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draft-ietf-netconf-udp-notif-13.txt
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NETCONF G. Zheng
Internet-Draft T. Zhou
Intended status: Standards Track Huawei
Expires: 29 December 2024 T. Graf
Swisscom
P. Francois
A. Huang Feng
INSA-Lyon
P. Lucente
NTT
27 June 2024
UDP-based Transport for Configured Subscriptions
draft-ietf-netconf-udp-notif-13
Abstract
This document describes a UDP-based protocol for YANG notifications
to collect data from network nodes. A shim header is proposed to
facilitate the data streaming directly from the publishing process on
network processor of line cards to receivers. The objective is to
provide a lightweight approach to enable higher frequency and less
performance impact on publisher and receiver processes compared to
already established notification mechanisms.
Requirements Language
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.
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."
Zheng, et al. Expires 29 December 2024 [Page 1]
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This Internet-Draft will expire on 29 December 2024.
Copyright Notice
Copyright (c) 2024 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
2. Configured Subscription to UDP-Notif . . . . . . . . . . . . 4
3. UDP-Based Transport . . . . . . . . . . . . . . . . . . . . . 5
3.1. Design Overview . . . . . . . . . . . . . . . . . . . . . 5
3.2. Format of the UDP-Notif Message Header . . . . . . . . . 5
3.3. Data Encoding . . . . . . . . . . . . . . . . . . . . . . 8
4. Options . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.1. Segmentation Option . . . . . . . . . . . . . . . . . . . 9
4.2. Private Encoding Option . . . . . . . . . . . . . . . . . 10
5. Applicability . . . . . . . . . . . . . . . . . . . . . . . . 11
5.1. Congestion Control . . . . . . . . . . . . . . . . . . . 11
5.2. Message Size . . . . . . . . . . . . . . . . . . . . . . 12
5.3. Reliability . . . . . . . . . . . . . . . . . . . . . . . 12
6. Secured layer for UDP-Notif . . . . . . . . . . . . . . . . . 12
6.1. Session lifecycle . . . . . . . . . . . . . . . . . . . . 13
6.1.1. DTLS Session Initiation . . . . . . . . . . . . . . . 13
6.1.2. Publish Data . . . . . . . . . . . . . . . . . . . . 13
6.1.3. Session termination . . . . . . . . . . . . . . . . . 14
7. A YANG Data Model for Management of UDP-Notif . . . . . . . . 14
7.1. YANG to configure UDP-Notif . . . . . . . . . . . . . . . 14
7.2. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 16
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19
8.1. IANA registries . . . . . . . . . . . . . . . . . . . . . 20
8.2. URI . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
8.3. YANG module name . . . . . . . . . . . . . . . . . . . . 21
8.4. Default Port number . . . . . . . . . . . . . . . . . . . 21
9. Implementation Status . . . . . . . . . . . . . . . . . . . . 22
9.1. Open Source Publisher . . . . . . . . . . . . . . . . . . 22
9.2. Open Source Receiver Library . . . . . . . . . . . . . . 22
9.3. Pmacct Data Collection . . . . . . . . . . . . . . . . . 22
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9.4. Huawei VRP . . . . . . . . . . . . . . . . . . . . . . . 22
10. Security Considerations . . . . . . . . . . . . . . . . . . . 22
11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 23
12. References . . . . . . . . . . . . . . . . . . . . . . . . . 23
12.1. Normative References . . . . . . . . . . . . . . . . . . 23
12.2. Informative References . . . . . . . . . . . . . . . . . 25
Appendix A. UDP-Notif Examples . . . . . . . . . . . . . . . . . 26
A.1. Configuration for UDP-Notif transport with DTLS
disabled . . . . . . . . . . . . . . . . . . . . . . . . 27
A.2. Configuration for UDP-Notif transport with DTLS
enabled . . . . . . . . . . . . . . . . . . . . . . . . . 28
A.3. YANG Push message with UDP-Notif transport protocol . . . 30
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 31
1. Introduction
The mechanism to support a subscription of a continuous and
customized stream of updates from a YANG datastore [RFC8342] is
defined in [RFC8639] and [RFC8641] and is abbreviated as Sub-Notif.
Requirements for Subscription to YANG Datastores are defined in
[RFC7923].
The mechanism separates the management and control of subscriptions
from the transport used to deliver the data. Three transport
mechanisms, namely NETCONF transport [RFC8640], RESTCONF transport
[RFC8650], and HTTPS transport [I-D.ietf-netconf-https-notif] have
been defined so far for such notification messages.
While powerful in their features and general in their architecture,
the currently available transport mechanisms need to be complemented
to support data publications at high velocity from network nodes that
feature a distributed architecture. The currently available
transports are based on TCP and lack the efficiency needed to
continuously send notifications at high velocity.
This document specifies a transport option for Sub-Notif that
leverages UDP. Specifically, it facilitates the distributed data
collection mechanism described in
[I-D.ietf-netconf-distributed-notif]. In the case of publishing from
multiple network processors on multiple line cards, centralized
designs require data to be internally forwarded from those network
processors to the push server, presumably on a route processor, which
then combines the individual data items into a single consolidated
stream. The centralized data collection mechanism can result in a
performance bottleneck, especially when large amounts of data are
involved.
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What is needed is a mechanism that allows for directly publishing
from multiple network processors on line cards, without passing them
through an additional processing stage for internal consolidation.
The proposed UDP-based transport allows for such a distributed data
publishing approach.
* Firstly, a UDP approach reduces the burden of maintaining a large
amount of active TCP connections at the receiver, notably in cases
where it collects data from network processors on line cards from
a large amount of network nodes.
* Secondly, as no connection state needs to be maintained, UDP
encapsulation can be easily implemented by the hardware of the
publication streamer, which further improves performance.
* Ultimately, such advantages allow for a larger data analysis
feature set, as more voluminous, finer grained data sets can be
streamed to the receiver.
The transport described in this document can be used for transmitting
notification messages over both IPv4 and IPv6.
This document describes the notification mechanism. It is intended
to be used in conjunction with [RFC8639], extended by
[I-D.ietf-netconf-distributed-notif].
Section 2 describes the control of the proposed transport mechanism.
Section 3 details the notification mechanism and message format.
Section 4 describes the use of options in the notification message
header. Section 5 covers the applicability of the proposed
mechanism. Section 6 describes a mechanism to secure the protocol in
open networks.
2. Configured Subscription to UDP-Notif
This section describes how the proposed mechanism can be controlled
using subscription channels based on NETCONF or RESTCONF.
As specified in Sub-Notif, configured subscriptions contain the
location information of all the receivers, including the IP address
and the port number, so that the publisher can actively send UDP-
Notif messages to the corresponding receivers.
Note that receivers MAY NOT be already up and running when the
configuration of the subscription takes effect on the monitored
network node. The first message MUST be a separate subscription-
started notification to indicate the Receiver that the stream has
started flowing. Then, the notifications can be sent immediately
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without delay. All the subscription state notifications, as defined
in Section 2.7 of [RFC8639], MUST be encapsulated in separate
notification messages.
Note also that the receiver nodes can be different from the nodes
managing the subscription. Therefore, publishers MAY NOT be aware of
the capabilities supported by the receivers.
3. UDP-Based Transport
In this section, we specify the UDP-Notif Transport behavior.
Section 3.1 describes the general design of the solution.
Section 3.2 specifies the UDP-Notif message format and Section 3.3
describes the encoding of the message payload.
3.1. Design Overview
As specified in Sub-Notif, the YANG data is encapsulated in a
NETCONF/RESTCONF notification message, which is then encapsulated and
carried using a transport protocols such as TLS or HTTP2. This
document defines a UDP based transport. Figure 1 illustrates the
structure of an UDP-Notif message.
* The Message Header contains information that facilitate the
message transmission before deserializing the notification
message.
* Notification Message is the encoded content that is transported by
the publication stream. The common encoding methods are listed in
Section 3.2. The structure of the Notification Message is defined
in Section 2.6 of [RFC8639] and a YANG model has been proposed in
[I-D.ahuang-netconf-notif-yang].
[I-D.ietf-netconf-notification-messages] proposes a structure to
send bundled notifications in a single message.
+-------+ +--------------+ +--------------+
| UDP | | Message | | Notification |
| | | Header | | Message |
+-------+ +--------------+ +--------------+
Figure 1: UDP-Notif Message Overview
3.2. Format of the UDP-Notif Message Header
The UDP-Notif Message Header contains information that facilitate the
message transmission before deserializing the notification message.
The data format is shown in Figure 2.
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-----+-+-------+---------------+-------------------------------+
| Ver |S| MT | Header Len | Message Length |
+-----+-+-------+---------------+-------------------------------+
| Message Publisher ID |
+---------------------------------------------------------------+
| Message ID |
+---------------------------------------------------------------+
~ Options ~
+---------------------------------------------------------------+
Figure 2: UDP-Notif Message Header Format
The Message Header contains the following field:
* Ver indicates the UDP-Notif protocol header version. The values
are allocated by the IANA registry "UDP-Notif header version".
The current header version number is 1.
* S represents the space of media type specified in the MT field.
When S is unset, MT represents the standard media types as defined
in this document. When S is set, MT represents a private space to
be freely used for non standard encodings. When S is set, the
Private Encoding Option defined in Section 4.2 SHOULD be present
in the UDP-Notif message header.
* MT is a 4 bit identifier to indicate the media type used for the
Notification Message. 16 types of encoding can be expressed. When
the S bit is unset, the following values apply:
- 0: Reserved;
- 1: application/yang-data+json [RFC8040]
- 2: application/yang-data+xml [RFC8040]
- 3: application/yang-data+cbor [RFC9254]
* Header Len is the length of the message header in octets,
including both the fixed header and the options.
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* Message Length is the total length of the UDP-Notif message within
one UDP datagram, measured in octets, including the message
header. When the Notification Message is segmented using the
Segmentation Options defined in Section 4.1 the Message Length is
the total length of the current, segmented UDP-Notif message, not
the length of the entire Notification message.
* Message Publisher ID is a 32-bit identifier defined in
[I-D.ietf-netconf-distributed-notif]. This identifier is unique
to the publisher node and identifies the publishing process of the
node to allow the disambiguation of an information source.
Message unicity is obtained from the conjunction of the Message
Publisher ID and the Message ID field described below. If Message
Publisher ID unicity is not preserved through the collection
domain, the source IP address of the UDP datagram SHOULD be used
in addition to the Message Publisher ID to identify the
information source. If a transport layer relay is used, Message
Publisher ID unicity must be preserved through the collection
domain.
* The Message ID is generated continuously by the publisher of UDP-
Notif messages. A publisher MUST use different Message ID values
for different messages generated with the same Message Publisher
ID. Note that the main purpose of the Message ID is to
reconstruct messages which are segmented using the segmentation
option described in section Section 4.1. The Message ID values
SHOULD be incremented by one for each successive message
originated with the same Message Publisher ID, so that message
loss can be detected. When the last value (2^32-1) of Message ID
has been generated, the Message ID wraps around and restarts at 0.
Different subscribers MAY share the same Message ID sequence.
* Options is a variable-length field in the TLV format. When the
Header Length is larger than 12 octets, which is the length of the
fixed header, Options TLVs follow directly after the fixed message
header (i.e., Message ID). The details of the options are
described in Section 4.
All the binary fields MUST be encoded in network byte order (big
endian).
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3.3. Data Encoding
UDP-Notif message data can be encoded in CBOR, XML or JSON format.
It is conceivable that additional encodings may be supported in the
future. This can be accomplished by augmenting the subscription data
model with additional identity statements used to refer to requested
encodings.
Private encodings can be using the S bit of the header. When the S
bit is set, the value of the MT field is left to be defined and
agreed upon by the users of the private encoding. An option is
defined in Section 4.2 for more verbose encoding descriptions than
what can be described with the MT field.
Implementation MAY support multiple encoding methods per
subscription. When bundled notifications are supported between the
publisher and the receiver, only subscribed notifications with the
same encoding can be bundled in a given message.
4. Options
All the options are defined with the following format, illustrated in
Figure 3.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+---------------+---------------+--------------------------------
| Type | Length | Variable-length data
+---------------+---------------+--------------------------------
Figure 3: Generic Option Format
* Type: 1 octet describing the option type;
* Length: 1 octet representing the total number of octets in the
TLV, including the Type and Length fields;
* Variable-length data: 0 or more octets of TLV Value.
When more than one option is used in the UDP-Notif header, options
MUST be ordered by the Type value. Messages with unordered options
MAY be dropped by the Receiver.
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4.1. Segmentation Option
The UDP payload length is limited to 65527 bytes (65535 - 8 bytes).
Application level headers will make the actual payload shorter. Even
though binary encodings such as CBOR may not require more space than
what is left, more voluminous encodings such as JSON and XML may
suffer from this size limitation. Although IPv4 and IPv6 publishers
can fragment outgoing packets exceeding their Maximum Transmission
Unit (MTU), fragmented IP packets may not be desired for operational
and performance reasons.
Consequently, implementations of the mechanism SHOULD provide a
configurable max-segment-size option to control the maximum size of a
payload.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+---------------+---------------+-----------------------------+-+
| Type | Length | Segment Number |L|
+---------------+---------------+-----------------------------+-+
Figure 4: Segmentation Option Format
The Segmentation Option is to be included when the message content is
segmented into multiple segments. Different segments of one message
share the same Message ID. An illustration is provided in Figure 4.
The fields of this TLV are:
* Type: Generic option field which indicates a Segmentation Option.
The Type value is to be assigned TBD1.
* Length: Generic option field which indicates the length of this
option in octets. It is a fixed value of 4 octets for the
Segmentation Option.
* Segment Number: 15-bit value indicating the sequence number of the
current segment. The first segment of a segmented message has a
Segment Number value of 0. The Segment Number cannot wrap around.
* L: is a flag to indicate whether the current segment is the last
one of the message. When 0 is set, the current segment is not the
last one. When 1 is set, the current segment is the last one,
meaning that the total number of segments used to transport this
message is the value of the current Segment Number + 1.
An implementation of this specification SHOULD NOT rely on IP
fragmentation by default to carry large messages. An implementation
of this specification SHOULD either restrict the size of individual
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messages carried over this protocol, or support the segmentation
option. The implementor or user SHOULD take into account the IP
layer header size when setting the max-segment-size parameter to
avoid fragmentation at the IP layer.
When a message has multiple options and is segmented using the
described mechanism, all the options MUST be present on the first
segment ordered by the options Type. The rest of segmented messages
MAY include all the options ordered by options type.
The receiver SHOULD support the reception of unordered segments. The
implementation of the receiver SHOULD provide an option to discard
the received segments if, after some time, one of the segments is
still missing and the reassembly of the message is not possible. If
the receiver collects a segment more than once, the implementation
SHOULD drop the duplicate segment.
4.2. Private Encoding Option
The space to describe private encodings in the MT field of the UDP-
Notif header being limited, an option is provided to describe custom
encodings. The fields of this option are as follows.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+---------------+---------------+--------------------------------
| Type | Length | Variable length enc. descr.
+---------------+---------------+--------------------------------
Figure 5: Private Encoding Option Format
* Type: Generic option field which indicates a Private Encoding
Option. The Type value is to be assigned TBD2.
* Length: Generic option field which indicates the length of this
option in octets. It is a variable value.
* Enc. Descr: The description of the private encoding used for this
message. The values to be used for such private encodings is left
to be defined by the users of private encodings.
This option SHOULD only be used when the S bit of the header is set,
as providing a private encoding description for standard encodings is
meaningless.
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5. Applicability
In this section, we provide an applicability statement for the
proposed mechanism, following the recommendations of [RFC8085].
The proposed mechanism falls in the category of UDP applications
"designed for use within the network of a single network operator or
on networks of an adjacent set of cooperating network operators, to
be deployed in controlled environments", as defined in [RFC8085].
Implementations of the proposed mechanism SHOULD thus follow the
recommendations in place for such specific applications. In the
following, we discuss recommendations on congestion control, message
size guidelines, reliability considerations and security
considerations.
The main use case of the proposed mechanism is the collection of
statistical metrics for accounting purposes, where potential loss is
not a concern, but should however be reported (such as IPFIX Flow
Records exported with UDP [RFC7011]). Such metrics are typically
exported in a periodical subscription as described in Section 3.1 of
[RFC8641].
5.1. Congestion Control
The proposed application falls into the category of applications
performing transfer of large amounts of data. It is expected that
the operator using the solution configures QoS on its related flows.
As per [RFC8085], such applications MAY choose not to implement any
form of congestion control, but follow the following principles.
It is NOT RECOMMENDED to use the proposed mechanism over congestion-
sensitive network paths. The only environments where UDP-Notif is
expected to be used are managed networks. The deployments require
that the network path has been explicitly provisioned to handle the
traffic through traffic engineering mechanisms, such as rate limiting
or capacity reservations.
Implementation of the proposal SHOULD NOT push unlimited amounts of
traffic by default, and SHOULD require the users to explicitly
configure such a mode of operation.
Burst mitigation through packet pacing is RECOMMENDED. Disabling
burst mitigation SHOULD require the users to explicitly configure
such a mode of operation.
Applications SHOULD monitor packet losses and provide means to the
user for retrieving information on such losses. The UDP-Notif
Message ID can be used to deduce congestion based on packet loss
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detection. Hence the receiver can notify the Publisher to use a
lower streaming rate. The interaction to control the streaming rate
on the Publisher is out of the scope of this document.
5.2. Message Size
[RFC8085] recommends not to rely on IP fragmentation for messages
whose size result in IP packets exceeding the MTU along the path.
The segmentation option of the current specification permits
segmentation of the UDP Notif message content without relying on IP
fragmentation. Implementation of the current specification SHOULD
allow for the configuration of the MTU.
It is RECOMMENDED that the size of a Notification Message is small
and segmentation does not result in segmenting the message into too
much segments to avoid dropping the entire message when there is a
lost segment. When a Notification Message is large, it is
RECOMMENDED to use a reliable transport such as HTTPS-notif
[I-D.ietf-netconf-https-notif].
5.3. Reliability
A receiver implementation for this protocol SHOULD deal with
potential loss of packets carrying a part of segmented payload, by
discarding packets that were received, but cannot be re-assembled as
a complete message within a given amount of time. This time SHOULD
be configurable.
6. Secured layer for UDP-Notif
In unsecured networks, UDP-Notif messages MUST be secured or
encrypted. In this section, a mechanism using DTLS 1.3 to secure
UDP-Notif protocol is presented. The following sections defines the
requirements for the implementation of the secured layer of DTLS for
UDP-Notif. No DTLS 1.3 extensions are defined in this document.
The DTLS 1.3 protocol [RFC9147] is designed to meet the requirements
of applications that need to secure datagram transport.
Implementations using DTLS to secure UDP-Notif messages MUST use DTLS
1.3 protocol as defined in [RFC9147].
When this security layer is used, the Publisher MUST always be a DTLS
client, and the Receiver MUST always be a DTLS server. The Receivers
MUST support accepting UDP-Notif Messages on the specified UDP port,
but MAY be configurable to listen on a different port. The Publisher
MUST support sending UDP-Notif messages to the specified UDP port,
but MAY be configurable to send messages to a different port. The
Publisher MAY use any source UDP port for transmitting messages.
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6.1. Session lifecycle
This section describes the lifecycle of UDP-Notif messages when they
are excrypted using DTLS.
6.1.1. DTLS Session Initiation
The Publisher initiates a DTLS connection by sending a DTLS
ClientHello to the Receiver. Implementations MAY support the denial
of service countermeasures defined by DTLS 1.3 if a given deployment
can ensure that DoS attacks are not a concern. When these
countermeasures are used, the Receiver responds with a DTLS
HelloRetryRequest containing a stateless cookie. The Publisher sends
a second DTLS ClientHello message containing the received cookie.
Details can be found in Section 5.1 of [RFC9147].
When DTLS is implemented, the Publisher MUST NOT send any UDP-Notif
messages before the DTLS handshake has successfully completed. Early
data mechanism (also known as 0-RTT data) as defined in [RFC9147]
MUST NOT be used.
Implementations of this security layer MUST support DTLS 1.3
[RFC9147] and MUST support the mandatory to implement cipher suite
TLS_AES_128_GCM_SHA256 and SHOULD implement TLS_AES_256_GCM_SHA384
and TLS_CHACHA20_POLY1305_SHA256 cipher suites, as specified in TLS
1.3 [RFC8446]. If additional cipher suites are supported, then
implementations MUST NOT negotiate a cipher suite that employs NULL
integrity or authentication algorithms.
Where confidentiality protection with DTLS is required,
implementations must negotiate a cipher suite that employs a non-NULL
encryption algorithm.
6.1.2. Publish Data
When DTLS is used, all UDP-Notif messages MUST be published as DTLS
"application_data". It is possible that multiple UDP-Notif messages
are contained in one DTLS record, or that a publication message is
transferred in multiple DTLS records. The application data is
defined with the following ABNF [RFC5234] expression:
APPLICATION-DATA = 1*UDP-NOTIF-FRAME
UDP-NOTIF-FRAME = MSG-LEN SP UDP-NOTIF-MSG
MSG-LEN = NONZERO-DIGIT *DIGIT
SP = %d32
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NONZERO-DIGIT = %d49-57
DIGIT = %d48 / NONZERO-DIGIT
UDP-NOTIF-MSG is defined in Section 3.
The Publisher SHOULD attempt to avoid IP fragmentation by using the
Segmentation Option in the UDP-Notif message.
6.1.3. Session termination
A Publisher MUST close the associated DTLS connection if the
connection is not expected to deliver any UDP-Notif Messages later.
It MUST send a DTLS close_notify alert before closing the connection.
A Publisher (DTLS client) MAY choose to not wait for the Receiver's
close_notify alert and simply close the DTLS connection. Once the
Receiver gets a close_notify from the Publisher, it MUST reply with a
close_notify.
When no data is received from a DTLS connection for a long time, the
Receiver MAY close the connection. Implementations SHOULD set the
timeout value to 10 minutes but application specific profiles MAY
recommend shorter or longer values. The Receiver (DTLS server) MUST
attempt to initiate an exchange of close_notify alerts with the
Publisher before closing the connection. Receivers that are
unprepared to receive any more data MAY close the connection after
sending the close_notify alert.
Although closure alerts are a component of TLS and so of DTLS, they,
like all alerts, are not retransmitted by DTLS and so may be lost
over an unreliable network.
7. A YANG Data Model for Management of UDP-Notif
7.1. YANG to configure UDP-Notif
The YANG model described in Section 7.2 defines a new receiver
instance for UDP-Notif transport. When this transport is used, four
new leaves and a dtls container allow configuring UDP-Notif receiver
parameters.
The source address of the UDP-Notif message can be configured using
the "source-address" leaf at the subscription level as defined in
Section 2.5 of [RFC8639] or by setting the leaf "local-address" using
the YANG model proposed in this document. When both are configured,
the UDP-Notif message MUST use the address configured in the "local-
address" leaf defined in the YANG proposed in this document.
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module: ietf-udp-notif-transport
augment /sn:subscriptions/snr:receiver-instances
/snr:receiver-instance/snr:transport-type:
+--:(udp-notif)
+--rw udp-notif-receiver
+--rw remote-address inet:host
+--rw remote-port? inet:port-number
+--rw local-address? inet:ip-address
| {local-binding-supported}?
+--rw local-port? inet:port-number
| {local-binding-supported}?
+--rw dtls! {dtls13}?
| +--rw client-identity!
| | +--rw (auth-type)
| | +--:(certificate) {client-ident-x509-cert}?
| | | ...
| | +--:(raw-public-key)
| | | {client-ident-raw-public-key}?
| | | ...
| | +--:(tls13-epsk) {client-ident-tls13-epsk}?
| | ...
| +--rw server-authentication
| | +--rw ca-certs! {server-auth-x509-cert}?
| | | +--rw (local-or-truststore)
| | | ...
| | +--rw ee-certs! {server-auth-x509-cert}?
| | | +--rw (local-or-truststore)
| | | ...
| | +--rw raw-public-keys! {server-auth-raw-public-key}?
| | | +--rw (local-or-truststore)
| | | ...
| | +--rw tls13-epsks? empty
| | {server-auth-tls13-epsk}?
| +--rw hello-params {tlscmn:hello-params}?
| | +--rw tls-versions
| | | +--rw tls-version* identityref
| | +--rw cipher-suites
| | +--rw cipher-suite* identityref
| +--rw keepalives {tls-client-keepalives}?
| +--rw peer-allowed-to-send? empty
| +--rw test-peer-aliveness!
| +--rw max-wait? uint16
| +--rw max-attempts? uint8
+--rw enable-segmentation? boolean {segmentation}?
+--rw max-segment-size? uint32 {segmentation}?
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7.2. YANG Module
This YANG module is used to configure, on a publisher, a receiver
willing to consume notification messages. This module augments the
"ietf-subscribed-notif-receivers" module to define a UDP-Notif
transport receiver. The grouping "udp-notif-receiver-grouping"
defines the necessary parameters to configure the transport defined
in this document using the generic "udp-client-grouping" grouping
from the "ietf-udp-client" module
[I-D.ahuang-netconf-udp-client-server] and the "tls-client-grouping"
defined in the "ietf-tls-client" module
[I-D.ietf-netconf-tls-client-server].
<CODE BEGINS> file "ietf-udp-notif-transport@2024-06-19.yang"
module ietf-udp-notif-transport {
yang-version 1.1;
namespace
"urn:ietf:params:xml:ns:yang:ietf-udp-notif-transport";
prefix unt;
import ietf-subscribed-notifications {
prefix sn;
reference
"RFC 8639: Subscription to YANG Notifications";
}
import ietf-subscribed-notif-receivers {
prefix snr;
reference
"RFC YYYY: An HTTPS-based Transport for
Configured Subscriptions";
}
import ietf-udp-client {
prefix udpc;
reference
"RFC ZZZZ: YANG Grouping for UDP Clients and UDP Servers";
}
import ietf-tls-client {
prefix tlsc;
reference
"RFC TTTT: YANG Groupings for TLS Clients and TLS Servers";
}
organization "IETF NETCONF (Network Configuration) Working Group";
contact
"WG Web: <http:/tools.ietf.org/wg/netconf/>
WG List: <mailto:netconf@ietf.org>
Authors: Guangying Zheng
<mailto:zhengguangying@huawei.com>
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Tianran Zhou
<mailto:zhoutianran@huawei.com>
Thomas Graf
<mailto:thomas.graf@swisscom.com>
Pierre Francois
<mailto:pierre.francois@insa-lyon.fr>
Alex Huang Feng
<mailto:alex.huang-feng@insa-lyon.fr>
Paolo Lucente
<mailto:paolo@ntt.net>";
description
"Defines UDP-Notif as a supported transport for subscribed
event notifications.
Copyright (c) 2024 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, is permitted pursuant to, and subject to the license
terms contained in, the Revised BSD License set forth in Section
4.c of the IETF Trust's Legal Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC-to-be; see the RFC
itself for full legal notices.";
revision 2024-06-19 {
description
"Initial revision";
reference
"RFC-to-be: UDP-based Transport for Configured Subscriptions";
}
/*
* FEATURES
*/
feature encode-cbor {
description
"This feature indicates that CBOR encoding of notification
messages is supported.";
}
feature dtls13 {
description
"This feature indicates that DTLS 1.3 encryption of UDP
packets is supported.";
}
feature segmentation {
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description
"This feature indicates segmentation of notification messages
is supported.";
}
/*
* IDENTITIES
*/
identity udp-notif {
base sn:transport;
description
"UDP-Notif is used as transport for notification messages
and state change notifications.";
}
identity encode-cbor {
base sn:encoding;
description
"Encode data using CBOR as described in RFC 9254.";
reference
"RFC 9254: CBOR Encoding of Data Modeled with YANG";
}
grouping udp-notif-receiver-grouping {
description
"Provides a reusable description of a UDP-Notif target
receiver.";
uses udpc:udp-client-grouping {
refine remote-port {
default 10000;
}
}
container dtls {
if-feature dtls13;
presence dtls;
uses tlsc:tls-client-grouping {
// Using tls-client-grouping without TLS1.2 parameters
// allowing only DTLS 1.3
refine "client-identity/auth-type/tls12-psk" {
// create the logical impossibility of enabling TLS1.2
if-feature "not tlsc:client-ident-tls12-psk";
}