One document matched: draft-ietf-ccamp-gmpls-g-694-lambda-labels-04.txt
Differences from draft-ietf-ccamp-gmpls-g-694-lambda-labels-03.txt
INTERNET DRAFT Tomohiro Otani
Updates: RFC 3471 KDDI
Intended status: standard track (Editor)
Expires: September 23, 2009 March 23, 2009
Generalized Labels for G.694 Lambda-Switching Capable Label Switching
Routers
Document: draft-ietf-ccamp-gmpls-g-694-lambda-labels-04.txt
Status of this Memo
This Internet-Draft is submitted to IETF in full conformance with
the provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet-
Drafts.
Internet-Drafts are draft documents valid for a maximum of six
months and may be updated, replaced, or obsoleted by other
documents at any time. It is inappropriate to use Internet-Drafts
as reference material or to cite them other than as "work in
progress."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt.
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html.
This Internet-Draft will expire on September 23, 2009.
Abstract
Technology in the optical domain is constantly evolving and as a
consequence new equipment providing lambda switching capability has
been developed and is currently being deployed. However, RFC 3471 has
defined that a wavelength label (section 3.2.1.1) "only has
significance between two neighbors" and global wavelength continuity
is not considered. In order to achieve interoperability in a network
composed of next generation lambda switch-capable equipment, this
document defines a standard lambda label format, being compliant with
ITU-T G.694. Moreover some consideration on how to ensure lambda
continuity with RSVP-TE is provided. This document is a companion to
the Generalized Multi-Protocol Label Switching (GMPLS) signaling. It
defines the label format when Lambda Switching is requested in an all
optical network.
T. Otani et al. Standard track - Expires Sept. 23, 2009 [Page 1]
Internet Drafts March 2009
Table of Contents
Abstract........................................................... 1
1. Introduction.................................................... 2
2. Conventions used in this document............................... 2
3. Assumed network model and related problem statement............. 2
4. Label Related Formats........................................... 5
5. Security Considerations......................................... 8
6. IANA Considerations............................................. 9
7. Acknowledgement................................................ 10
8. References..................................................... 11
8.1. Normative References......................................... 11
8.2. Informative References....................................... 11
Appendix A. DWDM Example.......................................... 11
Appendix B. CWDM Example.......................................... 12
Authors' address.................................................. 13
Intellectual property and Copyright Statement..................... 14
1. Introduction
As described in [RFC3945], Generalized MPLS (GMPLS) extends MPLS from
supporting only packet (Packet Switching Capable - PSC) interfaces
and switching to also include support for four new classes of
interfaces and switching:
o Layer-2 Switch Capable (L2SC)
o Time-Division Multiplex (TDM)
o Lambda Switch Capable (LSC)
o Fiber-Switch Capable (FSC).
A functional description of the extensions to MPLS signaling needed
to support new classes of interfaces and switching is provided in
[RFC3471].
This document presents details that are specific to the use of GMPLS
with a new generation of Lambda Switch Capable (LSC) equipment.
Technologies such as Reconfigurable Optical Add/Drop Multiplex
(ROADM) and Wavelength Cross-Connect (WXC) operate at the wavelength
switching level. As such, the wavelength is important information
that is necessary to set up a wavelength-based LSP appropriately and
the wavelength defined in [G.694] is widely utilized.
2. Conventions used in this document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC-2119 [RFC2119].
3. Assumed network model and related problem statement
T. Otani et al. Standard track - Expires Sept. 23, 2009 [Page 2]
Internet Drafts March 2009
Figure 1 depicts an all-optically switched network consisting of
different vendor's optical network domains. Vendor A's network
consists of ROADM or WXC, and vendor B's network consists of PXCs and
DWDMs, otherwise both vendors' networks might be based on the same
technology.
In this case, the use of standardized wavelength label information is
quite significant to establish a wavelength-based LSP. It is also an
important constraint when conducting CSPF calculation for RSVP-TE
signaling. The way the CSPF is performed is outside the scope of this
document, but defined in [GMPLS-CSPF].
It is needless to say, a LSP must be appropriately provisioned
between a selected pair of ports not only within Domain A but also
over multiple domains satisfying wavelength constraints.
Figure 2 illustrates in detail the interconnection between Domain A
and Domain B.
|
Domain A (or Vendor A) | Domain B (or Vendor B)
|
Node-1 Node-2 | Node-6 Node-7
+--------+ +--------+ | +-------+ +-+ +-+ +-------+
| ROADM | | ROADM +---|------+ PXC +-+D| |D+-+ PXC |
| or WXC +========+ or WXC +---|------+ +-+W+=====+W+-+ |
| (LSC) | | (LSC) +---|------+ (LSC) +-+D| |D+-+ (LSC) |
+--------+ +--------+ | | +-|M| |M+-+ |
|| || | +++++++++ +-+ +-+ +++++++++
|| Node-3 || | ||||||| |||||||
|| +--------+ || | +++++++++ +++++++++
||===| WXC +===|| | | DWDM | | DWDM |
| (LSC) | | +--++---+ +--++---+
||===+ +===|| | || ||
|| +--------+ || | +--++---+ +--++---+
|| || | | DWDM | | DWDM |
+--------+ +--------+ | +++++++++ +++++++++
| ROADM | | ROADM | | ||||||| |||||||
| or WXC +========+ or WXC +=+ | +-+ +++++++++ +-+ +-+ +++++++++
| (LSC) | | (LSC) | | | |D|-| PXC +-+D| |D+-+ PXC |
+--------+ +--------+ +=|==+W|-| +-+W+=====+W+-+ |
Node-4 Node-5 | |D|-| (LSC) +-+D| |D+-+ (LSC) |
| |M|-| +-+M| |M+-+ |
| +-+ +-------+ +-+ +-+ +-------+
| Node-8 Node-9
Figure 1 Wavelength-based network model.
+-------------------------------------------------------------+
| Domain A | Domain B |
T. Otani et al. Standard track - Expires Sept. 23, 2009 [Page 3]
Internet Drafts March 2009
| | |
| +---+ lambda 1 | +---+ |
| | |---------------|---------| | |
| WDM | N | lambda 2 | | N | WDM |
| =====| O |---------------|---------| O |===== |
| O | D | . | | D | O |
| T WDM | E | . | | E | WDM T |
| H =====| 2 | lambda n | | 6 |===== H |
| E | |---------------|---------| | E |
| R +---+ | +---+ R |
| | |
| N +---+ | +---+ N |
| O | | | | | O |
| D WDM | N | | | N | WDM D |
| E =====| O | WDM | | O |===== E |
| S | D |=========================| D | S |
| WDM | E | | | E | WDM |
| =====| 5 | | | 8 |===== |
| | | | | | |
| +---+ | +---+ |
+-------------------------------------------------------------+
Figure 2 Interconnecting details between two domains.
In the scenario of Figure 1, consider the setting up of a
bidirectional LSP from ingress switch 1 to egress switch 9. In order
to satisfy wavelength continuity constraint, a fixed wavelength
(lambda 1) needs to be used in domain A and domain B. A Path message
will be used for the signaling, the PATH message must contain the
upstream label and a label set object; both containing the same
lambda. The label set object is made by only one sub channel that
must be same as the upstream label. The path setup will continue
downstream to switch 9 by configuring each lambda switch based on the
wavelength label. This label allows the correct switching of lambda
switches and the label contents needs to be used over the inter-
domain. As same above, the path setup will continue downstream to
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
to enforce policy as each manufacturer may decide on a different
representation and therefore each domain may have its own label
formats. Moreover, manual provisioning may lead to misconfiguration
if domain-specific labels are used.
Therefore, a wavelength label should be standardized in order to
allow interoperability between multiple domains; otherwise
appropriate existing labels are identified in support of wavelength
availability. As identical wavelength information, the ITU-T
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
LSRs and should be followed as a wavelength label.
T. Otani et al. Standard track - Expires Sept. 23, 2009 [Page 4]
Internet Drafts March 2009
4. Label Related Formats
To deal with the widening scope of MPLS into the optical and time
domains, several new forms of "label" have been defined in [RFC3471].
This section contains clarifications for the Wavelength label based
on [G.694] and Label Set definition specific for LSC LSRs.
4.1 Wavelength Labels
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
convert the received value into a value that has local significance.
LSC equipment uses multiple wavelengths controlled by a single
control channel. In such case, the label indicates the wavelength to
be used for the LSP. This document proposes to standardize the
wavelength label. As an example of wavelength values, the reader is
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
the wavelength defined in [G.694.2]. In that sense, we can call G.694
wavelength labels.
Since the ITU-T DWDM grid is based on nominal central frequencies, we
need to indicate the appropriate table, the channel spacing in the
grid and a value n that allows the calculation of the frequency.
That value can be positive or negative.
The frequency is calculated as such in [G.694.1]:
Frequency (THz) = 193.1 THz + n * channel spacing (THz)
, 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
wider channel spacing such as 0.2 THz is utilized, the combination of
narrower channel spacing and the value n can provide proper frequency
with that channel spacing. Channel spacing is not utilized to
indicate the LSR capability but only to specify a frequency in
signaling.
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
the wavelength value in nm in this case. Examples of CWDM
wavelengths are 1471, 1491, etc. nm.
The wavelength is calculated as follows
Wavelength (nm) = 1471 nm + n * 20 nm
, where n is a two's-complement integer (positive, negative or 0).The
tables listed in [G.694.1] and [G.694.2] are not numbered and change
with the changing frequency spacing as technology advances, so an
index is not appropriate in this case.
T. Otani et al. Standard track - Expires Sept. 23, 2009 [Page 5]
Internet Drafts March 2009
4.2 DWDM Wavelength Label
For the case of DWDM, the information carried in a Wavelength label
is:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Grid | C.S | Reserved | n |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(1) Grid: 3 bits
The value for grid is set to 1 for ITU-T DWDM Grid as defined in
[G.694.1].
+----------+---------+
| Grid | Value |
+----------+---------+
| Reserved | 0 |
+----------+---------+
|ITU-T DWDM| 1 |
+----------+---------+
|ITU-T CWDM| 2 |
+----------+---------+
|Future use| 3 - 7 |
+----------+---------+
(2) C.S.(channel spacing): 4 bits
DWDM channel spacing is defined as follows.
+----------+---------+
| C.S(GHz) | Value |
+----------+---------+
| Reserved | 0 |
+----------+---------+
| 100 | 1 |
+----------+---------+
| 50 | 2 |
+----------+---------+
| 25 | 3 |
+----------+---------+
| 12.5 | 4 |
+----------+---------+
|Future use| 5 - 15 |
+----------+---------+
(3) n: 16 bits
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
above.
T. Otani et al. Standard track - Expires Sept. 23, 2009 [Page 6]
Internet Drafts March 2009
4.3 CWDM Wavelength Label
For the case of CWDM, the information carried in a Wavelength label
is:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Grid | C.S | Reserved | n |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The structure of the label in the case of CWDM is the same as that of
DWDM case.
(1) Grid: 3 bits
The value for grid is set to 2 for ITU-T CWDM Grid as defined in
[G.694.2].
+----------+---------+
| Grid | Value |
+----------+---------+
| Reserved | 0 |
+----------+---------+
|ITU-T DWDM| 1 |
+----------+---------+
|ITU-T CWDM| 2 |
+----------+---------+
|Future use| 3 - 7 |
+----------+---------+
(2) C.S.(channel spacing): 4 bits
CWDM channel spacing is defined as follows.
+----------+---------+
| C.S(nm) | Value |
+----------+---------+
| Reserved | 0 |
+----------+---------+
| 20 | 1 |
+----------+---------+
|Future use| 2 - 15 |
+----------+---------+
(3) n: 16 bits
n is a two's-complement integer. The value used to compute the
wavelength as shown above.
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
as above needs to be defined.
T. Otani et al. Standard track - Expires Sept. 23, 2009 [Page 7]
Internet Drafts March 2009
5. Security Considerations
This document introduces no new security considerations to [RFC3473].
GMPLS security is described in section 11 of [RFC3471] and refers to
[RFC3209] for RSVP-TE.
T. Otani et al. Standard track - Expires Sept. 23, 2009 [Page 8]
Internet Drafts March 2009
6. IANA Considerations
This document has no actions for IANA.
T. Otani et al. Standard track - Expires Sept. 23, 2009 [Page 9]
Internet Drafts March 2009
7. Acknowledgement
The authors would like to thank Adrian Farrel, Lawrence Mao, Zafar
Ali, Dan Li and Daniele Ceccarelli for the discussion and their
comments.
T. Otani et al. Standard track - Expires Sept. 23, 2009 [Page 10]
Internet Drafts March 2009
8. References
8.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,
and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP Tunnels", RFC
3209, December 2001.
[RFC3471] Berger, L., "Generalized Multi-Protocol Label Switching
(MPLS) Signaling Functional Description", RFC 3471, January 2003.
[RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching
(MPLS) Signaling - Resource ReserVation Protocol Traffic Engineering
(RSVP-TE) Extensions", RFC 3473, January 2003.
[RFC3945] Mannie, E., Ed., "Generalized Multiprotocol Label Switching
(GMPLS) Architecture", RFC 3945, October 2004.
8.2. Informative References
[GMPLS-CSPF] Otani, T., et al, "Considering Generalized Multiprotocol
Label Switching Traffic Engineering Attributes During Path
Computation", draft-otani-ccamp-gmpls-cspf-constraints-08.txt, Feb.
2008.
[G.694.1] ITU-T Recommendation G.694.1, "Spectral grids for WDM
applications: DWDM frequency grid", June 2002.
[G.694.2] ITU-T Recommendation G.694.2, "Spectral grids for WDM
applications: CWDM wavelength grid", December 2003.
Appendix A. DWDM Example
Considering the network displayed in figure 1 it is possible to show
an example of LSP set up using the lambda labels.
Node 1 receives the request for establishing an LSP from itself to
Node 9. The ITU-T grid to be used is the DWDM one, the channel
spacing is 50Ghz and the wavelength to be used is 193,35 THz.
Node 1 signals the LSP via a Path message including a Wavelength
Label structured as defined in section 4.2:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Grid | C.S | Reserved | n |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
T. Otani et al. Standard track - Expires Sept. 23, 2009 [Page 11]
Internet Drafts March 2009
Where:
Grid = 1 : ITU-T DWDM grid
C.S. = 2 : 50 GHz channel spacing
n = 5 :
Frequency (THz) = 193.1 THz + n * channel spacing (THz)
193.35 (THz) = 193.1 (THz) + n* 0.05 (THz)
n = (193.35-193.1)/0.05 = 5
Appendix B. CWDM Example
The network displayed in figure 1 can be used also to display an
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. Such LSP exploits the CWDM ITU-T grid with a 20nm
channel spacing and is to established using wavelength equal to 1331
nm.
Node 4 signals the LSP via a Path message including a Wavelength
Label structured as defined in section 4.3:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Grid | C.S | Reserved | n |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Where:
Grid = 2 : ITU-T CWDM grid
C.S. = 1 : 20 nm channel spacing
n = -7 :
Wavelength (nm) = 1471 nm + n * 20 nm
1331 (nm) = 1471 (nm) + n * 20 nm
n = (1331-1471)/20 = -7
T. Otani et al. Standard track - Expires Sept. 23, 2009 [Page 12]
Internet Drafts March 2009
Authors' address
Tomohiro Otani
KDDI Corporation
2-3-2 Nishishinjuku Shinjuku-ku Tokyo, 163-8003, Japan
Phone: +81-3-3347-6006
Email: tm-otani@kddi.com
Richard Rabbat
Google, Inc.
1600 Amphitheatre Pkwy
Mountain View, CA 94043
Email: rabbat@alum.mit.edu
Sidney Shiba
Email: sidney.shiba@yahoo.com
Hongxiang Guo
Email: hongxiang.guo@gmail.com
Keiji Miyazaki
Fujitsu Laboratories Ltd
4-1-1 Kotanaka Nakahara-ku, Kawasaki Kanagawa, 211-8588, Japan
Phone: +81-44-754-2765
Email: miyazaki.keiji@jp.fujitsu.com
Diego Caviglia
Ericsson
16153 Genova Cornigliano, ITALY
Phone: +390106003736
Email: diego.caviglia@ericsson.com
T. Otani et al. Standard track - Expires Sept. 23, 2009 [Page 13]
Internet Drafts March 2009
Full Copyright Statement
Copyright (c) 2009 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents in effect on the date of
publication of this document
(http://trustee.ietf.org/license-info). Please review these documents
carefully, as they describe your rights and restrictions with
respect to this document.
All IETF Documents and the information contained therein are provided
on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE
REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE
IETF TRUST AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL
WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY
WARRANTY THAT THE USE OF THE INFORMATION THEREIN WILL NOT INFRINGE
ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS
FOR A PARTICULAR PURPOSE.
Intellectual Property
The IETF Trust takes no position regarding the validity or scope of
any Intellectual Property Rights or other rights that might be
claimed to pertain to the implementation or use of the technology
described in any IETF Document or the extent to which any license
under such rights might or might not be available; nor does it
represent that it has made any independent effort to identify any
such rights.
Copies of Intellectual Property disclosures made to the IETF
Secretariat and any assurances of licenses to be made available, or
the result of an attempt made to obtain a general license or
permission for the use of such proprietary rights by implementers or
users of this specification can be obtained from the IETF on-line IPR
repository at http://www.ietf.org/ipr
The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement
any standard or specification contained in an IETF Document. Please
address the information to the IETF at ietf-ipr@ietf.org.
The definitive version of an IETF Document is that published by, or
under the auspices of, the IETF. Versions of IETF Documents that are
published by third parties, including those that are translated into
other languages, should not be considered to be definitive versions
of IETF Documents. The definitive version of these Legal Provisions
is that published by, or under the auspices of, the IETF. Versions of
these Legal Provisions that are published by third parties, including
T. Otani et al. Standard track - Expires Sept. 23, 2009 [Page 14]
Internet Drafts March 2009
those that are translated into other languages, should not be
considered to be definitive versions of these Legal Provisions.
For the avoidance of doubt, each Contributor to the IETF Standards
Process licenses each Contribution that he or she makes as part of
the IETF Standards Process to the IETF Trust pursuant to the
provisions of RFC 5378. No language to the contrary, or terms,
conditions or rights that differ from or are inconsistent with the
rights and licenses granted under RFC 5378, shall have any effect and
shall be null and void, whether published or posted by such
Contributor, or included with or in such Contribution.
T. Otani et al. Standard track - Expires Sept. 23, 2009 [Page 15]
| PAFTECH AB 2003-2026 | 2026-04-22 18:00:02 |