draft-ietf-ccamp-flexi-grid-fwk-07.txt | rfc7698.txt | |||
---|---|---|---|---|
CCAMP Working Group O. Gonzalez de Dios, Ed. | Internet Engineering Task Force (IETF) O. Gonzalez de Dios, Ed. | |||
Internet-Draft Telefonica I+D | Request for Comments: 7698 Telefonica I+D | |||
Intended status: Informational R. Casellas, Ed. | Category: Informational R. Casellas, Ed. | |||
Expires: March 2, 2016 CTTC | ISSN: 2070-1721 CTTC | |||
August 30, 2015 | F. Zhang | |||
Huawei | ||||
X. Fu | ||||
Stairnote | ||||
D. Ceccarelli | ||||
Ericsson | ||||
I. Hussain | ||||
Infinera | ||||
November 2015 | ||||
Framework and Requirements for GMPLS-based control of Flexi-grid DWDM | Framework and Requirements for GMPLS-Based Control | |||
networks | of Flexi-Grid Dense Wavelength Division Multiplexing (DWDM) Networks | |||
draft-ietf-ccamp-flexi-grid-fwk-07 | ||||
Abstract | Abstract | |||
To allow efficient allocation of optical spectral bandwidth for high | To allow efficient allocation of optical spectral bandwidth for | |||
bit-rate systems, the International Telecommunication Union | systems that have high bit-rates, the International Telecommunication | |||
Telecommunication Standardization Sector (ITU-T) has extended its | Union Telecommunication Standardization Sector (ITU-T) has extended | |||
Recommendations G.694.1 and G.872 to include a new dense wavelength | its Recommendations G.694.1 and G.872 to include a new Dense | |||
division multiplexing (DWDM) grid by defining a set of nominal | Wavelength Division Multiplexing (DWDM) grid by defining a set of | |||
central frequencies, channel spacings and the concept of "frequency | nominal central frequencies, channel spacings, and the concept of the | |||
slot". In such an environment, a data plane connection is switched | "frequency slot". In such an environment, a data-plane connection is | |||
based on allocated, variable-sized frequency ranges within the | switched based on allocated, variable-sized frequency ranges within | |||
optical spectrum creating what is known as a flexible grid (flexi- | the optical spectrum, creating what is known as a flexible grid | |||
grid). | (flexi-grid). | |||
Given the specific characteristics of flexi-grid optical networks and | Given the specific characteristics of flexi-grid optical networks and | |||
their associated technology, this document defines a framework and | their associated technology, this document defines a framework and | |||
the associated control plane requirements for the application of the | the associated control-plane requirements for the application of the | |||
existing GMPLS architecture and control plane protocols to the | existing GMPLS architecture and control-plane protocols to the | |||
control of flexi-grid DWDM networks. The actual extensions to the | control of flexi-grid DWDM networks. The actual extensions to the | |||
GMPLS protocols will be defined in companion documents. | GMPLS protocols will be defined in companion documents. | |||
Status of This Memo | Status of This Memo | |||
This Internet-Draft is submitted in full conformance with the | This document is not an Internet Standards Track specification; it is | |||
provisions of BCP 78 and BCP 79. | published for informational purposes. | |||
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 http://datatracker.ietf.org/drafts/current/. | ||||
Internet-Drafts are draft documents valid for a maximum of six months | This document is a product of the Internet Engineering Task Force | |||
and may be updated, replaced, or obsoleted by other documents at any | (IETF). It represents the consensus of the IETF community. It has | |||
time. It is inappropriate to use Internet-Drafts as reference | received public review and has been approved for publication by the | |||
material or to cite them other than as "work in progress." | Internet Engineering Steering Group (IESG). Not all documents | |||
approved by the IESG are a candidate for any level of Internet | ||||
Standard; see Section 2 of RFC 5741. | ||||
This Internet-Draft will expire on March 2, 2016. | Information about the current status of this document, any errata, | |||
and how to provide feedback on it may be obtained at | ||||
http://www.rfc-editor.org/info/rfc7698. | ||||
Copyright Notice | Copyright Notice | |||
Copyright (c) 2015 IETF Trust and the persons identified as the | Copyright (c) 2015 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 | |||
(http://trustee.ietf.org/license-info) in effect on the date of | (http://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 | |||
carefully, as they describe your rights and restrictions with respect | carefully, as they describe your rights and restrictions with respect | |||
to this document. Code Components extracted from this document must | to this document. Code Components extracted from this document must | |||
include Simplified BSD License text as described in Section 4.e of | include Simplified BSD License text as described in Section 4.e of | |||
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 . . . . . . . . . . . . . . . . . . . . . . . . 3 | 1. Introduction ....................................................4 | |||
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 | 2. Terminology .....................................................5 | |||
2.1. Requirements Language . . . . . . . . . . . . . . . . . . 4 | 2.1. Requirements Language ......................................5 | |||
2.2. Abbreviations . . . . . . . . . . . . . . . . . . . . . . 4 | 2.2. Abbreviations ..............................................5 | |||
3. Overview of Flexi-grid Networks . . . . . . . . . . . . . . . 5 | 3. Overview of Flexi-Grid Networks .................................6 | |||
3.1. Flexi-grid in the Context of OTN . . . . . . . . . . . . 5 | 3.1. Flexi-Grid in the Context of OTN ...........................6 | |||
3.2. Flexi-grid Terminology . . . . . . . . . . . . . . . . . 6 | 3.2. Flexi-Grid Terminology .....................................6 | |||
3.2.1. Frequency Slots . . . . . . . . . . . . . . . . . . . 6 | 3.2.1. Frequency Slots .....................................7 | |||
3.2.2. Media Layer Elements . . . . . . . . . . . . . . . . 8 | 3.2.2. Media-Layer Elements ................................9 | |||
3.2.3. Media Channels . . . . . . . . . . . . . . . . . . . 8 | 3.2.3. Media Channels .....................................10 | |||
3.2.4. Optical Tributary Signals . . . . . . . . . . . . . . 9 | 3.2.4. Optical Tributary Signals ..........................10 | |||
3.2.5. Composite Media Channels . . . . . . . . . . . . . . 9 | 3.2.5. Composite Media Channels ...........................11 | |||
3.3. Hierarchy in the Media Layer . . . . . . . . . . . . . . 10 | 3.3. Hierarchy in the Media Layer ..............................11 | |||
3.4. Flexi-grid Layered Network Model . . . . . . . . . . . . 10 | 3.4. Flexi-Grid Layered Network Model ..........................12 | |||
3.4.1. DWDM Flexi-grid Enabled Network Element Models . . . 12 | 3.4.1. DWDM Flexi-Grid Enabled Network Element Models .....13 | |||
4. GMPLS Applicability . . . . . . . . . . . . . . . . . . . . . 12 | 4. GMPLS Applicability ............................................14 | |||
4.1. General Considerations . . . . . . . . . . . . . . . . . 12 | 4.1. General Considerations ....................................14 | |||
4.2. Consideration of TE Links . . . . . . . . . . . . . . . . 13 | 4.2. Consideration of TE Links .................................14 | |||
4.3. Consideration of LSPs in Flexi-grid . . . . . . . . . . . 15 | 4.3. Consideration of LSPs in Flexi-Grid .......................17 | |||
4.4. Control Plane Modeling of Network Elements . . . . . . . 20 | 4.4. Control-Plane Modeling of Network Elements ................22 | |||
4.5. Media Layer Resource Allocation Considerations . . . . . 20 | 4.5. Media Layer Resource Allocation Considerations ............22 | |||
4.6. Neighbor Discovery and Link Property Correlation . . . . 24 | 4.6. Neighbor Discovery and Link Property Correlation ..........26 | |||
4.7. Path Computation / Routing and Spectrum Assignment (RSA) 25 | 4.7. Path Computation, Routing and Spectrum Assignment (RSA) ...27 | |||
4.7.1. Architectural Approaches to RSA . . . . . . . . . . . 25 | 4.7.1. Architectural Approaches to RSA ....................28 | |||
4.8. Routing and Topology Dissemination . . . . . . . . . . . 26 | 4.8. Routing and Topology Dissemination ........................29 | |||
4.8.1. Available Frequency Ranges/Slots of DWDM Links . . . 27 | 4.8.1. Available Frequency Ranges (Frequency | |||
4.8.2. Available Slot Width Ranges of DWDM Links . . . . . . 27 | Slots) of DWDM Links ...............................29 | |||
4.8.3. Spectrum Management . . . . . . . . . . . . . . . . . 27 | 4.8.2. Available Slot Width Ranges of DWDM Links ..........29 | |||
4.8.4. Information Model . . . . . . . . . . . . . . . . . . 28 | 4.8.3. Spectrum Management ................................29 | |||
5. Control Plane Requirements . . . . . . . . . . . . . . . . . 29 | 4.8.4. Information Model ..................................30 | |||
5.1. Support for Media Channels . . . . . . . . . . . . . . . 29 | 5. Control-Plane Requirements .....................................31 | |||
5.1.1. Signaling . . . . . . . . . . . . . . . . . . . . . . 30 | 5.1. Support for Media Channels ................................31 | |||
5.1.2. Routing . . . . . . . . . . . . . . . . . . . . . . . 30 | 5.1.1. Signaling ..........................................32 | |||
5.2. Support for Media Channel Resizing . . . . . . . . . . . 31 | 5.1.2. Routing ............................................32 | |||
5.3. Support for Logical Associations of Multiple Media | 5.2. Support for Media Channel Resizing ........................33 | |||
Channels . . . . . . . . . . . . . . . . . . . . . . . . 31 | 5.3. Support for Logical Associations of Multiple Media | |||
5.4. Support for Composite Media Channels . . . . . . . . . . 31 | Channels ..................................................33 | |||
5.5. Support for Neighbor Discovery and Link Property | 5.4. Support for Composite Media Channels ......................33 | |||
Correlation . . . . . . . . . . . . . . . . . . . . . . . 32 | 5.5. Support for Neighbor Discovery and Link Property | |||
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 32 | Correlation ...............................................34 | |||
7. Security Considerations . . . . . . . . . . . . . . . . . . . 32 | 6. Security Considerations ........................................34 | |||
8. Manageability Considerations . . . . . . . . . . . . . . . . 33 | 7. Manageability Considerations ...................................35 | |||
9. Authors . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 | 8. References .....................................................36 | |||
10. Contributing Authors . . . . . . . . . . . . . . . . . . . . 34 | 8.1. Normative References ......................................36 | |||
11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 37 | 8.2. Informative References ....................................37 | |||
12. References . . . . . . . . . . . . . . . . . . . . . . . . . 37 | Acknowledgments ...................................................39 | |||
12.1. Normative References . . . . . . . . . . . . . . . . . . 37 | Contributors ......................................................39 | |||
12.2. Informative References . . . . . . . . . . . . . . . . . 38 | Authors' Addresses ................................................41 | |||
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 40 | ||||
1. Introduction | 1. Introduction | |||
The term "Flexible grid" (flexi-grid for short) as defined by the | The term "flexible grid" ("flexi-grid" for short), as defined by the | |||
International Telecommunication Union Telecommunication | International Telecommunication Union Telecommunication | |||
Standardization Sector (ITU-T) Study Group 15 in the latest version | Standardization Sector (ITU-T) Study Group 15 in the latest version | |||
of [G.694.1], refers to the updated set of nominal central | of [G.694.1], refers to the updated set of nominal central | |||
frequencies (a frequency grid), channel spacing and optical spectrum | frequencies (a frequency grid), channel spacing, and optical spectrum | |||
management/allocation considerations that have been defined in order | management and allocation considerations that have been defined in | |||
to allow an efficient and flexible allocation and configuration of | order to allow an efficient and flexible allocation and configuration | |||
optical spectral bandwidth for high bit-rate systems. | of optical spectral bandwidth for systems that have high bit-rates. | |||
A key concept of flexi-grid is the "frequency slot"; a variable-sized | A key concept of flexi-grid is the "frequency slot": a variable-sized | |||
optical frequency range that can be allocated to a data connection. | optical frequency range that can be allocated to a data connection. | |||
As detailed later in the document, a frequency slot is characterized | As detailed later in the document, a frequency slot is characterized | |||
by its nominal central frequency and its slot width which, as per | by its nominal central frequency and its slot width, which, as per | |||
[G.694.1], is constrained to be a multiple of a given slot width | [G.694.1], is constrained to be a multiple of a given slot width | |||
granularity. | granularity. | |||
Compared to a traditional fixed grid network, which uses fixed size | Compared to a traditional fixed-grid network, which uses fixed-size | |||
optical spectrum frequency ranges or frequency slots with typical | optical spectrum frequency ranges or frequency slots with typical | |||
channel separations of 50 GHz, a flexible grid network can select its | channel separations of 50 GHz, a flexible-grid network can select its | |||
media channels with a more flexible choice of slot widths, allocating | media channels with a more flexible choice of slot widths, allocating | |||
as much optical spectrum as required. | as much optical spectrum as required. | |||
From a networking perspective, a flexible grid network is assumed to | From a networking perspective, a flexible-grid network is assumed to | |||
be a layered network [G.872][G.800] in which the media layer is the | be a layered network [G.872] [G.800] in which the media layer is the | |||
server layer and the optical signal layer is the client layer. In | server layer and the optical signal layer is the client layer. In | |||
the media layer, switching is based on a frequency slot, and the size | the media layer, switching is based on a frequency slot, and the size | |||
of a media channel is given by the properties of the associated | of a media channel is given by the properties of the associated | |||
frequency slot. In this layered network, a media channel can | frequency slot. In this layered network, a media channel can | |||
transport more than one Optical Tributary Signals (OTSi), as defined | transport more than one Optical Tributary Signal (OTSi), as defined | |||
later in this document. | later in this document. | |||
A Wavelength Switched Optical Network (WSON), addressed in [RFC6163], | A Wavelength Switched Optical Network (WSON), addressed in [RFC6163], | |||
is a term commonly used to refer to the application/deployment of a | is a term commonly used to refer to the application/deployment of a | |||
GMPLS-based control plane for the control (provisioning/recovery, | GMPLS-based control plane for the control (e.g., provisioning and | |||
etc.) of a fixed grid wavelength division multiplexing (WDM) network | recovery) of a fixed-grid Wavelength Division Multiplexing (WDM) | |||
in which media (spectrum) and signal are jointly considered. | network in which media (spectrum) and signal are jointly considered. | |||
This document defines the framework for a GMPLS-based control of | This document defines the framework for a GMPLS-based control of | |||
flexi-grid enabled dense wavelength division multiplexing (DWDM) | flexi-grid enabled Dense Wavelength Division Multiplexing (DWDM) | |||
networks (in the scope defined by ITU-T layered Optical Transport | networks (in the scope defined by ITU-T layered Optical Transport | |||
Networks [G.872]), as well as a set of associated control plane | Networks [G.872]), as well as a set of associated control-plane | |||
requirements. An important design consideration relates to the | requirements. An important design consideration relates to the | |||
decoupling of the management of the optical spectrum resource and the | decoupling of the management of the optical spectrum resource and the | |||
client signals to be transported. | client signals to be transported. | |||
2. Terminology | 2. Terminology | |||
Further terminology specific to flexi-grid networks can be found in | Further terminology specific to flexi-grid networks can be found in | |||
Section 3.2. | Section 3.2. | |||
2.1. Requirements Language | 2.1. Requirements Language | |||
skipping to change at page 4, line 47 | skipping to change at page 5, line 38 | |||
2.2. Abbreviations | 2.2. Abbreviations | |||
FS: Frequency Slot | FS: Frequency Slot | |||
FSC: Fiber-Switch Capable | FSC: Fiber-Switch Capable | |||
LSR: Label Switching Router | LSR: Label Switching Router | |||
NCF: Nominal Central Frequency | NCF: Nominal Central Frequency | |||
OCC: Optical Channel Carrier | ||||
OCh: Optical Channel | OCh: Optical Channel | |||
OCh-P: Optical Channel Payload | OCh-P: Optical Channel Payload | |||
OTN: Optical Transport Network | OTN: Optical Transport Network | |||
OTSi: Optical Tributary Signal | OTSi: Optical Tributary Signal | |||
OTSiG: OTSi Group is a set of OTSi | OTSiG: OTSi Group is a set of OTSi | |||
OCC: Optical Channel Carrier | ||||
PCE: Path Computation Element | PCE: Path Computation Element | |||
ROADM: Reconfigurable Optical Add/Drop Multiplexer | ||||
ROADM: Reconfigurable Optical Add-Drop Multiplexer | ||||
SSON: Spectrum-Switched Optical Network | SSON: Spectrum-Switched Optical Network | |||
SWG: Slot Width Granularity | SWG: Slot Width Granularity | |||
3. Overview of Flexi-grid Networks | 3. Overview of Flexi-Grid Networks | |||
3.1. Flexi-grid in the Context of OTN | 3.1. Flexi-Grid in the Context of OTN | |||
[G.872] describes, from a network level, the functional architecture | [G.872] describes, from a network level, the functional architecture | |||
of an OTN. It is decomposed into independent layer networks with | of an OTN. It is decomposed into independent-layer networks with | |||
client/layer relationships among them. A simplified view of the OTN | client/layer relationships among them. A simplified view of the OTN | |||
layers is shown in Figure 1. | layers is shown in Figure 1. | |||
+----------------+ | +----------------+ | |||
| Digital Layer | | | Digital Layer | | |||
+----------------+ | +----------------+ | |||
| Signal Layer | | | Signal Layer | | |||
+----------------+ | +----------------+ | |||
| Media Layer | | | Media Layer | | |||
+----------------+ | +----------------+ | |||
Figure 1: Generic OTN Overview | Figure 1: Generic OTN Overview | |||
In the OTN layering context, the media layer is the server layer of | In the OTN layering context, the media layer is the server layer of | |||
the optical signal layer. The optical signal is guided to its | the optical signal layer. The optical signal is guided to its | |||
destination by the media layer by means of a network media channel. | destination by the media layer by means of a network media channel. | |||
In the media layer, switching is based on a frequency slot. | In the media layer, switching is based on a frequency slot. | |||
In this scope, this document uses the term flexi-grid enabled DWDM | In this scope, this document uses the term "flexi-grid enabled DWDM | |||
network to refer to a network in which switching is based on | network" to refer to a network in which switching is based on | |||
frequency slots defined using the flexible grid, and covers mainly | frequency slots defined using the flexible grid. This document | |||
the Media Layer as well as the required adaptations from the Signal | mainly covers the media layer, as well as the required adaptations | |||
layer. The present document is thus focused on the control and | from the signal layer. The present document is thus focused on the | |||
management of the media layer. | control and management of the media layer. | |||
3.2. Flexi-grid Terminology | 3.2. Flexi-Grid Terminology | |||
This section presents the definition of the terms used in flexi-grid | This section presents the definitions of the terms used in flexi-grid | |||
networks. More detail about these terms can be found in the ITU-T | networks. More details about these terms can be found in ITU-T | |||
Recommendations [G.694.1], [G.872]), [G.870], [G.8080], and | Recommendations [G.694.1], [G.872], [G.870], [G.8080], and | |||
[G.959.1-2013]. | [G.959.1-2013]. | |||
Where appropriate, this documents also uses terminology and | Where appropriate, this document also uses terminology and | |||
lexicography from [RFC4397]. | lexicography from [RFC4397]. | |||
3.2.1. Frequency Slots | 3.2.1. Frequency Slots | |||
This subsection is focused on the frequency slot and related terms. | This subsection is focused on the frequency slot and related terms. | |||
o Frequency Slot [G.694.1]: The frequency range allocated to a slot | o Frequency Slot [G.694.1]: The frequency range allocated to a slot | |||
within the flexible grid and unavailable to other slots. A | within the flexible grid and unavailable to other slots. A | |||
frequency slot is defined by its nominal central frequency and its | frequency slot is defined by its nominal central frequency and its | |||
slot width. | slot width. | |||
o Nominal Central Frequency: Each of the allowed frequencies as per | o Nominal Central Frequency: Each of the allowed frequencies as per | |||
the definition of flexible DWDM grid in [G.694.1]. The set of | the definition of the flexible DWDM grid in [G.694.1]. The set of | |||
nominal central frequencies can be built using the following | nominal central frequencies can be built using the following | |||
expression | expression: | |||
f = 193.1 THz + n x 0.00625 THz | f = 193.1 THz + n x 0.00625 THz | |||
where 193.1 THz is ITU-T "anchor frequency" for transmission over | where 193.1 THz is the ITU-T "anchor frequency" for transmission | |||
the C band, and n is a positive or negative integer including 0. | over the C-band and 'n' is a positive or negative integer | |||
including 0. | ||||
-5 -4 -3 -2 -1 0 1 2 3 4 5 <- values of n | -5 -4 -3 -2 -1 0 1 2 3 4 5 <- values of n | |||
...+--+--+--+--+--+--+--+--+--+--+- | ...+--+--+--+--+--+--+--+--+--+--+- | |||
^ | ^ | |||
193.1 THz <- anchor frequency | 193.1 THz <- anchor frequency | |||
Figure 2: Anchor Frequency and Set of Nominal Central Frequencies | Figure 2: Anchor Frequency and Set of Nominal Central Frequencies | |||
o Nominal Central Frequency Granularity: This is the spacing between | o Nominal Central Frequency Granularity: The spacing between allowed | |||
allowed nominal central frequencies and it is set to 6.25 GHz | nominal central frequencies. It is set to 6.25 GHz [G.694.1]. | |||
[G.694.1]. | ||||
o Slot Width Granularity (SWG): 12.5 GHz, as defined in [G.694.1]. | o Slot Width Granularity (SWG): 12.5 GHz, as defined in [G.694.1]. | |||
o Slot Width: The slot width determines the "amount" of optical | o Slot Width: Determines the "amount" of optical spectrum, | |||
spectrum regardless of its actual "position" in the frequency | regardless of its actual "position" in the frequency axis. A slot | |||
axis. A slot width is constrained to be m x SWG (that is, m x | width is constrained to be m x SWG (that is, m x 12.5 GHz), | |||
12.5 GHz), where m is an integer greater than or equal to 1. | where 'm' is an integer greater than or equal to 1. | |||
Frequency Slot 1 Frequency Slot 2 | Frequency Slot 1 Frequency Slot 2 | |||
------------- ------------------- | ------------- ------------------- | |||
| | | | | | | | | | |||
-3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 | -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 | |||
...--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--... | ...--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--... | |||
------------- ------------------- | ------------- ------------------- | |||
^ ^ | ^ ^ | |||
Slot NCF = 193.1THz Slot NCF = 193.14375 THz | Slot NCF = 193.1 THz Slot NCF = 193.14375 THz | |||
Slot width = 25 GHz Slot width = 37.5 GHz | Slot width = 25 GHz Slot width = 37.5 GHz | |||
n=0, m=2 n=7, m=3 | n = 0, m = 2 n = 7, m = 3 | |||
Figure 3: Example Frequency Slots | Figure 3: Example Frequency Slots | |||
* The symbol '+' represents the allowed nominal central | * The symbol '+' represents the allowed nominal central | |||
frequencies | frequencies. | |||
* The '--' represents the nominal central frequency granularity | * The '--' represents the nominal central frequency granularity | |||
in units of 6.25 GHz | in units of 6.25 GHz. | |||
* The '^' represents the slot nominal central frequency | * The '^' represents the slot nominal central frequency. | |||
* The number on the top of the '+' symbol represents the 'n' in | * The number on the top of the '+' symbol represents the 'n' in | |||
the frequency calculation formula. | the frequency calculation formula. | |||
* The nominal central frequency is 193.1 THz when n equals to | * The nominal central frequency is 193.1 THz when n equals zero. | |||
zero. | ||||
o Effective Frequency Slot [G.870]: The effective frequency slot of | o Effective Frequency Slot [G.870]: That part of the frequency slots | |||
a media channel is that part of the frequency slots of the filters | of the filters along the media channel that is common to all of | |||
along the media channel that is common to all of the filters' | the filters' frequency slots. Note that both the terms "frequency | |||
frequency slots. Note that both the Frequency Slot and Effective | slot" and "effective frequency slot" are applied locally. | |||
Frequency Slot are local terms. | ||||
o Figure 4 shows the effect of combining two filters along a | o Figure 4 shows the effect of combining two filters along a | |||
channel. The combination of frequency slot 1 and frequency slot 2 | channel. The combination of Frequency Slot 1 and Frequency Slot 2 | |||
applied to the media channel is effective frequency slot shown. | applied to the media channel is the effective frequency slot | |||
shown. | ||||
Frequency Slot 1 | Frequency Slot 1 | |||
------------- | ------------- | |||
| | | | | | |||
-3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 | -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 | |||
..--+--+--+--+--X--+--+--+--+--+--+--+--+--+--+--+--... | ..--+--+--+--+--X--+--+--+--+--+--+--+--+--+--+--+--... | |||
Frequency Slot 2 | Frequency Slot 2 | |||
------------------- | ------------------- | |||
| | | | | | |||
-3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 | -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 | |||
..--+--+--+--+--X--+--+--+--+--+--+--+--+--+--+--+--... | ..--+--+--+--+--X--+--+--+--+--+--+--+--+--+--+--+--... | |||
=============================================== | =============================================== | |||
Effective Frequency Slot | Effective Frequency Slot | |||
------------- | ------------- | |||
| | | | | | |||
-3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 | -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 | |||
..--+--+--+--+--X--+--+--+--+--+--+--+--+--+--+--+--... | ..--+--+--+--+--X--+--+--+--+--+--+--+--+--+--+--+--... | |||
Figure 4: Effective Frequency Slot | Figure 4: Effective Frequency Slot | |||
3.2.2. Media Layer Elements | 3.2.2. Media-Layer Elements | |||
o Media Element: A media element directs an optical signal or | o Media Element: A media element directs an optical signal or | |||
affects the properties of an optical signal. It does not modify | affects the properties of an optical signal. It does not modify | |||
the properties of the information that has been modulated to | the properties of the information that has been modulated to | |||
produce the optical signal [G.870]. Examples of media elements | produce the optical signal [G.870]. Examples of media elements | |||
include fibers, amplifiers, filters, and switching matrices. | include fibers, amplifiers, filters, and switching matrices. | |||
o Media Channel Matrixes: The media channel matrix provides flexible | o Media Channel Matrix: The media channel matrix provides flexible | |||
connectivity for the media channels. That is, it represents a | connectivity for the media channels. That is, it represents a | |||
point of flexibility where relationships between the media ports | point of flexibility where relationships between the media ports | |||
at the edge of a media channel matrix may be created and broken. | at the edge of a media channel matrix may be created and broken. | |||
The relationship between these ports is called a matrix channel. | The relationship between these ports is called a "matrix channel". | |||
(Network) Media Channels are switched in a Media Channel Matrix. | (Network) media channels are switched in a media channel matrix. | |||
3.2.3. Media Channels | 3.2.3. Media Channels | |||
This section defines concepts such as (Network) Media Channel; the | This section defines concepts such as the (network) media channel; | |||
mapping to GMPLS constructs (i.e., LSP) is detailed in Section 4. | the mapping to GMPLS constructs (i.e., LSP) is detailed in Section 4. | |||
o Media Channel: A media association that represents both the | o Media Channel: A media association that represents both the | |||
topology (i.e., path through the media) and the resource | topology (i.e., path through the media) and the resource | |||
(frequency slot) that it occupies. As a topological construct, it | (frequency slot) that it occupies. As a topological construct, it | |||
represents a frequency slot (an effective frequency slot) | represents a frequency slot (an effective frequency slot) | |||
supported by a concatenation of media elements (fibers, | supported by a concatenation of media elements (fibers, | |||
amplifiers, filters, switching matrices...). This term is used to | amplifiers, filters, switching matrices...). This term is used to | |||
identify the end-to-end physical layer entity with its | identify the end-to-end physical-layer entity with its | |||
corresponding (one or more) frequency slots local at each link | corresponding (one or more) frequency slots local at each link | |||
filters. | filter. | |||
o Network Media Channel: [G.870] defines the Network Media Channel | o Network Media Channel: Defined in [G.870] as a media channel that | |||
as a media channel that transports a single OTSi, defined next. | transports a single OTSi (defined in the next subsection). | |||
3.2.4. Optical Tributary Signals | 3.2.4. Optical Tributary Signals | |||
o Optical Tributary Signal (OTSi) [G.959.1-2013]: The optical signal | o Optical Tributary Signal (OTSi): The optical signal that is placed | |||
that is placed within a network media channel for transport across | within a network media channel for transport across the optical | |||
the optical network. This may consist of a single modulated | network. This may consist of a single modulated optical carrier | |||
optical carrier or a group of modulated optical carriers or | or a group of modulated optical carriers or subcarriers. To | |||
subcarriers. To provide a connection between the OTSi source and | provide a connection between the OTSi source and the OTSi sink, | |||
the OTSi sink the optical signal must be assigned to a network | the optical signal must be assigned to a network media channel | |||
media channel. | (see also [G.959.1-2013]). | |||
o OTSi Group (OTSiG): The set of OTSi that are carried by a group of | o OTSi Group (OTSiG): The set of OTSi that are carried by a group of | |||
network media channels. Each OTSi is carried by one network media | network media channels. Each OTSi is carried by one network media | |||
channel. From a management perspective it SHOULD be possible to | channel. From a management perspective, it SHOULD be possible to | |||
manage both the OTSiG and a group of Network Media Channels as | manage both the OTSiG and a group of network media channels as | |||
single entities. | single entities. | |||
3.2.5. Composite Media Channels | 3.2.5. Composite Media Channels | |||
o It is possible to construct an end-to-end media channel as a | o It is possible to construct an end-to-end media channel as a | |||
composite of more than one network media channels. A composite | composite of more than one network media channel. A composite | |||
media channel carries a group of OTSi (i.e., OTSiG). Each OTSi is | media channel carries a group of OTSi (i.e., OTSiG). Each OTSi is | |||
carried by one network media channel. This group of OTSi are | carried by one network media channel. This OTSiG is carried over | |||
carried over a single fibre. | a single fiber. | |||
o In this case, the effective frequency slots may be contiguous | o In this case, the effective frequency slots may be contiguous | |||
(i.e., there is no spectrum between them that can be used for | (i.e., there is no spectrum between them that can be used for | |||
other media channels) or non-contiguous. | other media channels) or non-contiguous. | |||
o It is not currently envisaged that such composite media channels | o It is not currently envisaged that such composite media channels | |||
may be constructed from slots carried on different fibers whether | may be constructed from slots carried on different fibers whether | |||
those fibers traverse the same hop-by-hop path through the network | those fibers traverse the same hop-by-hop path through the network | |||
or not. | or not. | |||
o Furthermore, it is not considered likely that a media channel may | o Furthermore, it is not considered likely that a media channel may | |||
be constructed from a different variation of slot composition on | be constructed from a different variation of slot composition on | |||
each hop. That is, the slot composition (i.e., the group of OTSi | each hop. That is, the slot composition (i.e., the group of OTSi | |||
carried by the composite media channel) must be the same from one | carried by the composite media channel) must be the same from one | |||
end to the other of the media channel even if the specific slot | end of the media channel to the other, even if the specific slot | |||
for each OTSi and the spacing among slots may vary hop by hop. | for each OTSi and the spacing among slots may vary hop by hop. | |||
o How the signal is carried across such groups of network media | o How the signal is carried across such groups of network media | |||
channels is out of scope for this document. | channels is out of scope for this document. | |||
3.3. Hierarchy in the Media Layer | 3.3. Hierarchy in the Media Layer | |||
In summary, the concept of frequency slot is a logical abstraction | In summary, the concept of the frequency slot is a logical | |||
that represents a frequency range, while the media layer represents | abstraction that represents a frequency range, while the media layer | |||
the underlying media support. Media Channels are media associations, | represents the underlying media support. Media channels are media | |||
characterized by their (effective) frequency slot, respectively; and | associations, characterized by their respective (effective) frequency | |||
media channels are switched in media channel matrixes. From the | slots, and media channels are switched in media channel matrices. | |||
control and management perspective, a media channel can be logically | From the control and management perspective, a media channel can be | |||
split into network media channels. | logically split into network media channels. | |||
In Figure 5, a media channel has been configured and dimensioned to | In Figure 5, a media channel has been configured and dimensioned to | |||
support two network media channels, each of them carrying one OTSi. | support two network media channels, each of them carrying one OTSi. | |||
Media Channel Frequency Slot | Media Channel Frequency Slot | |||
+-------------------------------X------------------------------+ | +-------------------------------X------------------------------+ | |||
| | | | | | |||
| Frequency Slot Frequency Slot | | | Frequency Slot Frequency Slot | | |||
| +-----------X-----------+ +----------X-----------+ | | | +-----------X-----------+ +----------X-----------+ | | |||
| | OTSi | | OTSi | | | | | OTSi | | OTSi | | | |||
| | o | | o | | | | | o | | o | | | |||
| | | | | | | | | | | | | | | | | | |||
-4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 | -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 | |||
--+---+---+---+---+---+---+---+---+---+---+---+--+---+---+---+---+-- | --+---+---+---+---+---+---+---+---+---+---+---+--+---+---+---+---+-- | |||
<- Network Media Channel-> <- Network Media Channel-> | <- Network Media Channel -> <- Network Media Channel -> | |||
<------------------------ Media Channel -----------------------> | <------------------------ Media Channel -----------------------> | |||
X - Frequency Slot Central Frequency | X - Frequency Slot Central Frequency | |||
o - Signal Central Frequency | o - Signal Central Frequency | |||
Figure 5: Example of Media Channel / Network Media Channels and | Figure 5: Example of Media Channel, Network Media Channels, and | |||
Associated Frequency Slots | Associated Frequency Slots | |||
3.4. Flexi-grid Layered Network Model | 3.4. Flexi-Grid Layered Network Model | |||
In the OTN layered network, the network media channel transports a | In the OTN layered network, the network media channel transports a | |||
single OTSi (see Figure 6) | single OTSi (see Figure 6). | |||
| OTSi | | | OTSi | | |||
O - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - O | O - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - O | |||
| | | | | | |||
| Channel Port Network Media Channel Channel Port | | | Channel Port Network Media Channel Channel Port | | |||
O - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - O | O - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - O | |||
| | | | | | |||
+--------+ +-----------+ +--------+ | +--------+ +-----------+ +--------+ | |||
| \ (1) | | (1) | | (1) / | | | \ (1) | | (1) | | (1) / | | |||
| \----|-----------------|-----------|-------------------|-----/ | | | \----|-----------------|-----------|-------------------|-----/ | | |||
+--------+ Link Channel +-----------+ Link Channel +--------+ | +--------+ Link Channel +-----------+ Link Channel +--------+ | |||
Media Channel Media Channel Media Channel | Media Channel Media Channel Media Channel | |||
Matrix Matrix Matrix | Matrix Matrix Matrix | |||
The symbol (1) indicates a Matrix Channel | The symbol (1) indicates a matrix channel | |||
Figure 6: Simplified Layered Network Model | Figure 6: Simplified Layered Network Model | |||
Note that a particular example of OTSi is the OCh-P. Figure 7 shows | Note that a particular example of OTSi is the OCh-P. Figure 7 shows | |||
this specific example as defined in G.805 [G.805]. | this specific example as defined in G.805 [G.805]. | |||
OCh AP Trail (OCh) OCh AP | OCh AP Trail (OCh) OCh AP | |||
O- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - O | O- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - O | |||
| | | | | | |||
--- OCh-P OCh-P --- | --- OCh-P OCh-P --- | |||
skipping to change at page 11, line 43 | skipping to change at page 13, line 27 | |||
|Channel Port Network Media Channel Channel Port | | |Channel Port Network Media Channel Channel Port | | |||
O - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - O | O - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - O | |||
| | | | | | |||
+--------+ +-----------+ +---------+ | +--------+ +-----------+ +---------+ | |||
| \ (1) | OCh-P LC | (1) | OCh-P LC | (1) / | | | \ (1) | OCh-P LC | (1) | OCh-P LC | (1) / | | |||
| \----|-----------------|-----------|-----------------|------/ | | | \----|-----------------|-----------|-----------------|------/ | | |||
+--------+ Link Channel +-----------+ Link Channel +---------+ | +--------+ Link Channel +-----------+ Link Channel +---------+ | |||
Media Channel Media Channel Media Channel | Media Channel Media Channel Media Channel | |||
Matrix Matrix Matrix | Matrix Matrix Matrix | |||
The symbol (1) indicates a Matrix Channel | The symbol (1) indicates a matrix channel | |||
"LC" indicates a link connection | ||||
Figure 7: Layered Network Model According to G.805 | Figure 7: Layered Network Model According to G.805 | |||
3.4.1. DWDM Flexi-grid Enabled Network Element Models | 3.4.1. DWDM Flexi-Grid Enabled Network Element Models | |||
A flexible grid network is constructed from subsystems that include | A flexible-grid network is constructed from subsystems that include | |||
WDM links, tunable transmitters, and receivers, (i.e, media elements | WDM links, tunable transmitters, and receivers (i.e., media elements | |||
including media layer switching elements that are media matrices) as | including media-layer switching elements that are media matrices), as | |||
well as electro-optical network elements. This is just the same as | well as electro-optical network elements. This is just the same as | |||
in a fixed grid network except that each element has flexible grid | in a fixed-grid network, except that each element has flexible-grid | |||
characteristics. | characteristics. | |||
As stated in Clause 7 of [G.694.1] the flexible DWDM grid has a | As stated in Clause 7 of [G.694.1], the flexible DWDM grid has a | |||
nominal central frequency granularity of 6.25 GHz and a slot width | nominal central frequency granularity of 6.25 GHz and a slot width | |||
granularity of 12.5 GHz. However, devices or applications that make | granularity of 12.5 GHz. However, devices or applications that make | |||
use of the flexible grid might not be capable of supporting every | use of the flexible grid might not be capable of supporting every | |||
possible slot width or position. In other words, applications may be | possible slot width or position. In other words, applications may be | |||
defined where only a subset of the possible slot widths and positions | defined where only a subset of the possible slot widths and positions | |||
are required to be supported. For example, an application could be | is required to be supported. For example, an application could be | |||
defined where the nominal central frequency granularity is 12.5 GHz | defined where the nominal central frequency granularity is 12.5 GHz | |||
(by only requiring values of n that are even) and that only requires | (by only requiring values of n that are even) and where slot widths | |||
slot widths as a multiple of 25 GHz (by only requiring values of m | are a multiple of 25 GHz (by only requiring values of m that are | |||
that are even). | even). | |||
4. GMPLS Applicability | 4. GMPLS Applicability | |||
The goal of this section is to provide an insight into the | The goal of this section is to provide an insight into the | |||
application of GMPLS as a control mechanism in flexi-grid networks. | application of GMPLS as a control mechanism in flexi-grid networks. | |||
Specific control plane requirements for the support of flexi-grid | Specific control-plane requirements for the support of flexi-grid | |||
networks are covered in Section 5. This framework is aimed at | networks are covered in Section 5. This framework is aimed at | |||
controlling the media layer within the OTN hierarchy, and controlling | controlling the media layer within the OTN hierarchy and controlling | |||
the required adaptations of the signal layer. This document also | the required adaptations of the signal layer. This document also | |||
defines the term Spectrum-Switched Optical Network (SSON) to refer to | defines the term "Spectrum-Switched Optical Network" (SSON) to refer | |||
a Flexi-grid enabled DWDM network that is controlled by a GMPLS/PCE | to a flexi-grid enabled DWDM network that is controlled by a GMPLS or | |||
control plane. | PCE control plane. | |||
This section provides a mapping of the ITU-T G.872 architectural | This section provides a mapping of the ITU-T G.872 architectural | |||
aspects to GMPLS/Control plane terms, and considers the relationship | aspects to GMPLS and control-plane terms and also considers the | |||
between the architectural concept/construct of media channel and its | relationship between the architectural concept or construct of a | |||
control plane representations (e.g., as a TE link, as defined in | media channel and its control-plane representations (e.g., as a TE | |||
[RFC3945]). | link, as defined in [RFC3945]). | |||
4.1. General Considerations | 4.1. General Considerations | |||
The GMPLS control of the media layer deals with the establishment of | The GMPLS control of the media layer deals with the establishment of | |||
media channels that are switched in media channel matrices. GMPLS | media channels that are switched in media channel matrices. GMPLS | |||
labels are used to locally represent the media channel and its | labels are used to locally represent the media channel and its | |||
associated frequency slot. Network media channels are considered a | associated frequency slot. Network media channels are considered a | |||
particular case of media channels when the end points are | particular case of media channels when the endpoints are transceivers | |||
transceivers (that is, source and destination of an OTSi). | (that is, the source and destination of an OTSi). | |||
4.2. Consideration of TE Links | 4.2. Consideration of TE Links | |||
From a theoretical / abstract point of view, a fiber can be modeled | From a theoretical point of view, a fiber can be modeled as having a | |||
as having a frequency slot that ranges from minus infinity to plus | frequency slot that ranges from minus infinity to plus infinity. | |||
infinity. This representation helps understand the relationship | This representation helps us understand the relationship between | |||
between frequency slots and ranges. | frequency slots and ranges. | |||
The frequency slot is a local concept that applies within a component | The frequency slot is a local concept that applies within a component | |||
or element. When applied to a media channel, we are referring to its | or element. When applied to a media channel, we are referring to its | |||
effective frequency slot as defined in [G.872]. | effective frequency slot as defined in [G.872]. | |||
The association sequence of the three components (i.e., a filter, a | The association sequence of the three components (i.e., a filter, a | |||
fiber, and a filter), is a media channel in its most basic form. | fiber, and a filter) is a media channel in its most basic form. From | |||
From the control plane perspective this may modeled as a (physical) | the control-plane perspective, this may be modeled as a (physical) | |||
TE-link with a contiguous optical spectrum. This can be represented | TE link with a contiguous optical spectrum. This can be represented | |||
by saying that the portion of spectrum available at time t0 depends | by saying that the portion of spectrum available at time t0 depends | |||
on which filters are placed at the ends of the fiber and how they | on which filters are placed at the ends of the fiber and how they | |||
have been configured. Once filters are placed we have a one-hop | have been configured. Once filters are placed, we have a one-hop | |||
media channel. In practical terms, associating a fiber with the | media channel. In practical terms, associating a fiber with the | |||
terminating filters determines the usable optical spectrum. | terminating filters determines the usable optical spectrum. | |||
---------------+ +-----------------+ | ---------------+ +----------------- | |||
| | | | | | |||
+--------+ +--------+ | +--------+ +--------+ | |||
| | | | +--------- | | | | | +--------- | |||
---o| =============================== o--| | ---o| =============================== o--| | |||
| | Fiber | | | --\ /-- | | | Fiber | | | --\ /-- | |||
---o| | | o--| \/ | ---o| | | o--| \/ | |||
| | | | | /\ | | | | | | /\ | |||
---o| =============================== o--| --/ \-- | ---o| =============================== o--| --/ \-- | |||
| Filter | | Filter | | | | Filter | | Filter | | | |||
| | | | +--------- | | | | | +--------- | |||
+--------+ +--------+ | +--------+ +--------+ | |||
| | | | | | |||
|------- Basic Media Channel ---------| | |------- Basic Media Channel ---------| | |||
---------------+ +-----------------+ | ---------------+ +----------------- | |||
--------+ +-------- | --------+ +-------- | |||
|--------------------------------------| | |--------------------------------------| | |||
LSR | TE link | LSR | LSR | TE link | LSR | |||
|--------------------------------------| | |--------------------------------------| | |||
+--------+ +-------- | --------+ +-------- | |||
Figure 8: (Basic) Media Channel and TE Link | Figure 8: (Basic) Media Channel and TE Link | |||
Additionally, when a cross-connect for a specific frequency slot is | Additionally, when a cross-connect for a specific frequency slot is | |||
considered, the resulting media support of joining basic media | considered, the resulting media support of joining basic media | |||
channels is still a media channel, i.e., a longer association | channels is still a media channel, i.e., a longer association | |||
sequence of media elements and its effective frequency slot. In | sequence of media elements and its effective frequency slot. In | |||
other words, It is possible to "concatenate" several media channels | other words, it is possible to "concatenate" several media channels | |||
(e.g., patch on intermediate nodes) to create a single media channel. | (e.g., patch on intermediate nodes) to create a single media channel. | |||
The architectural construct resulting of the association sequence of | The architectural construct resulting from the association sequence | |||
basic media channels and media layer matrix cross-connects can be | of basic media channels and media-layer matrix cross-connects can be | |||
represented as (i.e., corresponds to) a Label Switched Path (LSP) | represented as (i.e., corresponds to) a Label Switched Path (LSP) | |||
from a control plane perspective. | from a control-plane perspective. | |||
----------+ +------------------------------+ +--------- | ----------+ +------------------------------+ +--------- | |||
| | | | | | | | | | |||
+------+ +------+ +------+ +------+ | +------+ +------+ +------+ +------+ | |||
| | | | +----------+ | | | | | | | | | +----------+ | | | | | |||
--o| ========= o--| |--o ========= o-- | --o| ========= o--| |--o ========= o-- | |||
| | Fiber | | | --\ /-- | | | Fiber | | | | | Fiber | | | --\ /-- | | | Fiber | | | |||
--o| | | o--| \/ |--o | | o-- | --o| | | o--| \/ |--o | | o-- | |||
| | | | | /\ | | | | | | | | | | | /\ | | | | | | |||
--o| ========= o--***********|--o ========= o-- | --o| ========= o--***********|--o ========= o-- | |||
|Filter| |Filter| | | |Filter| |Filter| | |Filter| |Filter| | | |Filter| |Filter| | |||
| | | | | | | | | | | | | | | | | | |||
+------+ +------+ +------+ +------+ | +------+ +------+ +------+ +------+ | |||
| | | | | | | | | | |||
<- Basic Media -> <- Matrix -> <- Basic Media-> | <- Basic Media -> <- Matrix -> <- Basic Media -> | |||
|Channel| Channel |Channel| | |Channel| Channel |Channel| | |||
----------+ +------------------------------+ +--------- | ----------+ +------------------------------+ +--------- | |||
<-------------------- Media Channel ----------------> | <-------------------- Media Channel ----------------> | |||
------+ +---------------+ +------ | ------+ +---------------+ +------ | |||
|------------------| |------------------| | |------------------| |------------------| | |||
LSR | TE link | LSR | TE link | LSR | LSR | TE link | LSR | TE link | LSR | |||
|------------------| |------------------| | |------------------| |------------------| | |||
------+ +---------------+ +------ | ------+ +---------------+ +------ | |||
Figure 9: Extended Media Channel | Figure 9: Extended Media Channel | |||
Furthermore, if appropriate, the media channel can also be | Furthermore, if appropriate, the media channel can also be | |||
represented as a TE link or Forwarding Adjacency (FA) [RFC4206], | represented as a TE link or Forwarding Adjacency (FA) [RFC4206], | |||
augmenting the control plane network model. | augmenting the control-plane network model. | |||
----------+ +------------------------------+ +--------- | ----------+ +------------------------------+ +--------- | |||
| | | | | | | | | | |||
+------+ +------+ +------+ +------+ | +------+ +------+ +------+ +------+ | |||
| | | | +----------+ | | | | | | | | | +----------+ | | | | | |||
--o| ========= o--| |--o ========= o-- | --o| ========= o--| |--o ========= o-- | |||
| | Fiber | | | --\ /-- | | | Fiber | | | | | Fiber | | | --\ /-- | | | Fiber | | | |||
--o| | | o--| \/ |--o | | o-- | --o| | | o--| \/ |--o | | o-- | |||
| | | | | /\ | | | | | | | | | | | /\ | | | | | | |||
--o| ========= o--***********|--o ========= o-- | --o| ========= o--***********|--o ========= o-- | |||
skipping to change at page 15, line 28 | skipping to change at page 17, line 32 | |||
----------+ +------------------------------+ +--------- | ----------+ +------------------------------+ +--------- | |||
<------------------------ Media Channel -----------> | <------------------------ Media Channel -----------> | |||
------+ +----- | ------+ +----- | |||
|------------------------------------------------------| | |------------------------------------------------------| | |||
LSR | TE link | LSR | LSR | TE link | LSR | |||
|------------------------------------------------------| | |------------------------------------------------------| | |||
------+ +----- | ------+ +----- | |||
Figure 10: Extended Media Channel / TE Link / FA | Figure 10: Extended Media Channel TE Link or FA | |||
4.3. Consideration of LSPs in Flexi-grid | 4.3. Consideration of LSPs in Flexi-Grid | |||
The flexi-grid LSP is a control plane representation of a media | The flexi-grid LSP is a control-plane representation of a media | |||
channel. Since network media channels are media channels, an LSP may | channel. Since network media channels are media channels, an LSP may | |||
also be the control plane representation of a network media channel | also be the control-plane representation of a network media channel | |||
(without considering the adaptation functions). From a control plane | (without considering the adaptation functions). From a control-plane | |||
perspective, the main difference (regardless of the actual effective | perspective, the main difference (regardless of the actual effective | |||
frequency slot which may be dimensioned arbitrarily) is that the LSP | frequency slot, which may be dimensioned arbitrarily) is that the LSP | |||
that represents a network media channel also includes the endpoints | that represents a network media channel also includes the endpoints | |||
(transceivers), including the cross-connects at the ingress and | (transceivers), including the cross-connects at the ingress and | |||
egress nodes. The ports towards the client can still be represented | egress nodes. The ports towards the client can still be represented | |||
as interfaces from the control plane perspective. | as interfaces from the control-plane perspective. | |||
Figure 11 shows an LSP routed between 3 nodes. The LSP is terminated | Figure 11 shows an LSP routed between three nodes. The LSP is | |||
before the optical matrix of the ingress and egress nodes and can | terminated before the optical matrix of the ingress and egress nodes | |||
represent a media channel. This case does not (and cannot) represent | and can represent a media channel. This case does not (and cannot) | |||
a network media channel because it does not include (and cannot | represent a network media channel because it does not include (and | |||
include) the transceivers. | cannot include) the transceivers. | |||
---------+ +--------------------------------+ +-------- | ---------+ +--------------------------------+ +-------- | |||
| | | | | | | | | | |||
+------+ +------+ +------+ +------+ | +------+ +------+ +------+ +------+ | |||
| | | | +----------+ | | | | | | | | | +----------+ | | | | | |||
-o| ========= o---| |---o ========= o- | -o| ========= o---| |---o ========= o- | |||
| | Fiber | | | --\ /-- | | | Fiber | | | | | Fiber | | | --\ /-- | | | Fiber | | | |||
-o|>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>o- | -o|>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>o- | |||
| | | | | /\ | | | | | | | | | | | /\ | | | | | | |||
-o| ========= o---***********|---o ========= o- | -o| ========= o---***********|---o ========= o- | |||
skipping to change at page 16, line 27 | skipping to change at page 18, line 33 | |||
| | | | | | | | | | |||
---------+ +--------------------------------+ +-------- | ---------+ +--------------------------------+ +-------- | |||
>>>>>>>>>>>>>>>>>>>>>>>>>>>> LSP >>>>>>>>>>>>>>>>>>>>>>>> | >>>>>>>>>>>>>>>>>>>>>>>>>>>> LSP >>>>>>>>>>>>>>>>>>>>>>>> | |||
-----+ +---------------+ +----- | -----+ +---------------+ +----- | |||
|------------------| |----------------| | |------------------| |----------------| | |||
LSR | TE link | LSR | TE link | LSR | LSR | TE link | LSR | TE link | LSR | |||
|------------------| |----------------| | |------------------| |----------------| | |||
-----+ +---------------+ +----- | -----+ +---------------+ +----- | |||
Figure 11: Flex-grid LSP Representing a Media Channel that Starts at | Figure 11: Flexi-Grid LSP Representing a Media Channel That Starts at | |||
the Filter of the Outgoing Interface of the Ingress LSR and ends at | the Filter of the Outgoing Interface of the Ingress LSR and Ends at | |||
the Filter of the Incoming Interface of the Egress LSR | the Filter of the Incoming Interface of the Egress LSR | |||
In Figure 12 a Network Media Channel is represented as terminated at | In Figure 12, a network media channel is represented as terminated at | |||
the network side of the transceivers. This is commonly named an | the network side of the transceivers. This is commonly named an | |||
OTSi-trail connection. | OTSi-trail connection. | |||
|--------------------- Network Media Channel ----------------------| | |--------------------- Network Media Channel ----------------------| | |||
+----------------------+ +----------------------+ | +----------------------+ +----------------------+ | |||
| | | | | | | | |||
+------+ +------+ +------+ +------+ | +------+ +------+ +------+ +------+ | |||
| | +----+ | | | | +----+ | |OTSi | | | +----+ | | | | +----+ | |OTSi | |||
OTSi| o-| |-o | +-----+ | o-| |-o |sink | OTSi| o-| |-o | +-----+ | o-| |-o |sink | |||
skipping to change at page 17, line 35 | skipping to change at page 20, line 5 | |||
LSP | LSP | |||
<------------------------------------------------------------------> | <------------------------------------------------------------------> | |||
+-----+ +--------+ +-----+ | +-----+ +--------+ +-----+ | |||
o--- | |-------------------| |----------------| |---o | o--- | |-------------------| |----------------| |---o | |||
| LSR | TE link | LSR | TE link | LSR | | | LSR | TE link | LSR | TE link | LSR | | |||
| |-------------------| |----------------| | | | |-------------------| |----------------| | | |||
+-----+ +--------+ +-----+ | +-----+ +--------+ +-----+ | |||
Figure 12: LSP Representing a Network Media Channel (OTSi Trail) | Figure 12: LSP Representing a Network Media Channel (OTSi Trail) | |||
In a third case, a Network Media Channel is terminated on the Filter | In a third case, a network media channel is terminated on the filter | |||
ports of the Ingress and Egress nodes. This is named in G.872 as | ports of the ingress and egress nodes. This is defined in G.872 as | |||
OTSi Network Connection. As can be seen from the figures, there is | an OTSi Network Connection. As can be seen from the figures, from a | |||
no difference from a GMPLS modelling perspective between these cases, | GMPLS modeling perspective there is no difference between these | |||
but they are shown as distinct examples to highlight the differences | cases, but they are shown as distinct examples to highlight the | |||
in the data plane. | differences in the data plane. | |||
|--------------------- Network Media Channel --------------------| | |--------------------- Network Media Channel --------------------| | |||
+------------------------+ +------------------------+ | +------------------------+ +------------------------+ | |||
+------+ +------+ +------+ +------+ | +------+ +------+ +------+ +------+ | |||
| | +----+ | | | | +----+ | | | | | +----+ | | | | +----+ | | | |||
| o-| |-o | +------+ | o-| |-o | | | o-| |-o | +------+ | o-| |-o | | |||
| | | | | =====+-+ +-+=====| | | | | | | | | | | | =====+-+ +-+=====| | | | | | | |||
T-o******o********************************************************O-R | T-o******o********************************************************O-R | |||
| | |\ /| | | | | | | | |\ /| | | | | | |\ /| | | | | | | | |\ /| | | | |||
skipping to change at page 18, line 32 | skipping to change at page 20, line 39 | |||
LSP | LSP | |||
LSP | LSP | |||
<--------------------------------------------------------------> | <--------------------------------------------------------------> | |||
+-----+ +--------+ +-----+ | +-----+ +--------+ +-----+ | |||
o--| |--------------------| |-------------------| |--o | o--| |--------------------| |-------------------| |--o | |||
| LSR | TE link | LSR | TE link | LSR | | | LSR | TE link | LSR | TE link | LSR | | |||
| |--------------------| |-------------------| | | | |--------------------| |-------------------| | | |||
+-----+ +--------+ +-----+ | +-----+ +--------+ +-----+ | |||
Figure 13: LSP Representing a Network Media Channel (OTSi Network | Figure 13: LSP Representing a Network Media Channel | |||
Connection) | (OTSi Network Connection) | |||
Applying the notion of hierarchy at the media layer, by using the LSP | Applying the notion of hierarchy at the media layer, by using the LSP | |||
as an FA (i.e., by using hierarchical LSPs), the media channel | as an FA (i.e., by using hierarchical LSPs), the media channel | |||
created can support multiple (sub-)media channels. | created can support multiple (sub-)media channels. | |||
+--------------+ +--------------+ | +--------------+ +--------------+ | |||
| Media Channel| TE | Media Channel| Virtual TE | | Media Channel| TE | Media Channel| Virtual TE | |||
| | link | | link | | | link | | link | |||
| Matrix |o- - - - - - - - - - o| Matrix |o- - - - - - | | Matrix |o- - - - - - - - - - o| Matrix |o- - - - - - | |||
+--------------+ +--------------+ | +--------------+ +--------------+ | |||
| +---------+ | | | +---------+ | | |||
| | Media | | | | | Media | | | |||
|o----| Channel |-----o| | |o----| Channel |-----o| | |||
| | | | | | |||
| Matrix | | | Matrix | | |||
+---------+ | +---------+ | |||
Figure 14: Topology View with TE Link / FA | Figure 14: Topology View with TE Link or FA | |||
Note that there is only one media layer switch matrix (one | Note that there is only one media-layer switch matrix (one | |||
implementation is a FlexGrid ROADM) in SSON, while a signal layer LSP | implementation is a flexi-grid ROADM) in SSON, while a signal-layer | |||
(Network Media Channel) is established mainly for the purpose of | LSP (network media channel) is established mainly for the purpose of | |||
management and control of individual optical signals. Signal layer | management and control of individual optical signals. Signal-layer | |||
LSPs with the same attributes (such as source and destination) can be | LSPs with the same attributes (such as source and destination) can be | |||
grouped into one media-layer LSP (media channel): this has advantages | grouped into one media-layer LSP (media channel); this has advantages | |||
in spectral efficiency (reduce guard band between adjacent OChs in | in spectral efficiency (reduced guard band between adjacent OChs in | |||
one FSC channel) and LSP management. However, assuming some network | one FSC channel) and LSP management. However, assuming that some | |||
elements perform signal layer switching in an SSON, there must be | network elements perform signal-layer switching in an SSON, there | |||
enough guard band between adjacent OTSis in any media channel to | must be enough guard band between adjacent OTSi in any media channel | |||
compensate for the filter concatenation effects and other effects | to compensate for the filter concatenation effects and other effects | |||
caused by signal layer switching elements. In such a situation, the | caused by signal-layer switching elements. In such a situation, the | |||
separation of the signal layer from the media layer does not bring | separation of the signal layer from the media layer does not bring | |||
any benefit in spectral efficiency or in other aspects, but makes the | any benefit in spectral efficiency or in other aspects, and it makes | |||
network switch and control more complex. If two OTSis must be | the network switching and control more complex. If two OTSi must be | |||
switched to different ports, it is better to carry them by diferent | switched to different ports, it is better to carry them via different | |||
FSC channels, and the media layer switch is enough in this scenario. | FSC channels, and the media-layer switch is enough in this scenario. | |||
As discussed in Section 3.2.5, a media channel may be constructed | As discussed in Section 3.2.5, a media channel may be constructed | |||
from a compsite of network media channels. This may be achieved in | from a composite of network media channels. This may be achieved in | |||
two ways using LSPs. These mechanisms may be compared to the | two ways using LSPs. These mechanisms may be compared to the | |||
techniques used in GMPLS to support inverse multiplexing in Time | techniques used in GMPLS to support inverse multiplexing in Time | |||
Division Multiplexing (TDM) networks and in OTN [RFC4606], [RFC6344], | Division Multiplexing (TDM) networks and in OTN [RFC4606] [RFC6344] | |||
and [RFC7139]. | [RFC7139]. | |||
o In the first case, a single LSP may be established in the control | o In the first case, a single LSP may be established in the control | |||
plane. The signaling messages include information for all of the | plane. The signaling messages include information for all of the | |||
component network media channels that make up the composite media | component network media channels that make up the composite media | |||
channel. | channel. | |||
o In the second case, each component network media channel is | o In the second case, each component network media channel is | |||
established using a separate control plane LSP, and these LSPs are | established using a separate control-plane LSP, and these LSPs are | |||
associated within the control plane so that the end points may see | associated within the control plane so that the endpoints may see | |||
them as a single media channel. | them as a single media channel. | |||
4.4. Control Plane Modeling of Network Elements | 4.4. Control-Plane Modeling of Network Elements | |||
Optical transmitters and receivers may have different tunability | Optical transmitters and receivers may have different tunability | |||
constraints, and media channel matrixes may have switching | constraints, and media channel matrices may have switching | |||
restrictions. Additionally, a key feature of their implementation is | restrictions. Additionally, a key feature of their implementation is | |||
their highly asymmetric switching capability which is described in | their highly asymmetric switching capability, which is described in | |||
detail in [RFC6163]. Media matrices include line side ports that are | detail in [RFC6163]. Media matrices include line-side ports that are | |||
connected to DWDM links, and tributary side input/output ports that | connected to DWDM links and tributary-side input/output ports that | |||
can be connected to transmitters/receivers. | can be connected to transmitters/receivers. | |||
A set of common constraints can be defined: | A set of common constraints can be defined: | |||
o Slot widths: The minimum and maximum slot width. | o Slot widths: The minimum and maximum slot width. | |||
o Granularity: The optical hardware may not be able to select | o Granularity: The optical hardware may not be able to select | |||
parameters with the lowest granularity (e.g., 6.25 GHz for nominal | parameters with the lowest granularity (e.g., 6.25 GHz for nominal | |||
central frequencies or 12.5 GHz for slot width granularity). | central frequencies or 12.5 GHz for slot width granularity). | |||
o Available frequency ranges: The set or union of frequency ranges | o Available frequency ranges: The set or union of frequency ranges | |||
that have not been allocated (i.e., are available). The relative | that have not been allocated (i.e., are available). The relative | |||
grouping and distribution of available frequency ranges in a fiber | grouping and distribution of available frequency ranges in a fiber | |||
is usually referred to as "fragmentation". | are usually referred to as "fragmentation". | |||
o Available slot width ranges: The set or union of slot width ranges | o Available slot width ranges: The set or union of slot width ranges | |||
supported by media matrices. It includes the following | supported by media matrices. It includes the following | |||
information. | information: | |||
* Slot width threshold: The minimum and maximum Slot Width | * Slot width threshold: The minimum and maximum slot width | |||
supported by the media matrix. For example, the slot width | supported by the media matrix. For example, the slot width | |||
could be from 50GHz to 200GHz. | could be from 50 GHz to 200 GHz. | |||
* Step granularity: The minimum step by which the optical filter | * Step granularity: The minimum step by which the optical filter | |||
bandwidth of the media matrix can be increased or decreased. | bandwidth of the media matrix can be increased or decreased. | |||
This parameter is typically equal to slot width granularity | This parameter is typically equal to slot width granularity | |||
(i.e., 12.5GHz) or integer multiples of 12.5GHz. | (i.e., 12.5 GHz) or integer multiples of 12.5 GHz. | |||
4.5. Media Layer Resource Allocation Considerations | 4.5. Media Layer Resource Allocation Considerations | |||
A media channel has an associated effective frequency slot. From the | A media channel has an associated effective frequency slot. From the | |||
perspective of network control and management, this effective slot is | perspective of network control and management, this effective slot is | |||
seen as the "usable" end-to-end frequency slot. The establishment of | seen as the "usable" end-to-end frequency slot. The establishment of | |||
an LSP is related to the establishment of the media channel and the | an LSP is related to the establishment of the media channel and the | |||
configuration of the effective frequency slot. | configuration of the effective frequency slot. | |||
A "service request" is characterized (at a minimum) by its required | A "service request" is characterized (at a minimum) by its required | |||
effective slot width. This does not preclude that the request may | effective slot width. This does not preclude the request from adding | |||
add additional constraints such as also imposing the nominal central | additional constraints, such as also imposing the nominal central | |||
frequency. A given effective frequency slot may be requested for the | frequency. A given effective frequency slot may be requested for the | |||
media channel in the control plane LSP setup messages, and a specific | media channel in the control-plane LSP setup messages, and a specific | |||
frequency slot can be requested on any specific hop of the LSP setup. | frequency slot can be requested on any specific hop of the LSP setup. | |||
Regardless of the actual encoding, the LSP setup message specifies a | Regardless of the actual encoding, the LSP setup message specifies a | |||
minimum effective frequency slot width that needs to be fulfilled in | minimum effective frequency slot width that needs to be fulfilled in | |||
order to successful establish the requsted LSP. | order to successfully establish the requested LSP. | |||
An effective frequency slot must equally be described in terms of a | An effective frequency slot must equally be described in terms of a | |||
central nominal frequency and its slot width (in terms of usable | central nominal frequency and its slot width (in terms of usable | |||
spectrum of the effective frequency slot). That is, it must be | spectrum of the effective frequency slot). That is, it must be | |||
possible to determine the end-to-end values of the n and m | possible to determine the end-to-end values of the n and m | |||
parameters. We refer to this by saying that the "effective frequency | parameters. We refer to this by saying that the "effective frequency | |||
slot of the media channel/LSP must be valid". | slot of the media channel or LSP must be valid". | |||
In GMPLS the requested effective frequency slot is represented to the | In GMPLS, the requested effective frequency slot is represented to | |||
TSpec present in the RSVP-TE Path message, and the effective | the TSpec present in the RSVP-TE Path message, and the effective | |||
frequency slot is mapped to the FlowSpec carried in the RSVP-TE Resv | frequency slot is mapped to the FlowSpec carried in the RSVP-TE Resv | |||
message. | message. | |||
In GMPLS-controlled systems, the switched element corresponds to the | In GMPLS-controlled systems, the switched element corresponds to the | |||
'label'. In flexi-grid where the switched element is a frequency | 'label'. In flexi-grid, the switched element is a frequency slot, | |||
slot, the label represents a frequency slot. In consequence, the | and the label represents a frequency slot. Consequently, the label | |||
label in flexi-grid conveys the necessary information to obtain the | in flexi-grid conveys the necessary information to obtain the | |||
frequency slot characteristics (i.e, central frequency and slot | frequency slot characteristics (i.e., central frequency and slot | |||
width: the n and m parameters). The frequency slot is locally | width: the n and m parameters). The frequency slot is locally | |||
identified by the label. | identified by the label. | |||
The local frequency slot may change at each hop, given hardware | The local frequency slot may change at each hop, given hardware | |||
constraints and capabilities (e.g., a given node might not support | constraints and capabilities (e.g., a given node might not support | |||
the finest granularity). This means that the values of n and m may | the finest granularity). This means that the values of n and m may | |||
change at each hop. As long as a given downstream node allocates | change at each hop. As long as a given downstream node allocates | |||
enough optical spectrum, m can be different along the path. This | enough optical spectrum, m can be different along the path. This | |||
covers the issue where media matrices can have different slot width | covers the issue where media matrices can have different slot width | |||
granularities. Such variations in the local value of m will appear | granularities. Such variations in the local value of m will appear | |||
in the allocated label that encodes the frequency slot as well as the | in the allocated label that encodes the frequency slot as well as in | |||
in the FlowSpec that describes the flow. | the FlowSpec that describes the flow. | |||
Different operational modes can be considered. For Routing and | Different operational modes can be considered. For Routing and | |||
Spectrum Assignment (RSA) with explicit label control, and for | Spectrum Assignment (RSA) with explicit label control, and for | |||
Routing and Distributed Spectrum Assignment (R+DSA), the GMPLS | Routing and Distributed Spectrum Assignment (R+DSA), the GMPLS | |||
signaling procedures are similar to those described in section 4.1.3 | signaling procedures are similar to those described in Section 4.1.3 | |||
of [RFC6163] for Routing and Wavelength Assignment (RWA) and for | of [RFC6163] for Routing and Wavelength Assignment (RWA) and for | |||
Routing and Distributed Wavelength Assignment (R+DWA). The main | Routing and Distributed Wavelength Assignment (R+DWA). The main | |||
difference is that the label set specifies the available nominal | difference is that the label set specifies the available nominal | |||
central frequencies that meet the slot width requirements of the LSP. | central frequencies that meet the slot width requirements of the LSP. | |||
The intermediate nodes use the control plane to collect the | The intermediate nodes use the control plane to collect the | |||
acceptable central frequencies that meet the slot width requirement | acceptable central frequencies that meet the slot width requirement | |||
hop by hop. The tail-end node also needs to know the slot width of | hop by hop. The tail-end node also needs to know the slot width of | |||
an LSP to assign the proper frequency resource. Except for | an LSP to assign the proper frequency resource. Except for | |||
identifying the resource (i.e., fixed wavelength for WSON, and | identifying the resource (i.e., fixed wavelength for WSON, and | |||
frequency resource for flexible grids), the other signaling | frequency resource for flexible grids), the other signaling | |||
requirements (e.g., unidirectional or bidirectional, with or without | requirements (e.g., unidirectional or bidirectional, with or without | |||
converters) are the same as for WSON as described in section 6.1 of | converters) are the same as for WSON as described in Section 6.1 of | |||
[RFC6163]. | [RFC6163]. | |||
Regarding how a GMPLS control plane can assign n and m hop-by-hop | Regarding how a GMPLS control plane can assign n and m hop by hop | |||
along the path of an LSP, different cases can apply: | along the path of an LSP, different cases can apply: | |||
a. n and m can both change. It is the effective frequency slot that | a. n and m can both change. It is the effective frequency slot that | |||
matters, it needs to remain valid along the path. | matters; it needs to remain valid along the path. | |||
b. m can change, but n needs to remain the same along the path. | b. m can change, but n needs to remain the same along the path. | |||
This ensures that the nominal central frequency stays the same, | This ensures that the nominal central frequency stays the same, | |||
but the width of the slot can vary along the path. Again, the | but the width of the slot can vary along the path. Again, the | |||
important thing is that the effective frequency slot remains | important thing is that the effective frequency slot remains | |||
valid and satisfies the requested parameters along the whole path | valid and satisfies the requested parameters along the whole path | |||
of the LSP. | of the LSP. | |||
c. n and m need to be unchanging along the path. This ensures that | c. n and m need to be unchanging along the path. This ensures that | |||
the frequency slot is well-known end-to-end, and is a simple way | the frequency slot is well known from end to end and is a simple | |||
to ensure that the effective frequency slot remains valid for the | way to ensure that the effective frequency slot remains valid for | |||
whole LSP. | the whole LSP. | |||
d. n can change, but m needs to remain the same along the path. | d. n can change, but m needs to remain the same along the path. | |||
This ensures that the effective frequency slot remains valid, but | This ensures that the effective frequency slot remains valid but | |||
allows the frequency slot to be moved within the spectrum from | also allows the frequency slot to be moved within the spectrum | |||
hop to hop. | from hop to hop. | |||
The selection of a path that ensures n and m continuity can be | The selection of a path that ensures n and m continuity can be | |||
delegated to a dedicated entity such as a Path Computation Element | delegated to a dedicated entity such as a Path Computation Element | |||
(PCE). Any constraint (including frequency slot and width | (PCE). Any constraint (including frequency slot and width | |||
granularities) can be taken into account during path computation. | granularities) can be taken into account during path computation. | |||
Alternatively, A PCE can compute a path leaving the actual frequency | Alternatively, A PCE can compute a path, leaving the actual frequency | |||
slot assignment to be done, for example, with a distributed | slot assignment to be done, for example, with a distributed | |||
(signaling) procedure: | (signaling) procedure: | |||
o Each downstream node ensures that m is >= requested_m. | o Each downstream node ensures that m is >= requested_m. | |||
o A downstream node cannot foresee what an upstream node will | o A downstream node cannot foresee what an upstream node will | |||
allocate. A way to ensure that the effective frequency slot is | allocate. A way to ensure that the effective frequency slot is | |||
valid along the length of the LSP is to ensure that the same value | valid along the length of the LSP is to ensure that the same value | |||
of n is allocated at each hop. By forcing the same value of n we | of n is allocated at each hop. By forcing the same value of n, we | |||
avoid cases where the effective frequency slot of the media | avoid cases where the effective frequency slot of the media | |||
channel is invalid (that is, the resulting frequency slot cannot | channel is invalid (that is, the resulting frequency slot cannot | |||
be described by its n and m parameters). | be described by its n and m parameters). | |||
o This may be too restrictive, since a node (or even a centralized/ | o This may be too restrictive, since a node (or even a centralized/ | |||
combined RSA entity) may be able to ensure that the resulting end- | combined RSA entity) may be able to ensure that the resulting | |||
to-end effective frequency slot is valid even if n varies locally. | end-to-end effective frequency slot is valid, even if n varies | |||
That means, the effective frequency slot that characterizes the | locally. That means that the effective frequency slot that | |||
media channel from end to end is consistent and is determined by | characterizes the media channel from end to end is consistent and | |||
its n and m values, but that the effective frequency slot and | is determined by its n and m values but that the effective | |||
those values are logical (i.e., do not map direct to the | frequency slot and those values are logical (i.e., do not map | |||
physically assigned spectrum) in the sense that they are the | "direct" to the physically assigned spectrum) in the sense that | |||
result of the intersection of locally-assigned frequency slots | they are the result of the intersection of locally assigned | |||
applicable at local components (such as filters) each of which may | frequency slots applicable at local components (such as filters), | |||
have assigned different frequency slots. | each of which may have different frequency slots assigned to them. | |||
For Figure 15 the effective slot is made valid by ensuring that the | ||||
minimum m is greater than the requested m. The effective slot | ||||
(intersection) is the lowest m (bottleneck). | ||||
For Figure 16 the effective slot is made valid by ensuring that it is | As shown in Figure 15, the effective slot is made valid by ensuring | |||
valid at each hop in the upstream direction. The intersection needs | that the minimum m is greater than the requested m. The effective | |||
to be computed because invalid slots could result otherwise. | slot (intersection) is the lowest m (bottleneck). | |||
C B A | C B A | |||
|Path(m_req) | ^ | | |Path(m_req) | ^ | | |||
|---------> | # | | |---------> | # | | |||
| | # ^ | | | # ^ | |||
-^--------------^----------------#----------------#-- | -^--------------^----------------#----------------#-- | |||
Effective # # # # | Effective # # # # | |||
FS n, m # . . . . . . .#. . . . . . . . # . . . . . . . .# <-fixed | FS n, m # . . . . . . .#. . . . . . . . # . . . . . . . .# <-fixed | |||
# # # # n | # # # # n | |||
-v--------------v----------------#----------------#--- | -v--------------v----------------#----------------#--- | |||
| | # v | | | # v | |||
| | # Resv | | | | # Resv | | |||
| | v <------ | | | | v <------ | | |||
| | |FlowSpec(n, m_a)| | | | |FlowSpec(n, m_a)| | |||
| | <--------| | | | | <--------| | | |||
| | FlowSpec (n, | | | | FlowSpec(n, | | |||
<--------| min(m_a, m_b)) | <--------| min(m_a, m_b)) | |||
FlowSpec (n, | | FlowSpec(n, | | |||
min(m_a, m_b, m_c)) | min(m_a, m_b, m_c)) | |||
m_a, m_b, m_c: Selected frequency slot widths | m_a, m_b, m_c: Selected frequency slot widths | |||
Figure 15: Distributed Allocation with Different m and Same n | Figure 15: Distributed Allocation with Different m and Same n | |||
In Figure 16, the effective slot is made valid by ensuring that it is | ||||
valid at each hop in the upstream direction. The intersection needs | ||||
to be computed; otherwise, invalid slots could result. | ||||
C B A | C B A | |||
|Path(m_req) ^ | | | |Path(m_req) ^ | | | |||
|---------> # | | | |---------> # | | | |||
| # ^ ^ | | # ^ ^ | |||
-^-------------#----------------#-----------------#-------- | -^-------------#----------------#-----------------#-------- | |||
Effective # # # # | Effective # # # # | |||
FS n, m # # # # | FS n, m # # # # | |||
# # # # | # # # # | |||
-v-------------v----------------#-----------------#-------- | -v-------------v----------------#-----------------#-------- | |||
| | # v | | | # v | |||
| | # Resv | | | | # Resv | | |||
| | v <------ | | | | v <------ | | |||
| | |FlowSpec(n_a, m_a) | | | |FlowSpec(n_a, m_a) | |||
| | <--------| | | | | <--------| | | |||
| | FlowSpec (FSb [intersect] FSa) | | | FlowSpec(FSb [intersect] FSa) | |||
<--------| | <--------| | |||
FlowSpec ([intersect] FSa,FSb,FSc) | FlowSpec([intersect] FSa,FSb,FSc) | |||
n_a: Selected nominal central frequencyfr by node A | n_a: Selected nominal central frequency by node A | |||
m_a: Selected frequency slot widths by node A | m_a: Selected frequency slot widths by node A | |||
FSa, FSb, FSc: Frequency slot at each hop A, B, C | FSa, FSb, FSc: Frequency slot at each hop A, B, C | |||
Figure 16: Distributed Allocation with Different m and Different n | Figure 16: Distributed Allocation with Different m and Different n | |||
Note, when a media channel is bound to one OTSi (i.e., is a network | Note that when a media channel is bound to one OTSi (i.e., is a | |||
media channel), the effective FS must be the one of the OTSi. The | network media channel), the effective FS must be the frequency slot | |||
media channel setup by the LSP may contain the effective FS of the | of the OTSi. The media channel set up by the LSP may contain the | |||
network media channel effective FS. This is an endpoint property: | effective FS of the network media channel effective FS. This is an | |||
the egress and ingress have to constrain the Effective FS to be the | endpoint property; the egress and ingress have to constrain the | |||
OTSi Effective FS. | effective FS to be the OTSi effective FS. | |||
4.6. Neighbor Discovery and Link Property Correlation | 4.6. Neighbor Discovery and Link Property Correlation | |||
There are potential interworking problems between fixed-grid DWDM and | There are potential interworking problems between fixed-grid DWDM | |||
flexi-grid DWDM nodes. Additionally, even two flexi-grid nodes may | nodes and flexi-grid DWDM nodes. Additionally, even two flexi-grid | |||
have different grid properties, leading to link property conflict | nodes may have different grid properties, leading to link property | |||
with resulting limited interworking. | conflict and resulting in limited interworking. | |||
Devices or applications that make use of the flexi-grid might not be | Devices or applications that make use of flexi-grid might not be able | |||
able to support every possible slot width. In other words, different | to support every possible slot width. In other words, different | |||
applications may be defined where each supports a different grid | applications may be defined where each supports a different grid | |||
granularity. In this case the link between two optical nodes with | granularity. In this case, the link between two optical nodes with | |||
different grid granularities must be configured to align with the | different grid granularities must be configured to align with the | |||
larger of both granularities. Furthermore, different nodes may have | larger of both granularities. Furthermore, different nodes may have | |||
different slot-width tuning ranges. | different slot width tuning ranges. | |||
In summary, in a DWDM Link between two nodes, at least the following | In summary, in a DWDM link between two nodes, at a minimum, the | |||
properties need to be negotiated: | following properties need to be negotiated: | |||
o Grid capability (channel spacing) - Between fixed-grid and flexi- | o Grid capability (channel spacing) - Between fixed-grid and | |||
grid nodes. | flexi-grid nodes. | |||
o Grid granularity - Between two flexi-grid nodes. | o Grid granularity - Between two flexi-grid nodes. | |||
o Slot width tuning range - Between two flexi-grid nodes. | o Slot width tuning range - Between two flexi-grid nodes. | |||
4.7. Path Computation / Routing and Spectrum Assignment (RSA) | 4.7. Path Computation, Routing and Spectrum Assignment (RSA) | |||
In WSON, if there is no (available) wavelength converter in an | In WSON, if there is no (available) wavelength converter in an | |||
optical network, an LSP is subject to the "wavelength continuity | optical network, an LSP is subject to the "wavelength continuity | |||
constraint" (see section 4 of [RFC6163]). Similarly in flexi-grid, | constraint" (see Section 4 of [RFC6163]). Similarly, in flexi-grid, | |||
if the capability to shift or convert an allocated frequency slot is | if the capability to shift or convert an allocated frequency slot is | |||
absent, the LSP is subject to the "Spectrum Continuity Constraint". | absent, the LSP is subject to the "spectrum continuity constraint". | |||
Because of the limited availability of wavelength/spectrum converters | Because of the limited availability of spectrum converters (in what | |||
(in what is called a "sparse translucent optical network") the | is called a "sparse translucent optical network"), the spectrum | |||
wavelength/spectrum continuity constraint always has to be | continuity constraint always has to be considered. When available, | |||
considered. When available, information regarding spectrum | information regarding spectrum conversion capabilities at the optical | |||
conversion capabilities at the optical nodes may be used by RSA | nodes may be used by RSA mechanisms. | |||
mechanisms. | ||||
The RSA process determines a route and frequency slot for an LSP. | The RSA process determines a route and frequency slot for an LSP. | |||
Hence, when a route is computed the spectrum assignment process (SA) | Hence, when a route is computed, the spectrum assignment process | |||
determines the central frequency and slot width based on the slot | determines the central frequency and slot width based on the | |||
width and available central frequencies information of the | following: | |||
transmitter and receiver, and utilizing the available frequency | ||||
ranges information and available slot width ranges of the links that | o the requested slot width | |||
the route traverses. | ||||
o the information regarding the transmitter and receiver | ||||
capabilities, including the availability of central frequencies | ||||
and their slot width granularity | ||||
o the information regarding available frequency slots (frequency | ||||
ranges) and available slot widths of the links traversed along | ||||
the route | ||||
4.7.1. Architectural Approaches to RSA | 4.7.1. Architectural Approaches to RSA | |||
Similar to RWA for fixed grids [RFC6163], different ways of | Similar to RWA for fixed grids [RFC6163], different ways of | |||
performing RSA in conjunction with the control plane can be | performing RSA in conjunction with the control plane can be | |||
considered. The approaches included in this document are provided | considered. The approaches included in this document are provided | |||
for reference purposes only: other possible options could also be | for reference purposes only; other possible options could also be | |||
deployed. | deployed. | |||
Note that all of these models allow the concept of a composite media | Note that all of these models allow the concept of a composite media | |||
channel supported by a single control plane LSP or by a set of | channel supported by a single control-plane LSP or by a set of | |||
associated LSPs. | associated LSPs. | |||
4.7.1.1. Combined RSA (R&SA) | 4.7.1.1. Combined RSA (R&SA) | |||
In this case, a computation entity performs both routing and | In this case, a computation entity performs both routing and | |||
frequency slot assignment. The computation entity needs access to | frequency slot assignment. The computation entity needs access to | |||
detailed network information, e.g., the connectivity topology of the | detailed network information, e.g., the connectivity topology of the | |||
nodes and links, the available frequency ranges on each link, the | nodes and links, available frequency ranges on each link, and node | |||
node capabilities, etc. | capabilities. | |||
The computation entity could reside on a dedicated PCE server, in the | The computation entity could reside on a dedicated PCE server, in | |||
provisioning application that requests the service, or on the ingress | the provisioning application that requests the service, or on the | |||
node. | ingress node. | |||
4.7.1.2. Separated RSA (R+SA) | 4.7.1.2. Separated RSA (R+SA) | |||
In this case, routing computation and frequency slot assignment are | In this case, routing computation and frequency slot assignment are | |||
performed by different entities. The first entity computes the | performed by different entities. The first entity computes the | |||
routes and provides them to the second entity. The second entity | routes and provides them to the second entity. The second entity | |||
assigns the frequency slot. | assigns the frequency slot. | |||
The first entity needs the connectivity topology to compute the | The first entity needs the connectivity topology to compute the | |||
proper routes. The second entity needs information about the | proper routes. The second entity needs information about the | |||
available frequency ranges of the links and the capabilities of the | available frequency ranges of the links and the capabilities of the | |||
nodes in order to assign the spectrum. | nodes in order to assign the spectrum. | |||
4.7.1.3. Routing and Distributed SA (R+DSA) | 4.7.1.3. Routing and Distributed SA (R+DSA) | |||
In this case an entity computes the route, but the frequency slot | In this case, an entity computes the route, but the frequency slot | |||
assignment is performed hop-by-hop in a distributed way along the | assignment is performed hop by hop in a distributed way along the | |||
route. The available central frequencies which meet the spectrum | route. The available central frequencies that meet the spectrum | |||
continuity constraint need to be collected hop-by-hop along the | continuity constraint need to be collected hop by hop along the | |||
route. This procedure can be implemented by the GMPLS signaling | route. This procedure can be implemented by the GMPLS signaling | |||
protocol. | protocol. | |||
4.8. Routing and Topology Dissemination | 4.8. Routing and Topology Dissemination | |||
In the case of the combined RSA architecture, the computation entity | In the case of the combined RSA architecture, the computation entity | |||
needs the detailed network information, i.e., connectivity topology, | needs the detailed network information, i.e., connectivity topology, | |||
node capabilities, and available frequency ranges of the links. | node capabilities, and available frequency ranges of the links. | |||
Route computation is performed based on the connectivity topology and | Route computation is performed based on the connectivity topology and | |||
node capabilities, while spectrum assignment is performed based on | node capabilities, while spectrum assignment is performed based on | |||
the available frequency ranges of the links. The computation entity | the available frequency ranges of the links. The computation entity | |||
may get the detailed network information via the GMPLS routing | may get the detailed network information via the GMPLS routing | |||
protocol. | protocol. | |||
For WSON, the connectivity topology and node capabilities can be | For WSON, the connectivity topology and node capabilities can be | |||
advertised by the GMPLS routing protocol (refer to section 6.2 of | advertised by the GMPLS routing protocol (refer to Section 6.2 of | |||
[RFC6163]. Except for wavelength-specific availability information, | [RFC6163]). Except for wavelength-specific availability information, | |||
the information for flexi-grid is the same as for WSON and can | the information for flexi-grid is the same as for WSON and can | |||
equally be distributed by the GMPLS routing protocol. | equally be distributed by the GMPLS routing protocol. | |||
This section analyses the necessary changes on link information | This section analyzes the necessary changes to link information | |||
brought by flexible grids. | required by flexible grids. | |||
4.8.1. Available Frequency Ranges/Slots of DWDM Links | 4.8.1. Available Frequency Ranges (Frequency Slots) of DWDM Links | |||
In the case of flexible grids, channel central frequencies span from | In the case of flexible grids, channel central frequencies span from | |||
193.1 THz towards both ends of the C band spectrum with 6.25 GHz | 193.1 THz towards both ends of the C-band spectrum with a granularity | |||
granularity. Different LSPs could make use of different slot widths | of 6.25 GHz. Different LSPs could make use of different slot widths | |||
on the same link. Hence, the available frequency ranges need to be | on the same link. Hence, the available frequency ranges need to be | |||
advertised. | advertised. | |||
4.8.2. Available Slot Width Ranges of DWDM Links | 4.8.2. Available Slot Width Ranges of DWDM Links | |||
The available slot width ranges need to be advertised in combination | The available slot width ranges need to be advertised in combination | |||
with the available frequency ranges, in order that the computing | with the available frequency ranges, so that the computing entity can | |||
entity can verify whether an LSP with a given slot width can be set | verify whether an LSP with a given slot width can be set up or not. | |||
up or not. This is constrained by the available slot width ranges of | This is constrained by the available slot width ranges of the media | |||
the media matrix. Depending on the availability of the slot width | matrix. Depending on the availability of the slot width ranges, it | |||
ranges, it is possible to allocate more spectrum than strictly needed | is possible to allocate more spectrum than what is strictly needed by | |||
by the LSP. | the LSP. | |||
4.8.3. Spectrum Management | 4.8.3. Spectrum Management | |||
The total available spectrum on a fiber can be described as a | The total available spectrum on a fiber can be described as a | |||
resource that can be partitioned. For example, a part of the | resource that can be partitioned. For example, a part of the | |||
spectrum could be assigned to a third party to manage, or parts of | spectrum could be assigned to a third party to manage, or parts of | |||
the spectrum could be assigned by the operator for different classes | the spectrum could be assigned by the operator for different classes | |||
of traffic. This partitioning creates the impression that spectrum | of traffic. This partitioning creates the impression that the | |||
is a hierarchy in view of Management and Control Plane: each | spectrum is a hierarchy in view of the management plane and the | |||
partition could be itself be partitioned. However, the hierarchy is | control plane: each partition could itself be partitioned. However, | |||
created purely within a management system: it defines a hierarchy of | the hierarchy is created purely within a management system; it | |||
access or management rights, but there is no corresponding resource | defines a hierarchy of access or management rights, but there is no | |||
hierarchy within the fiber. | corresponding resource hierarchy within the fiber. | |||
The end of fiber is a link end and presents a fiber port which | The end of the fiber is a link end and presents a fiber port that | |||
represents all of spectrum available on the fiber. Each spectrum | represents all of the spectrum available on the fiber. Each spectrum | |||
allocation appears as Link Channel Port (i.e., frequency slot port) | allocation appears as a Link Channel Port (i.e., frequency slot port) | |||
within fiber. Thus, while there is a hierarchy of ownership (the | within the fiber. Thus, while there is a hierarchy of ownership (the | |||
Link Channel Port and corresponding LSP are located on a fiber and so | Link Channel Port and corresponding LSP are located on a fiber and | |||
associated with a fiber port) there is no continued nesting hierarchy | therefore are associated with a fiber port), there is no continued | |||
of frequency slots within larger frequency slots. In its way, this | nesting hierarchy of frequency slots within larger frequency slots. | |||
mirrors the fixed grid behavior where a wavelength is associated with | In its way, this mirrors the fixed-grid behavior where a wavelength | |||
a port/fiber, but cannot be subdivided even though it is a partition | is associated with a fiber port but cannot be subdivided even though | |||
of the total spectrum available on the fiber. | it is a partition of the total spectrum available on the fiber. | |||
4.8.4. Information Model | 4.8.4. Information Model | |||
This section defines an information model to describe the data that | This section defines an information model to describe the data that | |||
represents the capabilities and resources available in an flexi-grid | represents the capabilities and resources available in a flexi-grid | |||
network. It is not a data model and is not intended to limit any | network. It is not a data model and is not intended to limit any | |||
protocol solution such as an encoding for an IGP. For example, | protocol solution such as an encoding for an IGP. For example, | |||
information required for routing/path selection may be the set of | information required for routing and path selection may be the set of | |||
available nominal central frequencies from which a frequency slot of | available nominal central frequencies from which a frequency slot of | |||
the required width can be allocated. A convenient encoding for this | the required width can be allocated. A convenient encoding for this | |||
information is for further study in an IGP encoding document. | information is left for further study in an IGP encoding document. | |||
Fixed DWDM grids can also be described via suitable choices of slots | Fixed DWDM grids can also be described via suitable choices of slots | |||
in a flexible DWDM grid. However, devices or applications that make | in a flexible DWDM grid. However, devices or applications that make | |||
use of the flexible grid may not be capable of supporting every | use of the flexible grid may not be capable of supporting every | |||
possible slot width or central frequency position. Thus, the | possible slot width or central frequency position. Thus, the | |||
information model needs to enable: | information model needs to enable: | |||
exchange of information to enable RSA in a flexi-grid network | o the exchange of information to enable RSA in a flexi-grid network | |||
representation of a fixed grid device participating in a flexi- | ||||
grid network | ||||
full interworking of fixed and flexible grid devices within the | o the representation of a fixed-grid device participating in a | |||
same network | flexi-grid network | |||
interworking of flexgrid devices with different capabilities. | o full interworking of fixed-grid and flexible-grid devices within | |||
the same network | ||||
The information model is represented using Routing Backus-Naur Format | o interworking of flexible-grid devices with different capabilities | |||
(RBNF) as defined in [RFC5511]. | The information model is represented using the Routing Backus-Naur | |||
Format (RBNF) as defined in [RFC5511]. | ||||
<Available Spectrum> ::= | <Available Spectrum> ::= | |||
<Available Frequency Range-List> | <Available Frequency Range-List> | |||
<Available NCFs> | <Available NCFs> | |||
<Available Slot Widths> | <Available Slot Widths> | |||
where | where | |||
<Available Frequency Range-List> ::= | <Available Frequency Range-List> ::= | |||
<Available Frequency Range> [<Available Frequency Range-List>] | <Available Frequency Range> [<Available Frequency Range-List>] | |||
<Available Frequency Range> ::= | <Available Frequency Range> ::= | |||
( <Start NCF> <End NCF> ) | | ( <Start NCF> <End NCF> ) | | |||
<FS defined by (n, m) containing contiguous available NCFs> | <FS defined by (n, m) containing contiguous available NCFs> | |||
and | and | |||
<Available NCFs> ::= | <Available NCFs> ::= | |||
<Available NCF Granularity> [<Offset>] | <Available NCF Granularity> [<Offset>] | |||
-- Subset of supported n values given by p x n + q | -- Subset of supported n values given by p x n + q | |||
-- where p is a positive integer | -- where p is a positive integer | |||
-- and q (offset) belongs to 0,..,p-1. | -- and q (offset) belongs to 0,..,p-1. | |||
and | and | |||
<Available Slot Widths> ::= | <Available Slot Widths> ::= | |||
<Available Slot Width Granularity> | <Available Slot Width Granularity> | |||
<Min Slot Width> | <Min Slot Width> | |||
-- given by j x 12.5GHz, with j a positive integer | -- given by j x 12.5 GHz, with j a positive integer | |||
<Max Slot Width> | <Max Slot Width> | |||
-- given by k x 12.5GHz, with k a positive integer (k >= j) | -- given by k x 12.5 GHz, with k a positive integer (k >= j) | |||
Figure 17: Routing Information Model | Figure 17: Routing Information Model | |||
5. Control Plane Requirements | 5. Control-Plane Requirements | |||
The control of a flexi-grid networks places additional requirements | The control of flexi-grid networks places additional requirements on | |||
on the GMPLS protocols. This section summarizes those requirements | the GMPLS protocols. This section summarizes those requirements for | |||
for signaling and routing. | signaling and routing. | |||
5.1. Support for Media Channels | 5.1. Support for Media Channels | |||
The control plane SHALL be able to support Media Channels, | The control plane SHALL be able to support media channels, | |||
characterized by a single frequency slot. The representation of the | characterized by a single frequency slot. The representation of the | |||
Media Channel in the GMPLS control plane is the so-called flexi-grid | media channel in the GMPLS control plane is the so-called "flexi-grid | |||
LSP. Since network media channels are media channels, an LSP may | LSP". Since network media channels are media channels, an LSP may | |||
also be the control plane representation of a network media channel. | also be the control-plane representation of a network media channel. | |||
Consequently, the control plane will also be able to support network | ||||
Consequently, the control plane will also be able to support Network | media channels. | |||
Media Channels. | ||||
5.1.1. Signaling | 5.1.1. Signaling | |||
The signaling procedure SHALL be able to configure the nominal | The signaling procedure SHALL be able to configure the nominal | |||
central frequency (n) of a flexi-grid LSP. | central frequency (n) of a flexi-grid LSP. | |||
The signaling procedure SHALL allow a flexible range of values for | The signaling procedure SHALL allow a flexible range of values for | |||
the frequency slot width (m) parameter. Specifically, the control | the frequency slot width (m) parameter. Specifically, the control | |||
plane SHALL allow setting up a media channel with frequency slot | plane SHALL allow setting up a media channel with frequency slot | |||
width (m) ranging from a minimum of m=1 (12.5GHz) to a maximum of the | width (m) ranging from a minimum of m = 1 (12.5 GHz) to a maximum of | |||
entire C-band (the wavelength range 1530 nm to 1565 nm, which | the entire C-band (the wavelength range 1530 nm to 1565 nm, which | |||
corresponds to the amplification range of erbium doped fiber | corresponds to the amplification range of erbium-doped fiber | |||
amplifiers) with a slot width granularity of 12.5GHz. | amplifiers) with a slot width granularity of 12.5 GHz. | |||
The signaling procedure SHALL be able to configure the minimum width | The signaling procedure SHALL be able to configure the minimum width | |||
(m) of a flexi-grid LSP. In addition, the signaling procedure SHALL | (m) of a flexi-grid LSP. In addition, the signaling procedure SHALL | |||
be able to configure local frequency slots. | be able to configure local frequency slots. | |||
The control plane architecture SHOULD allow for the support of L-band | The control-plane architecture SHOULD allow for the support of the | |||
(the wavelength range 1565 nm to 1625 nm) and S-band (the wavelength | L-band (the wavelength range 1565 nm to 1625 nm) and the S-band (the | |||
range 1460 nm to 1530 nm). | wavelength range 1460 nm to 1530 nm). | |||
The signalling process SHALL be able to collect the local frequency | The signaling process SHALL be able to collect the local frequency | |||
slot assigned at each link along the path. | slot assigned at each link along the path. | |||
The signaling procedures SHALL support all of the RSA architectural | The signaling procedures SHALL support all of the RSA architectural | |||
models (R&SA, R+SA, and R+DSA) within a single set of protocol | models (R&SA, R+SA, and R+DSA) within a single set of protocol | |||
objects although some objects may only be applicable within one of | objects, although some objects may only be applicable within one of | |||
the models. | the models. | |||
5.1.2. Routing | 5.1.2. Routing | |||
The routing protocol will support all functions as described in | The routing protocol will support all functions described in | |||
[RFC4202] and extend them to a flexi-grid data plane. | [RFC4202] and extend them to a flexi-grid data plane. | |||
The routing protocol SHALL distribute sufficient information to | The routing protocol SHALL distribute sufficient information to | |||
compute paths to enable the signaling procedure to establish LSPs as | compute paths to enable the signaling procedure to establish LSPs as | |||
described in the previous sections. This includes, at a minimum the | described in the previous sections. This includes, at a minimum, the | |||
data described by the Information Model in Figure 17. | data described by the information model in Figure 17. | |||
The routing protocol SHALL update its advertisements of available | The routing protocol SHALL update its advertisements of available | |||
resources and capabilities as the usage of resources in the network | resources and capabilities as the usage of resources in the network | |||
varies with the establishment or tear-down of LSPs. These updates | varies with the establishment or teardown of LSPs. These updates | |||
SHOULD be amenable to damping and thresholds as in other traffic | SHOULD be amenable to damping and thresholds as in other traffic | |||
engineering routing advertisements. | engineering routing advertisements. | |||
The routing protocol SHALL support all of the RSA architectural | The routing protocol SHALL support all of the RSA architectural | |||
models (R&SA, R+SA, and R+DSA) without any configuration or change of | models (R&SA, R+SA, and R+DSA) without any configuration or change of | |||
behavior. Thus, the routing protocols SHALL be agnostic to the | behavior. Thus, the routing protocols SHALL be agnostic to the | |||
computation and signaling model that is in use. | computation and signaling model that is in use. | |||
5.2. Support for Media Channel Resizing | 5.2. Support for Media Channel Resizing | |||
The signaling procedures SHALL allow resizing (grow or shrink) the | The signaling procedures SHALL allow the resizing (growing or | |||
frequency slot width of a media channel/network media channel. The | shrinking) of the frequency slot width of a media channel or network | |||
resizing MAY imply resizing the local frequency slots along the path | media channel. The resizing MAY imply resizing the local frequency | |||
of the flexi-grid LSP. | slots along the path of the flexi-grid LSP. | |||
The routing protocol SHALL update its advertisements of available | The routing protocol SHALL update its advertisements of available | |||
resources and capabilities as the usage of resources in the network | resources and capabilities as the usage of resources in the network | |||
varies with the resizing of LSP. These updates SHOULD be amenable to | varies with the resizing of LSPs. These updates SHOULD be amenable | |||
damping and thresholds as in other traffic engineering routing | to damping and thresholds as in other traffic engineering routing | |||
advertisements. | advertisements. | |||
5.3. Support for Logical Associations of Multiple Media Channels | 5.3. Support for Logical Associations of Multiple Media Channels | |||
A set of media channels can be used to transport signals that have a | A set of media channels can be used to transport signals that have a | |||
logical association between them. The control plane architecture | logical association between them. The control-plane architecture | |||
SHOULD allow multiple media channels to be logically associated. The | SHOULD allow multiple media channels to be logically associated. The | |||
control plane SHOULD allow the co-routing of a set of media channels | control plane SHOULD allow the co-routing of a set of media channels | |||
that are logically associated. | that are logically associated. | |||
5.4. Support for Composite Media Channels | 5.4. Support for Composite Media Channels | |||
As described in Section 3.2.5 and Section 4.3, a media channel may be | As described in Sections 3.2.5 and 4.3, a media channel may be | |||
composed of multiple network media channels. | composed of multiple network media channels. | |||
The signaling procedures SHOULD include support for signaling a | The signaling procedures SHOULD include support for signaling a | |||
single control plane LSP that includes information about multiple | single control-plane LSP that includes information about multiple | |||
network media channels that will comprise the single compound media | network media channels that will comprise the single compound media | |||
channel. | channel. | |||
The signaling procedures SHOULD include a mechanism to associate | The signaling procedures SHOULD include a mechanism to associate | |||
separately signaled control plane LSPs so that the end points may | separately signaled control-plane LSPs so that the endpoints may | |||
correlate them into a single compound media channel. | correlate them into a single compound media channel. | |||
The signaling procedures MAY include a mechanism to dynamically vary | The signaling procedures MAY include a mechanism to dynamically vary | |||
the composition of a composite media channel by allowing network | the composition of a composite media channel by allowing network | |||
media channels to be added to or removed from the whole. | media channels to be added to or removed from the whole. | |||
The routing protocols MUST provide sufficient information for the | The routing protocols MUST provide sufficient information for the | |||
computation of paths and slots for composite media channels using any | computation of paths and slots for composite media channels using any | |||
of the three RSA architectural models (R&SA, R+SA, and R+DSA). | of the three RSA architectural models (R&SA, R+SA, and R+DSA). | |||
5.5. Support for Neighbor Discovery and Link Property Correlation | 5.5. Support for Neighbor Discovery and Link Property Correlation | |||
The control plane MAY include support for neighbor discovery such | The control plane MAY include support for neighbor discovery such | |||
that an flexi-grid network can be constructed in a "plug-and-play" | that a flexi-grid network can be constructed in a "plug-and-play" | |||
manner. Note, however, that in common operational practice | manner. Note, however, that in common operational practice, | |||
validation processes are used rather than automatic discovery. | validation processes are used rather than automatic discovery. | |||
The control plane SHOULD allow the nodes at opposite ends of a link | The control plane SHOULD allow the nodes at opposite ends of a link | |||
to correlate the properties that they will apply to the link. Such | to correlate the properties that they will apply to the link. Such a | |||
correlation SHOULD include at least the identities of the node and | correlation SHOULD include at least the identities of the nodes and | |||
the identities they apply to the link. Other properties such as the | the identities that they apply to the link. Other properties, such | |||
link characteristics described for the routing information model in | as the link characteristics described for the routing information | |||
Figure 17 SHOULD also be correlated. | model in Figure 17, SHOULD also be correlated. | |||
Such neighbor discovery and link property correlation, if provided, | Such neighbor discovery and link property correlation, if provided, | |||
MUST be able to operate in both an out-of-band and an out-of-fiber | MUST be able to operate in both an out-of-band and an out-of-fiber | |||
control channel. | control channel. | |||
6. IANA Considerations | 6. Security Considerations | |||
This framework document makes no requests for IANA action. | ||||
7. Security Considerations | ||||
The control plane and data plane aspects of a flexi-grid system are | The control-plane and data-plane aspects of a flexi-grid system are | |||
fundamentally the same as a fixed grid system and there is no | fundamentally the same as a fixed-grid system, and there is no | |||
substantial reason to expect the security considerations to be any | substantial reason to expect the security considerations to be any | |||
different. | different. | |||
A good overview of the security considerations for a GMPLS-based | A good overview of the security considerations for a GMPLS-based | |||
control plane can be found in [RFC5920]. | control plane can be found in [RFC5920]. | |||
[RFC6163] includes a section describing security considerations for | [RFC6163] includes a section describing security considerations for | |||
WSON, and it is reasonable to infer that these considerations apply | WSON, and it is reasonable to infer that these considerations apply | |||
and may be exacerbated in a flexi-grid SSON system. In particular, | and may be exacerbated in a flexi-grid SSON system. In particular, | |||
the detailed and granular information describing a flexi- grid | the detailed and granular information describing a flexi-grid network | |||
network and the capabilities of nodes in that network could put | and the capabilities of nodes in that network could put stress on the | |||
stress on the routing protocol or the out-of-band control channel | routing protocol or the out-of-band control channel used by the | |||
used by the protocol. An attacker might be able to cause small | protocol. An attacker might be able to cause small variations in the | |||
variations in the use of the network or the available resources | use of the network or the available resources (perhaps by modifying | |||
(perhaps by modifying the environment of a fiber) and so trigger the | the environment of a fiber) and so trigger the routing protocol to | |||
routing protocol to make new flooding announcements. This situation | make new flooding announcements. This situation is explicitly | |||
is explicitly mitigated in the requirements for the routing protocol | mitigated in the requirements for the routing protocol extensions | |||
extensions where it is noted that the protocol must include damping | where it is noted that the protocol must include damping and | |||
and configurable thresholds as already exist in the core GMPLS | configurable thresholds as already exist in the core GMPLS routing | |||
routing protocols. | protocols. | |||
8. Manageability Considerations | 7. Manageability Considerations | |||
GMPLS systems already contain a number of management tools. | GMPLS systems already contain a number of management tools: | |||
o MIB modules exist to model the control plane protocols and the | o MIB modules exist to model the control-plane protocols and the | |||
network elements [RFC4802], [RFC4803], and there is early work to | network elements [RFC4802] [RFC4803], and there is early work to | |||
provide similar access through YANG. The features described in | provide similar access through YANG. The features described in | |||
these models are currently designed to represent fixed-label | these models are currently designed to represent fixed-label | |||
technologies such as optical networks using the fixed grid: | technologies such as optical networks using the fixed grid; | |||
extensions may be needed in order to represent bandwidth, | extensions may be needed in order to represent bandwidth, | |||
frequency slots, and effective frequency slots in flexi- grid | frequency slots, and effective frequency slots in flexi-grid | |||
networks. | networks. | |||
o There are protocol extensions within GMPLS signaling to allow | o There are protocol extensions within GMPLS signaling to allow | |||
control plane systems to report the presence of faults that affect | control-plane systems to report the presence of faults that affect | |||
LSPs [RFC4783], although it must be carefully noted that these | LSPs [RFC4783], although it must be carefully noted that these | |||
mechanisms do not constitute an alarm mechanism that could be used | mechanisms do not constitute an alarm mechanism that could be used | |||
to rapidly propagate information about faults in a way that would | to rapidly propagate information about faults in a way that would | |||
allow the data plane to perform protection switching. These | allow the data plane to perform protection switching. These | |||
mechanisms could easily be enhanced with the addition of | mechanisms could easily be enhanced with the addition of | |||
technology-specific reasons codes if any are needed. | technology-specific reason codes if any are needed. | |||
o The GMPLS protocols, themselves, already include fault detection | o The GMPLS protocols, themselves, already include fault detection | |||
and recovery mechanisms (such as the PathErr and Notify messages | and recovery mechanisms (such as the PathErr and Notify messages | |||
in RSVP-TE signaling as used by GMPLS [RFC3473]. It is not | in RSVP-TE signaling as used by GMPLS [RFC3473]). It is not | |||
anticipated that these mechanisms will need enhancement to support | anticipated that these mechanisms will need enhancement to support | |||
flexi-grid although additional reason codes may be needed to | flexi-grid, although additional reason codes may be needed to | |||
describe technology-specific error cases. | describe technology-specific error cases. | |||
o [RFC7260] describes a framework for the control and configuration | o [RFC7260] describes a framework for the control and configuration | |||
of data plane Operations, Administration, and Management (OAM). | of data-plane Operations, Administration, and Maintenance (OAM). | |||
It would not be appropriate for the IETF to define or describe | It would not be appropriate for the IETF to define or describe | |||
data plane OAM for optical systems, but the framework described in | data-plane OAM for optical systems, but the framework described in | |||
RFC 7260 could be used (with minor protocol extensions) to enable | RFC 7260 could be used (with minor protocol extensions) to enable | |||
data plane OAM that has been defined by the originators of the | data-plane OAM that has been defined by the originators of the | |||
flexi-grid data plane technology (the ITU-T). | flexi-grid data-plane technology (the ITU-T). | |||
o The Link Management Protocol [RFC4204] is designed to allow the | o The Link Management Protocol (LMP) [RFC4204] is designed to allow | |||
two ends of a network link to coordinate and confirm the | the two ends of a network link to coordinate and confirm the | |||
configuration and capabilities that they will apply to the link. | configuration and capabilities that they will apply to the link. | |||
This protocol is particularly applicable to optical links where | LMP is particularly applicable to optical links, where the | |||
the characteristics of the network devices may considerably affect | characteristics of the network devices may considerably affect how | |||
how the link is used and where misconfiguration of mis-fibering | the link is used and where misconfiguration or mis-fibering could | |||
could make physical interoperability impossible. LMP could easily | make physical interoperability impossible. LMP could easily be | |||
be extended to collect and report information between the end | extended to collect and report information between the endpoints | |||
points of links in a flexi-grid network. | of links in a flexi-grid network. | |||
9. Authors | ||||
Fatai Zhang | ||||
Huawei | ||||
Huawei Base, Longgang District, Chine | ||||
zhangfatai@huawei.com | ||||
Xihua Fu | ||||
ZTE | ||||
ZTE Plaza,No.10,Tangyan South Road, Gaoxin District, China | ||||
fu.xihua@zte.com.cn | ||||
Daniele Ceccarelli | ||||
Ericsson | ||||
Via Calda 5, Genova, Italy | ||||
daniele.ceccarelli@ericsson.com | ||||
Iftekhar Hussain | ||||
Infinera | ||||
140 Caspian Ct, Sunnyvale, 94089, USA | ||||
ihussain@infinera.com | ||||
10. Contributing Authors | ||||
Adrian Farrel | ||||
Old Dog Consulting | ||||
adrian@olddog.co.uk | ||||
Daniel King | ||||
Old Dog Consulting | ||||
daniel@olddog.co.uk | ||||
Xian Zhang | ||||
Huawei | ||||
zhang.xian@huawei.com | ||||
Cyril Margaria | ||||
Juniper Networks | ||||
cmargaria@juniper.net | ||||
Qilei Wang | ||||
ZTE | ||||
Ruanjian Avenue, Nanjing, China | ||||
wang.qilei@zte.com.cn | ||||
Malcolm Betts | ||||
ZTE | ||||
malcolm.betts@zte.com.cn | ||||
Sergio Belotti | ||||
Alcatel Lucent | ||||
Optics CTO | ||||
Via Trento 30 20059 Vimercate (Milano) Italy | ||||
+39 039 6863033 | ||||
sergio.belotti@alcatel-lucent.com | ||||
Yao Li | ||||
Nanjing University | ||||
wsliguotou@hotmail.com | ||||
Fei Zhang | ||||
Huawei | ||||
zhangfei7@huawei.com | ||||
Lei Wang | ||||
wang.lei@bupt.edu.cn | ||||
Guoying Zhang | ||||
China Academy of Telecom Research | ||||
No.52 Huayuan Bei Road, Beijing, China | ||||
zhangguoying@ritt.cn | ||||
Takehiro Tsuritani | ||||
KDDI R&D Laboratories Inc. | ||||
2-1-15 Ohara, Fujimino, Saitama, Japan | ||||
tsuri@kddilabs.jp | ||||
Lei Liu | ||||
U.C. Davis, USA | ||||
leiliu@ucdavis.edu | ||||
Eve Varma | ||||
Alcatel-Lucent | ||||
+1 732 239 7656 | ||||
eve.varma@alcatel-lucent.com | ||||
Young Lee | ||||
Huawei | ||||
Jianrui Han | ||||
Huawei | ||||
Sharfuddin Syed | ||||
Infinera | ||||
Rajan Rao | ||||
Infinera | ||||
Marco Sosa | ||||
Infinera | ||||
Biao Lu | ||||
Infinera | ||||
Abinder Dhillon | ||||
Infinera | ||||
Felipe Jimenez Arribas | ||||
Telefonica I+D | ||||
Andrew G. Malis | ||||
Huawei | ||||
agmalis@gmail.com | ||||
Huub van Helvoort | ||||
Hai Gaoming BV | ||||
The Neterlands | ||||
huubatwork@gmail.com | ||||
11. Acknowledgments | ||||
The authors would like to thank Pete Anslow for his insights and | ||||
clarifications, and to Matt Hartley and Jonas Maertensson for their | ||||
reviews. | ||||
This work was supported in part by the FP-7 IDEALIST project under | ||||
grant agreement number 317999. | ||||
12. References | ||||
12.1. Normative References | 8. References | |||
[G.694.1] International Telecomunications Union, "ITU-T | 8.1. Normative References | |||
Recommendation G.694.1, Spectral grids for WDM | ||||
applications: DWDM frequency grid", November 2012. | ||||
[G.800] International Telecomunications Union, "ITU-T | [G.694.1] International Telecommunication Union, "Spectral grids for | |||
Recommendation G.800, Unified functional architecture of | WDM applications: DWDM frequency grid", ITU-T | |||
transport networks.", February 2012. | Recommendation G.694.1, February 2012, | |||
<https://www.itu.int/rec/T-REC-G.694.1/en>. | ||||
[G.805] International Telecomunications Union, "ITU-T | [G.800] International Telecommunication Union, "Unified functional | |||
Recommendation G.805, Generic functional architecture of | architecture of transport networks", ITU-T | |||
transport networks.", March 2000. | Recommendation G.800, February 2012, | |||
<http://www.itu.int/rec/T-REC-G.800/>. | ||||
[G.8080] International Telecomunications Union, "ITU-T | [G.805] International Telecommunication Union, "Generic functional | |||
Recommendation G.8080/Y.1304, Architecture for the | architecture of transport networks", ITU-T | |||
automatically switched optical network", 2012. | Recommendation G.805, March 2000, | |||
<https://www.itu.int/rec/T-REC-G.805-200003-I/en>. | ||||
[G.870] International Telecomunications Union, "ITU-T | [G.8080] International Telecommunication Union, "Architecture for | |||
Recommendation G.870/Y.1352, Terms and definitions for | the automatically switched optical network", ITU-T | |||
optical transport networks", November 2012. | Recommendation G.8080/Y.1304, February 2012, | |||
<https://www.itu.int/rec/T-REC-G.8080-201202-I/en>. | ||||
[G.872] International Telecomunications Union, "ITU-T | [G.870] International Telecommunication Union, "Terms and | |||
Recommendation G.872, Architecture of optical transport | definitions for optical transport networks", ITU-T | |||
networks, draft v0.16 2012/09 (for discussion)", 2012. | Recommendation G.870/Y.1352, October 2012, | |||
<https://www.itu.int/rec/T-REC-G.870/en>. | ||||
[G.959.1-2013] | [G.872] International Telecommunication Union, "Architecture of | |||
International Telecomunications Union, "Update of ITU-T | optical transport networks", ITU-T Recommendation G.872, | |||
Recommendation G.959.1, Optical transport network physical | October 2012, | |||
layer interfaces", 2013. | <http://www.itu.int/rec/T-REC-G.872-201210-I>. | |||
[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, | |||
<http://www.rfc-editor.org/info/rfc2119>. | <http://www.rfc-editor.org/info/rfc2119>. | |||
[RFC3945] Mannie, E., Ed., "Generalized Multi-Protocol Label | [RFC3945] Mannie, E., Ed., "Generalized Multi-Protocol Label | |||
Switching (GMPLS) Architecture", RFC 3945, | Switching (GMPLS) Architecture", RFC 3945, | |||
DOI 10.17487/RFC3945, October 2004, | DOI 10.17487/RFC3945, October 2004, | |||
<http://www.rfc-editor.org/info/rfc3945>. | <http://www.rfc-editor.org/info/rfc3945>. | |||
[RFC4202] Kompella, K., Ed. and Y. Rekhter, Ed., "Routing Extensions | [RFC4202] Kompella, K., Ed., and Y. Rekhter, Ed., "Routing | |||
in Support of Generalized Multi-Protocol Label Switching | Extensions in Support of Generalized Multi-Protocol Label | |||
(GMPLS)", RFC 4202, DOI 10.17487/RFC4202, October 2005, | Switching (GMPLS)", RFC 4202, DOI 10.17487/RFC4202, | |||
<http://www.rfc-editor.org/info/rfc4202>. | October 2005, <http://www.rfc-editor.org/info/rfc4202>. | |||
[RFC4206] Kompella, K. and Y. Rekhter, "Label Switched Paths (LSP) | [RFC4206] Kompella, K. and Y. Rekhter, "Label Switched Paths (LSP) | |||
Hierarchy with Generalized Multi-Protocol Label Switching | Hierarchy with Generalized Multi-Protocol Label Switching | |||
(GMPLS) Traffic Engineering (TE)", RFC 4206, | (GMPLS) Traffic Engineering (TE)", RFC 4206, | |||
DOI 10.17487/RFC4206, October 2005, | DOI 10.17487/RFC4206, October 2005, | |||
<http://www.rfc-editor.org/info/rfc4206>. | <http://www.rfc-editor.org/info/rfc4206>. | |||
[RFC5511] Farrel, A., "Routing Backus-Naur Form (RBNF): A Syntax | [RFC5511] Farrel, A., "Routing Backus-Naur Form (RBNF): A Syntax | |||
Used to Form Encoding Rules in Various Routing Protocol | Used to Form Encoding Rules in Various Routing Protocol | |||
Specifications", RFC 5511, DOI 10.17487/RFC5511, April | Specifications", RFC 5511, DOI 10.17487/RFC5511, | |||
2009, <http://www.rfc-editor.org/info/rfc5511>. | April 2009, <http://www.rfc-editor.org/info/rfc5511>. | |||
12.2. Informative References | 8.2. Informative References | |||
[G.959.1-2013] | ||||
International Telecommunication Union, "Optical transport | ||||
network physical layer interfaces", Update to ITU-T | ||||
Recommendation G.959.1, 2013. | ||||
[RFC3473] Berger, L., Ed., "Generalized Multi-Protocol Label | [RFC3473] Berger, L., Ed., "Generalized Multi-Protocol Label | |||
Switching (GMPLS) Signaling Resource ReserVation Protocol- | Switching (GMPLS) Signaling Resource ReserVation Protocol- | |||
Traffic Engineering (RSVP-TE) Extensions", RFC 3473, | Traffic Engineering (RSVP-TE) Extensions", RFC 3473, | |||
DOI 10.17487/RFC3473, January 2003, | DOI 10.17487/RFC3473, January 2003, | |||
<http://www.rfc-editor.org/info/rfc3473>. | <http://www.rfc-editor.org/info/rfc3473>. | |||
[RFC4204] Lang, J., Ed., "Link Management Protocol (LMP)", RFC 4204, | [RFC4204] Lang, J., Ed., "Link Management Protocol (LMP)", RFC 4204, | |||
DOI 10.17487/RFC4204, October 2005, | DOI 10.17487/RFC4204, October 2005, | |||
<http://www.rfc-editor.org/info/rfc4204>. | <http://www.rfc-editor.org/info/rfc4204>. | |||
[RFC4397] Bryskin, I. and A. Farrel, "A Lexicography for the | [RFC4397] Bryskin, I. and A. Farrel, "A Lexicography for the | |||
Interpretation of Generalized Multiprotocol Label | Interpretation of Generalized Multiprotocol Label | |||
Switching (GMPLS) Terminology within the Context of the | Switching (GMPLS) Terminology within the Context of the | |||
ITU-T's Automatically Switched Optical Network (ASON) | ITU-T's Automatically Switched Optical Network (ASON) | |||
Architecture", RFC 4397, DOI 10.17487/RFC4397, February | Architecture", RFC 4397, DOI 10.17487/RFC4397, | |||
2006, <http://www.rfc-editor.org/info/rfc4397>. | February 2006, <http://www.rfc-editor.org/info/rfc4397>. | |||
[RFC4606] Mannie, E. and D. Papadimitriou, "Generalized Multi- | [RFC4606] Mannie, E. and D. Papadimitriou, "Generalized | |||
Protocol Label Switching (GMPLS) Extensions for | Multi-Protocol Label Switching (GMPLS) Extensions for | |||
Synchronous Optical Network (SONET) and Synchronous | Synchronous Optical Network (SONET) and Synchronous | |||
Digital Hierarchy (SDH) Control", RFC 4606, | Digital Hierarchy (SDH) Control", RFC 4606, | |||
DOI 10.17487/RFC4606, August 2006, | DOI 10.17487/RFC4606, August 2006, | |||
<http://www.rfc-editor.org/info/rfc4606>. | <http://www.rfc-editor.org/info/rfc4606>. | |||
[RFC4783] Berger, L., Ed., "GMPLS - Communication of Alarm | [RFC4783] Berger, L., Ed., "GMPLS - Communication of Alarm | |||
Information", RFC 4783, DOI 10.17487/RFC4783, December | Information", RFC 4783, DOI 10.17487/RFC4783, | |||
2006, <http://www.rfc-editor.org/info/rfc4783>. | December 2006, <http://www.rfc-editor.org/info/rfc4783>. | |||
[RFC4802] Nadeau, T., Ed., Farrel, A., and , "Generalized | [RFC4802] Nadeau, T., Ed., Farrel, A., and , "Generalized | |||
Multiprotocol Label Switching (GMPLS) Traffic Engineering | Multiprotocol Label Switching (GMPLS) Traffic Engineering | |||
Management Information Base", RFC 4802, | Management Information Base", RFC 4802, | |||
DOI 10.17487/RFC4802, February 2007, | DOI 10.17487/RFC4802, February 2007, | |||
<http://www.rfc-editor.org/info/rfc4802>. | <http://www.rfc-editor.org/info/rfc4802>. | |||
[RFC4803] Nadeau, T., Ed. and A. Farrel, Ed., "Generalized | [RFC4803] Nadeau, T., Ed., and A. Farrel, Ed., "Generalized | |||
Multiprotocol Label Switching (GMPLS) Label Switching | Multiprotocol Label Switching (GMPLS) Label Switching | |||
Router (LSR) Management Information Base", RFC 4803, | Router (LSR) Management Information Base", RFC 4803, | |||
DOI 10.17487/RFC4803, February 2007, | DOI 10.17487/RFC4803, February 2007, | |||
<http://www.rfc-editor.org/info/rfc4803>. | <http://www.rfc-editor.org/info/rfc4803>. | |||
[RFC5920] Fang, L., Ed., "Security Framework for MPLS and GMPLS | [RFC5920] Fang, L., Ed., "Security Framework for MPLS and GMPLS | |||
Networks", RFC 5920, DOI 10.17487/RFC5920, July 2010, | Networks", RFC 5920, DOI 10.17487/RFC5920, July 2010, | |||
<http://www.rfc-editor.org/info/rfc5920>. | <http://www.rfc-editor.org/info/rfc5920>. | |||
[RFC6163] Lee, Y., Ed., Bernstein, G., Ed., and W. Imajuku, | [RFC6163] Lee, Y., Ed., Bernstein, G., Ed., and W. Imajuku, | |||
skipping to change at page 39, line 46 | skipping to change at page 38, line 42 | |||
<http://www.rfc-editor.org/info/rfc6344>. | <http://www.rfc-editor.org/info/rfc6344>. | |||
[RFC7139] Zhang, F., Ed., Zhang, G., Belotti, S., Ceccarelli, D., | [RFC7139] Zhang, F., Ed., Zhang, G., Belotti, S., Ceccarelli, D., | |||
and K. Pithewan, "GMPLS Signaling Extensions for Control | and K. Pithewan, "GMPLS Signaling Extensions for Control | |||
of Evolving G.709 Optical Transport Networks", RFC 7139, | of Evolving G.709 Optical Transport Networks", RFC 7139, | |||
DOI 10.17487/RFC7139, March 2014, | DOI 10.17487/RFC7139, March 2014, | |||
<http://www.rfc-editor.org/info/rfc7139>. | <http://www.rfc-editor.org/info/rfc7139>. | |||
[RFC7260] Takacs, A., Fedyk, D., and J. He, "GMPLS RSVP-TE | [RFC7260] Takacs, A., Fedyk, D., and J. He, "GMPLS RSVP-TE | |||
Extensions for Operations, Administration, and Maintenance | Extensions for Operations, Administration, and Maintenance | |||
(OAM) Configuration", RFC 7260, DOI 10.17487/RFC7260, June | (OAM) Configuration", RFC 7260, DOI 10.17487/RFC7260, | |||
2014, <http://www.rfc-editor.org/info/rfc7260>. | June 2014, <http://www.rfc-editor.org/info/rfc7260>. | |||
Acknowledgments | ||||
The authors would like to thank Pete Anslow for his insights and | ||||
clarifications, and Matt Hartley and Jonas Maertensson for their | ||||
reviews. | ||||
This work was supported in part by the FP-7 IDEALIST project under | ||||
grant agreement number 317999. | ||||
Contributors | ||||
Adrian Farrel | ||||
Old Dog Consulting | ||||
Email: adrian@olddog.co.uk | ||||
Daniel King | ||||
Old Dog Consulting | ||||
Email: daniel@olddog.co.uk | ||||
Xian Zhang | ||||
Huawei | ||||
Email: zhang.xian@huawei.com | ||||
Cyril Margaria | ||||
Juniper Networks | ||||
Email: cmargaria@juniper.net | ||||
Qilei Wang | ||||
ZTE | ||||
Ruanjian Avenue, Nanjing, China | ||||
Email: wang.qilei@zte.com.cn | ||||
Malcolm Betts | ||||
ZTE | ||||
Email: malcolm.betts@zte.com.cn | ||||
Sergio Belotti | ||||
Alcatel-Lucent | ||||
Optics CTO | ||||
Via Trento 30 20059 Vimercate (Milano) Italy | ||||
Phone: +39 039 686 3033 | ||||
Email: sergio.belotti@alcatel-lucent.com | ||||
Yao Li | ||||
Nanjing University | ||||
Email: wsliguotou@hotmail.com | ||||
Fei Zhang | ||||
Huawei | ||||
Email: zhangfei7@huawei.com | ||||
Lei Wang | ||||
Email: wang.lei@bupt.edu.cn | ||||
Guoying Zhang | ||||
China Academy of Telecom Research | ||||
No.52 Huayuan Bei Road, Beijing, China | ||||
Email: zhangguoying@ritt.cn | ||||
Takehiro Tsuritani | ||||
KDDI R&D Laboratories Inc. | ||||
2-1-15 Ohara, Fujimino, Saitama, Japan | ||||
Email: tsuri@kddilabs.jp | ||||
Lei Liu | ||||
UC Davis, United States | ||||
Email: leiliu@ucdavis.edu | ||||
Eve Varma | ||||
Alcatel-Lucent | ||||
Phone: +1 732 239 7656 | ||||
Email: eve.varma@alcatel-lucent.com | ||||
Young Lee | ||||
Huawei | ||||
Jianrui Han | ||||
Huawei | ||||
Sharfuddin Syed | ||||
Infinera | ||||
Rajan Rao | ||||
Infinera | ||||
Marco Sosa | ||||
Infinera | ||||
Biao Lu | ||||
Infinera | ||||
Abinder Dhillon | ||||
Infinera | ||||
Felipe Jimenez Arribas | ||||
Telefonica I+D | ||||
Andrew G. Malis | ||||
Huawei | ||||
Email: agmalis@gmail.com | ||||
Huub van Helvoort | ||||
Hai Gaoming BV | ||||
The Netherlands | ||||
Email: huubatwork@gmail.com | ||||
Authors' Addresses | Authors' Addresses | |||
Oscar Gonzalez de Dios (editor) | Oscar Gonzalez de Dios (editor) | |||
Telefonica I+D | Telefonica I+D | |||
Don Ramon de la Cruz 82-84 | Ronda de la Comunicacion s/n | |||
Madrid 28045 | Madrid 28050 | |||
Spain | Spain | |||
Phone: +34913128832 | Phone: +34 91 312 96 47 | |||
Email: oscar.gonzalezdedios@telefonica.com | Email: oscar.gonzalezdedios@telefonica.com | |||
Ramon Casellas (editor) | Ramon Casellas (editor) | |||
CTTC | CTTC | |||
Av. Carl Friedrich Gauss n.7 | Av. Carl Friedrich Gauss n.7 | |||
Castelldefels Barcelona | Castelldefels Barcelona | |||
Spain | Spain | |||
Phone: +34 93 645 29 00 | Phone: +34 93 645 29 00 | |||
Email: ramon.casellas@cttc.es | Email: ramon.casellas@cttc.es | |||
Fatai Zhang | ||||
Huawei | ||||
Huawei Base, Bantian, Longgang District | ||||
Shenzhen 518129 | ||||
China | ||||
Phone: +86 755 28972912 | ||||
Email: zhangfatai@huawei.com | ||||
Xihua Fu | ||||
Stairnote | ||||
No.118, Taibai Road, Yanta District | ||||
Xi'An | ||||
China | ||||
Email: fu.xihua@stairnote.com | ||||
Daniele Ceccarelli | ||||
Ericsson | ||||
Via Calda 5 | ||||
Genova | ||||
Italy | ||||
Phone: +39 010 600 2512 | ||||
Email: daniele.ceccarelli@ericsson.com | ||||
Iftekhar Hussain | ||||
Infinera | ||||
140 Caspian Ct. | ||||
Sunnyvale, CA 94089 | ||||
United States | ||||
Phone: 408 572 5233 | ||||
Email: ihussain@infinera.com | ||||
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