Internet DRAFT - draft-wang-ccamp-gmpls-flexigrid-framework
draft-wang-ccamp-gmpls-flexigrid-framework
Network Working Group Qilei Wang
Internet-Draft Xihua Fu
Intended status: Standards Track ZTE Corporation
Expires: September 12, 2012 Mar 11, 2012
Framework for GMPLS Control of Flexible Grid Network
draft-wang-ccamp-gmpls-flexigrid-framework-01.txt
Abstract
This document provides a framework for applying Generalized Multi-
Protocol Label Switching (GMPLS) and the Path Computation Element
(PCE) architecture to control the flexible grid network base on the
Wavelength Switched Optical Networks (WSONs). GMPLS control of WSON
which is addressed in RFC6163 is out of the scope of this document.
This document focuses on the topological elements changes and new
path selection constraints that flexible grid technology takes.
Impairments related technology is not covered in this document.
Status of this Memo
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This Internet-Draft will expire on September 12, 2012.
Copyright Notice
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to this document. Code Components extracted from this document must
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Conventions used in this document . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Flexible Grid Networks . . . . . . . . . . . . . . . . . . . . 4
3.1. Flexible Grid Network . . . . . . . . . . . . . . . . . . 4
3.2. WDM Links . . . . . . . . . . . . . . . . . . . . . . . . 5
3.3. Optical Transmitters and Receivers . . . . . . . . . . . . 5
3.4. Optical Signals in Flexible Grid Network . . . . . . . . . 6
3.4.1. Optical Tributary Signals . . . . . . . . . . . . . . 7
3.4.2. WSON Signal Characteristics . . . . . . . . . . . . . 7
3.5. ROADMs, OXCs, Splitters, Combiners, and FOADMs . . . . . . 7
3.5.1. Reconfigurable Optical Add/Drop Multiplexers, OXCs
and FOADM . . . . . . . . . . . . . . . . . . . . . . 8
3.5.2. Splitters and Combiners . . . . . . . . . . . . . . . 9
3.6. Electro-Optical Systems . . . . . . . . . . . . . . . . . 9
4. Routing and wavelength Assignment in flexible grid network . . 10
5. GMPLS and PCE Control . . . . . . . . . . . . . . . . . . . . 11
5.1. Extension to GMPLS Signaling . . . . . . . . . . . . . . . 11
5.2. Extension to GMPLS Routing . . . . . . . . . . . . . . . . 11
5.2.1. Available Wavelength Range . . . . . . . . . . . . . . 12
5.2.2. Port Label Restriction . . . . . . . . . . . . . . . . 12
5.3. Optical Path Computation and Implications for PCE . . . . 13
5.3.1. Optical Path Constraints and Electro-Optical
Element Signal Compatibility . . . . . . . . . . . . . 13
5.3.2. Discovery of RWA-Capable PCEs . . . . . . . . . . . . 14
5.3.3. Use of GCO . . . . . . . . . . . . . . . . . . . . . . 14
6. Security Considerations . . . . . . . . . . . . . . . . . . . 14
7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 14
7.1. Normative References . . . . . . . . . . . . . . . . . . . 14
7.2. Informative References . . . . . . . . . . . . . . . . . . 14
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 15
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1. Introduction
Flexible grid is a new DWDM application which is defined in the
newest version of [G.694.1]. Compared to traditional fixed grid
network, a flexible grid network can select its data channels with
arbitrary slot width, and mainly be used to setup path with higher
bitrates (e.g., 100G or 400G or higher). whereas traditional fixed
grid DWDM technology always uses fixed slot width and is mainly used
to setup path with lower bitrates signals. Flexible grid network is
also a WDM-based optical network in which switching is performed
selectively based on the center wavelength of optical channels ,which
means flexible grid channels can be represented as a lambda capable
switching LSP by center wavelength and slot width from the control
plane perspective.
Wavelength Switched Optical Network (WSON) which is addressed in
[RFC6163] is the application of Generalized Multi-Protocol Label
Switching (GMPLS) [RFC3945] operation to traditional fixed grid WDM
network. As flexible grid network is a new WDM network which evolves
from traditional fixed grid network, GMPLS also can be used to
operate flexible grid network. Similar to fixed grid network,
flexible grid network is also constructed from subsystems that
include Wavelength Division Multiplexing (WDM) links, tunable
transmitters and receivers, Reconfigurable Optical Add/Drop
Multiplexers (ROADMs), wavelength converters, and electro-optical
network elements, which have flexible grid characteristics. WSON
specific descriptions are addressed in [RFC6163] and are out of the
scope of this document. People who are interested in this document
are supposed to be familiar with [RFC6163].
This document provides a framework for applying the GMPLS
architecture and protocols [RFC3945] and the PCE architecture
[RFC4655] to the control and operation of flexible grid networks. In
order to help GMPLS and PCE use for flexible grid network, this
document first focuses on the subsystems and characteristics
information that flexible grid network brings and then modeled the
characteristics information by GMPLS and PCE. This work will help
facilitate the development of protocol solution models and protocol
extensions within the GMPLS and PCE protocol families.
1.1. 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 [RFC2119].
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2. Terminology
o Flexible Grid: a new WDM technology different from traditional
fixed grid DWDM technology defined with the aim of allowing
flexible optical spectrum management, in which the Slot Width of
the wavelength ranges allocated to different channels are flexible
(variable sized).
o Wavelength Range: [RFC6163] gives a description of this
terminology.Wavelength range given a mapping between labels and
the ITU-T grids, each range could be expressed in terms of a
tuple, (lambda1, lambda2) or (freq1, freq2), where the lambdas or
frequencies can be represented by 32-bit integers.
o Frequency slot: The definition in [G.694.1] is shown here. The
frequency range allocated to a channel and unavailable to other
channels within a flexible grid. A frequency slot is defined by
its nominal central frequency and its slot width.
o Slot width: The full width of a frequency slot in a flexible grid.
3. Flexible Grid Networks
Wavelength Switched Optical Network (WSON) related documents cover
the constraints information that needs to be considered in the
process of path computation. Emergence of flexible grid DWDM
technology raises some new characteristics and these new
characteristics should be modeled by GMPLS and PCE from the
perspective of contral plane in order to help path computation. This
document mainly focus on the flexible grid subsystems'
characteristics information and constraints information that impact
the flexible grid path selection process (i.e. wavelength selection).
Subsequent sections review and model flexible grid characteristics
that need to be emphasized by control plane and these sections follow
the sequence of the section addressed in [RFC6163].
3.1. Flexible Grid Network
As described in the newest version of [G.694.1], flexible DWDM grid
allows frequency slots have a nominal central frequency (in THz)
defined by: 193.1 + n x 0.00625 where n is a positive or negative
integer including 0 and 0.00625 is the nominal central frequency
granularity in THz and a slot width defined by: 12.5 x m where m is a
positive integerand 12.5 is the slot width granularity in GHz. Any
combination of frequency slots is allowed as long as no two frequency
slots overlap.
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3.2. WDM Links
According to the review of the newest version of [G.694.1], the
nominal central frequencies for the flexible grid network are defined
with a granularity of 6.25 GHz and the frequency slot widths are
defined as a multiple of 12.5 GHz. A label representation which
includes the information of central frequency and slot width is
needed to provides a common label format to be used in signaling
optical paths. The flexible grid labels can also be used to describe
WDM links, ROADM ports, and wavelength converters for the purposes of
path selection.
As described in section 3.1 of [RFC 6163], putting WDM over different
types of fiber require significant engineering and a fairly limited
range of wavelengths. Parameters that include wavelength range and
channel spacing is needed to perform basic, impairment-unaware
modeling of a WDM link.
o Wavelength range: wavelength range can be used to give a mapping
between labels and the flexible grid and each range could be
expressed in terms of a tuple,(lambda1, lambda2) or (freq1,
freq2). Maybe new label representation is needed to describe
wavelength range.
o Channel Spacing: since flexible grid can provide a granularity of
6.25GHz, this new channel spacing value needs to be added.
In addition to the wavelength range and channel spacing, indication
SHOULD also be added to indicate the link support flexible grid DWDM
technology.
As indicated in [RFC6163], this information is relatively statically
for a particular link as changes to these properties generally
require hardware upgrades. Such information may be used locally
during wavelength assignment via signaling.
3.3. Optical Transmitters and Receivers
Similar to WSON, flexible grid WDM optical systems make use of
coupled optical transmitters and receivers to setup LSC LSP. In the
case of an optical network without wavelength converters, an optical
path needs to be routed from source transmitter to sink receiver and
must use a single wavelength. Flexible grid brings some new
characteristics to transmitters and receivers compare to traditional
fixed grid characteristics like "Tunable", "Tuning range", "Tuning
time" and "Spectral characteristics and stability" which are
addressed in [RFC6163] for fixed grid. This section examines the new
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characteristics that would impact optical transmitters and receivers
in the process of control plane path computation. Modeling
parameters for flexible grid optical transmitters and receivers from
the control plane perspective are:
o Tuning range: As described in [RFC6163], this is the frequency or
wavelength range over which the optics can be tuned. (lambda1,
lambda2) or (freq1, freq2) can be used to represent the wavelength
range, where lambda1 and lambda2 or freq1 and freq2 are the labels
representing the lower and upper bounds in wavelength. As nominal
central frequencies can't be figured out before the path setup in
flexible grid network and flexible grid label may be different
from fixed grid label, "Tuning range" may be encode with some
different format from traditional fixed grid technology.
o Slot width: this parameter indicates slot width needed by a
transmitter or receiver and SHOULD be considered in the process of
path computation.
When an end-to-end LSC LSP needs be setup, operator first sends a
path setup command which convey some characteristics information of
the LSP, such as bitrates, to the source node. Path setup request is
sent to path computation element to computes an end-to-end LSC LSP
with specific slot width information, which bases on the bitrates and
modulation format that transceiver and receiver support.
3.4. Optical Signals in Flexible Grid Network
Similar to the fixed grid swithing (e.g., WSON), the fundamental unit
of switching in flexible grid is also a "wavelength". The
transmitters and receivers in these networks will deal with one
wavelength at a time, while the switching systems themselves can deal
with multiple wavelengths at a time. Key non-impairment-related
parameters which are listed in [RFC6163] are shown below:
o (a) Minimum channel spacing (GHz)
o (b) Minimum and maximum central frequency
o (c) Bitrates/Line coding (modulation) of optical tributary signals
As described in [RFC6163], (a) and (b) are considered properties of
the link and restrictions on the GMPLS Labels while (c) is a property
of the "signal". For the purposes of modeling the flexible grid, new
parameters which are related to the properities of the link and
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restrictions and property of "signal" SHOULD be considered:
o (d) Minimum and Maximum Slot Width
o (e) Slot Width
(d) is considered properties of the link and restrictions on the
GMPLS Labels, and description can be found in the following section.
(e) is a property of the "signal" and this property is determined by
the transmitter and may be changed if signal traverse an OEO.
3.4.1. Optical Tributary Signals
In [RFC6163], "optical tributary signal classes" are characterized by
a modulation format and bitrates range and both of them are key
parameters in characterizing the optical tributary signal. Note
that, with advances in technology, optical tributary signal classes
that support flexible grid would be added.
For optical tributary signals in flexible grid, bitrates range and
modulation format are still two key parameters, as a single
wavelength with central frequency and slot width used by a signal
sent from transmitter can be deduced from these two parameters base
on the available wavelength and slot width range from the source to
the destination.
3.4.2. WSON Signal Characteristics
Description about WSON signal characteristics in [RFC6163] also can
be applied to this document. Fundamental unit of switching in
flexible grid network is also "wavelength". WSON signal
characteristics like optical tributary signal class (modulation
format), forward error correction (FEC), central frequency
(wavelength), bitrates and general protocol identifier (G-PID) are
still used in flexible grid network in the process of path
computation and some more modulation formats and FECs may be added to
describe flexible grid network signal characteristics.
Except the parameter that have been included in [RFC6163], the
parameter slot width is also needed here to specify the slot width
that signal occupies.
3.5. ROADMs, OXCs, Splitters, Combiners, and FOADMs
This section mainly focuses on optical devices such as ROADMs,
Optical Cross-Connects (OXCs), splitters, combiners, and Fixed
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Optical Add/Drop Multiplexers (FOADMs) which can be used in flexible
grid network and examines their parameters of these devices that can
be used in the process of control plane path computation.
3.5.1. Reconfigurable Optical Add/Drop Multiplexers, OXCs and FOADM
Tributary Side: E5 I5 E6 I6
O | O |
| | | |
| O | O
+-----------------------+
|+-----+ +-----+|
Line side-1 --->||Split| |WSS-2||---> Line side-2
Input (I1) |+-----+ +-----+| Output (E2)
Line side-1 <---||WSS-1| |Split||<--- Line side-2
Output (E1) |+-----+ +-----+| Input (I2)
| ROADM |
|+-----+ +-----+|
Line side-3 --->||Split| |WSS-4||---> Line side-4
Input (I3) |+-----+ +-----+| Output (E4)
Line side-3 <---||WSS-3| |Split||<--- Line side-4
Output (E3) |+-----+ +-----+| Input (I4)
+-----------------------+
| O | O
| | | |
O | O |
Tributary Side: E7 I7 E8 I8
Figure 1: ROADM
A picture is shown here to facilitate the description of ROADM.
ROADM is composed of WSSes (wavelength selective switch) and
splitters which are used massively in current WDM network. WSS can
be used to select the wavelength on the line side output port and
splitter can be used on the line side input port to split the income
wavelength.
Switched connectivity matrix is needed to show whether a wavelength
on input port can be connected to an output port internal.
Besides the switched connectivity matrix which is applied to line
side port and tributary side port included in [RFC6163], new
wavelength restriction of the line side port on a ROADM which are
brought by flexible grid are considered below:
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o (a) Available wavelength range:
This parameter indicates the available wavelength that can be
allocated to a LSP. (lambda1, lambda2) or (freq1, freq2) can be
used to represent the available wavelength range.
o (b) Maximum/Minimum slot width that a port support
This is an inherent attribution of the network subsystems, like
WSS, and can be treated as port label restriction. Requirements
and descriptions about the restrictions information can be found
in [draft-wangl-ccamp-ospf-ext-constraint-flexi-grid]. For
flexible grid subsystems' ports, the possible values of slot width
are within the range [Minimum Slot Width, Maximum Slot Width] and
with the slot width granularity of 2 * C.S. (Channel Spacing).
The combination of C.S. and [Minimum Slot Width, Maximum Slot
Width] can represent any slot width that ROADM support.
o (c) Wavelength Range allocation
The whole wavelength that ROADM support can be partitioned into
several wavelength ranges, and one wavelength range can only be
used for paths setup with the specific bit rate and/or modulation
format. The advertisement of this restrictions information will
help reduce fragments in flexible grid network. Requirements
related description can be found in
[draft-wang-ccamp-flexible-grid-wavelength-range-ospf-te]. This
is an optional requirement.
These restrictions information can also be applied to fixed optical
Add/Drop Multiplexers.
3.5.2. Splitters and Combiners
Nothing is new except switched connectivity matrix and this has been
addressed in [RFC6163].
3.6. Electro-Optical Systems
Some words can be found in [RFC6163]. OEO switches, wavelength
converters, and regenerators all share a similar property: they can
be more or less "transparent" to an "optical signal" depending on
their functionality and/or implementation. Properties can be applied
to flexible grid, and these properties can satisfy path computation
without taking any new characteristics into consideration. Modeling
of OEO switches, wavelength converters and regenerators can also be
applied to flexible grid.
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Regenerator can be used to restore signal quality. Bitrates range
and modulation formats that the regenerator support need to be taken
into consideration to help path computation, whereas slot width do
not (May be someone will talk about slot width). If one regenerator
is designed to handle signal with specific bitrates and modulation
formats, then it would support the corresponding slot width because
slot width can be derived by modulation format and bitrates. Even if
the slot width is changed by the electro-optical systems due to the
change of modulation format, the slot width that has already changed
may not be explicitly specified because bitrates and modulation
format are explicitly specified.
4. Routing and wavelength Assignment in flexible grid network
This section briefly describes the constraints information of routing
and wavelength assignment in the flexible grid network. Similar to
WSON, the input to basic RWA in flexible grid network are the
requested optical path's source and destination, the network
topology, the locations and capabilities of any wavelength
converters, the wavelengths available on each optical link and port
label constraints information such as slot width range that a port
support and wavelength range partition information by bitrates and/or
modulation formats. The output that provided by RWA in flexible grid
network are an explicit route through ROADMs, a wavelength for
optical transmitter, the slot width that this wavelength occupies,
and a set of locations (generally associated with ROADMs or switches)
where wavelength conversion is to occur and the new wavelength to be
used on each component link after that point in the route.Similar to
WSON, an optical flexible grid path that from source to destination
also must use a single wavelength that is available along that path
without "colliding" with a wavelength used by any other optical path
that may share an optical fiber.
In [RFC6163], three different ways of performing RWA in conjunction
with the control plane are shown here:
1) Combined RWA
2) Separated R and WA (R + WA)
3) Routing and Distributed WA (R + DWA)
These ways can also be applied to flexible grid control plane path
computation. Related description about these three architectures can
be found in section 4.1 of [RFC6163].
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5. GMPLS and PCE Control
Flexible grid brings some new characteristics to WDM network, and
consequently WSON would add some extensions or change in order to
control the flexible grid network. Extensions to GMPLS signaling,
routing and PCE are described in this section.
5.1. Extension to GMPLS Signaling
Support for WSON signaling exists in [RFC3471], [RFC4328] and
[draft-ietf-ccamp-wson-signaling]. However, a number of practical
issues arise in the identification of wavelengths and signals in
wavelength assignment in flexible grid.
A mapping between label and wavelength is needed to simplify the
characterization of WDM links and WSON devices. The mapping like the
one described in [draft-farrkingel-ccamp-flexigrid-lambda-label]
provides label and wavelength mapping for communication between PCE
and WSON PCCs. Different LSP may occupy different slot width if
paths have different bitrates and modulation format in flexible grid
network. So in the flexible grid network, not only central frequency
is needed, but also slot width SHOULD be included to identify a
channel in the process of path setup in flexible grid network.
GMPLS Signaling should be able to convey the central frequency and
slot width information that a LSC LSP occupies. If the slot width is
changed due to the change of modulation format, signaling should also
be able to express this. Except methods that are specified in
[draft-farrkingel-ccamp-flexigrid-lambda-label],
[draft-hussain-ccamp-super-channel-label] and
[draft-zhang-ccamp-flexible-grid-rsvp-te-ext] also provide methods to
carry central frequency and slot width information in the process of
signaling.
Note: extension to GMPLS signaling SHOULD be compatible with current
signaling protocol.
5.2. Extension to GMPLS Routing
The following subsystem's properties are needed by IGP to minimally
characterize WSON, also these properties are needed to characterize
flexible grid control plane. This section addresses the constraints
information needed to model flexible grid from the control plane
perspective base on the Wavelength Switched Optical Network (WSON).
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1) WDM link properties (allowed wavelengths)
2) Optical transmitters (wavelength range)
3) ROADM/FOADM properties (connectivity matrix, port wavelength
restrictions)
4) Wavelength converter properties (per network element, may change
if a common limited shared pool is used)
Here 1, 2 and 3 are re-considered in the flexible grid network.
5.2.1. Available Wavelength Range
Wavelengths available on WDM link and port of optical transmitters
are advertised through routing protocol, the wavelengths available
information can be used by path computation element to compute a
suitable end-to-end LSP. As different flexible grid channels always
have different slot widths and channels' central frequency position
and slot width can't be decided in advance, so mapping between label
and wavelength may not be able to use the representation similar to
[RFC6205] to represent every channel. Maybe new label formats and
representation of wavelength available are needed in routing protocol
to transfer IGP information between nodes and PCEs. Extensions to
label set field SHOULD be able to represent the wavelength available
validly in flexible grid network. Allowed wavelengths on WDM link
and wavelength range on optical transmitters neede to adapt to this
change.[draft-dhillon-ccamp-super-channel-ospfte-ext],
[draft-wangl-ccamp-ospf-ext-constraint-flexi-grid] and
[draft-zhang-ccamp-flexible-grid-ospf-ext] give some different
methods to represent the available wavelengths.
5.2.2. Port Label Restriction
Some new ROADM/FOADM properties brought by flexible grid need to be
advertised by routing protocol in order to help path computation. In
the section 3, properties of ROADM/FOADM are described as the port
label restrictions information.
The first one, maximum/minimum slot width supported on one port need
to be advertised. This slot width constraint information of a port
(i.e., available slot width range of a WSS) SHOULD be known by path
computation element in order to compute a suitable path. According
to [draft-wangl-ccamp-ospf-ext-constraint-flexi-grid], combination of
C.S. and [Minimum Slot Width, Maximum Slot Width] can represent any
slot width that ROADM support. LMP can be run between two neighbor
nodes to negotiate these attributes and related extension can be
found in [draft-li-ccamp-grid-property-lmp]. This is optional
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because routing protocol can also be used to deal with it.
The second one, wavelength range allocation information of ROADM/
FOADM needs to be advertised through routing protocol. Grouping of
wavelength of the same bitrates and/or modulation formats would help
reduce fragments. Channels in the same wavelength range with the
same bitrates looks almost like fixed grid technology, and they won't
generate much fragment in the path setup and release because every
channel use the same slot width. Requirements of wavelength range
allocation and protocol extensions can be found in
[draft-wang-ccamp-flexible-grid-wavelength-range-ospf-te].
5.3. Optical Path Computation and Implications for PCE
Extensions to PCEP can be found in [draft-lee-pce-wson-rwa-ext] base
on Wavelength Switched Optical Network. Emergence of flexible grid
brings some extension to current draft. PCEP SHOULD be able to
support flexible grid path computation.
5.3.1. Optical Path Constraints and Electro-Optical Element Signal
Compatibility
Flexible grid may not change the computation architectures of WSON,
but new constraints information SHOULD be taken into consideration in
the process of path computation. According to the description in
[RFC6163], when requesting a path computation to PCE, the PCC should
be able to indicate:
1) The G-PID type of an LSP
2) The signal attributes at the transmitter and receiver.
And the PCE should be able to respond to the PCC with the following:
1) The conformity of the requested optical characteristics
associated with the resulting LSP with the source, sink, and NE
along the LSP.
2) Additional LSP attributes modified along the path.
3) Slot width of the LSP. This should be respond to the PCC as
flexible grid channels always have different slot widths. Slot
width information may be contained in the wavelength object which
is carried in PCRep message from PCE to PCC.
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5.3.2. Discovery of RWA-Capable PCEs
Not all PCEs within a domain would necessarily need the capability of
flexible grid path computation. Therefore, it would be useful to
indicate that a PCE has the ability to deal with flexible grid via
the discovery mechanisms being established for PCE discovery in
[RFC5088]. Extensions to [RFC5088] are needed to achieve this goal.
5.3.3. Use of GCO
Though GCO is able to reduce the fragment of the wavelength or
spectrum, it is hard to be implemented in the network, because GCO
would involve massive LSPs and distrub current service. As fragment
can be reduced through early wavelength or spectrum allocation
planning, GCO maybe avoided.
6. Security Considerations
TBD
7. References
7.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3945] Mannie, E., "Generalized Multi-Protocol Label Switching
(GMPLS) Architecture", RFC 3945, October 2004.
7.2. Informative References
[G.694.1 v1]
International Telecommunications Union, "Draft revised
G.694.1 version 1.3".
[flexible-grid-ospf-ext]
Fatai Zhang, Xiaobing Zi, Ramon Casellas, O. Gonzalez de
Dios, and D. Ceccarelli, "GMPLS OSPF-TE Extensions in
support of Flexible-Grid in DWDM Networks",
draft-zhang-ccamp-flexible-grid-ospf-ext-00.txt .
[flexible-grid-requirements]
Fatai Zhang, Xiaobing Zi, O. Gonzalez de Dios, and Ramon
Casellas, "Requirements for GMPLS Control of Flexible
Grids",
Qilei Wang & Xihua Fu Expires September 12, 2012 [Page 14]
Internet-Draft flexible grid Mar 2012
draft-zhang-ccamp-flexible-grid-requirements-01.txt .
[flexible-grid-rsvp-te]
Fatai Zhang, O. Gonzalez de Dios, and D. Ceccarelli,
"RSVP-TE Signaling Extensions in support of Flexible
Grid",
draft-zhang-ccamp-flexible-grid-rsvp-te-ext-00.txt .
[flexigrid-lambda-label]
D. King, A. Farrel, Y. Li, F. Zhang, and R. Casellas,
"Generalized Labels for the Flexi-Grid in Lambda-Switch-
Capable (LSC) Label Switching Routers",
draft-farrkingel-ccamp-flexigrid-lambda-label-01.txt .
[ospf-ext-constraint-flexi-grid]
L Wang, Y Li, "OSPF Extensions for Routing Constraint
Encoding in Flexible-Grid Networks",
draft-wangl-ccamp-ospf-ext-constraint-flexi-grid-00.txt .
[super-channel-label]
Iftekhar Hussain, Abinder Dhillon, Zhong Pan, Marco Sosa
and Bert Basch, Steve Liu, Andrew G. Malis, "Generalized
Label for Super-Channel Assignment on Flexible Grid",
draft-hussain-ccamp-super-channel-label-02.txt .
[super-channel-ospfte]
Abinder Dhillon, Iftekhar Hussain, Rajan Rao, Marco Sosa,
"OSPFTE extension to support GMPLS for Flex Grid",
draft-dhillon-ccamp-super-channel-ospfte-ext-02.txt .
Authors' Addresses
Qilei Wang
ZTE Corporation
Email: wang.qilei@zte.com.cn
Xihua Fu
ZTE Corporation
ZTE Plaza, No.10, Tangyan South Road, Gaoxin District
Xi'an
P.R.China
Email: fu.xihua@zte.com.cn
Qilei Wang & Xihua Fu Expires September 12, 2012 [Page 15]
