Network Working Group Y. Zhu
Internet-Draft H. Chen
Intended status: Standards Track China Telecom
Expires: January 4, 2018 Z. Du
M. Chen
Huawei
July 3, 2017
ISIS Extensions for Flexible Ethernet
draft-zcdc-isis-flexe-extention-01
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 node 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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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 January 4, 2018.
Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. FlexE Link Advertisement . . . . . . . . . . . . . . . . . . 3
3. FlexE Sub-link Advertisement . . . . . . . . . . . . . . . . 6
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
4.1. FlexE Switching Type . . . . . . . . . . . . . . . . . . 6
4.2. FlexE LSP Encoding Type . . . . . . . . . . . . . . . . . 6
4.3. FlexE Interface Sub-TLV . . . . . . . . . . . . . . . . . 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
Flex Ethernet (FlexE) [I-D.izh-ccamp-flexe-fwk] 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 Ethernet traffic.
FlexE supports interface bonding, a bonded interface is consisted of
from 1 to n 100GBASE-R PHYs (other types of PHY will be supported in
the future), the bonded interface is called FlexE interface in this
document. FlexE also supports interface channelization, a FlexE
interface can be channelized into multiple sub-interfaces, the sub-
interface is called FlexE sub-interface in the rest of this document.
The FlexE mechanism operates using a calendar which assigns 66B block
positions on sub-calendars on each PHY of a FlexE interface to each
of the FlexE flows. The calendar has a granularity of 5G, and has a
length of 20 slots for a 100G interface. Currently, only 100GBASE-R
PHY and 5G granularity are supported in FlexE implementation
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agreement version 1.0 [FlexE], other types (e.g., 200G, 400G) of PHY
and granularities (e.g., 25G) will be supported in the future.
A FlexE interface has a number of time slots resource. These time
slots can be transparent to the up layer application, the up layer
application (e.g., RSVP-TE) can just treat the FlexE interface as a
normal Ethernet interface, or the time slots can be allocated to a
FlexE LSP though RSVP-TE signaling, or the time slots can be
allocated to form a FlexE sub-interface though configuration or some
dynamic protocols. How to signal the FlexE LSP or configure the
FlexE sub-interface is out of the scope of this document.
The logical link that connects two FlexE interfaces residing in two
adjacent nodes is called FlexE link, and the logical link that
connects two FlexE sub-interfaces residing in two adjacent nodes is
call FlexE sub-link.
More details about FlexE can be found in FlexE framework document
[I-D.izh-ccamp-flexe-fwk].
This document defines extensions to ISIS protocol to advertise the
FlexE TE link and sub-link state information.
2. FlexE Link Advertisement
This document re-uses the Interface Switching Capability Descriptor
(ISCD) sub-TLV for the advertisement of FlexE link state information.
The 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 figure (Figure 1) illustrates encoding of the Value
field of the ISCD 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 1: ISCD sub-TLV
To support FlexE link advertisement, new "Switching Cap" and
"Encoding" are defined as follows:
The Switching Capability (Switching Cap) for FlexE interface is as
below:
Value Name
----- --------------
TBD1 FlexE-Switching
The Encoding Type for FlexE:
Value Name
----- --------------
TBD2 FlexE
The "Switching Capability-specific information" field for FlexE
interface is defined as below. It is referred to as FlexE Interface
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 2: FlexE Interface 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 1 octet in length and its value identifies the
granularity of the FlexE time slots of a FlexE interface. Current
OIF agreement only allows the "5G" granularity, other granularities
may be defined in the future.
Value Granularity
----- --------------
0 Reserved
1 5G
2-254 Unassigned
255 Reserved
For each PHY of a FlexE interface, there are two calendars, one is
called Active calendar and the other is called Backup calendar. The
two calendars are used to facilitate reconfiguration, for example,
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FlexE flow resizing can be achieved through calendar updates. More
detail about FlexE calendar can be found [FlexE].
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 FlexE interface.
For a FlexE interface, as said above, 5G granularity is only
supported for now, but multiple granularities may be supported in the
future. To support this, FlexE Interface sub-TLV can occur multiple
times in a ISCD sub-TLV, but for each granularity, only one FlexE
Interface sub-TLV can be included and it carries the available time
slots of the granularity of the FlexE interface. When multiple FlexE
Interface sub-TLVs for the same granularity occur, only the first
FlexE Interface sub-TLV is considered to be valid, the rests MUST be
ignored.
3. FlexE Sub-link Advertisement
Through FlexE channelization, a FlexE Link can be sliced into a
number of FlexE sub-links, each FlexE sub-link has dedicated
bandwidth and is isolated from other FlexE sub-links. A set of FlexE
sub-links can be allocated to a specific application/user to form a
sliced network. From link characteristic point of view, a FlexE sub-
link is same as a real point-2-point link, it can be advertised and
used as a normal point-2-point link.
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
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4.3. FlexE Interface 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 "IS-IS TLV Codepoints" registry.
Value sub-TLV Name Reference
----- --------------- -------------
TBD3 FlexE Interface 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-03 (work in progress), June 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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