One document matched: draft-bernstein-ccamp-wson-info-02.txt
Differences from draft-bernstein-ccamp-wson-info-01.txt
Network Working Group Greg Bernstein
Internet Draft Grotto Networking
Intended status: Standards Track Young Lee
Expires: August 2008 Dan Li
Huawei
Wataru Imajuku
NTT
February 20, 2008
Routing and Wavelength Assignment Information for Wavelength
Switched Optical Networks
draft-bernstein-ccamp-wson-info-02.txt
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Copyright Notice
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Abstract
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This memo provides and information model and compact encodings for
information needed for path computation and wavelength assignment in
wavelength switched optical networks. Such encodings can be used in
extensions to Generalized Multi-Protocol Label Switching (GMPLS)
routing for control of wavelength switched optical networks (WSON) or
for other mechanisms, e.g. XML based, for conveying this information
to a path computation element.
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].
Table of Contents
1. Introduction...................................................3
2. Terminology....................................................3
3. High Level Information Model...................................4
3.1. Information Model.........................................4
3.2. Node Information..........................................5
3.2.1. ConnectivityMatrix...................................5
3.2.2. OEOWavelengthConverterInfo...........................6
3.3. Link Information..........................................6
3.3.1. Port Wavelength Restrictions.........................7
3.4. Dynamic Link Information..................................7
3.5. Dynamic Node Information..................................8
3.6. End System Information....................................8
4. Application to OSPF GMPLS extensions...........................8
4.1. Node Top Level TLV........................................8
4.2. Link Sub-TLVs.............................................9
4.3. Dealing with Dynamic Information..........................9
5. Type Length Value (TLV) Encoding of WSON Information...........9
5.1. Wavelength Information Encoding..........................10
5.2. Link Set Sub-TLV.........................................10
5.3. Wavelength Set Sub-TLV...................................12
5.3.1. Inclusive/Exclusive Wavelength Lists................13
5.3.2. Inclusive/Exclusive Wavelength Ranges...............14
5.3.3. Bitmap Wavelength Set...............................14
5.4. Connectivity Matrix Sub-TLV..............................15
5.5. Port Wavelength Restriction sub-TLV......................19
6. Security Considerations.......................................20
7. IANA Considerations...........................................20
8. Acknowledgments...............................................20
9. References....................................................21
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9.1. Normative References.....................................21
9.2. Informative References...................................21
10. Contributors.................................................22
Author's Addresses...............................................22
Intellectual Property Statement..................................23
Disclaimer of Validity...........................................24
1. Introduction
This document provides an information model and efficient encodings
of information needed by the routing and wavelength assignment (RWA)
process in wavelength switched optical networks (WSONs). Such
encodings can be to extend GMPLS IGPs. In addition these encodings or
information could be used by other mechanisms to convey this same
information to a path computation element (PCE). Note since these
encodings are relatively efficient they can provide more accurate
analysis of the control plane communications/processing load for
WSONs looking to utilize a GMPLS control plane.
2. Terminology
CWDM: Coarse Wavelength Division Multiplexing.
DWDM: Dense Wavelength Division Multiplexing.
FOADM: Fixed Optical Add/Drop Multiplexer.
ROADM: Reconfigurable Optical Add/Drop Multiplexer. A reduced port
count wavelength selective switching element featuring ingress and
egress line side ports as well as add/drop side ports.
RWA: Routing and Wavelength Assignment.
Wavelength Conversion/Converters: The process of converting an
information bearing optical signal centered at a given wavelength to
one with "equivalent" content centered at a different wavelength.
Wavelength conversion can be implemented via an optical-electronic-
optical (OEO) process or via a strictly optical process.
WDM: Wavelength Division Multiplexing.
Wavelength Switched Optical Networks (WSON): WDM based optical
networks in which switching is performed selectively based on the
center wavelength of an optical signal.
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3. High Level Information Model
The purpose of the following information model and encodings for
WSONs is to facilitate constrained lightpath computation. In
particular, the cases of no or a limited number of wavelength
converters available in the WSON. This constraint is frequently
referred to as the "wavelength continuity" constraint, and the
corresponding constrained lightpath computation is known as the
routing and wavelength assignment (RWA) problem. Hence the
information model must provide sufficient topology and wavelength
restriction and availability information to support this computation.
More details on the RWA process and WSON subsystems and their
properties can be found in [WSON-Frame].
3.1. Information Model
From [WSON-Frame] the following WSON information needs to be conveyed
via GMPLS routing or some other mechanism.
Information Static/Dynamic
---------------------------------------------------------
Connectivity matrix Static
Per port wavelength restrictions Static(2)
WDM link (fiber) lambda ranges Static(2)
WDM link channel spacing Static(2)
Laser Transmitter range Static(2)
Wavelength conversion capabilities Static(2)
Wavelength Availability Dynamic(2)
Wavelength Converter availability Dynamic(1,2)
Notes:
1. This could be dynamic in the case of a limited pool of converters
where the number available can change with connection
establishment. Note we may want to include regeneration
capabilities here since OEO converters are also regenerators.
2. Not necessarily needed in the case of distributed wavelength
assignment via signaling.
See [WSON-Frame] for more details on these types of WSON information
and their use.
For the purposes of conveying the information we can group the
information model into four categories regardless of whether they
stem from a switching subsystem or a line subsystem:
o Node Information
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o Link Information
o Dynamic Node Information
o Dynamic Link Information
o End System Information
In the following we use a BNF/Regular expression like syntax where
the symbol "|" indicates a choice between two or more elements; the
symbol "*" indicates zero or more occurrences of an element; the
symbol "?" indicates zero or one occurrences; and the symbol "+"
indicates one or more occurrences.
3.2. Node Information
Node information contains relatively static information related to a
WSON node. This includes internal information such as a connectivity
matrix and port wavelength constraints. Additional information could
include properties of wavelength converters in the node if any are
present.
Formally,
Node Information := Node_ID (ConnectivityMatrix?,
OEOWavelengthConverterInfo? )
Where the Node_ID would be a "Router ID" in OSPFv2.
3.2.1. ConnectivityMatrix
The ConnectivityMatrix represents the potential connectivity matrix
for asymmetric switches (e.g. ROADMs and such) and the connectivity
matrix for asymmetric fixed devices. The following provides a compact
representation of the connectivity via a list of pairs of link sets
that have connectivity to each other.
ConnectivityMatrix := ConnectivityFixed (LinkSetA, LinkSetB)+
Where ConnectivityFixed is a Boolean that takes the value true if the
device has fixed connectivity and false if the device is a switch or
ROADM. LinkSets are defined in Section 5.2. Only two valid
combinations of link sets A and B are permitted. In the first case
LinkSetA is a set of ingress links and LinkSetB is a set of egress
links. In the second case LinkSetA and LinkSetB are both bi-
directional link sets.
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3.2.2. OEOWavelengthConverterInfo
An OEO based wavelength converter can be characterized by an input
wavelength set and an output wavelength set. In addition any
constraints on the signal formats and rates accommodated by the
converter must be described. Such a wavelength converter can be
modeled by:
OEOWavelengthConverterInfo := RegeneratorLevel
(IngressWavelengthRange, EgressWavelengthRange, BitRateRange?,
AcceptableSignals? )
Where the RegeneratorLevel is used to model an OEO regenerator.
Regenerators are usually classified into three levels. Level 1
provides signal amplification, level 2 amplification and pulse
shaping, and level 3 amplification, pulse shaping and timing
regeneration. Level 2 regenerators can have a restricted bit rate
range, while level 3 regenerators can also be specialized to a
particular signal type. For ingress and egress wavelength ranges see
the WavelengthSet definition in section 5.3.
3.3. Link Information
WSONs contribute information in addition to that in RFC3630 (OSPF-TE)
and RFC4203 (OSPF for GMPLS) via additional link constraints. These
stem from (a) WDM line system characterization, laser transmitter
tuning restrictions, and switching subsystem port wavelength
constraints, e.g., colored ROADM drop ports.
As described below we add two new sub-elements to the link
information model derived from [RFC3630, RFC4203]: (a) the maximum
number of channels, and (b) link wavelength restrictions. Note that
network topology information is implicit in the link information
element.
LinkInfo := LocalLinkID LocalNodeID RemoteLinkID RemoteNodeID
(AdministrativeGroup?, InterfaceCapDesc?,
MaximumBandwidthPerChannel?, Protection?, SRLG*,
TrafficEngineeringMetric?, PortWavelengthRestriction?)
Note that RFC3630 provides other ways to identify local and remote
link ends in the case of numbered links. In the above we have
reinterpreted the Maximum Bandwidth of RFC3630 as the maximum
bandwidth per WDM channel and have omitted the Maximum Reservable
Bandwidth of RFC3630 since overbooking is not typically used in
circuit switching for obvious reasons. In addition we propose an
alternative to the Unreserved Bandwidth of RFC3630 in the next
section.
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3.3.1. Port Wavelength Restrictions
Models the wavelength restrictions that various optical devices such
as OXC, ROADMs, and waveband mulitplers may impose on a port.
PortWavelengthRestriction := (RestrictionKind, MaxNumChannels,
WavelengthSet )
Where RestrictionKind can take the following values and meanings:
0 Simple wavelength selective restriction. Max number of channels
indicates the number of wavelength permitted on the port and the
accompanying wavelength set indicates the permitted values.
1 Waveband device with a tunable center frequency and passband. In
this case the maximum number of channels indicates the maximum width
of the waveband in terms of the channels spacing given in the
wavelength set. The corresponding wavelength set is used to indicate
the overall tuning range. Specific center frequency tuning
information can be obtained from dynamic channel in use information.
It is assumed that both center frequency and bandwidth (Q) tuning can
be done without causing faults in existing signals.
A 16 bit non-negative integer would suffice for the maximum number of
channels. For example if the port is a "colored" drop port of a ROADM
then the value of RestrictionKind = 0 for a simple wavelength
selective restriction, the MaxNumberOfChannels = 1, and the
wavelength restriction is just a wavelength set consisting of a
single member corresponding to the frequency of the permitted
wavelength.
3.4. Dynamic Link Information
By dynamic information we mean information that is subject to change
on a link with subsequent connection establishment or teardown.
Currently for WSON the only information we currently envision is
wavelength availability.
DynamicLinkInfo := LocalLinkID LocalNodeID RemoteLinkID
RemoteNodeID AvailableWavelengths
Where, once again, the local and remote link and node IDs are used to
specify the particular link in the unnumbered case and
AvailableWavelengths is a WavelengthSet as defined in Section 5.3.
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3.5. Dynamic Node Information
Dynamic node information is used to hold information for a node that
can change frequently. Currently only wavelength converter
availability information is included as a possible (but not required)
information sub-element.
DynamicNodeInfo := NodeID AvailableWavelengthConverters?
Where NodeID is a node identifier such as the router ID in OSPFv2 and
the number of currently available wavelength converters is given by
AvailableWavelengthConverters.
3.6. End System Information
Current end system information of interest includes the tuning range
of laser transmitters, support or single or multiple wavelengths on a
port, etc...
4. Application to OSPF GMPLS extensions
RFC2370 defined the opaque link state advertisement (LSA) and its
various flavors based on flooding scope. RFC3630 defines the Traffic
Engineering (TE) LSA which is an opaque LSA of area flooding scope
with an LSA ID defined by:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 1 | Instance |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
"The Instance field is an arbitrary value used to maintain multiple
Traffic Engineering LSAs. A maximum of 16777216 Traffic Engineering
LSAs may be sourced by a single system. The LSA ID has no
topological significance." [RFC3630]
From RFC3630 the TE LSA can contain only one top level TLV and
RFC3630 defines two top level TLVs: (a) router address, and (b) link.
RFC4203 adds new sub-TLVs to the top level link TLV to support GMPLS,
but does not add any new top level TLVs.
4.1. Node Top Level TLV
As we saw in section 3.2. for WSON networks there can be a
significant amount of information specific to nodes in WSON networks
hence we recommend the addition of a new top level TE TLV (e.g. type
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5) for holding node related information. Currently we have defined
two sub-TLVs for the Node TLV: (a) Connectivity Matrix sub-TLV, (b)
OEO Wavelength converter information sub-TLV.
4.2. Link Sub-TLVs
As discussed in section 3.3. two new sub-TLVs are needed to
characterize WSON links: (a) Maximum number of channels sub-TLV and,
(b) wavelength constraints sub-TLV.
4.3. Dealing with Dynamic Information
In our information model we differentiated between relatively static
and dynamic information; defining dynamic information as that
information that is subject to change due to connection setup or
teardown. There are three ways that we could differentiate dynamic
from static information in flooding and processing, if desired.
A. Use a separate TE LSA instance for static and dynamic information
for the same modeled entity. For example, one could group all the
relatively static information concerning a specific link into one
instance and the wavelength availability information (subTLV of
the link TLV) into another TE LSA instance.
B. Use separate top level TLVs to differentiate static and dynamic
information. For example define a top level "dynamic link" TLV.
C. Define a new "dynamic TE LSA" type (e.g. opaque type 5)
specifically for conveying dynamic information
These three different options are ordered in reverse of the amount of
processing required to tell whether the information is dynamic or
not. For example in case (A) one must look all the way into the sub-
TLV type to understand that this is dynamic information, while in
case (C) this can easily be inferred from the LSA ID. Note that for
high level LSA processing the LSA ID is the finest granularity field
that would be looked at.
5. Type Length Value (TLV) Encoding of WSON Information
A TLV encoding of the high level WSON information model is given in
the following sections. This encoding is designed to be suitable for
use in routing protocols such as OSPFv2 via the extension mechanisms
of RFC2370 (opaque LSA), RFC3630 (OSPF-TE) and RFC4203 (OSPF-GMPLS),
and in PCE protocols such as PCEP. Note that the information in
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RFC3630 and RFC4203 is arranged via the nesting of sub-TLVs within
TLVs and we will make use of such constructs.
The following encodings have multiple uses in specifying WSON
information.
5.1. Wavelength Information Encoding
This document makes frequent use of the lambda label format defined
in [Otani] shown below:
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. |S| Reserved | n |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Where
Grid is used to indicate which ITU-T grid specification is being
used.
C.S. = Channel spacing used in a DWDM system, i.e., with a ITU-T
G.694.1 grid.
S = sign of the offset from the center frequency of 193.1THz for the
ITU-T 6.694.1 grid.
n = Used to specify the frequency as 193.1THz +/- n*(channel spacing)
where the + or - is chosen based on the sign (S) bit.
5.2. Link Set Sub-TLV
We will frequently want to describe properties of links. To do so
efficiently we can make use of a link set concept similar to the
label set concept of [RFC3471]. All links will be denoted by their
local link identifier as defined an used in[RFC4202, RFC4203,
RFC4205].
The information carried in a Link Set is defined by:
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Action |Dir| Format | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Identifier 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: : :
: : :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Identifier N |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Action: 8 bits
0 - Inclusive List
Indicates that the object/TLV contains one or more link elements
that are included in the Link Set.
1 - Exclusive List
Indicates that the object/TLV contains one or more link elements that
are excluded from the Link Set.
2 - Inclusive Range
Indicates that the object/TLV contains a range of links. The
object/TLV contains two link elements. The first element indicates
the start of the range. The second element indicates the end of the
range. A value of zero indicates that there is no bound on the
corresponding portion of the range.
3 - Exclusive Range
Indicates that the object/TLV contains a range of links that are
excluded from the Link Set. The object/TLV contains two link
elements. The first element indicates the start of the range. The
second element indicates the end of the range. A value of zero
indicates that there is no bound on the corresponding portion of the
range.
Dir: Directionality of the Link Set (2 bits)
0 -- bidirectional
1 -- ingress
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2 -- egress
In optical networks we think in terms of unidirectional as well as
bidirectional links. For example wavelength restrictions or
connectivity may be much different for an ingress port, than for its
"companion" egress port if it has one. Note that "interfaces" such as
discussed in the Interfaces MIB are assumed bidirectional, as well as
the links of various link state IGPs.
Format: The format of the link identifier (6 bits)
0 -- Link Local Identifier
Others TBD.
Reserved: 16 bits
This field is reserved. It MUST be set to zero on transmission and
MUST be ignored on receipt.
Link Identifier:
The link identifier represents the port which is being described
either for connectivity or wavelength restrictions. This can be the
link local identifier of [RFC4202], GMPLS routing, [RFC4203] GMPLS
OSPF routing, and [RFC4205] IS-IS GMPLS routing. The use of the link
local identifier format can result in more compact WSON encodings
when the assignments are done in a reasonable fashion.
5.3. Wavelength Set Sub-TLV
Wavelength sets come up frequently in WSONs to describe the range of
a laser transmitter, the wavelength restrictions on ROADM ports, or
the availability of wavelengths on a DWDM link. The general format
for a wavelength set is given below. This format uses the Action
concept from [RFC3471] with an additional Action to define a "bit
map" type of label set. Note that the second 32 bit field is a lambda
label in the previously defined format. This provides important
information on the WDM grid type and channel spacing that will be
used in the compact encodings listed.
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Action | Reserved | Num Wavelengths |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Grid | C.S. |S| Reserved | n for lowest frequency |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Additional fields as necessary per action |
|
Action:
0 - Inclusive List
1 - Exclusive List
2 - Inclusive Range
3 - Exclusive Range
4 - Bitmap Set
5.3.1. Inclusive/Exclusive Wavelength Lists
In the case of the inclusive/exclusive lists the wavelength set
format is given by:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Action=0 or 1 | Reserved | Num Wavelengths |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Grid | C.S. |S| Reserved | n for lowest frequency |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| n2 | n3 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| nm | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Where Num Wavelengths tells us the number of wavelength in this
inclusive or exclusive list this does not include the initial
wavelength in the list hence if the number of wavelengths is odd then
zero padding of the last half word is required.
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5.3.2. Inclusive/Exclusive Wavelength Ranges
In the case of inclusive/exclusive ranges the wavelength set format
is given by:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Action=2 or 3 | Reserved | Num Wavelengths |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Grid | C.S. |S| Reserved | n for lowest frequency |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
In this case Num Wavelengths specifies the number of wavelengths in
the range starting at the given wavelength and incrementing the Num
Wavelengths number of channel spacing up in frequency (regardless of
the value of the sign bit).
5.3.3. Bitmap Wavelength Set
In the case of Action = the bitmap the wavelength set format is given
by:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Action = 4 | Reserved | Num Wavelengths |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Grid | C.S. |S| Reserved | n for lowest frequency |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Bit Map Word #1 (Lowest frequency channels) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Bit Map Word #N (Highest frequency channels) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Where Num Wavelengths in this case tells us the number of wavelengths
represented by the bit map which is required to be ceiling[(Num
Wavelengths)/32]. Each bit in the bit map represents a particular
frequency with a value of 1/0 indicating whether the frequency is in
the set or not. Bit position zero represents the lowest frequency,
while each succeeding bit position represents the next frequency a
channel spacing (C.S.) above the previous.
Example:
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A 40 channel C-Band DWDM system with 100GHz spacing with lowest
frequency 192.0THz (1561.4nm) and highest frequency 195.9THz
(1530.3nm). These frequencies correspond to n = -11, and n = 28
respectively. Now suppose the following channels are available:
Frequency(THz) n Value bit map position
--------------------------------------------------
192.0 -11 0
192.5 -6 5
193.1 0 11
193.9 8 19
194.0 9 20
195.2 21 32
195.8 27 38
With the Grid value set to indicate an ITU-T G.694.1 DWDM grid, C.S.
set to indicate 100GHz, and with S (sign) set to indicate negative
this lambda bit map set would then be encoded as follows:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Action = 4 | Reserved | Num Wavelengths = 40 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Grid | C.S. |S| Reserved | n for lowest frequency = -11 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|1 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|1 0 0 0 0 0 1 0| Not used in 40 Channel system (all zeros) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
5.4. Connectivity Matrix Sub-TLV
The potential connectivity matrix for asymmetric switches (e.g.
ROADMs and such) and the connectivity matrix for asymmetric fixed
devices can be represented by a matrix A where Amn = 0 or 1,
depending upon whether a wavelength on ingress port m can be
connected to egress port n.
This can be compactly represented link sets as follows:
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Connectivity | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Set A #1 |
: : :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Set B #1
: : :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Additional Link set pairs as needed |
: to specify connectivity :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Where Connectivity = 0 if the device is fixed
1 if the device is reconfigurable (ROADM/OXC)
Issue for further study:
It may be useful to have a bit from the reserved field to indicate
whether "local" switching can take place or not, i.e., whether the
diagonal of Amn should be assumed to be 0 or 1 in cases where the
same port # appears in both ingress set list and egress set list. For
a typical ROADM Amm = 0.
Example:
Suppose we have a typical 2-degree 40 channel ROADM. In addition to
its two line side ports it has 80 add and 80 drop ports. The picture
below illustrates how a typical 2-degree ROADM system that works with
bi-directional fiber pairs is a highly asymmetrical system composed
of two unidirectional ROADM subsystems.
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(Tributary) Ports #3-#42
Ingress added to Egress dropped from
West Line Egress East Line Ingress
vvvv ^^^^
| |...| | |...|
+-----| |...|--------| |...|------+
| +----------------------+ |
| | | |
Egress | | Unidirectional ROADM | |
-----------------+ | | +--------------
<=====================| |===================<
-----------------+ +----------------------+ +--------------
| |
Port #1 | | Port #2
(West Line Side) | |(East Line Side)
-----------------+ +----------------------+ +--------------
>=====================| |===================>
-----------------+ | Unidirectional ROADM | +--------------
| | | |
| | _ | |
| +----------------------+ |
+-----| |...|--------| |...|------+
| |...| | |...|
vvvv ^^^^
(Tributary) Ports #43-#82
Egress dropped from Ingress added to
West Line ingress East Line egress
Referring to the figure we see that the ingress direction of ports
#3-#42 (add ports) can only potentially egress on port #1. While in
ingress side of port #2 (line side) can egress only on ports #3-#42
(drop) and #1 (pass through). Similarly, the ingress direction of
ports #43-#82 can only potentially egress on port #2 (line). While
the ingress direction of port #1 can only potentially egress on ports
#43-#82 (drop) or port #2 (pass through). We can now represent this
potential connectivity matrix as follows. This representation uses
only 30 32-bit words.
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Conn = 1 | Reserved |1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Note: adds to line
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Action=2 |0 1|0 0 0 0 0 0|Reserved(Note:inclusive range) |2
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Local Identifier = #3 |3
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Local Identifier = #42 |4
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Action=0 |1 0|0 0 0 0 0 0|Reserved (Note:inclusive list) |5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Local Identifier = #1 |6
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Note: line to drops
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Action=0 |0 1|0 0 0 0 0 0|Reserved (Note:inclusive list) |7
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Local Identifier = #2 |8
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Action=2 |1 0|0 0 0 0 0 0|Reserved(Note: inclusive range)|9
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Local Identifier = #3 |10
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Local Identifier = #42 |11
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Note: line to line
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Action=0 |0 1|0 0 0 0 0 0|Reserved (Note:inclusive list) |12
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Local Identifier = #2 |13
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Action=0 |1 0|0 0 0 0 0 0|Reserved(Note: inclusive range)|14
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Local Identifier = #1 |15
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Note: adds to line
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Action=2 |0 1|0 0 0 0 0 0|Reserved(Note:inclusive range) |16
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Local Identifier = #42 |17
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Local Identifier = #82 |18
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Action=0 |1 0|0 0 0 0 0 0|Reserved (Note:inclusive list) |19
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Local Identifier = #2 |20
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Note: line to drops
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Action=0 |0 1|0 0 0 0 0 0|Reserved (Note:inclusive list) |21
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Local Identifier = #1 |22
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Action=2 |1 0|0 0 0 0 0 0|Reserved(Note: inclusive range)|23
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Local Identifier = #43 |24
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Local Identifier = #82 |25
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Note: line to line
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Action=0 |0 1|0 0 0 0 0 0|Reserved (Note:inclusive list) |26
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Local Identifier = #1 |27
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Action=0 |1 0|0 0 0 0 0 0|Reserved(Note: inclusive range)|28
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Local Identifier = #2 |30
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
5.5. Port Wavelength Restriction sub-TLV
The port wavelength restriction of section 3.3.1. can be encoded as a
sub-TLV as follows.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|RestrictionKind| Reserved | MaxNumChannels |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
--Wavelength Set--
| Action | Reserved | Num Wavelengths |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Grid | C.S. |S| Reserved | n for lowest frequency |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Additional fields as necessary per action |
| |
Where the meanings of RestrictionKind, MaxNumChannels and the
Wavelength Set were defined in section 3.3.1.
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6. Security Considerations
This document has no requirement for a change to the security models
within GMPLS and associated protocols. That is the OSPF-TE, RSVP-TE,
and PCEP security models could be operated unchanged.
7. IANA Considerations
TBD. Once finalized in our approach we will need identifiers for such
things and modulation types, modulation parameters, wavelength
assignment methods, etc...
8. Acknowledgments
This document was prepared using 2-Word-v2.0.template.dot.
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9. References
9.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3471] Berger, L., "Generalized Multi-Protocol Label Switching
(GMPLS) Signaling Functional Description", RFC 3471,
January 2003.
[G.694.1] ITU-T Recommendation G.694.1, "Spectral grids for WDM
applications: DWDM frequency grid", June, 2002.
[RFC3630] Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering
(TE) Extensions to OSPF Version 2", RFC 3630, September
2003.
[RFC4202] Kompella, K., Ed., and Y. Rekhter, Ed., "Routing Extensions
in Support of Generalized Multi-Protocol Label Switching
(GMPLS)", RFC 4202, October 2005
[RFC4203] Kompella, K., Ed., and Y. Rekhter, Ed., "OSPF Extensions in
Support of Generalized Multi-Protocol Label Switching
(GMPLS)", RFC 4203, October 2005.
9.2. Informative References
[Otani] T. Otani, H. Guo, K. Miyazaki, D. Caviglia, "Generalized
Labels of Lambda-Switching Capable Label Switching Routers
(LSR)", work in progress: draft-otani-ccamp-gmpls-lambda-
labels-01.txt, November 2007.
[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.
[RFC4205] Kompella, K., Ed., and Y. Rekhter, Ed., "Intermediate
System to Intermediate System (IS-IS) Extensions in Support
of Generalized Multi-Protocol Label Switching (GMPLS)", RFC
4205, October 2005.
Bernstein and Lee Expires August 20, 2008 [Page 21]
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[WSON-Frame] G. Bernstein, Y. Lee, W. Imajuku, "Framework for GMPLS
and PCE Control of Wavelength Switched Optical Networks",
work in progress: draft-bernstein-ccamp-wavelength-
switched-02.txt, February 2008.
10. Contributors
Diego Caviglia
Ericsson
Via A. Negrone 1/A 16153
Genoa Italy
Phone: +39 010 600 3736
Email: diego.caviglia@(marconi.com, ericsson.com)
Anders Gavler
Acreo AB
Electrum 236
SE - 164 40 Kista Sweden
Email: Anders.Gavler@acreo.se
Jonas Martensson
Acreo AB
Electrum 236
SE - 164 40 Kista, Sweden
Email: Jonas.Martensson@acreo.se
Itaru Nishioka
NEC Corp.
1753 Simonumabe, Nakahara-ku, Kawasaki, Kanagawa 211-8666
Japan
Phone: +81 44 396 3287
Email: i-nishioka@cb.jp.nec.com
Author's Addresses
Greg Bernstein (ed.)
Grotto Networking
Fremont, CA, USA
Phone: (510) 573-2237
Email: gregb@grotto-networking.com
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Young Lee (ed.)
Huawei Technologies
1700 Alma Drive, Suite 100
Plano, TX 75075
USA
Phone: (972) 509-5599 (x2240)
Email: ylee@huawei.com
Dan Li
Huawei Technologies Co., Ltd.
F3-5-B R&D Center, Huawei Base,
Bantian, Longgang District
Shenzhen 518129 P.R.China
Phone: +86-755-28973237
Email: danli@huawei.com
Wataru Imajuku
NTT Network Innovation Labs
1-1 Hikari-no-oka, Yokosuka, Kanagawa
Japan
Phone: +81-(46) 859-4315
Email: imajuku.wataru@lab.ntt.co.jp
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