< draft-ietf-netconf-udp-notif-01.txt   draft-ietf-netconf-udp-notif-02.txt >
NETCONF G. Zheng NETCONF G. Zheng
Internet-Draft T. Zhou Internet-Draft T. Zhou
Intended status: Standards Track Huawei Intended status: Standards Track Huawei
Expires: 6 May 2021 T. Graf Expires: November 27, 2021 T. Graf
Swisscom Swisscom
P. Francois P. Francois
INSA-Lyon INSA-Lyon
P. Lucente P. Lucente
NTT NTT
2 November 2020 May 26, 2021
UDP-based Transport for Configured Subscriptions UDP-based Transport for Configured Subscriptions
draft-ietf-netconf-udp-notif-01 draft-ietf-netconf-udp-notif-02
Abstract Abstract
This document describes an UDP-based notification mechanism to This document describes an UDP-based notification mechanism to
collect data from networking devices. A shim header is proposed to collect data from networking devices. A shim header is proposed to
facilitate the streaming of data directly from line cards to a facilitate the data streaming directly from the publishing process on
collector. The objective is to rely on a lightweight approach to network processor of line cards to receivers. The objective is a
allow for higher frequency and better transit performance compared to lightweight approach to enable higher frequency and less performance
already established notification mechanisms. impact on publisher and receiver process compared to already
established notification mechanisms.
Requirements Language Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119]. document are to be interpreted as described in RFC 2119 [RFC2119].
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
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Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/. Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on 6 May 2021. This Internet-Draft will expire on November 27, 2021.
Copyright Notice Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the Copyright (c) 2021 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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Provisions Relating to IETF Documents (https://trustee.ietf.org/ Provisions Relating to IETF Documents
license-info) in effect on the date of publication of this document. (https://trustee.ietf.org/license-info) in effect on the date of
Please review these documents carefully, as they describe your rights publication of this document. Please review these documents
and restrictions with respect to this document. Code Components carefully, as they describe your rights and restrictions with respect
extracted from this document must include Simplified BSD License text to this document. Code Components extracted from this document must
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provided without warranty as described in the Simplified BSD License. the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Configured Subscription to UDP-Notif . . . . . . . . . . . . 4 2. Configured Subscription to UDP-Notif . . . . . . . . . . . . 4
3. UDP-Based Transport . . . . . . . . . . . . . . . . . . . . . 4 3. UDP-Based Transport . . . . . . . . . . . . . . . . . . . . . 4
3.1. Design Overview . . . . . . . . . . . . . . . . . . . . . 4 3.1. Design Overview . . . . . . . . . . . . . . . . . . . . . 4
3.2. Format of the UDP-Notif Message Header . . . . . . . . . 5 3.2. Format of the UDP-Notif Message Header . . . . . . . . . 5
3.3. Options . . . . . . . . . . . . . . . . . . . . . . . . . 6 3.3. Options . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.3.1. Segmentation Option . . . . . . . . . . . . . . . . . 7 3.3.1. Segmentation Option . . . . . . . . . . . . . . . . . 7
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7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
8. Security Considerations . . . . . . . . . . . . . . . . . . . 13 8. Security Considerations . . . . . . . . . . . . . . . . . . . 13
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 13 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 13
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 13 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 13
10.1. Normative References . . . . . . . . . . . . . . . . . . 13 10.1. Normative References . . . . . . . . . . . . . . . . . . 13
10.2. Informative References . . . . . . . . . . . . . . . . . 15 10.2. Informative References . . . . . . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15
1. Introduction 1. Introduction
Sub-Notif [RFC8639] defines a mechanism that lets a collector Sub-Notif [RFC8639] defines a mechanism that lets a receiver
subscribe to the publication of YANG-defined data maintained in a subscribe to the publication of YANG-defined data maintained in a
YANG [RFC7950] datastore. The mechanism separates the management and YANG [RFC7950] datastore. The mechanism separates the management and
control of subscriptions from the transport used to deliver the data. control of subscriptions from the transport used to deliver the data.
Three transport mechanisms, namely NETCONF transport [RFC8640], Three transport mechanisms, namely NETCONF transport [RFC8640],
RESTCONF transport [RFC8650], and HTTPS transport RESTCONF transport [RFC8650], and HTTPS transport
[I-D.ietf-netconf-https-notif] have been defined so far for such [I-D.ietf-netconf-https-notif] have been defined so far for such
notification messages. notification messages.
While powerful in their features and general in their architecture, While powerful in their features and general in their architecture,
the currently available transport mechanisms need to be complemented the currently available transport mechanisms need to be complemented
to support data publications at high velocity from devices that to support data publications at high velocity from devices that
feature a distributed architecture. The currently available feature a distributed architecture. The currently available
transports are based on TCP and lack the efficiency needed to transports are based on TCP and lack the efficiency needed to
continuously send notifications at high velocity. continuously send notifications at high velocity.
This document specifies a transport option for Sub-Notif that This document specifies a transport option for Sub-Notif that
leverages UDP. Specifically, it facilitates the distributed data leverages UDP. Specifically, it facilitates the distributed data
collection mechanism described in collection mechanism described in
[I-D.ietf-netconf-distributed-notif]. In the case of data [I-D.ietf-netconf-distributed-notif]. In the case of publishing from
originating from multiple line cards, centralized designs require multiple network processors on multiple line cards, centralized
data to be internally forwarded from those line cards to the push designs require data to be internally forwarded from those network
server, presumably on a route processor, which then combines the processors to the push server, presumably on a route processor, which
individual data items into a single consolidated stream. The then combines the individual data items into a single consolidated
centralized data collection mechanism can result in a performance stream. The centralized data collection mechanism can result in a
bottleneck, especially when large amounts of data are involved. performance bottleneck, especially when large amounts of data are
involved.
What is needed is the support for a mechanism that allows for What is needed is a mechanism that allows for directly publishing
directly pushing multiple substreams, e.g. one from each line card, from multiple network processors on line cards, without passing them
without passing them through an additional processing stage for through an additional processing stage for internal consolidation.
internal consolidation. The proposed UDP-based transport allows for The proposed UDP-based transport allows for such a distributed data
such a distributed data collection approach. publishing approach.
* Firstly, a UDP approach reduces the burden of maintaining a large o Firstly, a UDP approach reduces the burden of maintaining a large
amount of active TCP connections at the collector, notably in amount of active TCP connections at the receiver, notably in cases
cases where it collects data from the line cards of a large amount where it collects data from network processors on line cards from
of networking devices. a large amount of networking devices.
* Secondly, as no connection state needs to be maintained, UDP o Secondly, as no connection state needs to be maintained, UDP
encapsulation can be easily implemented by the hardware of the encapsulation can be easily implemented by the hardware of the
publication streamer, which will further improve performance. publication streamer, which will further improve performance.
* Ultimately, such advantages allow for a larger data analysis o Ultimately, such advantages allow for a larger data analysis
feature set, as more voluminous, finer grained data sets can be feature set, as more voluminous, finer grained data sets can be
streamed to the collector. streamed to the receiver.
The transport described in this document can be used for transmitting The transport described in this document can be used for transmitting
notification messages over both IPv4 and IPv6. notification messages over both IPv4 and IPv6.
This document describes the notification mechanism. It is intended This document describes the notification mechanism. It is intended
to be used in conjunction with [RFC8639], extended by to be used in conjunction with [RFC8639], extended by
[I-D.ietf-netconf-distributed-notif]. [I-D.ietf-netconf-distributed-notif].
Section 2 describes the control of the proposed transport mechanism. Section 2 describes the control of the proposed transport mechanism.
Section 3 details the notification mechanism and message format. Section 3 details the notification mechanism and message format.
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Note that receivers MAY NOT be already up and running when the Note that receivers MAY NOT be already up and running when the
configuration of the subscription takes effect on the monitored configuration of the subscription takes effect on the monitored
device. The first message MUST be a separate subscription-started device. The first message MUST be a separate subscription-started
notification to indicate the Receiver that the stream has started notification to indicate the Receiver that the stream has started
flowing. Then, the notifications can be sent immediately without flowing. Then, the notifications can be sent immediately without
delay. All the subscription state notifications, as defined in delay. All the subscription state notifications, as defined in
[RFC8639], MUST be encapsulated in separate notification messages. [RFC8639], MUST be encapsulated in separate notification messages.
3. UDP-Based Transport 3. UDP-Based Transport
In this section, we specify the UDP-Notif Transport behaviour. In this section, we specify the UDP-Notif Transport behavior.
Section 3.1 describes the general design of the solution. Section 3.1 describes the general design of the solution.
Section 3.2 specifies the UDP-Notif message format. Section 3.3 Section 3.2 specifies the UDP-Notif message format. Section 3.3
describes a generic optional sub TLV format. Section 3.3.1 uses such describes a generic optional sub TLV format. Section 3.3.1 uses such
options to provide a segmentation solution for large UDP-Notif options to provide a segmentation solution for large UDP-Notif
message payloads. Section 3.4 describes the encoding of the message message payloads. Section 3.4 describes the encoding of the message
payload. payload.
3.1. Design Overview 3.1. Design Overview
As specified in Sub-Notif, the telemetry data is encapsulated in the As specified in Sub-Notif, the telemetry data is encapsulated in the
NETCONF/RESTCONF notification message, which is then encapsulated and NETCONF/RESTCONF notification message, which is then encapsulated and
carried using transport protocols such as TLS or HTTP2. Figure 1 carried using transport protocols such as TLS or HTTP2. Figure 1
illustrates the the structure of an UDP-Notif message. illustrates the structure of an UDP-Notif message.
* The Message Header contains information that facilitate the o The Message Header contains information that facilitate the
message transmission before deserializing the notification message transmission before deserializing the notification
message. message.
* Notification Message is the encoded content that the publication o Notification Message is the encoded content that the publication
stream transports. The common encoding methods include, CBOR stream transports. The common encoding methods include, CBOR
[RFC7049], JSON, and XML. [RFC7049], JSON, and XML.
[I-D.ietf-netconf-notification-messages] describes the structure [I-D.ietf-netconf-notification-messages] describes the structure
of the Notification Message for single notifications and bundled of the Notification Message for single notifications and bundled
notifications. notifications.
+-------+ +--------------+ +--------------+ +-------+ +--------------+ +--------------+
| UDP | | Message | | Notification | | UDP | | Message | | Notification |
| | | Header | | Message | | | | Header | | Message |
+-------+ +--------------+ +--------------+ +-------+ +--------------+ +--------------+
Figure 1: UDP-Notif Message Overview Figure 1: UDP-Notif Message Overview
3.2. Format of the UDP-Notif Message Header 3.2. Format of the UDP-Notif Message Header
The UDP-Notif Message Header contains information that facilitate the The UDP-Notif Message Header contains information that facilitate the
message transmission before deserializing the notification message. message transmission before deserializing the notification message.
The data format is shown in Figure 2. The data format is shown in Figure 2.
0 1 2 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 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
+-----+-+-------+---------------+-------------------------------+ +-----+-+-------+---------------+-------------------------------+
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+---------------------------------------------------------------+ +---------------------------------------------------------------+
| Message-ID | | Message-ID |
+---------------------------------------------------------------+ +---------------------------------------------------------------+
~ Options ~ ~ Options ~
+---------------------------------------------------------------+ +---------------------------------------------------------------+
Figure 2: UDP-Notif Message Header Format Figure 2: UDP-Notif Message Header Format
The Message Header contains the following field: The Message Header contains the following field:
* Ver represents the PDU (Protocol Data Unit) encoding version. The o Ver represents the PDU (Protocol Data Unit) encoding version. The
initial version value is 0. initial version value is 0.
* S represents the space of encoding type specified in the ET field. o S represents the space of encoding type specified in the ET field.
When S is unset, ET represents the standard encoding types as When S is unset, ET represents the standard encoding types as
defined in this document. When S is set, ET represents a private defined in this document. When S is set, ET represents a private
space to be freely used for non standard encodings. space to be freely used for nonstandard encodings.
* ET is a 4 bit identifier to indicate the encoding type used for o ET is a 4 bit identifier to indicate the encoding type used for
the Notification Message. 16 types of encoding can be expressed. the Notification Message. 16 types of encoding can be expressed.
When the S bit is unset, the following values apply: When the S bit is unset, the following values apply:
- 0: CBOR; * 0: CBOR;
- 1: JSON; * 1: JSON;
* 2: XML;
- 2: XML; * others are reserved.
- others are reserved.
* Header Len is the length of the message header in octets, o Header Len is the length of the message header in octets,
including both the fixed header and the options. including both the fixed header and the options.
* Message Length is the total length of the message within one UDP o Message Length is the total length of the message within one UDP
datagram, measured in octets, including the message header. datagram, measured in octets, including the message header.
* Observation-Domain-ID is a 32-bit identifier of the Observation o Observation-Domain-ID is a 32-bit identifier of the Observation
Domain that led to the production of the notification message, as Domain that led to the production of the notification message, as
defined in [I-D.ietf-netconf-notification-messages]. This allows defined in [I-D.ietf-netconf-notification-messages]. This allows
disambiguation of an information source, such as the disambiguation of an information source, such as the
identification of different line cards sending the notification identification of different line cards sending the notification
messages. The source IP address of the UDP datagrams SHOULD NOT messages. The source IP address of the UDP datagrams SHOULD NOT
be interpreted as the identifier for the host that originated the be interpreted as the identifier for the host that originated the
UDP-Notif message. Indeed, the streamer sending the UDP-Notif UDP-Notif message. Indeed, the streamer sending the UDP-Notif
message could be a relay for the actual source of data carried message could be a relay for the actual source of data carried
within UDP-Notif messages. within UDP-Notif messages.
* The Message ID is generated continuously by the sender of UDP- o The Message ID is generated continuously by the sender of UDP-
Notif messages. Different subscribers share the same Message ID Notif messages. Different subscribers share the same Message ID
sequence. sequence.
* Options is a variable-length field in the TLV format. When the o 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 Header Length is larger than 12 octets, which is the length of the
fixed header, Options TLVs follow directly after the fixed message fixed header, Options TLVs follow directly after the fixed message
header (i.e., Message ID). The details of the options are header (i.e., Message ID). The details of the options are
described in the following section. described in the following section.
3.3. Options 3.3. Options
All the options are defined with the following format, illustrated in All the options are defined with the following format, illustrated in
Figure 3. Figure 3.
0 1 2 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 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 | Type | Length | Variable-length data
+---------------+---------------+-------------------------------- +---------------+---------------+--------------------------------
Figure 3: Generic Option Format Figure 3: Generic Option Format
* Type: 1 octet describing the option type; o Type: 1 octet describing the option type;
* Length: 1 octet representing the total number of octets in the o Length: 1 octet representing the total number of octets in the
TLV, including the Type and Length fields; TLV, including the Type and Length fields;
* Variable-length data: 0 or more octets of TLV Value. o Variable-length data: 0 or more octets of TLV Value.
3.3.1. Segmentation Option 3.3.1. Segmentation Option
The UDP payload length is limited to 65535. Application level The UDP payload length is limited to 65535. Application level
headers will make the actual payload shorter. Even though binary headers will make the actual payload shorter. Even though binary
encodings such as CBOR may not require more space than what is left, 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 more voluminous encodings such as JSON and XML may suffer from this
size limitation. Although IPv4 and IPv6 senders can fragment size limitation. Although IPv4 and IPv6 senders can fragment
outgoing packets exceeding their Maximum Transmission Unit(MTU), outgoing packets exceeding their Maximum Transmission Unit(MTU),
fragmented IP packets may not be desired for operational and fragmented IP packets may not be desired for operational and
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Consequently, implementations of the mechanism SHOULD provide a Consequently, implementations of the mechanism SHOULD provide a
configurable max-segment-size option to control the maximum size of a configurable max-segment-size option to control the maximum size of a
payload. payload.
0 1 2 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 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| | Type | Length | Segment Number |L|
+---------------+---------------+-----------------------------+-+ +---------------+---------------+-----------------------------+-+
Figure 4: Segmentation Option Format Figure 4: Segmentation Option Format
The Segmentation Option is to be included when the message content is The Segmentation Option is to be included when the message content is
segmented into multiple pieces. Different segments of one message segmented into multiple pieces. Different segments of one message
share the same Message ID. An illustration is provided in Figure 4. share the same Message ID. An illustration is provided in Figure 4.
The fields of this TLV are: The fields of this TLV are:
* Type: Generic option field which indicates a Segmentation Option. o Type: Generic option field which indicates a Segmentation Option.
The Type value is to be asigned. The Type value is to be assigned.
* Length: Generic option field which indicates the length of this o Length: Generic option field which indicates the length of this
option. It is a fixed value of 4 octets for the Segmentation option. It is a fixed value of 4 octets for the Segmentation
Option. Option.
* Segment Number: 15-bit value indicating the sequence number of the o Segment Number: 15-bit value indicating the sequence number of the
current segment. The first segment of a segmented message has a current segment. The first segment of a segmented message has a
Segment Number value of 0. Segment Number value of 0.
* L: is a flag to indicate whether the current segment is the last o 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 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, last one. When 1 is set, the current segment is the last one,
meaning that the total number of segments used to transport this meaning that the total number of segments used to transport this
message is the value of the current Segment Number + 1. message is the value of the current Segment Number + 1.
An implementation of this specification MUST NOT rely on IP An implementation of this specification MUST NOT rely on IP
fragmentation by default to carry large messages. An implementation fragmentation by default to carry large messages. An implementation
of this specification MUST either restrict the size of individual of this specification MUST either restrict the size of individual
messages carried over this protocol, or support the segmentation messages carried over this protocol, or support the segmentation
option. option.
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In this section, we provide an applicability statement for the In this section, we provide an applicability statement for the
proposed mechanism, following the recommendations of [RFC8085]. proposed mechanism, following the recommendations of [RFC8085].
The proposed mechanism falls in the category of UDP applications The proposed mechanism falls in the category of UDP applications
"designed for use within the network of a single network operator or "designed for use within the network of a single network operator or
on networks of an adjacent set of cooperating network operators, to on networks of an adjacent set of cooperating network operators, to
be deployed in controlled environments". Implementations of the be deployed in controlled environments". Implementations of the
proposed mechanism should thus follow the recommendations in place proposed mechanism should thus follow the recommendations in place
for such specific applications. In the following, we discuss for such specific applications. In the following, we discuss
recommendations on congestion control, message size guildelines, recommendations on congestion control, message size guidelines,
reliability considerations. reliability considerations.
4.1. Congestion Control 4.1. Congestion Control
The proposed application falls into the category of applications The proposed application falls into the category of applications
performing transfer of large amounts of data. It is expected that performing transfer of large amounts of data. It is expected that
the operator using the solution configures QoS on its related flows. the operator using the solution configures QoS on its related flows.
As per [RFC8085], such applications MAY choose not to implement any As per [RFC8085], such applications MAY choose not to implement any
form of congestion control, but follow the following principles. form of congestion control, but follow the following principles.
It is NOT RECOMMENDED to use the proposed mechanism over congestion- It is NOT RECOMMENDED to use the proposed mechanism over congestion-
sensitive network paths. The only environments where UDP-Notif is sensitive network paths. The only environments where UDP-Notif is
expected to be used are managed networks. The deployments require expected to be used are managed networks. The deployments require
that the network path has been explicitly provisioned to handle the that the network path has been explicitly provisioned to handle the
traffic through traffic engineering mechanisms, such as rate limiting traffic through traffic engineering mechanisms, such as rate limiting
or capacity reservations. or capacity reservations.
Implementation of the proposal SHOULD NOT push unlimited amounts of Implementation of the proposal SHOULD NOT push unlimited amounts of
traffic by default, and SHOULD require the users to explicitely traffic by default, and SHOULD require the users to explicitly
configure such a mode of operation. configure such a mode of operation.
Burst mitigation through packet pacing is RECOMMENDED. Disabling Burst mitigation through packet pacing is RECOMMENDED. Disabling
burst mitigation SHOULD require the users to explicitely configure burst mitigation SHOULD require the users to explicitly configure
such a mode of operation. such a mode of operation.
Applications SHOULD monitor packet losses and provide means to the Applications SHOULD monitor packet losses and provide means to the
user for retrieving information on such losses. The UDP-Notif user for retrieving information on such losses. The UDP-Notif
Message ID can be used to deduce congestion based on packet loss Message ID can be used to deduce congestion based on packet loss
detection. Hence the collector can notify the device to use a lower detection. Hence the receiver can notify the device to use a lower
streaming rate. The interaction to control the streaming rate on the streaming rate. The interaction to control the streaming rate on the
device is out of the scope of this document. device is out of the scope of this document.
4.2. Message Size 4.2. Message Size
[RFC8085] recommends not to rely on IP fragmentation for messages [RFC8085] recommends not to rely on IP fragmentation for messages
whose size result in IP packets exceeding the MTU along the path. whose size result in IP packets exceeding the MTU along the path.
The segmentation option of the current specification permits to The segmentation option of the current specification permits
perform segmentation of the UDP Notif message content so as to not segmentation of the UDP Notif message content without relying on IP
have to rely on IP fragmentation. Implementation of the current fragmentation. Implementation of the current specification SHOULD
specification SHOULD allow for the configuration of the MTU. allow for the configuration of the MTU.
4.3. Reliability 4.3. Reliability
The target application for UDP-Notif is the collection of data-plane The target application for UDP-Notif is the collection of data-plane
information. The lack of reliability of the data streaming mechanism information. The lack of reliability of the data streaming mechanism
is thus considered acceptable as the mechanism is to be used in is thus considered acceptable as the mechanism is to be used in
controlled environments, mitigating the risk of information loss, controlled environments, mitigating the risk of information loss,
while allowing for publication of very large amounts of data. while allowing for publication of very large amounts of data.
Moreover, in this context, sporadic events when incomplete data Moreover, in this context, sporadic events when incomplete data
collection is provided is not critical for the proper management of collection is provided is not critical for the proper management of
the network, as information collected for the devices through the the network, as information collected for the devices through the
means of the proposed mechanism is to be often refreshed. means of the proposed mechanism is to be often refreshed.
A collector implementation for this protocol SHOULD deal with A receiver implementation for this protocol SHOULD deal with
potential loss of packets carrying a part of segmented payload, by potential loss of packets carrying a part of segmented payload, by
discarding packets that were actually received, but cannot be re- discarding packets that were received, but cannot be re-assembled as
assembled as a complete message within a given amount of time. This a complete message within a given amount of time. This time SHOULD
time SHOULD be configurable. be configurable.
5. A YANG Data Model for Management of UDP-Notif 5. A YANG Data Model for Management of UDP-Notif
The YANG model defined in Section 9 has two leafs augmented into one The YANG model defined in Section 9 has two leaf's augmented into one
place of Sub-Notif [RFC8639], plus one identity. place of Sub-Notif [RFC8639], plus one identity.
module: ietf-udp-subscribed-notifications module: ietf-udp-subscribed-notifications
augment /sn:subscriptions/sn:subscription/sn:receivers/sn:receiver: augment /sn:subscriptions/sn:subscription/sn:receivers/sn:receiver:
+--rw address inet:ip-address +--rw address inet:ip-address
+--rw port inet:port-number +--rw port inet:port-number
+--rw enable-fragment? boolean +--rw enable-fragment? boolean
+--rw max-fragment-size? uint32 +--rw max-fragment-size? uint32
6. YANG Module 6. YANG Module
<CODE BEGINS> file "ietf-udp-notif@2020-04-27.yang" <CODE BEGINS> file "ietf-udp-notif@2020-04-27.yang"
module ietf-udp-notif { module ietf-udp-notif {
yang-version 1.1; yang-version 1.1;
namespace namespace
"urn:ietf:params:xml:ns:yang:ietf-udp-notif"; "urn:ietf:params:xml:ns:yang:ietf-udp-notif";
prefix un; prefix un;
import ietf-subscribed-notifications { import ietf-subscribed-notifications {
prefix sn; prefix sn;
reference reference
"RFC 8639: Subscription to YANG Notifications"; "RFC 8639: Subscription to YANG Notifications";
} }
import ietf-inet-types { import ietf-inet-types {
prefix inet; prefix inet;
reference reference
"RFC 6991: Common YANG Data Types"; "RFC 6991: Common YANG Data Types";
} }
organization "IETF NETCONF (Network Configuration) Working Group"; organization "IETF NETCONF (Network Configuration) Working Group";
contact contact
"WG Web: <http:/tools.ietf.org/wg/netconf/> "WG Web: <http:/tools.ietf.org/wg/netconf/>
WG List: <mailto:netconf@ietf.org> WG List: <mailto:netconf@ietf.org>
Authors: Guangying Zheng Authors: Guangying Zheng
<mailto:zhengguangying@huawei.com> <mailto:zhengguangying@huawei.com>
Tianran Zhou Tianran Zhou
<mailto:zhoutianran@huawei.com> <mailto:zhoutianran@huawei.com>
Thomas Graf Thomas Graf
<mailto:thomas.graf@swisscom.com> <mailto:thomas.graf@swisscom.com>
Pierre Francois Pierre Francois
<mailto:pierre.francois@insa-lyon.fr> <mailto:pierre.francois@insa-lyon.fr>
Paolo Lucente Paolo Lucente
<mailto:paolo@ntt.net>"; <mailto:paolo@ntt.net>";
description description
"Defines UDP-Notif as a supported transport for subscribed "Defines UDP-Notif as a supported transport for subscribed
event notifications. event notifications.
Copyright (c) 2018 IETF Trust and the persons identified as authors Copyright (c) 2018 IETF Trust and the persons identified as authors
of the code. All rights reserved. of the code. All rights reserved.
Redistribution and use in source and binary forms, with or without Redistribution and use in source and binary forms, with or without
modification, is permitted pursuant to, and subject to the license modification, is permitted pursuant to, and subject to the license
terms contained in, the Simplified BSD License set forth in Section terms contained in, the Simplified BSD License set forth in Section
4.c of the IETF Trust's Legal Provisions Relating to IETF Documents 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info). (https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see the RFC This version of this YANG module is part of RFC XXXX; see the RFC
itself for full legal notices."; itself for full legal notices.";
revision 2020-04-27 { revision 2020-04-27 {
description description
"Initial version"; "Initial version";
reference reference
"RFC XXXX: UDP-based Notifications for Streaming Telemetry"; "RFC XXXX: UDP-based Notifications for Streaming Telemetry";
} }
identity udp-notif { identity udp-notif {
base sn:transport; base sn:transport;
description description
"UDP-Notif is used as transport for notification messages "UDP-Notif is used as transport for notification messages
and state change notifications."; and state change notifications.";
} }
identity encode-cbor { identity encode-cbor {
base sn:encoding; base sn:encoding;
description description
"Encode data using CBOR as described in RFC 7049."; "Encode data using CBOR as described in RFC 7049.";
reference reference
"RFC 7049: Concise Binary Object Representation"; "RFC 7049: Concise Binary Object Representation";
} }
grouping target-receiver { grouping target-receiver {
description description
"Provides a reusable description of a UDP-Notif target receiver."; "Provides a reusable description of a UDP-Notif target receiver.";
leaf address { leaf address {
type inet:ip-address; type inet:ip-address;
mandatory true; mandatory true;
description description
"IP address of target UDP-Notif receiver, which can be an "IP address of target UDP-Notif receiver, which can be an
IPv4 address or an IPV6 address."; IPv4 address or an IPV6 address.";
} }
leaf port { leaf port {
type inet:port-number; type inet:port-number;
mandatory true; mandatory true;
description description
"Port number of target UDP-Notif receiver, if not specified, "Port number of target UDP-Notif receiver, if not specified,
the system should use default port number."; the system should use default port number.";
}
leaf enable-fragment { }
type boolean;
default false;
description
"The switch for the fragment feature. When disabled, the
publisher will not allow fragment for a very large data";
}
leaf max-fragment-size { leaf enable-fragment {
when "../enable-fragment = true"; type boolean;
type uint32; default false;
description "UDP-Notif provides a configurable max-fragment-size description
to control the size of each message."; "The switch for the fragment feature. When disabled, the
} publisher will not allow fragment for a very large data";
} }
augment "/sn:subscriptions/sn:subscription/sn:receivers/sn:receiver" { leaf max-fragment-size {
description when "../enable-fragment = true";
"This augmentation allows UDP-Notif specific parameters to be type uint32;
exposed for a subscription."; description "UDP-Notif provides a configurable max-fragment-size
uses target-receiver; to control the size of each message.";
} }
} }
<CODE ENDS>
augment "/sn:subscriptions/sn:subscription/sn:receivers/sn:receiver" {
description
"This augmentation allows UDP-Notif specific parameters to be
exposed for a subscription.";
uses target-receiver;
}
}
<CODE ENDS>
7. IANA Considerations 7. IANA Considerations
This RFC requests that IANA assigns one UDP port number in the This RFC requests that IANA assigns one UDP port number in the
"Registered Port Numbers" range with the service name "udp-notif". "Registered Port Numbers" range with the service name "udp-notif".
This port will be the default port for the UDP-based notification This port will be the default port for the UDP-based notification
Streaming Telemetry (UDP-Notif) for NETCONF and RESTCONF. Below is Streaming Telemetry (UDP-Notif) for NETCONF and RESTCONF. Below is
the registration template following the rules of [RFC6335]. the registration template following the rules of [RFC6335].
Service Name: udp-notif Service Name: udp-notif
Transport Protocol(s): UDP Transport Protocol(s): UDP
Assignee: IESG <iesg@ietf.org> Assignee: IESG <iesg@ietf.org>
Contact: IETF Chair <chair@ietf.org> Contact: IETF Chair <chair@ietf.org>
Description: UDP-based Publication Streaming Telemetry Description: UDP-based Publication Streaming Telemetry
Reference: RFC XXXX Reference: RFC XXXX
Port Number: PORT-X
Port Number: PORT-X
IANA is requested to assign a new URI from the IETF XML Registry IANA is requested to assign a new URI from the IETF XML Registry
[RFC3688]. The following URI is suggested: [RFC3688]. The following URI is suggested:
URI: urn:ietf:params:xml:ns:yang:ietf-udp-notif URI: urn:ietf:params:xml:ns:yang:ietf-udp-notif
Registrant Contact: The IESG. Registrant Contact: The IESG.
XML: N/A; the requested URI is an XML namespace. XML: N/A; the requested URI is an XML namespace.
This document also requests a new YANG module name in the YANG Module This document also requests a new YANG module name in the YANG Module
Names registry [RFC7950] with the following suggestion: Names registry [RFC7950] with the following suggestion:
skipping to change at page 15, line 25 skipping to change at page 15, line 20
[RFC8650] Voit, E., Rahman, R., Nilsen-Nygaard, E., Clemm, A., and [RFC8650] Voit, E., Rahman, R., Nilsen-Nygaard, E., Clemm, A., and
A. Bierman, "Dynamic Subscription to YANG Events and A. Bierman, "Dynamic Subscription to YANG Events and
Datastores over RESTCONF", RFC 8650, DOI 10.17487/RFC8650, Datastores over RESTCONF", RFC 8650, DOI 10.17487/RFC8650,
November 2019, <https://www.rfc-editor.org/info/rfc8650>. November 2019, <https://www.rfc-editor.org/info/rfc8650>.
10.2. Informative References 10.2. Informative References
[I-D.ietf-netconf-distributed-notif] [I-D.ietf-netconf-distributed-notif]
Zhou, T., Zheng, G., Voit, E., Graf, T., and P. Francois, Zhou, T., Zheng, G., Voit, E., Graf, T., and P. Francois,
"Subscription to Distributed Notifications", Work in "Subscription to Distributed Notifications", draft-ietf-
Progress, Internet-Draft, draft-ietf-netconf-distributed- netconf-distributed-notif-01 (work in progress), June
notif-01, June 2020, <https://tools.ietf.org/html/draft- 2020.
ietf-netconf-distributed-notif-01>.
[I-D.ietf-netconf-https-notif] [I-D.ietf-netconf-https-notif]
Jethanandani, M. and K. Watsen, "An HTTPS-based Transport Jethanandani, M. and K. Watsen, "An HTTPS-based Transport
for Configured Subscriptions", Work in Progress, Internet- for YANG Notifications", draft-ietf-netconf-https-notif-08
Draft, draft-ietf-netconf-https-notif-04, 27 July 2020, (work in progress), February 2021.
<http://www.ietf.org/internet-drafts/draft-ietf-netconf-
https-notif-04.txt>.
[I-D.ietf-netconf-notification-messages] [I-D.ietf-netconf-notification-messages]
Voit, E., Jenkins, T., Birkholz, H., Bierman, A., and A. Voit, E., Jenkins, T., Birkholz, H., Bierman, A., and A.
Clemm, "Notification Message Headers and Bundles", Work in Clemm, "Notification Message Headers and Bundles", draft-
Progress, Internet-Draft, draft-ietf-netconf-notification- ietf-netconf-notification-messages-08 (work in progress),
messages-08, 17 November 2019, <http://www.ietf.org/ November 2019.
internet-drafts/draft-ietf-netconf-notification-messages-
08.txt>.
Authors' Addresses Authors' Addresses
Guangying Zheng Guangying Zheng
Huawei Huawei
101 Yu-Hua-Tai Software Road 101 Yu-Hua-Tai Software Road
Nanjing Nanjing, Jiangsu
Jiangsu,
China China
Email: zhengguangying@huawei.com Email: zhengguangying@huawei.com
Tianran Zhou Tianran Zhou
Huawei Huawei
156 Beiqing Rd., Haidian District 156 Beiqing Rd., Haidian District
Beijing Beijing
China China
skipping to change at page 16, line 20 skipping to change at page 16, line 4
Email: zhengguangying@huawei.com Email: zhengguangying@huawei.com
Tianran Zhou Tianran Zhou
Huawei Huawei
156 Beiqing Rd., Haidian District 156 Beiqing Rd., Haidian District
Beijing Beijing
China China
Email: zhoutianran@huawei.com Email: zhoutianran@huawei.com
Thomas Graf Thomas Graf
Swisscom Swisscom
Binzring 17 Binzring 17
CH- Zuerich 8045 Zuerich 8045
Switzerland Switzerland
Email: thomas.graf@swisscom.com Email: thomas.graf@swisscom.com
Pierre Francois Pierre Francois
INSA-Lyon INSA-Lyon
Lyon Lyon
France France
Email: pierre.francois@insa-lyon.fr Email: pierre.francois@insa-lyon.fr
Paolo Lucente Paolo Lucente
NTT NTT
Siriusdreef 70-72 Siriusdreef 70-72
Hoofddorp, WT 2132 Hoofddorp, WT 2132
Netherlands NL
Email: paolo@ntt.net Email: paolo@ntt.net
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