draft-ietf-netconf-udp-pub-channel-02.txt   draft-ietf-netconf-udp-pub-channel-03.txt 
NETCONF G. Zheng NETCONF G. Zheng
Internet-Draft T. Zhou Internet-Draft T. Zhou
Intended status: Standards Track A. Clemm Intended status: Standards Track A. Clemm
Expires: September 19, 2018 Huawei Expires: January 1, 2019 Huawei
March 18, 2018 June 30, 2018
UDP based Publication Channel for Streaming Telemetry UDP based Publication Channel for Streaming Telemetry
draft-ietf-netconf-udp-pub-channel-02 draft-ietf-netconf-udp-pub-channel-03
Abstract Abstract
This document describes a UDP-based publication channel for streaming This document describes a UDP-based publication channel for streaming
telemetry use to collect data from devices. A new shim header is telemetry use to collect data from devices. A new shim header is
proposed to facilitate the distributed data collection mechanism proposed to facilitate the distributed data collection mechanism
which directly pushes data from line cards to the collector. Because which directly pushes data from line cards to the collector. Because
of the lightweight UDP encapsulation, higher frequency and better of the lightweight UDP encapsulation, higher frequency and better
transit performance can be achieved. transit performance can be achieved.
skipping to change at page 1, line 42 skipping to change at page 1, line 42
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 September 19, 2018. This Internet-Draft will expire on January 1, 2019.
Copyright Notice Copyright Notice
Copyright (c) 2018 IETF Trust and the persons identified as the Copyright (c) 2018 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of (https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
skipping to change at page 2, line 22 skipping to change at page 2, line 22
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Solution Overview . . . . . . . . . . . . . . . . . . . . . . 4 3. Solution Overview . . . . . . . . . . . . . . . . . . . . . . 4
4. Transport Mechanisms . . . . . . . . . . . . . . . . . . . . 5 4. Transport Mechanisms . . . . . . . . . . . . . . . . . . . . 5
4.1. Dynamic Subscription . . . . . . . . . . . . . . . . . . 5 4.1. Dynamic Subscription . . . . . . . . . . . . . . . . . . 5
4.2. Configured Subscription . . . . . . . . . . . . . . . . . 6 4.2. Configured Subscription . . . . . . . . . . . . . . . . . 7
5. UDP Transport for Publication Channel . . . . . . . . . . . . 7 5. UDP Transport for Publication Channel . . . . . . . . . . . . 8
5.1. Design Overview . . . . . . . . . . . . . . . . . . . . . 7 5.1. Design Overview . . . . . . . . . . . . . . . . . . . . . 8
5.2. Data Format of the Message Header . . . . . . . . . . . . 8 5.2. Data Format of the UPC Message Header . . . . . . . . . . 8
5.3. Options . . . . . . . . . . . . . . . . . . . . . . . . . 9 5.3. Options . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.3.1. Reliability Option . . . . . . . . . . . . . . . . . 10 5.3.1. Reliability Option . . . . . . . . . . . . . . . . . 10
5.3.2. Fragmentation Option . . . . . . . . . . . . . . . . 11 5.3.2. Fragmentation Option . . . . . . . . . . . . . . . . 11
5.4. Data Encoding . . . . . . . . . . . . . . . . . . . . . . 11 5.4. Data Encoding . . . . . . . . . . . . . . . . . . . . . . 12
6. Congestion Control . . . . . . . . . . . . . . . . . . . . . 12 6. Using DTLS to Secure UPC . . . . . . . . . . . . . . . . . . 12
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 6.1. Transport . . . . . . . . . . . . . . . . . . . . . . . . 12
8. Security Considerations . . . . . . . . . . . . . . . . . . . 12 6.2. Port Assignment . . . . . . . . . . . . . . . . . . . . . 13
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 13 6.3. DTLS Session Initiation . . . . . . . . . . . . . . . . . 13
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 13 6.4. Sending Data . . . . . . . . . . . . . . . . . . . . . . 14
10.1. Normative References . . . . . . . . . . . . . . . . . . 13 6.5. Closure . . . . . . . . . . . . . . . . . . . . . . . . . 14
10.2. Informative References . . . . . . . . . . . . . . . . . 13 7. Congestion Control . . . . . . . . . . . . . . . . . . . . . 15
10.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 14 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15
Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 14 9. Security Considerations . . . . . . . . . . . . . . . . . . . 16
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15 10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 16
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 16
11.1. Normative References . . . . . . . . . . . . . . . . . . 16
11.2. Informative References . . . . . . . . . . . . . . . . . 17
11.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 18
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 19
1. Introduction 1. Introduction
Streaming telemetry refers to sending a continuous stream of Streaming telemetry refers to sending a continuous stream of
operational data from a device to a remote receiver. This provides operational data from a device to a remote receiver. This provides
an ability to monitor a network from remote and to provide network an ability to monitor a network from remote and to provide network
analytics. Devices generate telemetry data and push that data to a analytics. Devices generate telemetry data and push that data to a
collector for further analysis. By streaming the data, much better collector for further analysis. By streaming the data, much better
performance, finer-grained sampling, monitoring accuracy, and performance, finer-grained sampling, monitoring accuracy, and
bandwidth utilization can be achieved than with polling-based bandwidth utilization can be achieved than with polling-based
alternatives. alternatives.
Sub-Notif [I-D.ietf-netconf-subscribed-notifications] and YANG-Push Sub-Notif [I-D.ietf-netconf-subscribed-notifications] defines a
[I-D.ietf-netconf-yang-push] defines a mechanism that allows a mechanism that allows a collector to subscribe to updates of YANG-
collector to subscribe to updates of YANG-defined data that is defined data that is maintained in a YANG [RFC7950] datastore. The
maintained in a YANG [RFC7950] datastore. The mechanism separates mechanism separates the management and control of subscriptions from
the management and control of subscriptions from the transport that the transport that is used to actually stream and deliver the data.
is used to actually stream and deliver the data. Two transports, Two transports, NETCONF transport
NETCONF transport [I-D.ietf-netconf-netconf-event-notifications] and [I-D.ietf-netconf-netconf-event-notifications] and HTTP transport
HTTP transport [I-D.ietf-netconf-restconf-notif], have been defined [I-D.ietf-netconf-restconf-notif], have been defined so far for the
so far for the notification messages. notification messages.
While powerful in its features and general in its architecture, in While powerful in its features and general in its architecture, in
its current form the mechanism needs to be extended to stream its current form the mechanism needs to be extended to stream
telemetry data at high velocity from devices that feature a telemetry data at high velocity from devices that feature a
distributed architecture. The transports that have been defined so distributed architecture. The transports that have been defined so
far, NETCONF and HTTP, are ultimately based on TCP and lack the far, NETCONF and HTTP, are ultimately based on TCP and lack the
efficiency needed to stream data continuously at high velocity. A efficiency needed to stream data continuously at high velocity. A
lighter-weight, more efficient transport, e.g. a transport based on lighter-weight, more efficient transport, e.g. a transport based on
UDP is needed. UDP is needed.
skipping to change at page 3, line 36 skipping to change at page 3, line 40
o 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 hardware which will encapsulation can be easily implemented by hardware which will
further improve the performance. further improve the performance.
o Thirdly, because of the lightweight UDP encapsulation, higher o Thirdly, because of the lightweight UDP encapsulation, higher
frequency and better transit performance can be achieved, which is frequency and better transit performance can be achieved, which is
important for streaming telemetry. important for streaming telemetry.
This document specifies a higher-performance transport option for This document specifies a higher-performance transport option for
YANG-Push that leverages UDP. Specifically, it facilitates the Sub-Notif that leverages UDP. Specifically, it facilitates the
distributed data collection mechanism described in distributed data collection mechanism described in
[I-D.zhou-netconf-multi-stream-originators]. In the case of data [I-D.zhou-netconf-multi-stream-originators]. In the case of data
originating from multiple line cards, the centralized design requires originating from multiple line cards, the centralized design requires
data to be internally forwarded from those line cards to the push data to be internally forwarded from those line cards to the push
server, presumably on a main board, which then combines the server, presumably on a main board, which then combines the
individual data items into a single consolidated stream. The individual data items into a single consolidated stream. The
centralized data collection mechanism can result in a performance centralized data collection mechanism can result in a performance
bottleneck, especially when large amounts of data are involved. What bottleneck, especially when large amounts of data are involved. What
is needed instead is the support for a distributed mechanism that is needed instead is the support for a distributed mechanism that
allows to directly push multiple individual substreams, e.g. one from allows to directly push multiple individual substreams, e.g. one from
skipping to change at page 4, line 10 skipping to change at page 4, line 14
additional processing stage for internal consolidation, but still additional processing stage for internal consolidation, but still
allowing those substreams to be managed and controlled via a single allowing those substreams to be managed and controlled via a single
subscription. The proposed UDP based Publication Channel (UPC) subscription. The proposed UDP based Publication Channel (UPC)
natively supports the distributed data collection mechanism. natively supports the distributed data collection mechanism.
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 [RFC8200]. notification messages over both IPv4 and IPv6 [RFC8200].
While this document will focus on the data publication channel, the While this document will focus on the data publication channel, the
subscription can be used in conjunction with the mechanism proposed subscription can be used in conjunction with the mechanism proposed
in [I-D.ietf-netconf-yang-push] with extensions in [I-D.ietf-netconf-subscribed-notifications] with extensions
[I-D.zhou-netconf-multi-stream-originators]. [I-D.zhou-netconf-multi-stream-originators].
2. Terminology 2. Terminology
Streaming Telemetry: refers to sending a continuous stream of Streaming Telemetry: refers to sending a continuous stream of
operational data from a device to a remote receiver. This provides operational data from a device to a remote receiver. This provides
an ability to monitor a network from remote and to provide network an ability to monitor a network from remote and to provide network
analytics. analytics.
Component Subscription: A subscription that defines the data from
each individual telemetry source which is managed and controlled by a
single Subscription Server.
Component Subscription Server: An agent that streams telemetry data
per the terms of a component subscription.
3. Solution Overview 3. Solution Overview
The typical distributed data collection solution is shown in Fig. 1. The typical distributed data collection solution is shown in Fig. 1.
Both the Collector and the Subscribed Domain can be distributed. The Both the Collector and the Publisher can be distributed. The
Collector includes the Subscriber and a set of Receivers. And the Collector includes the Subscriber and a set of Receivers. And the
Subscribed Domain includes a Master and a set of Agents. The Publisher includes a Subscription Server and a set of Component
Subscriber cannot see the Agents directly, so it will send the Global Subscription Servers. The Subscriber cannot see the Component
Subscription information to the Master (e.g., main board) via the Subscription Servers directly, so it will send the Global
Subscription Channel. When receiving a Global Subscription, the Subscription information to the Subscription Server (e.g., main
Master decomposes the subscription request into multiple Component board) via the Subscription Channel. When receiving a Global
Subscriptions, each involving data from a separate internal telemetry Subscription, the Subscription Server decomposes the subscription
source, for example a line card. The Component Subscriptions are request into multiple Component Subscriptions, each involving data
distributed to the Agents. Subsequently, each data originator from a separate internal telemetry source, for example a line card.
generates its own stream of telemetry data, collecting and The Component Subscriptions are distributed to the Component
encapsulating the packets per the Component Subscription and Subscription Server. Subsequently, each data originator generates
streaming them to the designated Receivers. This distributed data its own stream of telemetry data, collecting and encapsulating the
collection mechanism may form multiple Publication Channels between packets per the Component Subscription and streaming them to the
the Data Originators and the Receivers. The Collector is able to designated Receivers. This distributed data collection mechanism may
assemble many pieces of data associated with one Global Subscription. form multiple Publication Channels to the Receivers. The Receiver is
able to assemble many pieces of data associated with one Global
Subscription.
The Publication Channel supports the reliable data streaming, for The Publication Channel supports the reliable data streaming, for
example for some alarm events. The Collector has the option of example for some alarm events. The Collector has the option of
deducing the packet loss and the disorder based on the information deducing the packet loss and the disorder based on the information
carried by the notification data. And the Collector will decide the carried by the notification data. And the Collector may decide the
behavior to request retransmission. behavior to request retransmission.
The rest of the draft describes the UDP based Publication Channel The rest of the draft describes the UDP based Publication Channel
(UPC). (UPC).
+---------------------------------+ +-------------------------------------+
| Collector | | Collector |
| | | |
| +------------+ +-----------+ | | +------------+ +-----------+ |
| | Subscriber | | Receivers | | | | Subscriber | | Receivers | |
| +----+-------+ +--^----^---+ | | +----+-------+ +--^----^---+ |
| | | | | | | | | |
+---------------------------------+ +-------------------------------------+
| | | | | |
Subscription | | | Publication Subscription | | | Publication
Channel | | | Channel Channel | | | Channel
| +---------+ | | +---------+ |
| | | | | |
+---------------------------------+ +-------------------------------------+
| | | | | | | | | |
| +---v---+--+ +------+-+ | | +----v---+-----+ +------+-------+ |
| | Master | | Agents | | | | Subscription | | Component | |
| +----------+ +--------+ | | | Server | | Subscription | |
| | | | | | Servers | |
| Subscribed Domain | | +--------------+ +--------------+ |
+---------------------------------+ | |
| Publisher |
+-------------------------------------+
Fig. 1 Distributed Data Collection Fig. 1 Distributed Data Collection
4. Transport Mechanisms 4. Transport Mechanisms
For a complete pub-sub mechanism, this section will describe how the For a complete pub-sub mechanism, this section will describe how the
UPC is used to interact with the Subscription Channel relying on UPC is used to interact with the Subscription Channel relying on
NETCONF or RESTCONF. NETCONF or RESTCONF.
4.1. Dynamic Subscription 4.1. Dynamic Subscription
Dynamic subscriptions for YANG-Push [I-D.ietf-netconf-yang-push] are Dynamic subscriptions for Sub-Notif are configured and managed via
configured and managed via signaling messages transported over signaling messages transported over NETCONF [RFC6241] or RESTCONF
NETCONF [RFC6241] or RESTCONF [RFC8040]. The YANG-Push defined RPCs [RFC8040]. The Sub-Notif defined RPCs which are sent and responded
are sent and responded via the Subscription Channel (a), between the via the Subscription Channel (a), between the Subscriber and the
Subscriber and the Master of the Subscribed Domain. In this case, Subscription Server of the Publisher. In this case, only one
only one Receiver is associated with the Subscriber. In the Receiver is associated with the Subscriber. In the Publisher, there
Subscribed Domain, there may be multiple Data Originators. may be multiple data originators. Notification messages are pushed
Notification messages are pushed on separate channels (b), from on separate channels (b), from different data originators to the
different Data Originators to the Receiver . Receiver.
+--------------+ +--------------+ +--------------+ +--------------+
| Collector | | Subscribed | | Collector | | Publisher |
| | | Domain | | | | |
| (a) (b) | | (a) (b) | | (a) (b) | | (a) (b) |
+--+------+----+ +--+-------+---+ +--+------+----+ +--+-------+---+
| | | | | | | |
| | RPC:establish-subscription | | | | RPC:establish-subscription | |
+----------------------------------------> | +----------------------------------------> |
| | RPC Reply: OK | | | | RPC Reply: OK | |
<----------------------------------------+ | <----------------------------------------+ |
| | UPC:notifications | | | | UPC:notifications | |
| <-----------------------------------------+ | <-----------------------------------------+
| | | | | | | |
| | RPC:modify-subscription | | | | RPC:modify-subscription | |
+----------------------------------------> | +----------------------------------------> |
| | RPC Reply: OK | | | | RPC Reply: OK | |
<----------------------------------------+ | <----------------------------------------+ |
| | UPC:notifications | | | | UPC:notifications | |
| <-----------------------------------------+ | <-----------------------------------------+
| | | | | | | |
| | RPC:delete subscription | | | | RPC:delete-subscription | |
+----------------------------------------> | +----------------------------------------> |
| | RPC Reply: OK | | | | RPC Reply: OK | |
<----------------------------------------+ | <----------------------------------------+ |
| | | | | | | |
| | | | | | | |
+ + + + + + + +
Fig. 2 Call Flow for Dynamic Subscription Fig. 2 Call Flow For Dynamic Subscription
In the case of dynamic subscription, the Receiver and the Subscriber In the case of dynamic subscription, the Receiver and the Subscriber
SHOULD be collocated. So UPC can use the source IP address of the SHOULD be colocated. So UPC can use the source IP address of the
Subscription Channel as it's destination IP address. The Receiver Subscription Channel as it's destination IP address. The Receiver
MUST support listening messages at the IANA-assigned PORT-X, but MAY MUST support listening messages at the IANA-assigned PORT-X or PORT-
be configured to listen at a different port. Y, but MAY be configured to listen at a different port.
The Publication Channels MUST share fate with the subscription
session. In other words, when the delete-subscription is received or
the subscription session is broken, all the associated Publication
Channels MUST be closed.
4.2. Configured Subscription 4.2. Configured Subscription
For a Configured Subscription, there is no guarantee that the For a Configured Subscription, there is no guarantee that the
Subscriber is currently in place with the associated Receiver(s). As Subscriber is currently in place with the associated Receiver(s). As
defined in [I-D.ietf-netconf-yang-push], the subscription defined in Sub-Notif, the subscription configuration contains the
configuration contains the location information of all the receivers, location information of all the receivers, including the IP address
including the IP address and the port number. So that the Data and the port number. So that the data originator can actively send
Originator can actively send generated messages to the corresponding generated messages to the corresponding Receivers via the UPC.
Receivers via the UPC.
The first message MUST be a separate subscription-started The first message MUST be a separate subscription-started
notification to indicate the Receiver that the pushing is started. notification to indicate the Receiver that the pushing is started.
Then, the notifications can be sent immediately without any wait. Then, the notifications can be sent immediately without any wait.
All the subscription state notifications, as defined in All the subscription state notifications, as defined in
[I-D.ietf-netconf-subscribed-notifications], MUST be encapsulated to [I-D.ietf-netconf-subscribed-notifications], MUST be encapsulated to
be separated notification messages. be separated notification messages.
+--------------+ +--------------+ +--------------+ +--------------+
| Collector | | Subscribed | | Collector | | Publisher |
| | | Domain | | | | |
| (a) (b) | | (a) (b) | | (a) (b) | | (a) (b) |
+--+------+----+ +--+-------+---+ +--+------+----+ +--+-------+---+
| | | | | | | |
| | Capability Exchange | | | | Capability Exchange | |
<----------------------------------------> | <----------------------------------------> |
| | | | | | | |
| | Edit config(create) | | | | Edit config(create) | |
+----------------------------------------> | +----------------------------------------> |
| | RPC Reply: OK | | | | RPC Reply: OK | |
<----------------------------------------+ | <----------------------------------------+ |
skipping to change at page 7, line 41 skipping to change at page 7, line 50
| | Edit config(delete) | | | | Edit config(delete) | |
+----------------------------------------> | +----------------------------------------> |
| | RPC Reply: OK | | | | RPC Reply: OK | |
<----------------------------------------+ | <----------------------------------------+ |
| | UPC:subscription terminated | | | | UPC:subscription terminated | |
| <-----------------------------------------+ | <-----------------------------------------+
| | | | | | | |
| | | | | | | |
+ + + + + + + +
Fig. 3 Call Flow for Configured Subscription Fig. 3 Call Flow For Configured Subscription
5. UDP Transport for Publication Channel 5. UDP Transport for Publication Channel
5.1. Design Overview 5.1. Design Overview
As specified in YANG-Push, 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 in the transport protocols, e.g. TLS, HTTP2. The following carried in the transport protocols, e.g. TLS, HTTP2. The following
figure shows the overview of the typical UDP publication message figure shows the overview of the typical UPC message structure.
structure.
o The Message Header contains information that can facilitate the o The Message Header contains information that can facilitate the
message transmission before de-serializing the notification message transmission before de-serializing the notification
message. message.
o Notification Message is the encoded content that the publication o Notification Message is the encoded content that the publication
channel transports. The common encoding method includes GPB [1], channel transports. The common encoding method includes GPB [1],
CBOR [RFC7049], JSON, and XML. CBOR [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 both single notification and of the Notification Message for both single notification and
multiple bundled notifications. multiple bundled notifications.
+-------+ +--------------+ +--------------+ +-------+ +--------------+ +--------------+
| UDP | | Message | | Notification | | UDP | | Message | | Notification |
| | | Header | | Message | | | | Header | | Message |
+-------+ +--------------+ +--------------+ +-------+ +--------------+ +--------------+
Fig. 4 UDP Publication Message Overview Fig. 4 UDP Publication Message Overview
5.2. Data Format of the Message Header 5.2. Data Format of the UPC Message Header
The Message Header contains information that can facilitate the The UPC Message Header contains information that can facilitate the
message transmission before de-serializing the notification message. message transmission before de-serializing the notification message.
The data format is shown as follows. The data format is shown as follows.
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
+-------+---------------+-------+-------------------------------+ +-------+---------------+-------+-------------------------------+
| Vers. | Flag | ET | Length | | Vers. | Flag | ET | Length |
+-------+---------------+-------+-------------------------------+ +-------+---------------+-------+-------------------------------+
| Subscribed Domain ID | | Message-Generator-ID |
+---------------------------------------------------------------+ +---------------------------------------------------------------+
| Message ID | | Message ID |
+---------------------------------------------------------------+ +---------------------------------------------------------------+
~ Options ~ ~ Options ~
+---------------------------------------------------------------+ +---------------------------------------------------------------+
Fig. 5 Message Header Format Fig. 3 UPC Message Header Format
The Message Header contains the following field: The Message Header contains the following field:
o Vers.: represents the PDU (Protocol Data Unit) encoding version. o Vers.: represents the PDU (Protocol Data Unit) encoding version.
The initial version value is 0. The initial version value is 0.
o Flag: is a bitmap indicating what features this packet has and the o Flag: is a bitmap indicating what features this packet has and the
corresponding options attached. Each bit associates to one corresponding options attached. Each bit associates to one
feature and one option data. When the bit is set to 1, the feature and one option data. When the bit is set to 1, the
associated feature is enabled and the option data is attached. associated feature is enabled and the option data is attached.
skipping to change at page 9, line 4 skipping to change at page 9, line 14
The Message Header contains the following field: The Message Header contains the following field:
o Vers.: represents the PDU (Protocol Data Unit) encoding version. o Vers.: represents the PDU (Protocol Data Unit) encoding version.
The initial version value is 0. The initial version value is 0.
o Flag: is a bitmap indicating what features this packet has and the o Flag: is a bitmap indicating what features this packet has and the
corresponding options attached. Each bit associates to one corresponding options attached. Each bit associates to one
feature and one option data. When the bit is set to 1, the feature and one option data. When the bit is set to 1, the
associated feature is enabled and the option data is attached. associated feature is enabled and the option data is attached.
The sequence of the presence of the options follows the bit order The sequence of the presence of the options follows the bit order
of the bitmap. In this document, the flag is specified as of the bitmap. In this document, the flag is specified as
follows: follows:
* bit 0, the reliability flag; * bit 0, the reliability flag;
* bit 1, the fragmentation flag; * bit 1, the fragmentation flag;
* other bits are reserved. All the reserved bits MUST be set to * other bits are reserved.
0.
o ET: is a 4 bits identifier to indicate the encoding type used for o ET: is a 4 bits identifier to indicate the encoding type used for
the Notification Message. While 16 types of encoding can be the Notification Message. 16 types of encoding can be expressed:
expressed, this document specifies the following usage:
* 0: GPB; * 0: GPB;
* 1: CBOR; * 1: CBOR;
* 2: JSON; * 2: JSON;
* 3: XML; * 3: XML;
* others are reserved. * others are reserved.
o Length: is the total length of the message, measured in octets, o Length: is the total length of the message, measured in octets,
including message header. If the notification message is including message header.
fragmented, this Length indicates the actual length of the current
message fragmentation.
o Subscribed Domain ID: is a 32-bit identifier of the Subscribed o Message-Generator-ID: is a 32-bit identifier of the process which
Domain. With this parameter, the receiver can easily identify created the notification message. This allows disambiguation of
messages generated from the same Subscription Domain. One an information source, such as the identification of different
possible value is the visible IPv4 address of the Master. line cards sending the notification messages. The source IP
address of the UDP datagrams SHOULD NOT be interpreted as the
identifier for the host that originated the UPC message. The
entity sending the UPC message could be merely a relay.
o The Message ID is generated continuously by the Data Originator. o The Message ID is generated continuously by the message generator.
Different subscribers share the same Message ID sequence. Different subscribers share the same notification ID sequence.
Different fragmentations of one message share the same Message ID.
o Options: is a variable-length field. The details of the Options o Options: is a variable-length field. The details of the Options
will be described in the respective sections below. will be described in the respective sections below.
5.3. Options 5.3. Options
The order of packing the data fields in the Options field follows the The order of packing the data fields in the Options field follows the
bit order of the Flag field. bit order of the Flag field.
5.3.1. Reliability Option 5.3.1. Reliability Option
The UDP based publication transport described in this document The UDP based publication transport described in this document
provides two streaming modes, the reliable mode an the unreliable provides two streaming modes, the reliable mode an the unreliable
mode, for different SLA (Service Level Agreement) and telemetry mode, for different SLA (Service Level Agreement) and telemetry
requirements. requirements.
In the unreliable streaming mode, the line card pushes the In the unreliable streaming mode, the line card pushes the
encapsulated data to the data collector without any sequence encapsulated data to the data collector without any sequence
information. So the subscriber does not know whether the data is information. So the subscriber does not know whether the data is
correctly received or not. correctly received or not. Hence no retransmission happens.
The reliable streaming mode provides sequence information in the UDP The reliable streaming mode provides sequence information in the UDP
packet, based on which the subscriber can deduce the packet loss and packet, based on which the subscriber can deduce the packet loss and
disorder. Then the subscriber can decide whether to request the disorder. Then the subscriber can decide whether to request the
retransmission of the lost packets. retransmission of the lost packets.
In most case, the unreliable streaming mode is preferred. Because In most case, the unreliable streaming mode is preferred. Because
the reliable streaming mode will cost more network bandwidth and the reliable streaming mode will cost more network bandwidth and
precious device resource. Different from the unreliable streaming precious device resource. Different from the unreliable streaming
mode, the line card cannot remove the sent reliable notifications mode, the line card cannot remove the sent reliable notifications
skipping to change at page 10, line 43 skipping to change at page 10, line 48
following option data will be attached following option data will be attached
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
+---------------------------------------------------------------+ +---------------------------------------------------------------+
| Previous Message ID | | Previous Message ID |
+---------------------------------------------------------------+ +---------------------------------------------------------------+
Fig. 4 Reliability Option Format Fig. 4 Reliability Option Format
The Data Originator has the capability of index the Previous Message Current Message ID and Previous Message ID will be added in the
ID for the message. Together with the current Message ID, the packets.
Receiver can detect whether the current message is in a right order.
For example, there are two subscriber A and B, For example, there are two subscriber A and B,
o Message IDs for the generator are : [1, 2, 3, 4, 5, 6, 7, 8, 9], o Message IDs for the generator are : [1, 2, 3, 4, 5, 6, 7, 8, 9],
in which Subscriber A subscribes [1,2,3,6,7] and Subscriber B in which Subscriber A subscribes [1,2,3,6,7] and Subscriber B
subscribes [1,2,4,5,7,8,9]. subscribes [1,2,4,5,7,8,9].
o Subscriber A will receive : [0,1][1,2][2,3][3,6][6,7]. o Subscriber A will receive [Previous Message ID, Current Message
ID] like: [0,1][1,2][2,3][3,6][6,7].
o Subscriber B will receive : [0,1][1,2][2,4][4,5][5,7][7,8]. o Subscriber B will receive [Previous Message ID, Current Message
ID] like: [0,1][1,2][2,4][4,5][5,7][7,8][8,9].
5.3.2. Fragmentation Option 5.3.2. Fragmentation Option
UDP payload has a theoretical length limitation to 65535. Other UDP palyload has a theoretical length limitation to 65535. Other
encapsulation headers will make the actual payload even shorter. encapsulation headers will make the actual payload even shorter.
Binary encodings like GPB and CBOR can generate a compact Binary encodings like GPB and CBOR can make the message compact. So
notification message. So that the message can fit in one UDP packet. that the message can be encapsulated within one UDP packet, hence
In this case, fragmentation will not easily happen. However, text fragmentation will not easily happen. However, text encodings like
encodings like JSON and XML can easily generate a notification JSON and XML can easily make the message exceed the UDP length
message exceeding the UDP length limitation. limitation.
The fragmentation flag in the fixed header is set to 1 only when the
Notification Message is actually fragmented. And the Fragmentation
Option is available in the message header when the fragmentation flag
is set to 1.
The Fragmentation Option is formatted as follow: The Fragmentation Option can help not Application layer can split the
YANG tree into several leaves. Or table into several rows. But the
leaf or the row cannot be split any further. Now we consider a very
long path. Since the GPB and CBOR are so compact, it's easy to fit
into a UDP packet. But for JSON or XML, it is possible that even one
leaf will exceed the UDP boundary.
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
+-------------------------------------------------------------+-+ +-------------------------------------------------------------+-+
| Fragment Number |L| | Fagment Number |L|
+---------------------------------------------------------------+ +-------------------------------------------------------------+-+
Fig. 5 Fragmentation Option Format Fig. 5 Fragmentation Option Format
This option contains: The Fragmentation Option is available in the message header when the
fragmentation flag is set to 1. The option contains:
o Fragment Number: indicates the sequence number of the current Fragment Number: indicates the sequence number of the current
fragment. Together with the Message ID, the Receiver can compose fragment.
the entire Notification Message.
o L: is a flag to indicate whether the current fragment is the last L: is a flag to indicate whether the current fragment is the last
one. When 0 is set, current fragment is not the last one, hence one. When 0 is set, current fragment is not the last one, hence more
more fragments are expected. When 1 is set, current fragment is fragments are expected. When 1 is set, current fragment is the last
the last one. one.
5.4. Data Encoding 5.4. Data Encoding
Subscribed data can be encoded in GPB, CBOR, XML or JSON format. It Subscribed data can be encoded in GPB, CBOR, XML or JSON format. It
is conceivable that additional encodings may be supported as options is conceivable that additional encodings may be supported as options
in the future. This can be accomplished by augmenting the in the future. This can be accomplished by augmenting the
subscription data model with additional identity statements used to subscription data model with additional identity statements used to
refer to requested encodings. refer to requested encodings.
Implementation may support different encoding method per Implementation may support different encoding method per
subscription. When bundled notifications is supported between the subscription. When bundled notifications is supported between the
publisher and the receiver, only subscribed notifications with the publisher and the receiver, only subscribed notifications with the
same encoding can be bundled as one message. same encoding can be bundled as one message.
6. Congestion Control 6. Using DTLS to Secure UPC
The Datagram Transport Layer Security (DTLS) protocol [RFC6347] is
designed to meet the requirements of applications that need secure
datagram transport.
DTLS can be used as a secure transport to counter all the primary
threats to UDP based Publication Channel:
o Confidentiality to counter disclosure of the message contents.
o Integrity checking to counter modifications to a message on a hop-
by-hop basis.
o Server or mutual authentication to counter masquerade.
In addition, DTLS also provides:
o A cookie exchange mechanism during handshake to counter Denial of
Service attacks.
o A sequence number in the header to counter replay attacks.
6.1. Transport
As shown in Figure 6, the DTLS is layered next to the UDP transport
is to provide reusable security and authentication functions over
UDP. No DTLS extension is required to enable UPC messages over DTLS.
+-----------------------------+
| UPC Message |
+-----------------------------+
| DTLS |
+-----------------------------+
| UDP |
+-----------------------------+
| IP |
+-----------------------------+
Fig. 6: Protocol Stack for DTLS secured UPC
The application implementer will map a unique combination of the
remote address, remote port number, local address, and local port
number to a session.
Each UPC message is delivered by the DTLS record protocol, which
assigns a sequence number to each DTLS record. Although the DTLS
implementer may adopt a queue mechanism to resolve reordering, it may
not assure that all the messages are delivered in order when mapping
on the UDP transport.
Since UDP is an unreliable transport, with DTLS, an originator or
relay may not realize that a collector has gone down or lost its DTLS
connection state, so messages may be lost.
The DTLS record has its own sequence number, the encryption and
decryption will done by DTLS layer, UPC Message layer will not
concern this.
6.2. Port Assignment
The Publisher is always a DTLS client, and the Receiver is always a
DTLS server. The Receivers MUST support accepting UPC Messages on
the UDP port PORT-Y, but MAY be configurable to listen on a different
port. The Publisher MUST support sending UPC messages to the UDP
port PORT-Y, but MAY be configurable to send messages to a different
port. The Publisher MAY use any source UDP port for transmitting
messages.
6.3. DTLS Session Initiation
The Publisher initiates a DTLS connection by sending a DTLS Client
Hello to the Receiver. Implementations MUST support the denial of
service countermeasures defined by DTLS. When these countermeasures
are used, the Receiver responds with a DTLS Hello Verify Request
containing a cookie. The Publisher responds with a DTLS Client Hello
containing the received cookie, which initiates the DTLS handshake.
The Publisher MUST NOT send any UPC messages before the DTLS
handshake has successfully completed.
Implementations MUST support DTLS 1.0 [RFC4347] and MUST support the
mandatory to implement cipher suite, which is
TLS_RSA_WITH_AES_128_CBC_SHA [RFC5246] as specified in DTLS 1.0. If
additional cipher suites are supported, then implementations MUST NOT
negotiate a cipher suite that employs NULL integrity or
authentication algorithms.
Where privacy is REQUIRED, then implementations must either negotiate
a cipher suite that employs a non-NULL encryption algorithm or else
achieve privacy by other means, such as a physically secured network.
6.4. Sending Data
All UPC messages MUST be sent as DTLS "application data". It is
possible that multiple UPC messages be contained in one DTLS record,
or that a publication message be transferred in multiple DTLS
records. The application data is defined with the following ABNF
[RFC5234] expression:
APPLICATION-DATA = 1*UPC-FRAME
UPC-FRAME = MSG-LEN SP UPC-MSG
MSG-LEN = NONZERO-DIGIT *DIGIT
SP = %d32
NONZERO-DIGIT = %d49-57
DIGIT = %d48 / NONZERO-DIGIT
UPC-MSG is defined in section 5.2.
6.5. Closure
A Publisher MUST close the associated DTLS connection if the
connection is not expected to deliver any UPC 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
(where the application decides what "long" means), Receiver MAY close
the connection. 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. Congestion Control
Congestion control mechanisms that respond to congestion by reducing Congestion control mechanisms that respond to congestion by reducing
traffic rates and establish a degree of fairness between flows that traffic rates and establish a degree of fairness between flows that
share the same path are vital to the stable operation of the Internet share the same path are vital to the stable operation of the Internet
[RFC2914]. While efficient, UDP has no build-in congestion control [RFC2914]. While efficient, UDP has no build-in congestion control
mechanism. Because streaming telemetry can generate unlimited mechanism. Because streaming telemetry can generate unlimited
amounts of data, transferring this data over UDP is generally amounts of data, transferring this data over UDP is generally
problematic. It is not recommended to use the UPC over congestion- problematic. It is not recommended to use the UDP based publication
sensitive network paths. The only environments where the UPC MAY be channel over congestion-sensitive network paths. The only
used are managed networks. The deployments require the network path environments where the UDP based publication channel MAY be used are
has been explicitly provisioned for the UPC through traffic managed networks. The deployments require the network path has been
engineering mechanisms, such as rate limiting or capacity explicitly provisioned for the UDP based publication channel through
traffic engineering mechanisms, such as rate limiting or capacity
reservations. reservations.
7. IANA Considerations 8. IANA Considerations
This RFC requests that IANA assigns one UDP port number in the This RFC requests that IANA assigns three UDP port numbers in the
"Registered Port Numbers" range with the service names "udp-pub-ch". "Registered Port Numbers" range with the service names "upc" and
This port will be the default port for the UDP based publication "upc-dtls". These ports will be the default ports for the UDP based
channel for NETCONF and RESTCONF. Below is the registration template Publication Channel for NETCONF and RESTCONF. Below is the
following the rules in [RFC6335]. registration template following the rules in [RFC6335].
Service Name: udp-pub-ch Service Name: upc
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: NETCONF Call Home (SSH) Description: UDP based Publication Channel
Reference: RFC XXXX Reference: RFC XXXX
Port Number: PORT-X Port Number: PORT-X
8. Security Considerations Service Name: upc-dtls
Transport Protocol(s): UDP
Assignee: IESG <iesg@ietf.org>
Contact: IETF Chair <chair@ietf.org>
Description: UDP based Publication Channel (DTLS)
Reference: RFC XXXX
Port Number: PORT-Y
9. Security Considerations
TBD TBD
9. Acknowledgements 10. Acknowledgements
The authors of this documents would like to thank Eric Voit, Tim The authors of this documents would like to thank Eric Voit, Tim
Jenkins, and Huiyang Yang for the initial comments. Jenkins, and Huiyang Yang for the initial comments.
10. References 11. References
10.1. Normative References 11.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC2914] Floyd, S., "Congestion Control Principles", BCP 41, [RFC2914] Floyd, S., "Congestion Control Principles", BCP 41,
RFC 2914, DOI 10.17487/RFC2914, September 2000, RFC 2914, DOI 10.17487/RFC2914, September 2000,
<https://www.rfc-editor.org/info/rfc2914>. <https://www.rfc-editor.org/info/rfc2914>.
[RFC4347] Rescorla, E. and N. Modadugu, "Datagram Transport Layer
Security", RFC 4347, DOI 10.17487/RFC4347, April 2006,
<https://www.rfc-editor.org/info/rfc4347>.
[RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", STD 68, RFC 5234,
DOI 10.17487/RFC5234, January 2008,
<https://www.rfc-editor.org/info/rfc5234>.
[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
(TLS) Protocol Version 1.2", RFC 5246,
DOI 10.17487/RFC5246, August 2008,
<https://www.rfc-editor.org/info/rfc5246>.
[RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., [RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
and A. Bierman, Ed., "Network Configuration Protocol and A. Bierman, Ed., "Network Configuration Protocol
(NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011, (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
<https://www.rfc-editor.org/info/rfc6241>. <https://www.rfc-editor.org/info/rfc6241>.
[RFC6335] Cotton, M., Eggert, L., Touch, J., Westerlund, M., and S.
Cheshire, "Internet Assigned Numbers Authority (IANA)
Procedures for the Management of the Service Name and
Transport Protocol Port Number Registry", BCP 165,
RFC 6335, DOI 10.17487/RFC6335, August 2011,
<https://www.rfc-editor.org/info/rfc6335>.
[RFC6347] Rescorla, E. and N. Modadugu, "Datagram Transport Layer
Security Version 1.2", RFC 6347, DOI 10.17487/RFC6347,
January 2012, <https://www.rfc-editor.org/info/rfc6347>.
[RFC7049] Bormann, C. and P. Hoffman, "Concise Binary Object [RFC7049] Bormann, C. and P. Hoffman, "Concise Binary Object
Representation (CBOR)", RFC 7049, DOI 10.17487/RFC7049, Representation (CBOR)", RFC 7049, DOI 10.17487/RFC7049,
October 2013, <https://www.rfc-editor.org/info/rfc7049>. October 2013, <https://www.rfc-editor.org/info/rfc7049>.
[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
RFC 7950, DOI 10.17487/RFC7950, August 2016, RFC 7950, DOI 10.17487/RFC7950, August 2016,
<https://www.rfc-editor.org/info/rfc7950>. <https://www.rfc-editor.org/info/rfc7950>.
[RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF [RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017, Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
<https://www.rfc-editor.org/info/rfc8040>. <https://www.rfc-editor.org/info/rfc8040>.
[RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6 [RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", STD 86, RFC 8200, (IPv6) Specification", STD 86, RFC 8200,
DOI 10.17487/RFC8200, July 2017, DOI 10.17487/RFC8200, July 2017,
<https://www.rfc-editor.org/info/rfc8200>. <https://www.rfc-editor.org/info/rfc8200>.
10.2. Informative References 11.2. Informative References
[I-D.ietf-netconf-netconf-event-notifications] [I-D.ietf-netconf-netconf-event-notifications]
Prieto, A., Voit, E., Clemm, A., Nilsen-Nygaard, E., and Voit, E., Clemm, A., Prieto, A., Nilsen-Nygaard, E., and
A. Tripathy, "NETCONF Support for Event Notifications", A. Tripathy, "NETCONF Support for Event Notifications",
draft-ietf-netconf-netconf-event-notifications-08 (work in draft-ietf-netconf-netconf-event-notifications-09 (work in
progress), February 2018. progress), May 2018.
[I-D.ietf-netconf-notification-messages] [I-D.ietf-netconf-notification-messages]
Voit, E., Birkholz, H., Bierman, A., Clemm, A., and T. Voit, E., Birkholz, H., Bierman, A., Clemm, A., and T.
Jenkins, "Notification Message Headers and Bundles", Jenkins, "Notification Message Headers and Bundles",
draft-ietf-netconf-notification-messages-03 (work in draft-ietf-netconf-notification-messages-03 (work in
progress), February 2018. progress), February 2018.
[I-D.ietf-netconf-restconf-notif] [I-D.ietf-netconf-restconf-notif]
Voit, E., Tripathy, A., Nilsen-Nygaard, E., Clemm, A., Voit, E., Rahman, R., Nilsen-Nygaard, E., Clemm, A., and
Prieto, A., and A. Bierman, "RESTCONF and HTTP Transport A. Bierman, "RESTCONF and HTTP Transport for Event
for Event Notifications", draft-ietf-netconf-restconf- Notifications", draft-ietf-netconf-restconf-notif-06 (work
notif-04 (work in progress), January 2018. in progress), June 2018.
[I-D.ietf-netconf-subscribed-notifications] [I-D.ietf-netconf-subscribed-notifications]
Voit, E., Clemm, A., Prieto, A., Nilsen-Nygaard, E., and Voit, E., Clemm, A., Prieto, A., Nilsen-Nygaard, E., and
A. Tripathy, "Custom Subscription to Event Streams", A. Tripathy, "Customized Subscriptions to a Publisher's
draft-ietf-netconf-subscribed-notifications-10 (work in Event Streams", draft-ietf-netconf-subscribed-
progress), February 2018. notifications-13 (work in progress), June 2018.
[I-D.ietf-netconf-yang-push]
Clemm, A., Voit, E., Prieto, A., Tripathy, A., Nilsen-
Nygaard, E., Bierman, A., and B. Lengyel, "YANG Datastore
Subscription", draft-ietf-netconf-yang-push-15 (work in
progress), February 2018.
[I-D.zhou-netconf-multi-stream-originators] [I-D.zhou-netconf-multi-stream-originators]
Zhou, T., Zheng, G., Voit, E., Clemm, A., and A. Bierman, Zhou, T., Zheng, G., Voit, E., Clemm, A., and A. Bierman,
"Subscription to Multiple Stream Originators", draft-zhou- "Subscription to Multiple Stream Originators", draft-zhou-
netconf-multi-stream-originators-01 (work in progress), netconf-multi-stream-originators-02 (work in progress),
November 2017. May 2018.
10.3. URIs 11.3. URIs
[1] https://developers.google.com/protocol-buffers/ [1] https://developers.google.com/protocol-buffers/
Appendix A. Change Log Appendix A. Change Log
(To be removed by RFC editor prior to publication) (To be removed by RFC editor prior to publication)
A.1. draft-ietf-zheng-udp-pub-channel-00 to v00 A.1. draft-ietf-zheng-udp-pub-channel-00 to v00
o Modified the message header format. o Modified the message header format.
skipping to change at page 15, line 18 skipping to change at page 19, line 7
o Modified the message header format. o Modified the message header format.
A.2. v02 A.2. v02
o Add the section on the transport mechanism. o Add the section on the transport mechanism.
o Modified the fixed message header format. o Modified the fixed message header format.
o Add the fragmentation option for the message header. o Add the fragmentation option for the message header.
A.2. v03
o Clarify term through the document.
o Add a section on DTLS support.
Authors' Addresses Authors' Addresses
Guangying Zheng Guangying Zheng
Huawei Huawei
101 Yu-Hua-Tai Software Road 101 Yu-Hua-Tai Software Road
Nanjing, Jiangsu Nanjing, Jiangsu
China China
Email: zhengguangying@huawei.com Email: zhengguangying@huawei.com
 End of changes. 67 change blocks. 
176 lines changed or deleted 367 lines changed or added

This html diff was produced by rfcdiff 1.47. The latest version is available from http://tools.ietf.org/tools/rfcdiff/