draft-ietf-ccamp-gmpls-g-694-lambda-labels-08.txt   draft-ietf-ccamp-gmpls-g-694-lambda-labels-09.txt 
Network Working Group Tomohiro Otani(Ed.) Network Working Group Tomohiro Otani(Ed.)
Internet Draft KDDI Internet Draft KDDI
Updates: RFC3471 Dan Li(Ed.) Updates: RFC3471 Dan Li(Ed.)
Category: Standards Track Huawei Category: Standards Track Huawei
Expires: May 2011 November 17, 2010 Expires: June 2011 December 9, 2010
Generalized Labels for Lambda-Switching Capable Label Switching Generalized Labels for Lambda-Switching Capable Label Switching
Routers Routers
draft-ietf-ccamp-gmpls-g-694-lambda-labels-08.txt draft-ietf-ccamp-gmpls-g-694-lambda-labels-09.txt
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Abstract Abstract
Technology in the optical domain is constantly evolving and as a Technology in the optical domain is constantly evolving and as a
consequence new equipment providing lambda switching capability has consequence new equipment providing lambda switching capability has
been developed and is currently being deployed. However, [RFC3471] been developed and is currently being deployed. [RFC3471] has
has defined that a wavelength label (section 3.2.1.1) "only has defined that a wavelength label (section 3.2.1.1) "only has
significance between two neighbors" and global wavelength continuity significance between two neighbors" and global wavelength semantics
is not considered. In order to achieve interoperability in a network is not considered. In order to facilitate interoperability in a
composed of next generation lambda switch-capable equipment, this network composed of next generation lambda switch-capable equipment,
document defines a standard lambda label format, being compliant this document defines a standard lambda label format, which is
with either [G.694.1](DWDM-grid) or [G.694.2](CWDM-grid). Moreover compliant with both [G.694.1](DWDM-grid) or [G.694.2](CWDM-grid).
some consideration on how to ensure lambda continuity with RSVP-TE This document is a companion to the Generalized Multi-Protocol Label
is provided. This document is a companion to the Generalized Multi- Switching (GMPLS) signaling. It defines the label format when Lambda
Protocol Label Switching (GMPLS) signaling. It defines the label Switching is requested in an all optical network.
format when Lambda Switching is requested in an all optical network.
Conventions used in this document Conventions used in this document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119]. document are to be interpreted as described in [RFC2119].
Table of Contents Table of Contents
1. Introduction.................................................3 1. Introduction ................................................. 2
2. Assumed network model and related problem statement..........3 2. Assumed network model and related problem statement........... 3
3. Label Related Formats........................................6 3. Label Related Formats ........................................ 6
3.1. Wavelength Labels.......................................6 3.1. Wavelength Labels ....................................... 6
3.2. DWDM Wavelength Label...................................7 3.2. DWDM Wavelength Label ................................... 7
3.3. CWDM Wavelength Label...................................8 3.3. CWDM Wavelength Label ................................... 8
4. Security Considerations.....................................10 4. Security Considerations ..................................... 10
5. IANA Considerations.........................................10 5. IANA Considerations ......................................... 10
6. Acknowledgments.............................................10 6. Acknowledgments ............................................. 10
7. References..................................................10 7. References .................................................. 10
7.1. Normative References...................................10 7.1. Normative References ................................... 10
7.2. Informative References.................................11 7.2. Informative References ................................. 11
8. Author's Address............................................12 8. Author's Address ............................................ 12
9. Appendix A. DWDM Example....................................13 9. Appendix A. DWDM Example .................................... 13
10. Appendix B. CWDM Example...................................13 10. Appendix B. CWDM Example ................................... 13
1. Introduction 1. Introduction
As described in [RFC3945], Generalized MPLS (GMPLS) extends MPLS As described in [RFC3945], Generalized MPLS (GMPLS) extends MPLS
from supporting only packet (Packet Switching Capable - PSC) from supporting only packet (Packet Switching Capable - PSC)
interfaces and switching to also include support for four new interfaces and switching to also include support for four new
classes of interfaces and switching: classes of interfaces and switching:
o Layer-2 Switch Capable (L2SC) o Layer-2 Switch Capable (L2SC)
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o Lambda Switch Capable (LSC) o Lambda Switch Capable (LSC)
o Fiber-Switch Capable (FSC). o Fiber-Switch Capable (FSC).
A functional description of the extensions to MPLS signaling needed A functional description of the extensions to MPLS signaling needed
to support new classes of interfaces and switching is provided in to support new classes of interfaces and switching is provided in
[RFC3471]. [RFC3471].
This document presents details that are specific to the use of GMPLS This document presents details that are specific to the use of GMPLS
with a new generation of Lambda Switch Capable (LSC) equipment. with Lambda Switch Capable (LSC) equipment. Technologies such as
Technologies such as Reconfigurable Optical Add/Drop Multiplex (ROADM) Reconfigurable Optical Add/Drop Multiplex (ROADM) and Wavelength
and Wavelength Cross-Connect (WXC) operate at the wavelength Cross-Connect (WXC) operate at the wavelength switching level.
switching level. As such, the wavelength is important information [RFC3471] has defined that a wavelength label (section 3.2.1.1) "only
that is necessary to set up a wavelength-based LSP appropriately and has significance between two neighbors" and global wavelength
the wavelength defined in [G.694.1] or [G.694.2] is widely utilized. semantics is not considered. In order to facilitate interoperability
in a network composed of lambda switch-capable equipment, this
document defines a standard lambda label format, which is compliant
with both [G.694.1](DWDM-grid) or [G.694.2](CWDM-grid).
2. Assumed network model and related problem statement 2. Assumed network model and related problem statement
Figure 1 depicts an all-optically switched network consisting of Figure 1 depicts an all-optically switched network consisting of
different vendor's optical network domains. Vendor A's network different vendor's optical network domains. Vendor A's network
consists of ROADM or WXC, and vendor B's network consists of number consists of ROADM or WXC, and vendor B's network consists of number
of photonic cross-connect (PXC) and Dense wavelength division of photonic cross-connect (PXC) and Dense wavelength division
multiplexing (DWDM) multiplexer & demultiplexer, otherwise both multiplexing (DWDM) multiplexer & demultiplexer, otherwise both
vendors' networks might be based on the same technology. vendors' networks might be based on the same technology.
In this case, the use of standardized wavelength label information is In this case, the use of standardized wavelength label information is
quite significant to establish a wavelength-based LSP. It is also an quite significant to establish a wavelength-based LSP. It is also an
important constraint when conducting CSPF calculation for RSVP-TE important constraint when conducting CSPF calculation for use by
signaling. The way the Constrained Shortest Path First (CSPF) is Generalized Multi-Protocol Label Switching (GMPLS) RSVP-TE signaling,
[RFC3473]. The way the Constrained Shortest Path First (CSPF) is
performed is outside the scope of this document. performed is outside the scope of this document.
It is needless to say, a LSP must be appropriately provisioned It is needless to say, a LSP must be appropriately provisioned
between a selected pair of ports not only within Domain A but also between a selected pair of ports not only within Domain A but also
over multiple domains satisfying wavelength constraints. over multiple domains satisfying wavelength constraints.
Figure 2 illustrates in detail the interconnection between Domain A Figure 2 illustrates in detail the interconnection between Domain A
and Domain B. and Domain B.
| |
skipping to change at page 5, line 32 skipping to change at page 5, line 32
| S | D |=========================| D | S | | S | D |=========================| D | S |
| WDM | E | | | E | WDM | | WDM | E | | | E | WDM |
| =====| 5 | | | 8 |===== | | =====| 5 | | | 8 |===== |
| | | | | | | | | | | | | |
| +---+ | +---+ | | +---+ | +---+ |
+-------------------------------------------------------------+ +-------------------------------------------------------------+
Figure 2 Interconnecting details between two domains Figure 2 Interconnecting details between two domains
In the scenario of Figure 1, consider the setting up of a In the scenario of Figure 1, consider the setting up of a
bidirectional LSP from ingress switch 1 to egress switch 9. In order bidirectional LSP from ingress switch 1 to egress switch 9 using
to satisfy wavelength continuity constraint, a fixed wavelength GMPLS RSVP-TE. In order to satisfy wavelength continuity constraint,
(lambda 1) needs to be used in domain A and domain B. A Path message a fixed wavelength (lambda 1) needs to be used in domain A and domain
will be used for the signaling, the PATH message must contain the B. A Path message will be used for signaling. The Path message will
upstream label and a label set object; both containing the same contain the Upstream_Label object and a Label_Set object; both
lambda. The label set object is made by only one sub channel that containing the same value. The Label_Set object is made by only one
must be same as the upstream label. The path setup will continue sub channel that must be same as the Upstream_Label object. The Path
downstream to switch 9 by configuring each lambda switch based on the setup will continue downstream to switch 9 by configuring each lambda
wavelength label. This label allows the correct switching of lambda switch based on the wavelength label. If a node has a tunable
switches and the label contents needs to be used over the inter- wavelength transponder, the tuning wavelength is considered as a part
domain. As same above, the path setup will continue downstream to of wavelength switching operation.
switch 9 by configuring lambda switch based on multiple wavelength
labels. If the node has a tunable wavelength transponder, the tuning
wavelength is considered as a part of wavelength switching operation.
Not using a standardized label would add undue burden on the operator Not using a standardized label would add undue burden on the operator
to enforce policy as each manufacturer may decide on a different to enforce policy as each manufacturer may decide on a different
representation and therefore each domain may have its own label representation and therefore each domain may have its own label
formats. Moreover, manual provisioning may lead to misconfiguration formats. Moreover, manual provisioning may lead to misconfiguration
if domain-specific labels are used. if domain-specific labels are used.
Therefore, a wavelength label should be standardized in order to Therefore, a wavelength label should be standardized in order to
allow interoperability between multiple domains; otherwise allow interoperability between multiple domains; otherwise
appropriate existing labels are identified in support of wavelength appropriate existing labels are identified in support of wavelength
availability. As identical wavelength information, the ITU-T availability. As identical wavelength information, the ITU-T
frequency grid specified in [G.694.1] for Dense WDM (DWDM) and frequency grid specified in [G.694.1] for Dense WDM (DWDM) and
wavelength information in [G.694.2] for Coarse WDM (CWDM) are used by wavelength information in [G.694.2] for Coarse WDM (CWDM) are used by
LSRs and should be followed as a wavelength label. LSRs and should be followed as a wavelength label.
3. Label Related Formats 3. Label Related Formats
To deal with the widening scope of MPLS into the optical and time To deal with the widening scope of MPLS into the optical and time
domains, several new forms of "label" have been defined in [RFC3471]. domains, several new forms of "label" have been defined in [RFC3471].
This section contains clarifications for the Wavelength label based This section contains a definition of a Wavelength label based on
on [G.694.1] or [G.694.2] and Label Set definition specific for LSC [G.694.1] or [G.694.2] for use by LSC LSRs.
LSRs.
3.1. Wavelength Labels 3.1. Wavelength Labels
In section 3.2.1.1 of [RFC3471], a Wavelength label is defined to In section 3.2.1.1 of [RFC3471], a Wavelength label is defined to
have significance between two neighbors, and the receiver may need to have significance between two neighbors, and the receiver may need to
convert the received value into a value that has local significance. convert the received value into a value that has local significance.
LSC equipment uses multiple wavelengths controlled by a single LSC equipment uses multiple wavelengths controlled by a single
control channel. In such case, the label indicates the wavelength to control channel. In a case, the label indicates the wavelength to be
be used for the LSP. This document proposes to standardize the used for the LSP. This document defines a standardize wavelength
wavelength label. As an example of wavelength values, the reader is label format. As an example of wavelength values, the reader is
referred to [G.694.1] which lists the frequencies from the ITU-T DWDM referred to [G.694.1] which lists the frequencies from the ITU-T DWDM
frequency grid. The same can be done for CWDM technology by using frequency grid. The same can be done for CWDM technology by using
the wavelength defined in [G.694.2]. In that sense, we can call the wavelength defined in [G.694.2].
wavelength labels.
Since the ITU-T DWDM grid is based on nominal central frequencies, we Since the ITU-T DWDM grid is based on nominal central frequencies, we
need to indicate the appropriate table, the channel spacing in the need to indicate the appropriate table, the channel spacing in the
grid and a value n that allows the calculation of the frequency. That grid and a value n that allows the calculation of the frequency. That
value can be positive or negative. value can be positive or negative.
The frequency is calculated as such in [G.694.1]: The frequency is calculated as such in [G.694.1]:
Frequency (THz) = 193.1 THz + n * channel spacing (THz) Frequency (THz) = 193.1 THz + n * channel spacing (THz)
, where n is a two's-complement integer (positive, negative or 0) and Where "n" is a two's-complement integer (positive, negative or 0) and
channel spacing is defined to be 0.0125, 0.025, 0.05 or 0.1 THz. When "channel spacing" is defined to be 0.0125, 0.025, 0.05 or 0.1 THz.
wider channel spacing such as 0.2 THz is utilized, the combination of When wider channel spacing such as 0.2 THz is utilized, the
narrower channel spacing and the value n can provide proper frequency combination of narrower channel spacing and the value "n" can provide
with that channel spacing. Channel spacing is not utilized to proper frequency with that channel spacing. Channel spacing is not
indicate the LSR capability but only to specify a frequency in utilized to indicate the LSR capability but only to specify a
signaling. frequency in signaling.
For the other example of the case of the ITU-T CWDM grid, the spacing For the other example of the case of the ITU-T CWDM grid, the spacing
between different channels was defined to be 20nm, so we need to pass between different channels was defined to be 20nm, so we need to pass
the wavelength value in nm in this case. Examples of CWDM wavelengths the wavelength value in nanometers(nm) in this case. Examples of CWDM
are 1471, 1491, etc. nm. wavelengths are 1471, 1491, etc. nm.
The wavelength is calculated as follows The wavelength is calculated as follows
Wavelength (nm) = 1471 nm + n * 20 nm Wavelength (nm) = 1471 nm + n * 20 nm
, where n is a two's-complement integer (positive, negative or 0). Where "n" is a two's-complement integer (positive, negative or 0).
The grids listed in [G.694.1] and [G.694.2] are not numbered and The grids listed in [G.694.1] and [G.694.2] are not numbered and
change with the changing frequency spacing as technology advances, so change with the changing frequency spacing as technology advances, so
an index is not appropriate in this case. an index is not appropriate in this case.
3.2. DWDM Wavelength Label 3.2. DWDM Wavelength Label
For the case of DWDM, the information carried in a Wavelength label For the case of lambda switching (LSC) of DWDM, the information
is: carried in a Wavelength label is:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Grid | C.S | Identifier | n | |Grid | C.S | Identifier | n |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(1) Grid: 3 bits (1) Grid: 3 bits
The value for grid is set to 1 for ITU-T DWDM Grid as defined in The value for grid is set to 1 for ITU-T DWDM Grid as defined in
skipping to change at page 8, line 42 skipping to change at page 8, line 42
corresponding LSP. corresponding LSP.
(4) n: 16 bits (4) n: 16 bits
n is a two's-complement integer to take either a negative, zero or a n is a two's-complement integer to take either a negative, zero or a
positive value. The value used to compute the frequency as shown positive value. The value used to compute the frequency as shown
above. above.
3.3. CWDM Wavelength Label 3.3. CWDM Wavelength Label
For the case of CWDM, the information carried in a Wavelength label For the case of lambda switching (LSC) of CWDM, the information
is: carried in a Wavelength label is:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Grid | C.S | Identifier | n | |Grid | C.S | Identifier | n |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The structure of the label in the case of CWDM is the same as that of The structure of the label in the case of CWDM is the same as that of
DWDM case. DWDM case.
skipping to change at page 10, line 25 skipping to change at page 10, line 25
n is a two's-complement integer. The value used to compute the n is a two's-complement integer. The value used to compute the
wavelength as shown above. wavelength as shown above.
We do not need to define a new type as the information stored is We do not need to define a new type as the information stored is
either a port label or a wavelength label. Only the wavelength label either a port label or a wavelength label. Only the wavelength label
as above needs to be defined. as above needs to be defined.
4. Security Considerations 4. Security Considerations
This document introduces no new security considerations to [RFC3473]. This document introduces no new security considerations to [RFC3473].
GMPLS security is described in section 11 of [RFC3471] and refers to For a general discussion on MPLS and GMPLS related security issues,
[RFC3209] for RSVP-TE. see the MPLS/GMPLS security framework [RFC5920].
5. IANA Considerations 5. IANA Considerations
This document has no actions for IANA. This document has no actions for IANA.
6. Acknowledgments 6. Acknowledgments
The authors would like to thank Adrian Farrel, Lou Berger, Lawrence The authors would like to thank Adrian Farrel, Lou Berger, Lawrence
Mao, Zafar Ali and Daniele Ceccarelli for the discussion and their Mao, Zafar Ali and Daniele Ceccarelli for the discussion and their
comments. comments.
skipping to change at page 12, line 5 skipping to change at page 11, line 24
(GMPLS) Architecture", RFC 3945, October 2004. (GMPLS) Architecture", RFC 3945, October 2004.
7.2. Informative References 7.2. Informative References
[G.694.1] ITU-T Recommendation G.694.1, "Spectral grids for WDM [G.694.1] ITU-T Recommendation G.694.1, "Spectral grids for WDM
applications: DWDM frequency grid", June 2002. applications: DWDM frequency grid", June 2002.
[G.694.2] ITU-T Recommendation G.694.2, "Spectral grids for WDM [G.694.2] ITU-T Recommendation G.694.2, "Spectral grids for WDM
applications: CWDM wavelength grid", December 2003. applications: CWDM wavelength grid", December 2003.
[RFC5920] Fang, L., "Security Framework for MPLS and GMPLS
Networks", RFC 5920, July 2010.
8. Author's Address 8. Author's Address
Tomohiro Otani Tomohiro Otani
KDDI Corporation KDDI Corporation
2-3-2 Nishishinjuku Shinjuku-ku 2-3-2 Nishishinjuku Shinjuku-ku
Tokyo, 163-8003, Japan Tokyo, 163-8003, Japan
Phone: +81-3-3347-6006 Phone: +81-3-3347-6006
Email: tm-otani@kddi.com Email: tm-otani@kddi.com
Richard Rabbat Richard Rabbat
skipping to change at page 13, line 40 skipping to change at page 13, line 40
Frequency (THz) = 193.1 THz + n * channel spacing (THz) Frequency (THz) = 193.1 THz + n * channel spacing (THz)
193.35 (THz) = 193.1 (THz) + n* 0.05 (THz) 193.35 (THz) = 193.1 (THz) + n* 0.05 (THz)
n = (193.35-193.1)/0.05 = 5 n = (193.35-193.1)/0.05 = 5
10. Appendix B. CWDM Example 10. Appendix B. CWDM Example
The network displayed in figure 1 can be used also to display an The network displayed in figure 1 can be used also to display an
example of signaling using the Wavelength Label in a CWDM environment. example of signaling using the Wavelength Label in a CWDM
environment.
This time the signaling of an LSP from Node 4 to Node 7 is considered. This time the signaling of an LSP from Node 4 to Node 7 is
Such LSP exploits the CWDM ITU-T grid with a 20nm channel spacing and considered. Such LSP exploits the CWDM ITU-T grid with a 20nm
is to established using wavelength equal to 1331 nm. channel spacing and is to established using wavelength equal to 1331
nm.
Node 4 signals the LSP via a Path message including a Wavelength Node 4 signals the LSP via a Path message including a Wavelength
Label structured as defined in section 4.3: Label structured as defined in section 4.3:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Grid | C.S | Identifier | n | |Grid | C.S | Identifier | n |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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