Network Working Group Y. Zhu
Internet-Draft H. Chen
Intended status: Standards Track China Telecom
Expires: September 14, 2017 Z. Du
M. Chen
Huawei
March 13, 2017
ISIS Extensions for Flexible Ethernet
draft-zcdc-isis-flexe-extention-00
Abstract
This document specifies the extensions to the IS-IS routing protocol
to carry and flood Flex Ethernet (FlexE) link state information. The
FlexE link state information is necessary for a device or a
controller to compute a path that is required to over FlexE links.
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
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Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on September 14, 2017.
Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved.
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This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Extensions for Aggregated FlexE Link . . . . . . . . . . . . 3
2.1. Interface Switch Capability Descriptor . . . . . . . . . 3
3. Extensions for Channelized FlexE Link . . . . . . . . . . . . 5
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
4.1. FlexE Switching Type . . . . . . . . . . . . . . . . . . 6
4.2. FlexE LSP Encoding Type . . . . . . . . . . . . . . . . . 6
4.3. FlexE Group Sub-TLV . . . . . . . . . . . . . . . . . . . 6
4.4. FlexE Capable Link . . . . . . . . . . . . . . . . . . . 7
5. Security Consideration . . . . . . . . . . . . . . . . . . . 7
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 7
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
7.1. Normative References . . . . . . . . . . . . . . . . . . 7
7.2. Informative References . . . . . . . . . . . . . . . . . 7
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8
1. Introduction
Flexible Ethernet (FlexE) is defined in [FlexE], it provides a
generic mechanism for supporting a variety of Ethernet MAC rates that
may or may not correspond to any existing Ethernet PHY rate. This
includes MAC rates that are both greater than (through bonding) and
less than (through sub-rate and channelization) the Ethernet PHY
rates used to carry FlexE.
A FlexE group [FlexE] can be treated as an aggregated interface that
is composed of from 1 to n 100GBASE-R PHYs (other types of PHY, e.g.,
400GbE under development in the IEEE P802.3bs project, may be
supported in the future). A FlexE link is a logic/virtual link that
connects two adjacent FlexE groups. When a FlexE group is considered
as a single interface, the link connecting two FlexE groups is
referred to as an aggregated FlexE link. When a FlexE group is
channelized to multiple sub-interfaces, the link connecting a pair of
sub-interfaces is referred to as a channelized FlexE link. Each
channelized FlexE link corresponds to a FlexE client [FlexE].
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FlexE Group 1 FlexE Group 1'
+-------+ +--------+
| FlexE | aggregated FlexE link | FlexE |
| |========================| |
| Shim | | Shim |
+-------+ +--------+
Figure 1: Aggregated FlexE link between two FlexE groups
FlexE Group 1 FlexE Group 1'
+-------+ channelized FlexE link 1 +--------+
| FlexE |==========================| FlexE |
| | ... | |
| Shim |==========================| Shim |
+-------+ channelized FlexE link n +--------+
Figure 2: Channelized FlexE links between two FlexE groups
The GMPLS routing and signaling framework for FlexE is defined in
[I-D.izh-ccamp-flexe-fwk].
This document defines extensions to ISIS protocol to carry and flood
the FlexE link state information.
2. Extensions for Aggregated FlexE Link
An aggregated FlexE link can be used as a whole link and mapped to a
single FlexE client. Or it can be treated as a resource and be
allocated to different FlexE clients as needed.
In order to compute and establish a path/LSP spanning multiple FlexE
nodes/links, the following information of an aggregated FlexE link
should be included:
o FlexE switching capability of the interface (whether an interface
support FlexE Switching)
o FlexE switching granularity of the interface
o The bandwidth (used and unused) information of the interface
2.1. Interface Switch Capability Descriptor
The Interface Switching Capability Descriptor (ISCD) is a sub-TLV of
the extended IS reachability TLV [RFC5307], it is defined to
describes the switching capability of an interface. The following
illustrates encoding of the Value field of the Interface Switching
Capability Descriptor sub-TLV.
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Switching Cap | Encoding | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max LSP Bandwidth at priority 0 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max LSP Bandwidth at priority 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max LSP Bandwidth at priority 2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max LSP Bandwidth at priority 3 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max LSP Bandwidth at priority 4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max LSP Bandwidth at priority 5 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max LSP Bandwidth at priority 6 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max LSP Bandwidth at priority 7 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Switching Capability-specific information |
| (variable) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: ISCD sub-TLV
To support aggregated FlexE link advertisement, new "Switching Cap"
and "Encoding" are defined as follows:
The Switching Capability (Switching Cap) for FlexE:
Value Name
----- --------------
TBD1 FlexE-Switching
The Encoding Type for FlexE:
Value Name
----- --------------
TBD2 FlexE
The content of the Switching Capability specific information field
depends on the value of the Switching Capability field. When the
Switching Capability is FlexE-Switching, the "Switching Capability-
specific information" is defined as below. It is referred to as
FlexE Group sub-TLV in this document.
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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 = TBD3 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Granularity | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Available Slots at priority 0 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Available Slots at priority 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Available Slots at priority 2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Available Slots at priority 3 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Available Slots at priority 4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Available Slots at priority 5 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Available Slots at priority 6 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Available Slots at priority 7 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: FlexE Group sub-TLV
The Type field is 2 octets in length and the value is TBD3.
The Length field is 2 octets in length that indicates the total
length of the TLV in octet.
The Granularity is 2 octets in length and its values map to the
granularities of a FlexE time slot. Current OIF agreement only
allows the "5G" granularity.
Value Granularity
----- --------------
1 5G
Each Available Slots at priority n is 4-octet in length that
indicates the maximum number of slots available at priority 'n' on
active calendar of the TE Link.
3. Extensions for Channelized FlexE Link
A channelized FlexE link is a logic/virtual point-2-point link and
corresponds to a FlexE client. Although it's a logic/virtual link,
from link characteristic point of view, it's same as a real point-
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2-point link. It can be advertised and used as a normal point-
2-point link.
In a network, it's possible that not all devices/links are FlexE
capable, especially at the beginning of FlexE deployment. Since a
channelized FlexE link has dedicated resource, it can provide a
certain degree of service isolation and service level assurance
(SLA), operators may want to deploy some services over only FlexE
capable links. So, it needs a mechanism to identify whether a link
is FlexE capable. This document defines a bit value (TBD4) in link-
attributes sub-TLV [RFC5029] to identify whether a link is FlexE
capable.
4. IANA Considerations
4.1. FlexE Switching Type
IANA is requested to allocate a new switching type from the
"Switching Types" registry of "Generalized Multi-Protocol Label
Switching (GMPLS) Signaling Parameters" registry.
Value Name Reference
----- --------------- -------------
TBD1 FlexE-Switching This document
4.2. FlexE LSP Encoding Type
IANA is requested to allocate a new LSP encoding type from the "LSP
Encoding Types" registry of "Generalized Multi-Protocol Label
Switching (GMPLS) Signaling Parameters" registry.
Value Name Reference
----- ------- -------------
TBD2 FlexE This document
4.3. FlexE Group Sub-TLV
IANA is requested to create and maintain a new sub-registry, the
"Types for sub-TLVs of FlexE Switching Capability Specific
Information" registry under the "Open Shortest Path First (OSPF)
Traffic Engineering TLVs" registry.
Value sub-TLV Name Reference
----- ------------ -------------
TBD3 FlexE Group This document
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4.4. FlexE Capable Link
IANA is requested to allocate the following bit value in ISIS "link-
attributes sub-TLV" registry.
Value Name Reference
----- ------------- -------------
TBD3 FlexE Capable This document
5. Security Consideration
This document describes a mechanism for advertising FlexE link state
information through IS-IS LSPs and does not introduce any new
security issues.
6. Acknowledgements
7. References
7.1. 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,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC5029] Vasseur, JP. and S. Previdi, "Definition of an IS-IS Link
Attribute Sub-TLV", RFC 5029, DOI 10.17487/RFC5029,
September 2007, <http://www.rfc-editor.org/info/rfc5029>.
[RFC5307] Kompella, K., Ed. and Y. Rekhter, Ed., "IS-IS Extensions
in Support of Generalized Multi-Protocol Label Switching
(GMPLS)", RFC 5307, DOI 10.17487/RFC5307, October 2008,
<http://www.rfc-editor.org/info/rfc5307>.
7.2. Informative References
[FlexE] OIF, "Flex Ethernet Implementation Agreement Version 1.0
(OIF-FLEXE-01.0)", March 2016.
[I-D.izh-ccamp-flexe-fwk]
Hussain, I., Valiveti, R., Wang, Q., Andersson, L., Chen,
M., and z. zhenghaomian@huawei.com, "GMPLS Routing and
Signaling Framework for Flexible Ethernet (FlexE)", draft-
izh-ccamp-flexe-fwk-01 (work in progress), February 2017.
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Authors' Addresses
Yongqing Zhu
China Telecom
109, West Zhongshan Road, Tianhe District, Guangzhou,China
Email: zhuyq@gsta.com
Huanan Chen
China Telecom
109, West Zhongshan Road, Tianhe District, Guangzhou,China
Email: chenhuanan@gsta.com
Zongpeng Du
Huawei
Email: duzongpeng@huawei.com
Mach(Guoyi) Chen
Huawei
Email: mach.chen@huawei.com
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