Internet DRAFT - draft-liu-lsr-isis-ifit-node-capability
draft-liu-lsr-isis-ifit-node-capability
Link State 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
IS-IS Extensions for Advertising In-situ Flow Information Telemetry
(IFIT) Node Capability
draft-liu-lsr-isis-ifit-node-capability-03
Abstract
This document defines a way for an Intermediate System to
Intermediate System (IS-IS) routers to advertise IFIT (In-situ Flow
Information Telemetry) capabilities. This document extends a new
optional sub-TLV in the IS-IS Router CAPABILITY TLV [RFC7981], which
allows a router to announce its IFIT node capabilities within an IS-
IS level or the entire routing domain. Such advertisements enable
IFIT applications in the network domain.
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.
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This Internet-Draft will expire on September 10, 2020.
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Copyright Notice
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. IFIT Domain . . . . . . . . . . . . . . . . . . . . . . . 3
1.2. IFIT Node Capability Information . . . . . . . . . . . . 3
2. Advertisement of the IFIT Node Capabilities in ISIS . . . . . 3
2.1. IFIT Node Capability Sub-TLV . . . . . . . . . . . . . . 3
3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
3.1. Sub-TLVs for the IS-IS Router CAPABILITY TLV (242) . . . 5
4. Security Considerations . . . . . . . . . . . . . . . . . . . 5
5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 5
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 5
6.1. Normative References . . . . . . . . . . . . . . . . . . 5
6.2. Informative References . . . . . . . . . . . . . . . . . 6
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6
1. Introduction
IFIT provides a complete framework architecture and a reflection-loop
working solution for on-path flow telemetry
[I-D.song-opsawg-ifit-framework]. At present, there are a family of
emerging on-path flow telemetry techniques, 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. IFIT is a
solution focusing on network domains. The "network domain" consists
of a set of network devices or entities within a single
administration. For example, a network domain can be one or more IGP
routing domains. The family of emerging on-path flow telemetry
techniques may be selectively or partially implemented in different
vendors' devices as an emerging feature for various use cases of
application-aware network operations. Hence, in order to enable IFIT
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applications in an operational network domain, IFIT node capabilities
SHOULD be advertised by every Intermediate System to Intermediate
System (IS-IS) router in the network domain.
1.1. IFIT Domain
IFIT is expected to be deployed in a specific domain referred as the
IFIT domain. An IFIT domain may cross multiple network domains. One
network domain may consists of multiple IFIT domain. Within the IFIT
domain, the IFIT data fields of flow information head MAY be updated
by network nodes that the packet traverses.
1.2. IFIT Node Capability Information
Each IFIT node is configured with a node-id which uniquely identifies
a node within the associated IFIT domain. To accommodate the
different use cases or requirements of in-situ flow information
telemetry, IFIT data fields updated by network nodes fall into
different categories which are referred as different IFIT option
types, including IOAM Trace Option-Types [I-D.ietf-ippm-ioam-data],
IOAM Edge-to-Edge (E2E) Option-Type [I-D.ietf-ippm-ioam-data], IOAM
DEX Option-Type [I-D.ioamteam-ippm-ioam-direct-export] and Enhanced
Alternate Marking (EAM) Option-Type
[I-D.zhou-ippm-enhanced-alternate-marking]. So IFIT Option Types
SHOULD be carried in IFIT node capability advertisment.
2. Advertisement of the IFIT Node Capabilities in ISIS
The IS-IS Extensions for Advertising Router Information TLV named IS-
IS Router CAPABILITY TLV [RFC7981], which allows a router to announce
its capabilities within an IS-IS level or the entire routing domain,
has been chosen for IFIT node capabilities advertisement. IS-IS
Router CAPABILITY TLV is formed of multiple sub-TLVs [RFC5305].
2.1. IFIT Node Capability Sub-TLV
According to the format of IS-IS Router CAPABILITY TLV [RFC7981], the
IFIT Node Capability sub-TLV is composed of three fields, a one-octet
Type field, a one-octet Length field, and zero or more octets of
Value. The Type field indicates the type of items in the Value
field. The Length field indicates the length of the Value field in
octets. The Value field indicates the IFIT Node Capability, which is
a 2-octet IFIT Option Type-enabled Flag.
The IFIT Node-capability Sub-TLV has the following format:
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+---------------+---------------+-------------------------------+
| Type | Length |IFIT Option Type-enabled Flag |
+---------------+---------------+-------------------------------+
Fig. 1 IFIT Node Capability Sub-TLV Format
Type: To be assigned by IANA
Length: A 8-bit field that indicates the length of the value portion
in octets.
IFIT Option Type-enabled Flag: A 2-octet field that is defined as
following:
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-------------------------------+
|p|i|d|e|m| Reserved |
+-------------------------------+
Where:
p-Flag: iOAM Pre-allocated Trace Option Type-enabled flag. If p bit
is set (1), the router is capable of iOAM Pre-allocated Trace
[I-D.ietf-ippm-ioam-data].
i-Flag: iOAM Incremental Trace Option Type-enabled flag. If i bit is
set (1), the router is capable of iOAM Incremental Tracing
[I-D.ietf-ippm-ioam-data].
d-Flag: iOAM DEX Option Type-enabled flag. If d bit is set (1), the
router is capable of iOAM DEX [I-D.ioamteam-ippm-ioam-direct-export].
e-Flag: iOAM E2E Option Type-enabled flag. If e bit is set (1), the
router is capable of iOAM E2E processing [I-D.ietf-ippm-ioam-data].
m-Flag: Enhanced Alternative Marking enabled flag. If m bit is set
(1), then the router is capable of processing Enhanced Alternative
Marking packets [I-D.zhou-ippm-enhanced-alternate-marking].
Reserved: Must be set to zero upon transmission and ignored upon
receipt.
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An IFIT node SHALL be capable of more than one IFIT option types. So
for this case, IFIT Option Type-enabled Flag bitmap SHOULD has more
than one bit being set.
3. IANA Considerations
Note to RFC Editor: this section may be removed on publication as an
RFC.
3.1. Sub-TLVs for the IS-IS Router CAPABILITY TLV (242)
This document makes the following registrations for a Sub-TLV type of
the new Sub-TLV proposed in Section 3 of this document from the "Sub-
TLVs for TLV 242 (IS-IS Router CAPABILITY TLV)" registry.
+------+----------------------+
| Type | Description |
+------+----------------------+
| TBD | IFIT Node Capability |
+------+----------------------+
4. Security Considerations
This document introduces new sub-TLVs for the existing IS-IS Router
capability TLV. It does not introduce any new security risks to
ISIS.
5. Acknowledgements
6. References
6.1. 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>.
[RFC5305] "IS-IS Extensions for Traffic Engineering",
<https://www.rfc-editor.org/info/rfc5305>.
[RFC7981] "IS-IS Extensions for Advertising Router Information",
<https://www.rfc-editor.org/info/rfc7981>.
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6.2. Informative References
[I-D.ietf-ippm-ioam-data]
"Data Fields for In-situ OAM".
[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
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Ran Pang
China Unicom
9 Shouti South Rd., Haidian District
Beijing
China
Email: pangran@chinaunicom.cn
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