1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
|
<pre>Internet Engineering Task Force (IETF) G. Bernstein, Ed.
Request for Comments: 7689 Grotto Networking
Category: Standards Track S. Xu
ISSN: 2070-1721 NICT
Y. Lee, Ed.
Huawei
G. Martinelli
Cisco
H. Harai
NICT
November 2015
<span class="h1">Signaling Extensions for Wavelength Switched Optical Networks</span>
Abstract
This document provides extensions to Generalized Multiprotocol Label
Switching (GMPLS) signaling for control of Wavelength Switched
Optical Networks (WSONs). Such extensions are applicable in WSONs
under a number of conditions including: (a) when optional processing,
such as regeneration, must be configured to occur at specific nodes
along a path, (b) where equipment must be configured to accept an
optical signal with specific attributes, or (c) where equipment must
be configured to output an optical signal with specific attributes.
This document provides mechanisms to support distributed wavelength
assignment with a choice of distributed wavelength assignment
algorithms.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in <a href="./rfc5741#section-2">Section 2 of RFC 5741</a>.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
<a href="http://www.rfc-editor.org/info/rfc7689">http://www.rfc-editor.org/info/rfc7689</a>.
<span class="grey">Bernstein, et al. Standards Track [Page 1]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-2" ></span>
<span class="grey"><a href="./rfc7689">RFC 7689</a> WSON Signaling Extensions November 2015</span>
Copyright Notice
Copyright (c) 2015 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to <a href="https://www.rfc-editor.org/bcp/bcp78">BCP 78</a> and the IETF Trust's Legal
Provisions Relating to IETF Documents
(<a href="http://trustee.ietf.org/license-info">http://trustee.ietf.org/license-info</a>) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
<a href="#section-1">1</a>. Introduction ....................................................<a href="#page-3">3</a>
<a href="#section-2">2</a>. Terminology .....................................................<a href="#page-3">3</a>
<a href="#section-2.1">2.1</a>. Conventions Used in This Document ..........................<a href="#page-4">4</a>
<a href="#section-3">3</a>. Requirements for WSON Signaling .................................<a href="#page-4">4</a>
<a href="#section-3.1">3.1</a>. WSON Signal Characterization ...............................<a href="#page-4">4</a>
<a href="#section-3.2">3.2</a>. Per-Node Processing Configuration ..........................<a href="#page-5">5</a>
<a href="#section-3.3">3.3</a>. Bidirectional WSON LSPs ....................................<a href="#page-5">5</a>
<a href="#section-3.4">3.4</a>. Distributed Wavelength Assignment Selection Method .........<a href="#page-6">6</a>
<a href="#section-3.5">3.5</a>. Optical Impairments ........................................<a href="#page-6">6</a>
<a href="#section-4">4</a>. WSON Signal Traffic Parameters, Attributes, and Processing ......<a href="#page-6">6</a>
<a href="#section-4.1">4.1</a>. Traffic Parameters for Optical Tributary Signals ...........<a href="#page-7">7</a>
<a href="#section-4.2">4.2</a>. WSON Processing Hop Attribute TLV ..........................<a href="#page-7">7</a>
<a href="#section-4.2.1">4.2.1</a>. ResourceBlockInfo Sub-TLV ...........................<a href="#page-8">8</a>
<a href="#section-4.2.2">4.2.2</a>. WavelengthSelection Sub-TLV .........................<a href="#page-9">9</a>
<a href="#section-5">5</a>. Security Considerations ........................................<a href="#page-11">11</a>
<a href="#section-6">6</a>. IANA Considerations ............................................<a href="#page-11">11</a>
<a href="#section-7">7</a>. References .....................................................<a href="#page-13">13</a>
<a href="#section-7.1">7.1</a>. Normative References ......................................<a href="#page-13">13</a>
<a href="#section-7.2">7.2</a>. Informative References ....................................<a href="#page-14">14</a>
Acknowledgments ...................................................<a href="#page-15">15</a>
Contributors ......................................................<a href="#page-15">15</a>
Author's Addresses ................................................<a href="#page-16">16</a>
<span class="grey">Bernstein, et al. Standards Track [Page 2]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-3" ></span>
<span class="grey"><a href="./rfc7689">RFC 7689</a> WSON Signaling Extensions November 2015</span>
<span class="h2"><a class="selflink" id="section-1" href="#section-1">1</a>. Introduction</span>
This document provides extensions to Generalized Multiprotocol Label
Switching (GMPLS) signaling for control of Wavelength Switched
Optical Networks (WSONs). Fundamental extensions are given to permit
simultaneous bidirectional wavelength assignment, while more advanced
extensions are given to support the networks described in [<a href="./rfc6163" title=""Framework for GMPLS and Path Computation Element (PCE) Control of Wavelength Switched Optical Networks (WSONs)"">RFC6163</a>],
which feature connections requiring configuration of input, output,
and general signal processing capabilities at a node along a Label
Switched Path (LSP).
These extensions build on previous work for the control of lambda and
G.709-based networks.
Related documents are [<a href="./rfc7446" title=""Routing and Wavelength Assignment Information Model for Wavelength Switched Optical Networks"">RFC7446</a>] that provides a high-level
information model and [<a href="./rfc7581" title=""Routing and Wavelength Assignment Information Encoding for Wavelength Switched Optical Networks"">RFC7581</a>] that provides common encodings that
can be applicable to other protocol extensions such as routing.
<span class="h2"><a class="selflink" id="section-2" href="#section-2">2</a>. Terminology</span>
CWDM: Coarse Wavelength Division Multiplexing.
DWDM: Dense Wavelength Division Multiplexing.
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
information bearing optical signal centered at a given frequency
(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 (WSONs): WDM-based optical
networks in which switching is performed selectively based on the
frequency of an optical signal.
AWG: Arrayed Waveguide Grating.
OXC: Optical Cross-Connect.
<span class="grey">Bernstein, et al. Standards Track [Page 3]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-4" ></span>
<span class="grey"><a href="./rfc7689">RFC 7689</a> WSON Signaling Extensions November 2015</span>
Optical Transmitter: A device that has both a laser, tuned on a
certain wavelength, and electronic components that convert
electronic signals into optical signals.
Optical Receiver: A device that has both optical and electronic
components. It detects optical signals and converts optical
signals into electronic signals.
Optical Transponder: A device that has both an optical transmitter
and an optical receiver.
Optical End Node: The end of a wavelength (optical lambdas) lightpath
in the data plane. It may be equipped with some
optical/electronic devices such as wavelength
multiplexers/demultiplexer (e.g., AWG), optical transponder, etc.,
which are employed to transmit/terminate the optical signals for
data transmission.
FEC: Forward Error Correction. FEC is a digital signal processing
technique used to enhance data reliability. It does this by
introducing redundant data, called error correcting code, prior to
data transmission or storage. FEC provides the receiver with the
ability to correct errors without a reverse channel to request the
retransmission of data.
3R Regeneration: The process of amplifying (correcting loss),
reshaping (correcting noise and dispersion), retiming
(synchronizing with the network clock), and retransmitting an
optical signal.
<span class="h3"><a class="selflink" id="section-2.1" href="#section-2.1">2.1</a>. Conventions Used in This Document</span>
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 [<a href="./rfc2119" title=""Key words for use in RFCs to Indicate Requirement Levels"">RFC2119</a>].
<span class="h2"><a class="selflink" id="section-3" href="#section-3">3</a>. Requirements for WSON Signaling</span>
The following requirements for GMPLS-based WSON signaling are in
addition to the functionality already provided by existing GMPLS
signaling mechanisms.
<span class="h3"><a class="selflink" id="section-3.1" href="#section-3.1">3.1</a>. WSON Signal Characterization</span>
WSON signaling needs to convey sufficient information characterizing
the signal to allow systems along the path to determine compatibility
and perform any required local configuration. Examples of such
systems include intermediate nodes (ROADMs, OXCs, wavelength
<span class="grey">Bernstein, et al. Standards Track [Page 4]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-5" ></span>
<span class="grey"><a href="./rfc7689">RFC 7689</a> WSON Signaling Extensions November 2015</span>
converters, regenerators, OEO switches, etc.), links (WDM systems),
and end systems (detectors, demodulators, etc.). The details of any
local configuration processes are outside the scope of this document.
From [<a href="./rfc6163" title=""Framework for GMPLS and Path Computation Element (PCE) Control of Wavelength Switched Optical Networks (WSONs)"">RFC6163</a>], we have the following list of WSON signal
characteristics:
1. Optical tributary signal class (modulation format).
2. FEC: whether forward error correction is used in the digital
stream and what type of error correcting code is used
3. Center frequency (wavelength)
4. Bit rate
5. G-PID: General Protocol Identifier for the information format
The first three items on this list can change as a WSON signal
traverses a network with regenerators, OEO switches, or wavelength
converters. These parameters are summarized in the Optical Interface
Class as defined in [<a href="./rfc7446" title=""Routing and Wavelength Assignment Information Model for Wavelength Switched Optical Networks"">RFC7446</a>], and the assumption is that a class
always includes signal compatibility information. An ability to
control wavelength conversion already exists in GMPLS signaling along
with the ability to share client signal type information (G-PID). In
addition, bit rate is a standard GMPLS signaling traffic parameter.
It is referred to as bandwidth encoding in [<a href="./rfc3471" title=""Generalized Multi-Protocol Label Switching (GMPLS) Signaling Functional Description"">RFC3471</a>].
<span class="h3"><a class="selflink" id="section-3.2" href="#section-3.2">3.2</a>. Per-Node Processing Configuration</span>
In addition to configuring a node along an LSP to input or output a
signal with specific attributes, we may need to signal the node to
perform specific processing, such as 3R regeneration, on the signal
at a particular node. [<a href="./rfc6163" title=""Framework for GMPLS and Path Computation Element (PCE) Control of Wavelength Switched Optical Networks (WSONs)"">RFC6163</a>] discussed three types of processing:
(A) Regeneration (possibly different types)
(B) Fault and Performance Monitoring
(C) Attribute Conversion
The extensions here provide for the configuration of these types of
processing at nodes along an LSP.
<span class="h3"><a class="selflink" id="section-3.3" href="#section-3.3">3.3</a>. Bidirectional WSON LSPs</span>
WSON signaling can support LSP setup consistent with the wavelength
continuity constraint for bidirectional connections. The following
cases need to be supported separately:
(a) Where the same wavelength is used for both upstream and
downstream directions
<span class="grey">Bernstein, et al. Standards Track [Page 5]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-6" ></span>
<span class="grey"><a href="./rfc7689">RFC 7689</a> WSON Signaling Extensions November 2015</span>
(b) Where different wavelengths are used for both upstream and
downstream directions.
This document will review existing GMPLS bidirectional solutions
according to WSON case.
<span class="h3"><a class="selflink" id="section-3.4" href="#section-3.4">3.4</a>. Distributed Wavelength Assignment Selection Method</span>
WSON signaling can support the selection of a specific distributed
wavelength assignment method.
This method is beneficial in cases of equipment failure, etc., where
fast provisioning used in quick recovery is critical to protect
carriers/users against system loss. This requires efficient
signaling that supports distributed wavelength assignment, in
particular, when the wavelength assignment capability is not
available.
As discussed in [<a href="./rfc6163" title=""Framework for GMPLS and Path Computation Element (PCE) Control of Wavelength Switched Optical Networks (WSONs)"">RFC6163</a>], different computational approaches for
wavelength assignment are available. One method is the use of
distributed wavelength assignment. This feature would allow the
specification of a particular approach when more than one is
implemented in the systems along the path.
<span class="h3"><a class="selflink" id="section-3.5" href="#section-3.5">3.5</a>. Optical Impairments</span>
This document does not address signaling information related to
optical impairments.
<span class="h2"><a class="selflink" id="section-4" href="#section-4">4</a>. WSON Signal Traffic Parameters, Attributes, and Processing</span>
As discussed in [<a href="./rfc6163" title=""Framework for GMPLS and Path Computation Element (PCE) Control of Wavelength Switched Optical Networks (WSONs)"">RFC6163</a>], single-channel optical signals used in
WSONs are called "optical tributary signals" and come in a number of
classes characterized by modulation format and bit rate. Although
WSONs are fairly transparent to the signals they carry, to ensure
compatibility amongst various networks devices and end systems, it
can be important to include key lightpath characteristics as traffic
parameters in signaling [<a href="./rfc6163" title=""Framework for GMPLS and Path Computation Element (PCE) Control of Wavelength Switched Optical Networks (WSONs)"">RFC6163</a>].
LSPs signaled through extensions provided in this document MUST apply
the following signaling parameters:
o Switching Capability = WSON-LSC [<a href="./rfc7688" title=""GMPLS OSPF Enhancement for Signal and Network Element Compatibility for Wavelength Switched Optical Networks"">RFC7688</a>]
o Encoding Type = Lambda [<a href="./rfc3471" title=""Generalized Multi-Protocol Label Switching (GMPLS) Signaling Functional Description"">RFC3471</a>]
o Label Format = as defined in [<a href="./rfc6205" title=""Generalized Labels for Lambda-Switch-Capable (LSC) Label Switching Routers"">RFC6205</a>]
[<a id="ref-RFC6205">RFC6205</a>] defines the label format as applicable to LSC capable
devices.
<span class="grey">Bernstein, et al. Standards Track [Page 6]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-7" ></span>
<span class="grey"><a href="./rfc7689">RFC 7689</a> WSON Signaling Extensions November 2015</span>
<span class="h3"><a class="selflink" id="section-4.1" href="#section-4.1">4.1</a>. Traffic Parameters for Optical Tributary Signals</span>
In [<a href="./rfc3471" title=""Generalized Multi-Protocol Label Switching (GMPLS) Signaling Functional Description"">RFC3471</a>] we see that the G-PID (client signal type) and bit rate
(byte rate) of the signals are defined as parameters, and in
[<a href="./rfc3473" title=""Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource ReserVation Protocol- Traffic Engineering (RSVP-TE) Extensions"">RFC3473</a>] they are conveyed in the Generalized Label Request object
and the RSVP SENDER_TSPEC/FLOWSPEC objects, respectively.
<span class="h3"><a class="selflink" id="section-4.2" href="#section-4.2">4.2</a>. WSON Processing Hop Attribute TLV</span>
<a href="#section-3.1">Section 3.1</a> provides requirements to signal to a node along an LSP
what type of processing to perform on an optical signal and how to
configure itself to accept or transmit an optical signal with
particular attributes.
To target a specific node, this section defines a WSON Processing Hop
Attribute TLV. This TLV is encoded as an attributes TLV; see
[<a href="./rfc5420" title=""Encoding of Attributes for MPLS LSP Establishment Using Resource Reservation Protocol Traffic Engineering (RSVP-TE)"">RFC5420</a>]. The TLV is carried in the ERO and RRO Hop Attributes
subobjects and processed according to the procedures defined in
[<a href="./rfc7570" title=""Label Switched Path (LSP) Attribute in the Explicit Route Object (ERO)"">RFC7570</a>]. The type value of the WSON Processing Hop Attribute TLV
is 4 as assigned by IANA.
The WSON Processing Hop Attribute TLV carries one or more sub-TLVs
with the following format:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
// Value //
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ... | Padding |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type
The identifier of the sub-TLV.
Length
Indicates the total length of the sub-TLV in octets. That is, the
combined length of the Type, Length, and Value fields, i.e., two
plus the length of the Value field in octets.
Value
Zero or more octets of data carried in the sub-TLV.
<span class="grey">Bernstein, et al. Standards Track [Page 7]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-8" ></span>
<span class="grey"><a href="./rfc7689">RFC 7689</a> WSON Signaling Extensions November 2015</span>
Padding
Variable
The entire sub-TLV MUST be padded with zeros to ensure four-octet
alignment of the sub-TLV.
Sub-TLV ordering is significant and MUST be preserved. Error
processing follows [<a href="./rfc7570" title=""Label Switched Path (LSP) Attribute in the Explicit Route Object (ERO)"">RFC7570</a>].
The following sub-TLV types are defined in this document:
Sub-TLV Name Type Length
--------------------------------------------------------------
ResourceBlockInfo 1 variable
WavelengthSelection 2 8 octets (2-octet padding)
The TLV can be represented in Reduced Backus-Naur Form (RBNF)
[<a href="./rfc5511" title=""Routing Backus-Naur Form (RBNF): A Syntax Used to Form Encoding Rules in Various Routing Protocol Specifications"">RFC5511</a>] syntax as:
<WSON Processing Hop Attribute> ::= <ResourceBlockInfo>
[<ResourceBlockInfo>] [<WavelengthSelection>]
<span class="h4"><a class="selflink" id="section-4.2.1" href="#section-4.2.1">4.2.1</a>. ResourceBlockInfo Sub-TLV</span>
The format of the ResourceBlockInfo sub-TLV value field is defined in
<a href="./rfc7581#section-4">Section 4 of [RFC7581]</a>. It is a list of available Optical Interface
Classes and processing capabilities.
At least one ResourceBlockInfo sub-TLV MUST be present in the WSON
Processing Hop Attribute TLV. No more than two ResourceBlockInfo
sub-TLVs SHOULD be present. Any present ResourceBlockInfo sub-TLVs
MUST be processed in the order received, and extra (unprocessed) sub-
TLVs SHOULD be ignored.
The ResourceBlockInfo field contains several information elements as
defined by [<a href="./rfc7581" title=""Routing and Wavelength Assignment Information Encoding for Wavelength Switched Optical Networks"">RFC7581</a>]. The following rules apply to the sub-TLV:
o RB Set field can carry one or more RB Identifier. Only the first
RB Identifier listed in the RB Set field SHALL be processed; any
others SHOULD be ignored.
o In the case of unidirectional LSPs, only one ResourceBlockInfo
sub-TLV SHALL be processed, and the I and O bits can be safely
ignored.
<span class="grey">Bernstein, et al. Standards Track [Page 8]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-9" ></span>
<span class="grey"><a href="./rfc7689">RFC 7689</a> WSON Signaling Extensions November 2015</span>
o In the case of a bidirectional LSP, there MUST be either:
(a) only one ResourceBlockInfo sub-TLV present in a WSON
Processing Hop Attribute TLV, and the bits I and O both set to
1, or
(b) two ResourceBlockInfo sub-TLVs present, one with only the I
bit set and the other with only the O bit set.
o The rest of the information carried within the ResourceBlockInfo
sub-TLV includes the Optical Interface Class List, Input Bit Rate
List, and Processing Capability List. These lists MAY contain one
or more elements. These elements apply equally to both
bidirectional and unidirectional LSPs.
Any violation of these rules detected by a transit or egress node
SHALL be treated as an error and be processed per [<a href="./rfc7570" title=""Label Switched Path (LSP) Attribute in the Explicit Route Object (ERO)"">RFC7570</a>].
A ResourceBlockInfo sub-TLV can be constructed by a node and added to
an ERO Hop Attributes subobject in order to be processed by
downstream nodes (transit and egress). As defined in [<a href="./rfc7570" title=""Label Switched Path (LSP) Attribute in the Explicit Route Object (ERO)"">RFC7570</a>], the
R bit reflects the LSP_REQUIRED_ATTRIBUTE and LSP_ATTRIBUTE semantic
defined in [<a href="./rfc5420" title=""Encoding of Attributes for MPLS LSP Establishment Using Resource Reservation Protocol Traffic Engineering (RSVP-TE)"">RFC5420</a>], and it SHOULD be set accordingly.
Once a node properly parses a ResourceBlockInfo sub-TLV received in
an ERO Hop Attributes subobject (according to the rules stated above
and in [<a href="./rfc7570" title=""Label Switched Path (LSP) Attribute in the Explicit Route Object (ERO)"">RFC7570</a>]), the node allocates the indicated resources, e.g.,
the selected regeneration pool, for the LSP. In addition, the node
SHOULD report compliance by adding an RRO Hop Attributes subobject
with the WSON Processing Hop Attribute TLV (and its sub-TLVs)
indicating the utilized resources. ResourceBlockInfo sub-TLVs
carried in an RRO Hop Attributes subobject are subject to [<a href="./rfc7570" title=""Label Switched Path (LSP) Attribute in the Explicit Route Object (ERO)"">RFC7570</a>]
and standard RRO processing; see [<a href="./rfc3209" title=""RSVP-TE: Extensions to RSVP for LSP Tunnels"">RFC3209</a>].
<span class="h4"><a class="selflink" id="section-4.2.2" href="#section-4.2.2">4.2.2</a>. WavelengthSelection Sub-TLV</span>
Routing + Distributed Wavelength Assignment (R+DWA) is one of the
options defined by [<a href="./rfc6163" title=""Framework for GMPLS and Path Computation Element (PCE) Control of Wavelength Switched Optical Networks (WSONs)"">RFC6163</a>]. The output from the routing function
will be a path, but the wavelength will be selected on a hop-by-hop
basis.
As discussed in [<a href="./rfc6163" title=""Framework for GMPLS and Path Computation Element (PCE) Control of Wavelength Switched Optical Networks (WSONs)"">RFC6163</a>], the wavelength assignment can be either
for a unidirectional lightpath or for a bidirectional lightpath
constrained to use the same lambda in both directions.
In order to indicate wavelength assignment directionality and
wavelength assignment method, the WavelengthSelection sub-TLV is
carried in the WSON Processing Hop Attribute TLV defined above.
<span class="grey">Bernstein, et al. Standards Track [Page 9]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-10" ></span>
<span class="grey"><a href="./rfc7689">RFC 7689</a> WSON Signaling Extensions November 2015</span>
The WavelengthSelection sub-TLV value field is defined as:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|W| WA Method | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Where:
W (1 bit): 0 denotes requiring the same wavelength in both
directions; 1 denotes that different wavelengths on both
directions are allowed.
Wavelength Assignment (WA) Method (7 bits):
0: unspecified (any); This does not constrain the WA method used
by a specific node. This value is implied when the
WavelengthSelection sub-TLV is absent.
1: First-Fit. All the wavelengths are numbered, and this WA
method chooses the available wavelength with the lowest index.
2: Random. This WA method chooses an available wavelength
randomly.
3: Least-Loaded (multi-fiber). This WA method selects the
wavelength that has the largest residual capacity on the most
loaded link along the route. This method is used in multi-
fiber networks. If used in single-fiber networks, it is
equivalent to the First-Fit WA method.
4-127: Unassigned.
The processing rules for this TLV are as follows:
If a receiving node does not support the attribute(s), its behaviors
are specified below:
- W bit not supported: a PathErr MUST be generated with the Error
Code "Routing Problem" (24) with error sub-code "Unsupported
WavelengthSelection Symmetry value" (107).
- WA method not supported: a PathErr MUST be generated with the
Error Code "Routing Problem" (24) with error sub-code "Unsupported
Wavelength Assignment value" (108).
<span class="grey">Bernstein, et al. Standards Track [Page 10]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-11" ></span>
<span class="grey"><a href="./rfc7689">RFC 7689</a> WSON Signaling Extensions November 2015</span>
A WavelengthSelection sub-TLV can be constructed by a node and added
to an ERO Hop Attributes subobject in order to be processed by
downstream nodes (transit and egress). As defined in [<a href="./rfc7570" title=""Label Switched Path (LSP) Attribute in the Explicit Route Object (ERO)"">RFC7570</a>], the
R bit reflects the LSP_REQUIRED_ATTRIBUTE and LSP_ATTRIBUTE semantic
defined in [<a href="./rfc5420" title=""Encoding of Attributes for MPLS LSP Establishment Using Resource Reservation Protocol Traffic Engineering (RSVP-TE)"">RFC5420</a>], and it SHOULD be set accordingly.
Once a node properly parses the WavelengthSelection sub-TLV received
in an ERO Hop Attributes subobject, the node use the indicated
wavelength assignment method (at that hop) for the LSP. In addition,
the node SHOULD report compliance by adding an RRO Hop Attributes
subobject with the WSON Processing Hop Attribute TLV (and its sub-
TLVs) that indicate the utilized method. WavelengthSelection sub-
TLVs carried in an RRO Hop Attributes subobject are subject to
[<a href="./rfc7570" title=""Label Switched Path (LSP) Attribute in the Explicit Route Object (ERO)"">RFC7570</a>] and standard RRO processing; see [<a href="./rfc3209" title=""RSVP-TE: Extensions to RSVP for LSP Tunnels"">RFC3209</a>].
<span class="h2"><a class="selflink" id="section-5" href="#section-5">5</a>. Security Considerations</span>
This document is built on the mechanisms defined in [<a href="./rfc3473" title=""Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource ReserVation Protocol- Traffic Engineering (RSVP-TE) Extensions"">RFC3473</a>], and
only differs in the specific information communicated. The specific
additional information (optical resource and wavelength selection
properties) is not viewed as substantively changing or adding to the
security considerations of the existing GMPLS signaling protocol
mechanisms. See [<a href="./rfc3473" title=""Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource ReserVation Protocol- Traffic Engineering (RSVP-TE) Extensions"">RFC3473</a>] for details of the supported security
measures. Additionally, [<a href="./rfc5920" title=""Security Framework for MPLS and GMPLS Networks"">RFC5920</a>] provides an overview of security
vulnerabilities and protection mechanisms for the GMPLS control
plane.
<span class="h2"><a class="selflink" id="section-6" href="#section-6">6</a>. IANA Considerations</span>
IANA has assigned a new value in the existing "Attributes TLV Space"
registry located at
<<a href="http://www.iana.org/assignments/rsvp-te-parameters">http://www.iana.org/assignments/rsvp-te-parameters</a>>, as updated by
[<a href="./rfc7570" title=""Label Switched Path (LSP) Attribute in the Explicit Route Object (ERO)"">RFC7570</a>]:
Type Name Allowed on Allowed on Allowed on Reference
LSP LSP REQUIRED RO LSP
ATTRIBUTES ATTRIBUTES Attribute
Subobject
4 WSON No No Yes <a href="./rfc7689">RFC 7689</a>
Processing
Hop
Attribute
TLV
<span class="grey">Bernstein, et al. Standards Track [Page 11]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-12" ></span>
<span class="grey"><a href="./rfc7689">RFC 7689</a> WSON Signaling Extensions November 2015</span>
IANA has created a new registry named "Sub-TLV Types for WSON
Processing Hop Attribute TLV" located at
<<a href="http://www.iana.org/assignments/rsvp-te-parameters">http://www.iana.org/assignments/rsvp-te-parameters</a>>.
The following entries have been added:
Value Sub-TLV Type Reference
0 Reserved <a href="./rfc7689">RFC 7689</a>
1 ResourceBlockInfo <a href="./rfc7689">RFC 7689</a>
2 WavelengthSelection <a href="./rfc7689">RFC 7689</a>
All assignments are to be performed via Standards Action or
Specification Required policies as defined in [<a href="./rfc5226" title="">RFC5226</a>].
IANA has created a new registry named "Values for Wavelength
Assignment Method field in WavelengthSelection Sub-TLV" located at
<<a href="http://www.iana.org/assignments/rsvp-te-parameters">http://www.iana.org/assignments/rsvp-te-parameters</a>>.
The following entries have been added:
Value Meaning Reference
0 unspecified <a href="./rfc7689">RFC 7689</a>
1 First-Fit <a href="./rfc7689">RFC 7689</a>
2 Random <a href="./rfc7689">RFC 7689</a>
3 Least-Loaded (multi-fiber) <a href="./rfc7689">RFC 7689</a>
4-127 Unassigned
All assignments are to be performed via Standards Action or
Specification Required policies as defined in [<a href="./rfc5226" title="">RFC5226</a>]. The
assignment policy chosen for any specific code point must be clearly
stated in the document that describes the code point so that IANA can
apply the correct policy.
<span class="grey">Bernstein, et al. Standards Track [Page 12]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-13" ></span>
<span class="grey"><a href="./rfc7689">RFC 7689</a> WSON Signaling Extensions November 2015</span>
IANA has assigned new values in the existing "Sub-Codes - 24 Routing
Problem" registry located at
<<a href="http://www.iana.org/assignments/rsvp-parameters">http://www.iana.org/assignments/rsvp-parameters</a>>:
Value Description Reference
107 Unsupported WavelengthSelection
symmetry value <a href="./rfc7689">RFC 7689</a>
108 Unsupported Wavelength Assignment
value <a href="./rfc7689">RFC 7689</a>
<span class="h2"><a class="selflink" id="section-7" href="#section-7">7</a>. References</span>
<span class="h3"><a class="selflink" id="section-7.1" href="#section-7.1">7.1</a>. Normative References</span>
[<a id="ref-RFC2119">RFC2119</a>] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", <a href="https://www.rfc-editor.org/bcp/bcp14">BCP 14</a>, <a href="./rfc2119">RFC 2119</a>,
DOI 10.17487/RFC2119, March 1997,
<<a href="http://www.rfc-editor.org/info/rfc2119">http://www.rfc-editor.org/info/rfc2119</a>>.
[<a id="ref-RFC3209">RFC3209</a>] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,
and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
Tunnels", <a href="./rfc3209">RFC 3209</a>, DOI 10.17487/RFC3209, December 2001,
<<a href="http://www.rfc-editor.org/info/rfc3209">http://www.rfc-editor.org/info/rfc3209</a>>.
[<a id="ref-RFC3471">RFC3471</a>] Berger, L., Ed., "Generalized Multi-Protocol Label
Switching (GMPLS) Signaling Functional Description", <a href="./rfc3471">RFC</a>
<a href="./rfc3471">3471</a>, DOI 10.17487/RFC3471, January 2003,
<<a href="http://www.rfc-editor.org/info/rfc3471">http://www.rfc-editor.org/info/rfc3471</a>>.
[<a id="ref-RFC3473">RFC3473</a>] Berger, L., Ed., "Generalized Multi-Protocol Label
Switching (GMPLS) Signaling Resource ReserVation Protocol-
Traffic Engineering (RSVP-TE) Extensions", <a href="./rfc3473">RFC 3473</a>,
DOI 10.17487/RFC3473, January 2003,
<<a href="http://www.rfc-editor.org/info/rfc3473">http://www.rfc-editor.org/info/rfc3473</a>>.
[<a id="ref-RFC5226">RFC5226</a>] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", <a href="https://www.rfc-editor.org/bcp/bcp26">BCP 26</a>, <a href="./rfc5226">RFC 5226</a>,
DOI 10.17487/RFC5226, May 2008,
<<a href="http://www.rfc-editor.org/info/rfc5226">http://www.rfc-editor.org/info/rfc5226</a>>.
[<a id="ref-RFC5420">RFC5420</a>] Farrel, A., Ed., Papadimitriou, D., Vasseur, JP., and A.
Ayyangarps, "Encoding of Attributes for MPLS LSP
Establishment Using Resource Reservation Protocol Traffic
Engineering (RSVP-TE)", <a href="./rfc5420">RFC 5420</a>, DOI 10.17487/RFC5420,
February 2009, <<a href="http://www.rfc-editor.org/info/rfc5420">http://www.rfc-editor.org/info/rfc5420</a>>.
<span class="grey">Bernstein, et al. Standards Track [Page 13]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-14" ></span>
<span class="grey"><a href="./rfc7689">RFC 7689</a> WSON Signaling Extensions November 2015</span>
[<a id="ref-RFC5511">RFC5511</a>] Farrel, A., "Routing Backus-Naur Form (RBNF): A Syntax
Used to Form Encoding Rules in Various Routing Protocol
Specifications", <a href="./rfc5511">RFC 5511</a>, DOI 10.17487/RFC5511, April
2009, <<a href="http://www.rfc-editor.org/info/rfc5511">http://www.rfc-editor.org/info/rfc5511</a>>.
[<a id="ref-RFC6205">RFC6205</a>] Otani, T., Ed., and D. Li, Ed., "Generalized Labels for
Lambda-Switch-Capable (LSC) Label Switching Routers", <a href="./rfc6205">RFC</a>
<a href="./rfc6205">6205</a>, DOI 10.17487/RFC6205, March 2011,
<<a href="http://www.rfc-editor.org/info/rfc6205">http://www.rfc-editor.org/info/rfc6205</a>>.
[<a id="ref-RFC7570">RFC7570</a>] Margaria, C., Ed., Martinelli, G., Balls, S., and B.
Wright, "Label Switched Path (LSP) Attribute in the
Explicit Route Object (ERO)", <a href="./rfc7570">RFC 7570</a>,
DOI 10.17487/RFC7570, July 2015,
<<a href="http://www.rfc-editor.org/info/rfc7570">http://www.rfc-editor.org/info/rfc7570</a>>.
[<a id="ref-RFC7581">RFC7581</a>] Bernstein, G., Ed., Lee, Y., Ed., Li, D., Imajuku, W., and
J. Han, "Routing and Wavelength Assignment Information
Encoding for Wavelength Switched Optical Networks", <a href="./rfc7581">RFC</a>
<a href="./rfc7581">7581</a>, DOI 10.17487/RFC7581, June 2015,
<<a href="http://www.rfc-editor.org/info/rfc7581">http://www.rfc-editor.org/info/rfc7581</a>>.
[<a id="ref-RFC7688">RFC7688</a>] Lee, Y., Ed., and G. Bernstein, Ed., "GMPLS OSPF
Enhancement for Signal and Network Element Compatibility
for Wavelength Switched Optical Networks", <a href="./rfc7688">RFC 7688</a>,
DOI 10.17487/RFC7688, November 2015,
<<a href="http://www.rfc-editor.org/info/rfc7688">http://www.rfc-editor.org/info/rfc7688</a>>.
<span class="h3"><a class="selflink" id="section-7.2" href="#section-7.2">7.2</a>. Informative References</span>
[<a id="ref-RFC5920">RFC5920</a>] Fang, L., Ed., "Security Framework for MPLS and GMPLS
Networks", <a href="./rfc5920">RFC 5920</a>, DOI 10.17487/RFC5920, July 2010,
<<a href="http://www.rfc-editor.org/info/rfc5920">http://www.rfc-editor.org/info/rfc5920</a>>.
[<a id="ref-RFC6163">RFC6163</a>] Lee, Y., Ed., Bernstein, G., Ed., and W. Imajuku,
"Framework for GMPLS and Path Computation Element (PCE)
Control of Wavelength Switched Optical Networks (WSONs)",
<a href="./rfc6163">RFC 6163</a>, DOI 10.17487/RFC6163, April 2011,
<<a href="http://www.rfc-editor.org/info/rfc6163">http://www.rfc-editor.org/info/rfc6163</a>>.
[<a id="ref-RFC7446">RFC7446</a>] Lee, Y., Ed., Bernstein, G., Ed., Li, D., and W. Imajuku,
"Routing and Wavelength Assignment Information Model for
Wavelength Switched Optical Networks", <a href="./rfc7446">RFC 7446</a>,
DOI 10.17487/RFC7446, February 2015,
<<a href="http://www.rfc-editor.org/info/rfc7446">http://www.rfc-editor.org/info/rfc7446</a>>.
<span class="grey">Bernstein, et al. Standards Track [Page 14]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-15" ></span>
<span class="grey"><a href="./rfc7689">RFC 7689</a> WSON Signaling Extensions November 2015</span>
Acknowledgments
The authors would like to thanks Lou Berger, Cyril Margaria, and Xian
Zhang for their comments and suggestions.
Contributors
Nicola Andriolli
Scuola Superiore Sant'Anna
Pisa, Italy
Email: nick@sssup.it
Alessio Giorgetti
Scuola Superiore Sant'Anna
Pisa, Italy
Email: a.giorgetti@sssup.it
Lin Guo
Key Laboratory of Optical Communication and Lightwave Technologies
Ministry of Education
P.O. Box 128, Beijing University of Posts and Telecommunications
China
Email: guolintom@gmail.com
Yuefeng Ji
Key Laboratory of Optical Communication and Lightwave Technologies
Ministry of Education
P.O. Box 128, Beijing University of Posts and Telecommunications
China
Email: jyf@bupt.edu.cn
Daniel King
Old Dog Consulting
Email: daniel@olddog.co.uk
<span class="grey">Bernstein, et al. Standards Track [Page 15]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-16" ></span>
<span class="grey"><a href="./rfc7689">RFC 7689</a> WSON Signaling Extensions November 2015</span>
Authors' Addresses
Greg M. Bernstein (editor)
Grotto Networking
Fremont, CA
United States
Phone: (510) 573-2237
Email: gregb@grotto-networking.com
Sugang Xu
National Institute of Information and Communications Technology
4-2-1 Nukui-Kitamachi, Koganei,
Tokyo, 184-8795
Japan
Phone: +81 42-327-6927
Email: xsg@nict.go.jp
Young Lee (editor)
Huawei Technologies
5340 Legacy Dr. Building 3
Plano, TX 75024
United States
Phone: (469) 277-5838
Email: leeyoung@huawei.com
Giovanni Martinelli
Cisco
Via Philips 12
20052 Monza
Italy
Phone: +39 039-209-2044
Email: giomarti@cisco.com
Hiroaki Harai
National Institute of Information and Communications Technology
4-2-1 Nukui-Kitamachi, Koganei,
Tokyo, 184-8795
Japan
Phone: +81 42-327-5418
Email: harai@nict.go.jp
Bernstein, et al. Standards Track [Page 16]
</pre>
|
