Interdomain Routing Working Group M. Liu
Internet-Draft Y. Wang
Intended status: Standards Track Huawei
Expires: September 10, 2020 R. Pang
China Unicom
March 09, 2020
BGP Flow Specification Extensions to Enable In-situ Flow Information
Telemetry (IFIT)
draft-liu-idr-flowspec-ifit-03
Abstract
BGP Flowspec mechanism propogates both traffic Flow Specifications
and Traffic Filtering Actions by making use of the BGP NLRI and the
BGP Extended Community encoding formats. This document specifies a
new BGP Extended Community named IFIT Action Specific Extended
Community to distribute In-situ Flow Information Telemetry (IFIT)
actions so as to address the automatical deployment of IPv6 unicast
and VPNv6 unicast on-path flow telemetry.
Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on September 10, 2020.
Liu, et al. Expires September 10, 2020 [Page 1]
Internet-Draft draft-liu-idr-flowspec-ifit-03 March 2020
Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminologies . . . . . . . . . . . . . . . . . . . . . . . . 3
3. IFIT Application . . . . . . . . . . . . . . . . . . . . . . 3
4. IFIT Action Specific Extended Community . . . . . . . . . . . 4
4.1. IOAM Pre-allocated Trace Option sub-type . . . . . . . . 5
4.2. IOAM Incremental Trace Option sub-type . . . . . . . . . 5
4.3. IOAM DEX Option sub-type . . . . . . . . . . . . . . . . 6
4.4. IOAM Edge-to-Edge Option sub-type . . . . . . . . . . . . 7
4.5. Enhanced Alternate Marking Option sub-type . . . . . . . 7
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
5.1. IFIT Action Extended Community Types . . . . . . . . . . 8
6. Security Considerations . . . . . . . . . . . . . . . . . . . 9
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 9
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 9
8.1. Normative References . . . . . . . . . . . . . . . . . . 9
8.2. Informative References . . . . . . . . . . . . . . . . . 9
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10
1. Introduction
At present, a family of on-path flow telemetry techniques referred in
[I-D.song-opsawg-ifit-framework] are emerging, including In-situ OAM
(IOAM) [I-D.ietf-ippm-ioam-data], PBT
[I-D.song-ippm-postcard-based-telemetry] , IOAM Direct Export (DEX)
[I-D.ioamteam-ippm-ioam-direct-export] , Enhanced Alternate Marking
(EAM) [I-D.zhou-ippm-enhanced-alternate-marking], etc. we categorize
these on-path telemetry echniques as the hybrid OAM type I according
to the classification defined in [RFC7799]. These techniques provide
flow information on the entire forwarding path on a per-packet basis
in real time, which are invaluable for application-aware network
operations not only in data center and enterprise networks but also
Liu, et al. Expires September 10, 2020 [Page 2]
Internet-Draft draft-liu-idr-flowspec-ifit-03 March 2020
in carrier networks which may cross multiple domains. The data
provided by on-path telemetry are especially useful for network
operations in aspects of SLA compliance, service path enforcement,
fault diagnosis, and network resource optimization. In IFIT
reflection-loop architecture [I-D.song-opsawg-ifit-framework], an
IFIT application needs to choose a suite of telemetry tecchniques and
apply an initial technique to the data plane in accordance to the
monitoring and measurement requirements. Then the IFIT head nodes
also need to decide the target flows and packets to enable the IFIT-
specific functions and the telemetry data sets.
However, applying only a single underlying on-path telemetry
technique may lead to defective result. A comprehensive solution
needs the flexibility to switch between different underlying
techniques and adjust the configurations and parameters to adapt to
different network conditions and different application requirements.
Hence, it's necessary to make the control and configuration
dynamically to the IFIT nodes.
As we know, Dissemination of Flow Specification Rules
[I-D.ietf-idr-rfc5575bis] provides a protocol extension for
propagation of traffic flow information for the purpose of rate
limiting, filtering, shaping, classifying or redirecting. And BGP
extended community encoding formats can be used to propagate traffic
filtering actions along with the flow specification NLRI. Those
traffic filtering actions encode actions a routing system can take if
the packet matches the flow specifications. And the other document
[I-D.ietf-idr-flow-spec-v6] extends BGP Flowspec
[I-D.ietf-idr-rfc5575bis] and to make it also usable and applicable
to IPv6 data packets.
From an operational perspective, the utilization of BGP Flowspec as
the carrier for the specific flow information allows a network
service provider to reuse BGP route distribute infrastructure.
Therefore, this document defines the IFIT action BGP Extended
Communities to enable the IFIT application.
2. Terminologies
IFIT: in-situ Flow Information Telemetry
NLRI: Network Layer Reachability Information
3. IFIT Application
The IFIT applications, which enable the future autonomous network
operation, will pick one of proper in-situ telemetry techniques and
apply a flow, packet, and data selection policy to monitor the
Liu, et al. Expires September 10, 2020 [Page 3]
Internet-Draft draft-liu-idr-flowspec-ifit-03 March 2020
specific traffic flow for application-aware network operation. In
current deployments, there have been relatively static methods, ACL-
like CLI and Netconf with YANG model to enable the specific flow or
packets from the target flow to be monitored on the relevant IFIT-
capable nodes.
However, with the evolution of intent-based and automatic network
operation, and the trends of network virtualization, network
convergence, and packet-optical integration, future data plane
telemetry will support an on-demand and interactive fashion.
Flexibility and extensibility of data defining and acquiring must be
considered. Therefore, flexible configurations and actions need to
be deployed based on the real-time telemetry data analysis results
and telemetry requirements of different application.
BGP Flowspec mechanism is preferred in the reflective-loop network
telemetry system. This document defines IFIT Action BGP Extended
Communities to enable IFIT actions for the relevant flows that
matches the traffic Flow Specifications along with the BGP NLRI
defined in [I-D.ietf-idr-rfc5575bis] and [I-D.ietf-idr-flow-spec-v6].
4. IFIT Action Specific Extended Community
This section defines a new BGP Extended Community and different sub-
types for IFIT actions in accordance with different IFIT option
types.
The BGP Extended Community is encoded as an 8-octet quantity, which
contains Type field and Value field [RFC4360]. The Types are to be
assigned by IANA registry. The Value field contains the IFIT
actions.
In IFIT framework architecture, there are a few of available option
types for the specified traffic flow, e.g. IOAM pre-allocated/
incremental trace [I-D.ietf-ippm-ioam-data], IOM Edge-to-Edge
[I-D.ietf-ippm-ioam-data], IOAM Direct Export (DEX)
[I-D.ioamteam-ippm-ioam-direct-export], Enhanced Alternate Marking
(EAM) [I-D.zhou-ippm-enhanced-alternate-marking], etc. As different
IFIT options have different formats of parameters, following defines
various Sub-types in accordance with different IFIT option types.
o Type xx: IFIT Action
o Sub-type xx: IOAM Pre-allocated Trace Option
o Sub-type xx: IOAM Incremental Trace Option
o Sub-type xx: IOAM DEX Option
Liu, et al. Expires September 10, 2020 [Page 4]
Internet-Draft draft-liu-idr-flowspec-ifit-03 March 2020
o Sub-type xx: IOAM Edge-to-Edge Option
o Sub-type xx: Enhanced Alternate Marking Option
In the following sections, the different IFIT action Extened
Communities encoding formats are presented.
4.1. IOAM Pre-allocated Trace Option sub-type
The IOAM tracing data is expected to be collected at every node that
a packet traverses to ensure visibility into the entire path a packet
takes within an IOAM domain. The pre-allocated tracing option will
create pre-allocated space for each node to populate its information.
The format of IOAM pre-allocated trace option Extended Community is
defined as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-------------------------------+-------------------------------+
| Type | Sub-type | NamespaceID |
+---------------------------------------------------------------+
| Flags | IOAM-Trace-Type | Rsvd |
+---------------------------------------------------------------+
Fig. 1 IOAM Pre-allocated Trace Option Extended Community
Where:
Namespace ID: A 16-bit identifier of an IOAM-Namespace. The
definition is the same as described in section 4.4
of[I-D.ietf-ippm-ioam-data] .
Flags: A 4-bit field. The definition is the same as described in [I-
D.ietf-ippm-ioam-flags] and section 4.4 of [I-D.ietf-ippm-ioam-data].
IOAM-Trace-Type: A 24-bit identifier which specifies which data types
are used in the node data list. The definition is the same as
described in section 4.4 of [I-D.ietf-ippm-ioam-data].
Rsvd: A 4-bit field reserved for further usage. It MUST be zero.
4.2. IOAM Incremental Trace Option sub-type
The incremental tracing option contains a variable node data fields
where each node allocates and pushes its node data immediately
following the option header.
Liu, et al. Expires September 10, 2020 [Page 5]
Internet-Draft draft-liu-idr-flowspec-ifit-03 March 2020
The format of IOAM incremental trace option Extended Community is
defined as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-------------------------------+-------------------------------+
| Type | Sub-type | NamespaceID |
+---------------------------------------------------------------+
| Flags | IOAM-Trace-Type | Rsvd |
+---------------------------------------------------------------+
Fig. 2 IOAM Incremental Trace Option Extended Community
Where:
All the other fields definistion is the same as the pre-allocated
trace option Extended Community in section 3.2.1.
4.3. IOAM DEX Option sub-type
The DEX option is used as a trigger to export IOAM data to a
collector. Moreover, IOAM nodes MAY send exported data for all
traversing packets that carry the DEX option, or MAY selectively
export data only for a subset of these packets. The DEX option
specifies which data fields should be exported to the collector, as
specified in Section 3.2 of [I-D.ioamteam-ippm-ioam-direct-export].
The format of IOAM DEX option Extended Community is defined as
follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-------------------------------+-------------------------------+
| Type | Sub-type | NamespaceID |
+---------------------------------------------------------------+
| IOAM-Trace-Type | Flags |
+---------------------------------------------------------------+
Fig. 3 IOAM DEX Option Extended Community
Where:
Namespace-ID: a 16-bit identifier of the IOAM namespace, as defined
in section 4.4 of [I-D.ietf-ippm-ioam-data].
Liu, et al. Expires September 10, 2020 [Page 6]
Internet-Draft draft-liu-idr-flowspec-ifit-03 March 2020
IOAM-Trace-Type: a 24-bit identifier which specifies which data
fields should be exported. The format of this field is as defined in
section 4.4 of[I-D.ietf-ippm-ioam-data]
Flags: A 8-bit field, comprised of 8 one-bit subfields. Flags are
allocated by IANA.
4.4. IOAM Edge-to-Edge Option sub-type
The IOAM edge to edge option is to carry data that is added by the
IOAM encapsulating node and interpreted by IOAM decapsulating node.
The format of IOAM edge-to-edge option Extended Community is defined
as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-------------------------------+-------------------------------+
| Type | Sub-type | Rsvd |
+---------------------------------------------------------------+
| NamespaceID | IOAM-E2E-Type |
+---------------------------------------------------------------+
Fig. 4 IOAM Edge-to-Edge Option Extended Community
Where:
Namespace ID: A 16-bit identifier of an IOAM-Namespace. The
definition is the same as described in section 4.6
of[I-D.ietf-ippm-ioam-data].
IOAM-E2E-Type: A 16-bit identifier which specifies which data types
are used in the E2E option data. The definition is the same as
described in section 4.6 of [I-D.ietf-ippm-ioam-data].
Rsvd: A 16-bit field reserved for further usage. It MUST be zero.
4.5. Enhanced Alternate Marking Option sub-type
The Alternate Marking [RFC8321] technique is an hybrid performance
measurement method and can be used to measure packet loss, latency,
and jitter on live traffic because it is based on marking consecutive
batches of packets.
The Enhanced Alternate Marking (EAM)
[I-D.zhou-ippm-enhanced-alternate-marking] defines data fields for
Liu, et al. Expires September 10, 2020 [Page 7]
Internet-Draft draft-liu-idr-flowspec-ifit-03 March 2020
the alternate marking with enough space, in particular for Postcard-
based Telemetry. More information can be considered within the
alternate marking field to facilitate the efficiency and ease the
deployment.
The format of EAM Option Extended Community is defined as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-------------------------------+-------------------------------+
| Type | Sub-type | Rsvd |
+---------------+---------------+-------+---------------+-------+
| FlowMonID | Period | Rsvd |
+---------------------------------------+---------------+-------+
Fig. 5 Enhanced Alternate Marking Option Extended Community
Where:
FlowMonID: A 20-bit identifier to uniquely identify a monitored flow
within the measurement domain. The definition is the same as
described in section 2 of [I-D.zhou-ippm-enhanced-alternate-marking].
Period: A 8-bit field. Time interval between two alternate marking
period. The unit is second.
Rsvd: reserved for further usage. It MUST be zero.
5. IANA Considerations
5.1. IFIT Action Extended Community Types
This document requests a new Transitive Extended Community Type and
five new registery sub-types. The new Transitive Extended Community
Type name shall be "IFIT Action Extended Community (Sub-Types are
defined in the "IFIT Action Extended Community Sub-Type" registery)".
Type Value Name
--------- ----------
TBD IFIT Action
Liu, et al. Expires September 10, 2020 [Page 8]
Internet-Draft draft-liu-idr-flowspec-ifit-03 March 2020
Sub-type Value Name
-------------- ----------
TBD IOAM Pre-allocated Trace Option
TBD IOAM Incremental Trace Option
TBD IOAM DEX Option
TBD IOAM Edge-to-Edge Option
TBD Enhanced Alternate Marking
6. Security Considerations
No new security issues are introduced to the BGP Flow Specifications
in [I-D.ietf-idr-flow-spec-v6] and [I-D.ietf-idr-rfc5575bis].
7. Acknowledgements
8. References
8.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC4360] "BGP Extended Communities Attribute",
<https://www.rfc-editor.org/info/rfc4360>.
[RFC7799] "Active and Passive Metrics and Methods (with Hybrid Types
In-Between)", <https://www.rfc-editor.org/info/rfc7799>.
[RFC8321] "Alternate-Marking Method for Passive and Hybrid
Performance Monitoring",
<https://www.rfc-editor.org/info/rfc8321>.
8.2. Informative References
[I-D.ietf-idr-flow-spec-v6]
"Dissemination of Flow Specification Rules for IPv6",
<https://datatracker.ietf.org/doc/draft-ietf-idr-flow-
spec-v6/>.
[I-D.ietf-idr-rfc5575bis]
"Dissemination of Flow Specification Rules",
<https://datatracker.ietf.org/doc/draft-ietf-idr-
rfc5575bis/>.
Liu, et al. Expires September 10, 2020 [Page 9]
Internet-Draft draft-liu-idr-flowspec-ifit-03 March 2020
[I-D.ietf-ippm-ioam-data]
"Data Fields for In-situ OAM",
<https://datatracker.ietf.org/doc/draft-ietf-ippm-ioam-
data/>.
[I-D.ioamteam-ippm-ioam-direct-export]
"In-situ OAM Direct Exporting",
<https://datatracker.ietf.org/doc/draft-ioamteam-ippm-
ioam-direct-export/>.
[I-D.song-ippm-postcard-based-telemetry]
"Postcard-based On-Path Flow Data Telemetry",
<https://datatracker.ietf.org/doc/draft-song-ippm-
postcard-based-telemetry/>.
[I-D.song-opsawg-ifit-framework]
"In-situ Flow Information Telemetry Framework",
<https://datatracker.ietf.org/doc/draft-song-opsawg-ifit-
framework/>.
[I-D.zhou-ippm-enhanced-alternate-marking]
"Enhanced Alternate Marking Method",
<https://datatracker.ietf.org/doc/draft-zhou-ippm-
enhanced-alternate-marking/>.
Authors' Addresses
Min Liu
Huawei
156 Beiqing Rd., Haidian District
Beijing
China
Email: lucy_liumin@huawei.com
Yali Wang
Huawei
156 Beiqing Rd., Haidian District
Beijing
China
Email: wangyali11@huawei.com
Liu, et al. Expires September 10, 2020 [Page 10]
Internet-Draft draft-liu-idr-flowspec-ifit-03 March 2020
Ran Pang
China Unicom
9 Shouti South Rd., Haidian District
Beijing
China
Email: pangran@chinaunicom.cn
Liu, et al. Expires September 10, 2020 [Page 11]