a YANG data model for network hardware
inventory data information.
The YANG data model presented in this document is intended to be used
as the basis toward a generic YANG data model for network hardware
inventory data information which can be augmented, when required,
with technology-specific (e.g., optical) inventory data, to be
defined either in a future version of this document or in another
document.
The YANG data model defined in this document conforms to the Network
Management Datastore Architecture (NMDA).
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 https://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 8 January 2024.
Yu, et al. Expires 8 January 2024 [Page 1]
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Copyright Notice
Copyright (c) 2023 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 (https://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 Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Terminology and Notations . . . . . . . . . . . . . . . . 4
1.2. Requirements Notation . . . . . . . . . . . . . . . . . . 6
1.3. Tree Diagram . . . . . . . . . . . . . . . . . . . . . . 6
1.4. Prefix in Data Node Names . . . . . . . . . . . . . . . . 6
2. YANG Data Model for Network Hardware Inventory . . . . . . . 6
2.1. YANG Model Overview . . . . . . . . . . . . . . . . . . . 7
2.1.1. Common Design for All Inventory Objects . . . . . . . 9
2.1.2. Reference from RFC8348 . . . . . . . . . . . . . . . 10
2.1.3. Changes with respect to RFC8348 . . . . . . . . . . . 12
2.1.4. Equipment Room . . . . . . . . . . . . . . . . . . . 14
2.1.5. Rack . . . . . . . . . . . . . . . . . . . . . . . . 14
2.1.6. Network Element . . . . . . . . . . . . . . . . . . . 16
2.1.7. Relationship between Hardware Inventory and Network
Topology models . . . . . . . . . . . . . . . . . . . 16
2.2. Efficiency Issue . . . . . . . . . . . . . . . . . . . . 18
2.3. Some Other Considerations . . . . . . . . . . . . . . . . 19
3. Tree Diagrams . . . . . . . . . . . . . . . . . . . . . . . . 19
3.1. Network Hardware Inventory Tree Diagram . . . . . . . . . 19
3.2. Relationship between Topology and Network Inventory Tree
Diagram . . . . . . . . . . . . . . . . . . . . . . . . . 21
4. YANG Data Models . . . . . . . . . . . . . . . . . . . . . . 21
4.1. YANG Data Model for Network Hardware Inventory . . . . . 21
4.2. YANG Data Model for Relationship between Topology and
Network Inventory . . . . . . . . . . . . . . . . . . . . 34
5. Manageability Considerations . . . . . . . . . . . . . . . . 37
6. Security Considerations . . . . . . . . . . . . . . . . . . . 37
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 37
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 37
8.1. Normative References . . . . . . . . . . . . . . . . . . 37
8.2. Informative References . . . . . . . . . . . . . . . . . 38
Appendix A. Appendix . . . . . . . . . . . . . . . . . . . . . . 39
Yu, et al. Expires 8 January 2024 [Page 2]
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A.1. Comparison With Openconfig-platform Data Model . . . . . 39
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 42
Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 43
1. Introduction
Network hardware inventory management is a key component in
operators' OSS architectures.
Network hardware inventory is a fundamental functionality in network
management and was specified many years ago. Given the emergence of
data models and their deployment in operator's management and control
systems, the traditional function of inventory management is also
requested to be defined as a data model.
Network hardware inventory management and monitoring is a critical
part for ensuring the network stays healthy, well-planned, and
functioning in the operator's network. Network hardware inventory
management allows the operator to keep track of which physical
devices are deployed in the network including relevant software and
hardware versions.
The network hardware inventory management also helps the operator to
know when to acquire new assets and what is needed, or to
decommission old or faulty ones, which can help to improve network
performance and capacity planning.
In [I-D.ietf-teas-actn-poi-applicability] a gap was identified
regarding the lack of a YANG data model that could be used at ACTN
MPI interface level to report whole/partial network hardware
inventory information available at domain controller level towards
north-bound systems (e.g., MDSC or OSS layer).
[RFC8345] initial goal was to make possible the augmentation of the
YANG data model with network hardware inventory data model but this
was never developed and the scope was kept limited to network
topology data only.
It is key for operators to drive the industry towards the use of a
standard YANG data model for network hardware inventory data instead
of using vendors proprietary APIs (e.g., REST API).
In the ACTN architecture, this would bring also clear benefits at
MDSC level for packet over optical integration scenarios since this
would enable the correlation of the inventory information with the
links information reported in the network topology model.
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The intention is to define a generic YANG data model that would be as
much as possible technology agnostic (valid for IP, optical and
microwave networks) and that could be augmented, when required, to
include some technology-specific inventory details.
[RFC8348] defines a YANG data model for the management of the
hardware on a single server and therefore it is more applicable to
the domain controller South Bound Interface (SBI) towards the network
elements rather than at the domain controller's northbound. However,
the YANG data model defined in [RFC8348] has been used as a reference
for defining the YANG network hardware inventory data model presented
in this draft.
For optical network hardware inventory, the network hardware
inventory YANG data model should support the use cases (4a and 4b)
and requirements as defined in [ONF_TR-547], in order to guarantee a
seamless integration at MDSC/OSS/orchestration layers.
The proposed YANG data model has been analysed at the present stage
to cover the requirements and use cases for Optical Network Hardware
Inventory.
Being based on [RFC8348], this data model should be a good starting
point toward a generic data model and applicable to any technology.
However, further analysis of requirements and use cases is needed to
extend the applicability of this YANG data model to other types of
networks (IP and microwave) and to identify which aspects are generic
and which aspects are technology-specific for optical networks.
This document defines two YANG modules: "ietf-network-hardware-
inventory", defined in Section 4.1, and "ietf-hw-inventory-ref-topo",
defined in Section 4.2.
The YANG data models defined in this document conform to the Network
Management Datastore Architecture [RFC8342].
1.1. Terminology and Notations
The following terms are defined in [RFC7950] and are not redefined
here:
* client
* server
* augment
* data model
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* data node
The following terms are defined in [RFC6241] and are not redefined
here:
* configuration data
* state data
The terminology for describing YANG data models is found in
[RFC7950].
TBD: Recap the concept of chassis/slot/component/board/... in
[TMF_SD2-20].
Following terms are used for the representation of the hierarchies in
the network hardware inventory.
Network Element:
a device installed on one or several chassis and can afford some
specific transmission function independently.
Rack:
a holder of the device and provides power supply for the device in
it.
Chassis:
a holder of the device installation.
Slot:
a holder of the board.
Component:
holders and equipment of the network element, including chassis,
slot, sub-slot, board and port.
Board/Card:
a pluggable equipment can be inserted into one or several slots/
sub-slots and can afford a specific transmission function
independently.
Port:
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an interface on board
1.2. Requirements Notation
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
1.3. Tree Diagram
A simplified graphical representation of the data model is used in
Section 3 of this document. The meaning of the symbols in this
diagram is defined in [RFC8340].
1.4. Prefix in Data Node Names
In this document, names of data nodes and other data model objects
are prefixed using the standard prefix associated with the
corresponding YANG imported modules, as shown in the following table.
+========+=================================+=============+
| Prefix | Yang Module | Reference |
+========+=================================+=============+
| inet | ietf-inet-types | [RFC6991] |
+--------+---------------------------------+-------------+
| yang | ietf-yang-types | [RFC6991] |
+--------+---------------------------------+-------------+
| ianahw | iana-hardware | [IANA_YANG] |
+--------+---------------------------------+-------------+
| ni | ietf-network-hardware-inventory | RFC XXXX |
+--------+---------------------------------+-------------+
| hirt | ietf-hw-inventory-ref-topo | RFC XXXX |
+--------+---------------------------------+-------------+
Table 1: Prefixes and corresponding YANG modules
RFC Editor Note: Please replace XXXX with the RFC number assigned to
this document. Please remove this note.
2. YANG Data Model for Network Hardware Inventory
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2.1. YANG Model Overview
Based on TMF classification in [TMF_SD2-20], inventory objects can be
divided into two groups, holder group and equipment group. The
holder group contains rack, chassis, slot, sub-slot while the
equipment group contains network-element, board and port. With the
requirement of GIS and on-demand domain controller selection raised,
the equipment room becomes a new inventory object to be managed
besides TMF classification.
Logically, the relationship between these inventory objects can be
described by Figure 1 below:
+-------------+
| inventory |
+-------------+
// \\
1:N // \\ 1:M
// \\
+----------------+ +-----------------+
| equipment room | | network element |
+----------------+ +-----------------+
|| ||
|| 1:N ||
\/ ||
+------------+ ||1:M
| rack | ||
+------------+ ||
|| ||
|| 1:N \/
||______________\+-------------+
|---------------/| chassis/ |---+
| sub-chassis |<--|
+-------------+
||
______1:N______||_____1:M_______
||------------------ ---------||
\/ \/
+--------------+ +-----------+
+---| slot | | board |
|-->| /sub-slot | | |
+--------------+ +-----------+
||
||1:N
\/
+-----------+
| port |
+-----------+
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Figure 1: Relationship between inventory objects
In [RFC8348], rack, chassis, slot, sub-slot, board and port are
defined as components of network elements with generic attributes.
Considering there are some special scenarios, there is no direct
relationship between the rack and network element. In some cases,
one network element contains multiple racks while in other cases one
rack contains several shelves belonging to one or more network
elements.
While [RFC8348] is used to manage the hardware of a single server
(e.g., a network element), the Network Hardware Inventory YANG data
model is used to retrieve the network hardware inventory information
that a controller discovers from all the network elements under its
control.
However, the YANG data model defined in [RFC8348] has been used as a
reference for defining the YANG network hardware inventory data
model. This approach can simplify the implementation of this network
hardware inventory model when the controller uses the YANG data model
defined in [RFC8348] to retrieve the hardware from the network
elements under its control.
Note: review in future versions of this document whether to re-use
definitions from [RFC8348] or use schema-mount.
+--ro network-hardware-inventory
+--ro equipment-rooms
| +--ro equipment-room* [uuid]
| +--ro uuid yang:uuid
| ...................................
| +--ro racks
| +--ro rack* [uuid]
| +--ro uuid yang:uuid
| ...................................
| +--ro contained-chassis* [ne-ref component-ref]
| +--ro ne-ref? leafref
| +--ro component-ref? leafref
+--ro network-elements
+--ro network-element* [uuid]
+--ro uuid yang:uuid
...................................
+--ro components
+--ro component* [uuid]
+--ro uuid yang:uuid
...................................
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2.1.1. Common Design for All Inventory Objects
For all the inventory objects, there are some common attributes
existing. Such as:
Identifier: here we suggest to use uuid format which is widely
implemented with systems. It is guaranteed to be globally unique.
Name: name is a human-readable label information which could be used
to present on GUI. This name is suggested to be provided by server.
Alias: alias is also a human-readable label information which could
be modified by user. It could also be present on GUI instead of
name.
Description: description is a human-readable information which could
be also input by user. Description provides more detailed
information to prompt users when performing maintenance operations.
Location: location is a common management requirement of operators.
This location could be an absolute position (e.g. mailing address),
or a relative position (e.g. port index). Different types of
inventory objects may require different types of position.
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module: ietf-network-hardware-inventory
+--ro network-hardware-inventory
+--ro equipment-rooms
| +--ro equipment-room* [uuid]
| +--ro uuid yang:uuid
| +--ro name? string
| +--ro description? string
| +--ro alias? string
| +--ro location? string
| ...................................
| +--ro racks
| +--ro rack* [uuid]
| +--ro uuid yang:uuid
| +--ro name? string
| +--ro description? string
| +--ro alias? string
| +--ro rack-location
| | +--ro equipment-room-name? leafref
| | +--ro row-number? uint32
| | +--ro column-number? uint32
| ...................................
+--ro network-elements
+--ro network-element* [uuid]
+--ro uuid yang:uuid
+--ro name? string
+--ro description? string
+--ro alias? string
+--ro ne-location
| +--ro equipment-room-name* leafref
...................................
+--ro components
+--ro component* [uuid]
+--ro uuid yang:uuid
+--ro name? string
+--ro description? string
+--ro alias? string
+--ro location string
...................................
2.1.2. Reference from RFC8348
The YANG data model for network hardware inventory mainly follows the
same approach of [RFC8348] and reports the network hardware inventory
as a list of components with different types (e.g., chassis, module,
port).
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+--ro components
+--ro component* [uuid]
+--ro uuid yang:uuid
+--ro name? string
+--ro description? string
+--ro class? identityref
+--ro contained-child* -> ../uuid
+--ro hardware-rev? string
+--ro firmware-rev? string
+--ro software-rev? string
+--ro serial-num? string
+--ro mfg-name? string
+--ro asset-id? string
+--ro is-fru? boolean
+--ro mfg-date? yang:date-and-time
+--ro uri* inet:uri
Some of the definitions taken from [RFC8348] are actually based on
the ENTITY-MIB [RFC6933].
For the component location information, the suggested pattern is the
same as the pattern defined in section 4.2 of [ONF_TR-547] for the
INVENTORY_ID property.
In this draft the term 'chassis' is used instead of the term 'shelf',
used in [ONF_TR-547], since the term 'chassis' has broader
applicability than the term 'shelf' and it is aligned with the
terminology of [RFC8348]. However, the component location string
will use the acronyms 'sh' and 's_sh' for consistency with the
[ONF_TR-547] definitions.
Table 2 summarizes the relationship between the <field> defined in
[ONF_TR-547] and the components defined in this document.
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+=========+=======================+
| <field> | meaning |
+=========+=======================+
| ne | network element |
+---------+-----------------------+
| r | rack |
+---------+-----------------------+
| sh | chassis component |
+---------+-----------------------+
| s_sh | sub-chassis component |
+---------+-----------------------+
| sl | slot component |
+---------+-----------------------+
| s_sl | sub-slot component |
+---------+-----------------------+
| p | port component |
+---------+-----------------------+
Table 2: Meaning of <field>
This pattern is a common practice in optical transport networks, but
we consider it as also applicable for other technologies.
For state data like admin-state, oper-state and so on, we consider
they are related to device hardware management and not hardware
inventory. Therefore, they are outside of scope of this document.
Same for the sensor-data, they should be defined in some other
performance monitoring data models instead of inventory data model.
We re-defined some attributes listed in [RFC8348], based on some
integration experience for network wide inventory data.
2.1.3. Changes with respect to RFC8348
2.1.3.1. New Parent Identifiers' Reference
[RFC8348] provided a "parent-ref" attribute, which was an identifier
reference to its parent component. When the MDSC or OSS systems want
to find this component's grandparent or higher level component in the
hierarchy, they need to retrieve this parent-ref step by step. To
reduce this iterative work, we decided to provide a list of
hierarchical parent components' identifier references.
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+--ro components
+--ro component* [uuid]
...................................
+--ro parent-component-references
| +--ro component-reference* [index]
| +--ro index uint8
| +--ro class? -> ../../../class
| +--ro uuid? -> ../../../uuid
...................................
The hierarchical components' identifier could be found by the
"component-reference" list. The "index" attribute is used to order
the list by the hierarchical relationship from topmost component
(with the "index" set to 0) to bottom component.
2.1.3.2. Component-Specific Info Design
According to the management requirements from operators, some
important attributes are not defined in [RFC8348]. These attributes
could be component-specific and are not suitable to define under the
component list node. So, we defined a choice-case structure for this
component-specific extension, as follows:
+--ro components
+--ro component* [uuid]
...................................
+--ro (component-class)?
+--:(chassis)
| +--ro chassis-specific-info
+--:(container)
| +--ro slot-specific-info
+--:(module)
| +--ro board-specific-info
+--:(port)
+--ro port-specific-info
...................................
Note: The detail of each *-specific-info YANG container is still
under discussion, and the leaf attributes will be defined in future.
2.1.3.3. Part Number
According to the description in [RFC8348], the attribute named
"model-name" under the component, is preferred to have a customer-
visible part number value. "Model-name" is not straightforward to
understand and we suggest to rename it as "part-number" directly.
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+--ro components
+--ro component* [uuid]
...................................
+--ro part-number? string
...................................
2.1.4. Equipment Room
Usually the information about equipment rooms is not detectable by
domain controller and configured manually. Sometimes, this
information is not configured in the domain controller but directly
in the Operators' owned OSS and therefore reporting information about
the equipment rooms is optional when implementing this data model.
Another scenario to analyze is when racks are not located in any
equipment room: one possible solution is that the domain controller
provides a "default" equipment room that contains all these racks.
Note: add some more attributes about equipment room in the future.
2.1.5. Rack
Likewise for equipment rooms, usually the information about the rack
is not detectable by domain controller and configured manually.
Therefore reporting information about the racks is optional when
implementing this data model.
Besides the common attributes mentioned in above section, rack could
have some specific attributes, such as appearance-related attributes
and electricity-related attributes. The height, depth and width are
described by the figure below (please consider that the door of the
rack is facing the user):
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---------------- ---
/| /| |
/ | / | |
/ | / | |
----|-----------| | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | height
| | | | |
| | | | |
| | | | |
| | Door Q | | |
| | Q | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| | | | |
| /-----------|---- ---
| / | / /
| / | / depth
|/ | / /
----------------- ---
|______width____|
| |
Figure 2: height, width and depth of rack
The rack attributes include:
+--ro racks
+--ro rack* [uuid]
...................................
+--ro height? uint16
+--ro width? uint16
+--ro depth? uint16
+--ro max-voltage? uint16
...................................
Max-voltage: the maximum voltage supported by the rack.
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2.1.6. Network Element
We consider that some of the attributes defined in [RFC8348] for
components are also applicable for network element. These attributes
include:
+--ro network-elements
+--ro network-element* [uuid]
...................................
+--ro hardware-rev? string
+--ro software-rev? string
+--ro mfg-name? string
+--ro mfg-date? yang:date-and-time
+--ro part-number? string
+--ro serial-number? string
+--ro product-name? string
...................................
Note: Not all the attributes defined in [RFC8348] are applicable for
network element. And there could also be some missing attributes
which are not recognized by [RFC8348]. More extensions could be
introduced in later revisions after the missing attributes are fully
discussed.
2.1.7. Relationship between Hardware Inventory and Network Topology
models
Network topology is a logical abstraction based on hardware inventory
objects. The abstraction may be based on technology requirements
(e.g., layer 0 or layer 1 resources) or on some specific requirements
(e.g., for path computation or service provisioning).
Therefore the relationship between hardware inventory objects and
network topology objects can be 1:N (N>=1).
Taking the Optical technology as example, an Optical Transport
Network (OTN) Network Element (NE) can be installed with several
kinds of boards, including an Ethernet client signal switching board,
a line board which is used for OTN layer switching. This line board
may also be used as a starting point for the WDM layer. In terms of
technologies, this OTN NE supports multi-layer network topology
connections, so that it should appear in L0, L1 and L2 network
topology.
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It is important to describe this relationship for the sake of network
Operation and Maintenance (O&M). For example, the actual path of a
connection is described by the objects in network topology. When
there is a failure along this connection, the O&M engineers are more
concerned with the physical location information behind the network
objects for troubleshooting.
Generally speaking, a node object in the network topology corresponds
to a network element object in the hardware inventory. A Link
Termination Point (LTP) object in the network topology corresponds to
a port component in the hardware inventory. A link object in the
network topology corresponds to a fiber/cable object in the hardware
inventory.
NOTE: take fiber&cable object into scope in the future version.
Compared with network topology, hardware inventory objects are the
most basic of the network: from an automation perspective, the MDSC
or OSS systems would integrate with hardware inventory data before
network topology data.
Therefore it is better to keep separated the network topology
information and the hardware inventory information: the "ietf-hw-
inventory-ref-topo" YANG module provides this relationship augmenting
the network topology model, when required, with references between
network topology objects and corresponding hardware inventory
objects.
This figure below shows the relationship between the three modules:
+------------------+
| Network topology |
| module |
+------------------+
^
|
|augments
|
+------------------+ +------------------+
| ietf-hw-inventory| imports | ietf-network-hard|
| -ref-topo |--------> | ware-inventory |
+------------------+ +------------------+
Figure 3: Relationship between the three YANG modules
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module: ietf-hw-inventory-ref-topo
augment /nw:networks/nw:network/nw:node:
+--ro inventory-id? leafref
augment /nw:networks/nw:network/nw:node/nt:termination-point:
+--ro inventory-id? leafref
NOTE: the association between a link and a fiber&cable object has to
be added in the future version.
2.2. Efficiency Issue
During the integration with OSS in some operators, some efficiency/
scalability concerns have been discovered when synchronizing network
hardware inventory data for big networks. More discussions are
needed to address these concerns.
Considering that relational databases are widely used by traditional
OSS systems and also by some network controllers, the inventory
objects are most likely to be saved in different tables. With the
model defined in current draft, when doing a full synchronization,
network controller needs to convert all inventory objects of each NE
into component objects and combine them together into a single list,
and then construct a response and send to OSS or MDSC. The OSS or
MDSC needs to classify the component list and divide them into
different groups, in order to save them in different tables. The
combining-regrouping steps are impacting the network controller &
OSS/MDSC processing, which may result in efficiency/scalability
limitations in large scale networks.
An alternative YANG model structure, which defines the inventory
objects directly, instead of defining generic components, has also
been analyzed. However, also with this model, there still could be
some scalability limitations when synchronizing full inventory
resources in large scale of networks. This scalability limitation is
caused by the limited transmission capabilities of HTTP protocol. We
think that this scalability limitation should be solved at protocol
level rather than data model level.
The model proposed by this draft is designed to be as generic as
possible so to cover future special types of inventory objects that
could be used in other technologies, that have not been identified
yet. If the inventory objects were to be defined directly with fixed
hierarchical relationships in YANG model, this new type of inventory
objects needs to be manually defined, which is not a backward