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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285
  
     | 
    
      <pre>Internet Engineering Task Force (IETF)                       Y. Lee, Ed.
Request for Comments: 7446                                        Huawei
Category: Informational                                G. Bernstein, Ed.
ISSN: 2070-1721                                        Grotto Networking
                                                                   D. Li
                                                                  Huawei
                                                              W. Imajuku
                                                                     NTT
                                                           February 2015
          <span class="h1">Routing and Wavelength Assignment Information Model</span>
                <span class="h1">for Wavelength Switched Optical Networks</span>
Abstract
   This document provides a model of information needed by the Routing
   and Wavelength Assignment (RWA) process in Wavelength Switched
   Optical Networks (WSONs).  The purpose of the information described
   in this model is to facilitate constrained optical path computation
   in WSONs.  This model takes into account compatibility constraints
   between WSON signal attributes and network elements but does not
   include constraints due to optical impairments.  Aspects of this
   information that may be of use to other technologies utilizing a
   GMPLS control plane are discussed.
Status of This Memo
   This document is not an Internet Standards Track specification; it is
   published for informational purposes.
   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).  Not all documents
   approved by the IESG are a candidate for any level of Internet
   Standard; see <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/rfc7446">http://www.rfc-editor.org/info/rfc7446</a>.
<span class="grey">Lee, et al.                   Informational                     [Page 1]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-2" ></span>
<span class="grey"><a href="./rfc7446">RFC 7446</a>                 WSON Information Model            February 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-3">3</a>. Routing and Wavelength Assignment Information Model .............<a href="#page-3">3</a>
      <a href="#section-3.1">3.1</a>. Dynamic and Relatively Static Information ..................<a href="#page-4">4</a>
   <a href="#section-4">4</a>. Node Information (General) ......................................<a href="#page-4">4</a>
      <a href="#section-4.1">4.1</a>. Connectivity Matrix ........................................<a href="#page-5">5</a>
   <a href="#section-5">5</a>. Node Information (WSON Specific) ................................<a href="#page-5">5</a>
      <a href="#section-5.1">5.1</a>. Resource Accessibility/Availability ........................<a href="#page-7">7</a>
      <a href="#section-5.2">5.2</a>. Resource Signal Constraints and Processing Capabilities ...<a href="#page-11">11</a>
      <a href="#section-5.3">5.3</a>. Compatibility and Capability Details ......................<a href="#page-12">12</a>
           <a href="#section-5.3.1">5.3.1</a>. Shared Input or Output Indication ..................<a href="#page-12">12</a>
           <a href="#section-5.3.2">5.3.2</a>. Optical Interface Class List .......................<a href="#page-12">12</a>
           <a href="#section-5.3.3">5.3.3</a>. Acceptable Client Signal List ......................<a href="#page-13">13</a>
           <a href="#section-5.3.4">5.3.4</a>. Processing Capability List .........................<a href="#page-13">13</a>
   <a href="#section-6">6</a>. Link Information (General) .....................................<a href="#page-13">13</a>
      <a href="#section-6.1">6.1</a>. Administrative Group ......................................<a href="#page-14">14</a>
      <a href="#section-6.2">6.2</a>. Interface Switching Capability Descriptor .................<a href="#page-14">14</a>
      <a href="#section-6.3">6.3</a>. Link Protection Type (for This Link) ......................<a href="#page-14">14</a>
      <a href="#section-6.4">6.4</a>. Shared Risk Link Group Information ........................<a href="#page-14">14</a>
      <a href="#section-6.5">6.5</a>. Traffic Engineering Metric ................................<a href="#page-15">15</a>
      <a href="#section-6.6">6.6</a>. Port Label Restrictions ...................................<a href="#page-15">15</a>
           <a href="#section-6.6.1">6.6.1</a>. Port-Wavelength Exclusivity Example ................<a href="#page-17">17</a>
   <a href="#section-7">7</a>. Dynamic Components of the Information Model ....................<a href="#page-18">18</a>
      <a href="#section-7.1">7.1</a>. Dynamic Link Information (General) ........................<a href="#page-19">19</a>
      <a href="#section-7.2">7.2</a>. Dynamic Node Information (WSON Specific) ..................<a href="#page-19">19</a>
   <a href="#section-8">8</a>. Security Considerations ........................................<a href="#page-19">19</a>
   <a href="#section-9">9</a>. References .....................................................<a href="#page-20">20</a>
      <a href="#section-9.1">9.1</a>. Normative References ......................................<a href="#page-20">20</a>
      <a href="#section-9.2">9.2</a>. Informative References ....................................<a href="#page-21">21</a>
   Contributors ......................................................<a href="#page-22">22</a>
   Authors' Addresses ................................................<a href="#page-23">23</a>
<span class="grey">Lee, et al.                   Informational                     [Page 2]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-3" ></span>
<span class="grey"><a href="./rfc7446">RFC 7446</a>                 WSON Information Model            February 2015</span>
<span class="h2"><a class="selflink" id="section-1" href="#section-1">1</a>.  Introduction</span>
   The purpose of the WSON information model described in this document
   is to facilitate constrained optical path computation, and as such it
   is not a general-purpose network management information model.  This
   constraint is frequently referred to as the "wavelength continuity"
   constraint, and the corresponding constrained optical path
   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 [<a href="./rfc6163" title=""Framework for GMPLS and Path Computation Element (PCE) Control of Wavelength Switched Optical Networks (WSONs)"">RFC6163</a>].  The model
   defined here includes constraints between WSON signal attributes and
   network elements but does not include optical impairments.
   In addition to presenting an information model suitable for path
   computation in WSON, this document also highlights model aspects that
   may have general applicability to other technologies utilizing a
   GMPLS control plane.  The portion of the information model applicable
   to technologies beyond WSON is referred to as "general" to
   distinguish it from the "WSON-specific" portion that is applicable
   only to WSON technology.
<span class="h2"><a class="selflink" id="section-2" href="#section-2">2</a>.  Terminology</span>
   Refer to [<a href="./rfc6163" title=""Framework for GMPLS and Path Computation Element (PCE) Control of Wavelength Switched Optical Networks (WSONs)"">RFC6163</a>] for definitions of Reconfigurable Optical Add/Drop
   Multiplexer (ROADM), RWA, Wavelength Conversion, Wavelength Division
   Multiplexing (WDM), WSON, and other related terminology used in this
   document.
<span class="h2"><a class="selflink" id="section-3" href="#section-3">3</a>.  Routing and Wavelength Assignment Information Model</span>
   The WSON RWA information model in this document comprises four
   categories of information.  The categories are independent of whether
   the information comes from a switching subsystem or from a line
   subsystem -- a switching subsystem refers to WSON nodes such as a
   ROADM or an Optical Add/Drop Multiplexer (OADM), and a line subsystem
   refers to devices such as WDM or Optical Amplifier.  The categories
   are these:
   o  Node Information
   o  Link Information
   o  Dynamic Node Information
   o  Dynamic Link Information
<span class="grey">Lee, et al.                   Informational                     [Page 3]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-4" ></span>
<span class="grey"><a href="./rfc7446">RFC 7446</a>                 WSON Information Model            February 2015</span>
   Note that this is roughly the categorization used in Section 7 of
   [<a href="#ref-G.7715" title=""Architecture and requirements for routing in the automatically switched optical networks"">G.7715</a>].
   In the following, where applicable, the Reduced Backus-Naur Form
   (RBNF) syntax of [<a href="#ref-RBNF" title=""Routing Backus-Naur Form (RBNF): A Syntax Used to Form Encoding Rules in Various Routing Protocol Specifications"">RBNF</a>] is used to aid in defining the RWA
   information model.
<span class="h3"><a class="selflink" id="section-3.1" href="#section-3.1">3.1</a>.  Dynamic and Relatively Static Information</span>
   All the RWA information of concern in a WSON network is subject to
   change over time.  Equipment can be upgraded; links may be placed in
   or out of service and the like.  However, from the point of view of
   RWA computations, there is a difference between information that can
   change with each successive connection establishment in the network
   and information that is relatively static and independent of
   connection establishment.  A key example of the former is link
   wavelength usage since this can change with connection setup/teardown
   and this information is a key input to the RWA process.  Examples of
   relatively static information are the potential port connectivity of
   a WDM ROADM, and the channel spacing on a WDM link.
   This document separates, where possible, dynamic and static
   information so that these can be kept separate in possible encodings.
   This allows for separate updates of these two types of information,
   thereby reducing processing and traffic load caused by the timely
   distribution of the more dynamic RWA WSON information.
<span class="h2"><a class="selflink" id="section-4" href="#section-4">4</a>.  Node Information (General)</span>
   The node information described here contains the relatively static
   information related to a WSON node.  This includes connectivity
   constraints amongst ports and wavelengths since WSON switches can
   exhibit asymmetric switching properties.  Additional information
   could include properties of wavelength converters in the node, if any
   are present.  In [<a href="#ref-Switch" title=""Modeling WDM Wavelength Switching Systems for Use in GMPLS and Automated Path Computation"">Switch</a>] it was shown that the wavelength
   connectivity constraints for a large class of practical WSON devices
   can be modeled via switched and fixed connectivity matrices along
   with corresponding switched and fixed port constraints.  These
   connectivity matrices are included with the node information, while
   the switched and fixed port wavelength constraints are included with
   the link information.
   Formally,
   <Node_Information> ::= <Node_ID> [<ConnectivityMatrix>...]
   Where the Node_ID would be an appropriate identifier for the node
   within the WSON RWA context.
<span class="grey">Lee, et al.                   Informational                     [Page 4]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-5" ></span>
<span class="grey"><a href="./rfc7446">RFC 7446</a>                 WSON Information Model            February 2015</span>
   Note that multiple connectivity matrices are allowed and hence can
   fully support the most-general cases enumerated in [<a href="#ref-Switch" title=""Modeling WDM Wavelength Switching Systems for Use in GMPLS and Automated Path Computation"">Switch</a>].
<span class="h3"><a class="selflink" id="section-4.1" href="#section-4.1">4.1</a>.  Connectivity Matrix</span>
   The connectivity matrix (ConnectivityMatrix) represents either the
   potential connectivity matrix for asymmetric switches (e.g., ROADMs
   and such) or fixed connectivity for an asymmetric device such as a
   multiplexer.  Note that this matrix does not represent any particular
   internal blocking behavior but indicates which input ports and
   wavelengths could possibly be connected to a particular output port.
   For a switch or ROADM, representing blocking that is dependent on the
   internal state is beyond the scope of this document.  Due to its
   highly implementation-dependent nature, it would most likely not be
   subject to standardization in the future.  The connectivity matrix is
   a conceptual M by N matrix representing the potential switched or
   fixed connectivity, where M represents the number of input ports and
   N the number of output ports.  This is a "conceptual" matrix since
   the matrix tends to exhibit structure that allows for very compact
   representations that are useful for both transmission and path
   computation.
   Note that the connectivity matrix information element can be useful
   in any technology context where asymmetric switches are utilized.
   <ConnectivityMatrix> ::= <MatrixID>
                            <ConnType>
                            <Matrix>
   Where
   <MatrixID> is a unique identifier for the matrix.
   <ConnType> can be either 0 or 1 depending upon whether the
   connectivity is either fixed or switched.
   <Matrix> represents the fixed or switched connectivity in that
   Matrix(i, j) = 0 or 1 depending on whether input port i can connect
   to output port j for one or more wavelengths.
<span class="h2"><a class="selflink" id="section-5" href="#section-5">5</a>.  Node Information (WSON Specific)</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>], a WSON node may contain electro-optical
   subsystems such as regenerators, wavelength converters or entire
   switching subsystems.  The model present here can be used in
   characterizing the accessibility and availability of limited
<span class="grey">Lee, et al.                   Informational                     [Page 5]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-6" ></span>
<span class="grey"><a href="./rfc7446">RFC 7446</a>                 WSON Information Model            February 2015</span>
   resources such as regenerators or wavelength converters as well as
   WSON signal attribute constraints of electro-optical subsystems.  As
   such, this information element is fairly specific to WSON
   technologies.
   In this document, the term "resource" is used to refer to a physical
   component of a WSON node such as a regenerator or a wavelength
   converter.  Multiple instances of such components are often present
   within a single WSON node.  This term is not to be confused with the
   concept of forwarding or switching resources such as bandwidth or
   lambdas.
   A WSON node may include regenerators or wavelength converters
   arranged in a shared pool.  As discussed in [<a href="./rfc6163" title=""Framework for GMPLS and Path Computation Element (PCE) Control of Wavelength Switched Optical Networks (WSONs)"">RFC6163</a>], a WSON node
   can also include WDM switches that use optical-electronic-optical
   (OEO) processing.  There are a number of different approaches used in
   the design of WDM switches containing regenerator or converter pools.
   However, from the point of view of path computation, the following
   need to be known:
   1.  The nodes that support regeneration or wavelength conversion.
   2.  The accessibility and availability of a wavelength converter to
       convert from a given input wavelength on a particular input port
       to a desired output wavelength on a particular output port.
   3.  Limitations on the types of signals that can be converted and the
       conversions that can be performed.
   Since resources tend to be packaged together in blocks of similar
   devices, e.g., on line cards or other types of modules, the
   fundamental unit of identifiable resource in this document is the
   "resource block".
   A resource block is a collection of resources from the same WSON node
   that are grouped together for administrative reasons and for ease of
   encoding in the protocols.  All resources in the same resource block
   behave in the same way and have similar characteristics relevant to
   the optical system, e.g., processing properties, accessibility, etc.
   A resource pool is a collection of resource blocks for the purpose of
   representing throughput or cross-connect capabilities in a WSON node.
   A resource pool associates input ports or links on the node with
   output ports or links and is used to indicate how signals may be
   passed from an input port or link to an output port or link by way of
   a resource block (in other words, by way of a resource).  A resource
   pool may, therefore, be modeled as a matrix.
<span class="grey">Lee, et al.                   Informational                     [Page 6]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-7" ></span>
<span class="grey"><a href="./rfc7446">RFC 7446</a>                 WSON Information Model            February 2015</span>
   A resource block may be present in multiple resource pools.
   This leads to the following formal high-level model:
   <Node_Information> ::= <Node_ID>
                          [<ConnectivityMatrix>...]
                          [<ResourcePool>]
   Where
   <ResourcePool> ::= <ResourceBlockInfo>...
                     [<ResourceAccessibility>...]
                     [<ResourceWaveConstraints>...]
                     [<RBPoolState>]
   First, the accessibility of resource blocks is addressed; then, their
   properties are discussed.
<span class="h3"><a class="selflink" id="section-5.1" href="#section-5.1">5.1</a>.  Resource Accessibility/Availability</span>
   A similar technique as used to model ROADMs, and optical switches can
   be used to model regenerator/converter accessibility.  This technique
   was generally discussed in [<a href="./rfc6163" title=""Framework for GMPLS and Path Computation Element (PCE) Control of Wavelength Switched Optical Networks (WSONs)"">RFC6163</a>] and consisted of a matrix to
   indicate possible connectivity along with wavelength constraints for
   links/ports.  Since regenerators or wavelength converters may be
   considered a scarce resource, it is desirable that the model include,
   if desired, the usage state (availability) of individual regenerators
   or converters in the pool.  Models that incorporate more state to
   further reveal blocking conditions on input or output to particular
   converters are for further study and not included here.
   The three-stage model is shown schematically in Figures 1 and 2.  The
   difference between the two figures is that in Figure 1 it's assumed
   that each signal that can get to a resource block may do so, while in
   Figure 2 the access to sets of resource blocks is via a shared fiber
   that imposes its own wavelength collision constraint.  Figure 1 shows
   that there can be more than one input to each resource block since
   each input represents a single wavelength signal, while Figure 2
   shows a single WDM input or output, e.g., a fiber, to/from each set
   of blocks.
<span class="grey">Lee, et al.                   Informational                     [Page 7]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-8" ></span>
<span class="grey"><a href="./rfc7446">RFC 7446</a>                 WSON Information Model            February 2015</span>
   This model assumes N input ports (fibers), P resource blocks
   containing one or more identical resources (e.g., wavelength
   converters), and M output ports (fibers).  Since not all input ports
   can necessarily reach each resource block, the model starts with a
   resource pool input matrix RI(i,p) = {0,1} depending on whether input
   port i can potentially reach resource block p.
   Since not all wavelengths can necessarily reach all the resources or
   the resources may have limited input wavelength range, the model has
   a set of relatively static input port constraints for each resource.
   In addition, if the access to a set of resource blocks is via a
   shared fiber (Figure 2), this would impose a dynamic wavelength
   availability constraint on that shared fiber.  The resource block
   input port constraint is modeled via a static wavelength set
   mechanism, and the case of shared access to a set of blocks is
   modeled via a dynamic wavelength set mechanism.
   Next, a state vector RA(j) = {0,...,k} is used to track the number of
   resources in resource block j in use.  This is the only state kept in
   the resource pool model.  This state is not necessary for modeling
   "fixed" transponder system or full OEO switches with WDM interfaces,
   i.e., systems where there is no sharing.
   After that, a set of static resource output wavelength constraints
   and possibly dynamic shared output fiber constraints maybe used.  The
   static constraints indicate what wavelengths a particular resource
   block can generate or is restricted to generating, e.g., a fixed
   regenerator would be limited to a single lambda.  The dynamic
   constraints would be used in the case where a single shared fiber is
   used to output the resource block (Figure 2).
   Finally, to complete the model, a resource pool output matrix RE(p,k)
   = {0,1} depending on whether the output from resource block p can
   reach output port k, may be used.
<span class="grey">Lee, et al.                   Informational                     [Page 8]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-9" ></span>
<span class="grey"><a href="./rfc7446">RFC 7446</a>                 WSON Information Model            February 2015</span>
      I1   +-------------+                       +-------------+ O1
     ----->|             |      +--------+       |             |----->
      I2   |             +------+ Rb #1  +-------+             | O2
     ----->|             |      +--------+       |             |----->
           |             |                       |             |
           | Resource    |      +--------+       |  Resource   |
           | Pool        +------+        +-------+  Pool       |
           |             |      + Rb #2  +       |             |
           | Input       +------+        +-------|  Output     |
           | Connection  |      +--------+       |  Connection |
           | Matrix      |           .           |  Matrix     |
           |             |           .           |             |
           |             |           .           |             |
      IN   |             |      +--------+       |             | OM
     ----->|             +------+ Rb #P  +-------+             |----->
           |             |      +--------+       |             |
           +-------------+   ^               ^   +-------------+
                             |               |
                             |               |
                             |               |
                             |               |
                    Input wavelength      Output wavelength
                    constraints for       constraints for
                    each resource         each resource
   Note: Rb is a resource block.
           Figure 1: Schematic Diagram of the Resource Pool Model
<span class="grey">Lee, et al.                   Informational                     [Page 9]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-10" ></span>
<span class="grey"><a href="./rfc7446">RFC 7446</a>                 WSON Information Model            February 2015</span>
    I1   +-------------+                       +-------------+ O1
   ----->|             |      +--------+       |             |----->
    I2   |             +======+ Rb #1  +-+     |             | O2
   ----->|             |      +--------+ |     |             |----->
         |             |                 |=====|             |
         | Resource    |      +--------+ |     |  Resource   |
         | Pool        |    +-+ Rb #2  +-+     |  Pool       |
         |             |    | +--------+       |             |
         | Input       |====|                  |  Output     |
         | Connection  |    | +--------+       |  Connection |
         | Matrix      |    +-| Rb #3  |=======|  Matrix     |
         |             |      +--------+       |             |
         |             |           .           |             |
         |             |           .           |             |
         |             |           .           |             |
    IN   |             |      +--------+       |             | OM
   ----->|             +======+ Rb #P  +=======+             |----->
         |             |      +--------+       |             |
         +-------------+   ^               ^   +-------------+
                           |               |
                           |               |
                           |               |
               Single (shared) fibers for block input and output
                Input wavelength          Output wavelength
                availability for          availability for
                each block input fiber    each block output fiber
   Note: Rb is a resource block.
    Figure 2: Schematic Diagram of the Resource Pool Model with
                    Shared Block Accessibility
   Formally, the model can be specified as:
   <ResourceAccessibility> ::= <PoolInputMatrix>
                               <PoolOutputMatrix>
   <ResourceWaveConstraints> ::= <InputWaveConstraints>
                                 <OutputWaveConstraints>
   <RBSharedAccessWaveAvailability> ::= [<InAvailableWavelengths>]
                                        [<OutAvailableWavelengths>]
<span class="grey">Lee, et al.                   Informational                    [Page 10]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-11" ></span>
<span class="grey"><a href="./rfc7446">RFC 7446</a>                 WSON Information Model            February 2015</span>
   <RBPoolState> ::=    <ResourceBlockID>
                        <NumResourcesInUse>
                        [<RBSharedAccessWaveAvailability>]
                        [<RBPoolState>]
   Note that, except for <RBPoolState>, all the components of
   <ResourcePool> are relatively static.  Also, the
   <InAvailableWavelengths> and <OutAvailableWavelengths> are only used
   in the cases of shared input or output access to the particular
   block.  See the resource block information in the next section for
   how this is specified.
<span class="h3"><a class="selflink" id="section-5.2" href="#section-5.2">5.2</a>.  Resource Signal Constraints and Processing Capabilities</span>
   The wavelength conversion abilities of a resource (e.g., regenerator,
   wavelength converter) were modeled in the <OutputWaveConstraints>
   previously discussed.  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 constraints on
   an electro-optical resource can be modeled in terms of input
   constraints, processing capabilities, and output constraints:
   <ResourceBlockInfo> ::= <ResourceBlockSet>
                           [<InputConstraints>]
                           [<ProcessingCapabilities>]
                           [<OutputConstraints>]
   Where  <ResourceBlockSet> is a list of resource block identifiers
   with the same characteristics.  If this set is missing, the
   constraints are applied to the entire network element.
   The <InputConstraints> are constraints are based on signal
   compatibility and/or shared access constraint indication.  The
   details of these constraints are defined in <a href="#section-5.3">Section 5.3</a>.
   <InputConstraints> ::= <SharedInput>
                          [<OpticalInterfaceClassList>]
                          [<ClientSignalList>]
   The <ProcessingCapabilities> are important operations that the
   resource (or network element) can perform on the signal.  The details
   of these capabilities are defined in <a href="#section-5.3">Section 5.3</a>.
<span class="grey">Lee, et al.                   Informational                    [Page 11]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-12" ></span>
<span class="grey"><a href="./rfc7446">RFC 7446</a>                 WSON Information Model            February 2015</span>
   <ProcessingCapabilities> ::= [<NumResources>]
                                [<RegenerationCapabilities>]
                                [<FaultPerfMon>]
                                [<VendorSpecific>]
   The <OutputConstraints> are either restrictions on the properties of
   the signal leaving the block, options concerning the signal
   properties when leaving the resource, or shared fiber output
   constraint indication.
   <OutputConstraints> := <SharedOutput>
                          [<OpticalInterfaceClassList>]
                          [<ClientSignalList>]
<span class="h3"><a class="selflink" id="section-5.3" href="#section-5.3">5.3</a>.  Compatibility and Capability Details</span>
<span class="h4"><a class="selflink" id="section-5.3.1" href="#section-5.3.1">5.3.1</a>.  Shared Input or Output Indication</span>
   As discussed in <a href="#section-5.2">Section 5.2</a> and shown in Figure 2, the input or
   output access to a resource block may be via a shared fiber.  The
   <SharedInput> and <SharedOutput> elements are indicators for this
   condition with respect to the block being described.
<span class="h4"><a class="selflink" id="section-5.3.2" href="#section-5.3.2">5.3.2</a>.  Optical Interface Class List</span>
      <OpticalInterfaceClassList> ::= <OpticalInterfaceClass> ...
   The Optical Interface Class is a unique number that identifies all
   information related to optical characteristics of a physical
   interface.  The class may include other optical parameters related to
   other interface properties.  A class always includes signal
   compatibility information.
   The content of each class is out of the scope of this document and
   can be defined by other entities (e.g., the ITU, optical equipment
   vendors, etc.).
   Since even current implementation of physical interfaces may support
   different optical characteristics, a single interface may support
   multiple interface classes.  Which optical interface class is used
   among all the ones available for an interface is out of the scope of
   this document but is an output of the RWA process.
<span class="grey">Lee, et al.                   Informational                    [Page 12]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-13" ></span>
<span class="grey"><a href="./rfc7446">RFC 7446</a>                 WSON Information Model            February 2015</span>
<span class="h4"><a class="selflink" id="section-5.3.3" href="#section-5.3.3">5.3.3</a>.  Acceptable Client Signal List</span>
   The list is simply:
   <ClientSignalList>::=[<G-PID>]...
   Where the Generalized Protocol Identifiers (G-PID) object represents
   one of the IETF-standardized G-PID values as defined in [<a href="./rfc3471" title=""Generalized Multi-Protocol Label Switching (GMPLS) Signaling Functional Description"">RFC3471</a>] and
   [<a href="./rfc4328" title=""Generalized Multi-Protocol Label Switching (GMPLS) Signaling Extensions for G.709 Optical Transport Networks Control"">RFC4328</a>].
<span class="h4"><a class="selflink" id="section-5.3.4" href="#section-5.3.4">5.3.4</a>.  Processing Capability List</span>
   The ProcessingCapabilities are defined in <a href="#section-5.2">Section 5.2</a>.
   The processing capability list sub-TLV is a list of processing
   functions that the WSON network element (NE) can perform on the
   signal including:
      1.  number of resources within the block
      2.  regeneration capability
      3.  fault and performance monitoring
      4.  vendor-specific capability
   Note that the code points for fault and performance monitoring and
   vendor-specific capability are subject to further study.
<span class="h2"><a class="selflink" id="section-6" href="#section-6">6</a>.  Link Information (General)</span>
   MPLS-TE routing protocol extensions for OSPF [<a href="./rfc3630" title=""RTP Payload Format for Transport of MPEG-4 Elementary Streams"">RFC3630</a>] and IS-IS
   [<a href="./rfc5305" title=""IS-IS Extensions for Traffic Engineering"">RFC5305</a>], along with GMPLS routing protocol extensions for OSPF
   [<a href="./rfc4203" title=""OSPF Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)"">RFC4203</a>] and IS-IS [<a href="./rfc5307" title=""IS-IS Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)"">RFC5307</a>] provide the bulk of the relatively
   static link information needed by the RWA process.  However, WSONs
   bring in additional link-related constraints.  These stem from
   characterizing WDM line systems, restricting laser transmitter
   tuning, and switching subsystem port wavelength constraints, e.g.,
   "colored" ROADM drop ports.
   The following syntax summarizes both information from existing GMPLS
   routing protocols and new information that may be needed by the RWA
   process.
<span class="grey">Lee, et al.                   Informational                    [Page 13]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-14" ></span>
<span class="grey"><a href="./rfc7446">RFC 7446</a>                 WSON Information Model            February 2015</span>
   <LinkInfo> ::=  <LinkID>
                   [<AdministrativeGroup>]
                   [<InterfaceCapDesc>]
                   [<Protection>]
                   [<SRLG>...]
                   [<TrafficEngineeringMetric>]
                   [<PortLabelRestriction>...]
   Note that these additional link characteristics only apply to line-
   side ports of a WDM system or add/drop ports pertaining to the
   resource pool (e.g., regenerator or wavelength converter pool).  The
   advertisement of input/output tributary ports is not intended here.
<span class="h3"><a class="selflink" id="section-6.1" href="#section-6.1">6.1</a>.  Administrative Group</span>
   Administrative Group: Defined in [<a href="./rfc3630" title=""RTP Payload Format for Transport of MPEG-4 Elementary Streams"">RFC3630</a>] and extended for MPLS-TE
   [<a href="./rfc7308" title=""Extended Administrative Groups in MPLS Traffic Engineering (MPLS-TE)"">RFC7308</a>].  Each set bit corresponds to one administrative group
   assigned to the interface.  A link may belong to multiple groups.
   This is a configured quantity and can be used to influence routing
   decisions.
<span class="h3"><a class="selflink" id="section-6.2" href="#section-6.2">6.2</a>.  Interface Switching Capability Descriptor</span>
   InterfaceSwCapDesc: Defined in [<a href="./rfc4202" title=""Routing Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)"">RFC4202</a>]; lets us know the different
   switching capabilities on this GMPLS interface.  In both [<a href="./rfc4203" title=""OSPF Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)"">RFC4203</a>]
   and [<a href="./rfc5307" title=""IS-IS Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)"">RFC5307</a>], this information gets combined with the maximum Link
   State Protocol Data Unit (LSP) bandwidth that can be used on this
   link at eight different priority levels.
<span class="h3"><a class="selflink" id="section-6.3" href="#section-6.3">6.3</a>.  Link Protection Type (for This Link)</span>
   Protection: Defined in [<a href="./rfc4202" title=""Routing Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)"">RFC4202</a>] and implemented in [<a href="./rfc4203" title=""OSPF Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)"">RFC4203</a>] and
   [<a href="./rfc5307" title=""IS-IS Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)"">RFC5307</a>].  Used to indicate what protection, if any, is guarding
   this link.
<span class="h3"><a class="selflink" id="section-6.4" href="#section-6.4">6.4</a>.  Shared Risk Link Group Information</span>
   SRLG: Defined in [<a href="./rfc4202" title=""Routing Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)"">RFC4202</a>] and implemented in [<a href="./rfc4203" title=""OSPF Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)"">RFC4203</a>] and
   [<a href="./rfc5307" title=""IS-IS Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)"">RFC5307</a>].  This allows for the grouping of links into shared risk
   groups, i.e., those links that are likely, for some reason, to fail
   at the same time.
<span class="grey">Lee, et al.                   Informational                    [Page 14]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-15" ></span>
<span class="grey"><a href="./rfc7446">RFC 7446</a>                 WSON Information Model            February 2015</span>
<span class="h3"><a class="selflink" id="section-6.5" href="#section-6.5">6.5</a>.  Traffic Engineering Metric</span>
   TrafficEngineeringMetric: Defined in [<a href="./rfc3630" title=""RTP Payload Format for Transport of MPEG-4 Elementary Streams"">RFC3630</a>] and [<a href="./rfc5305" title=""IS-IS Extensions for Traffic Engineering"">RFC5305</a>].  This
   allows for the identification of a data-channel link metric value for
   traffic engineering that is separate from the metric used for path
   cost computation of the control plane.
   Note that multiple "link metric values" could find use in optical
   networks; however, it would be more useful to the RWA process to
   assign these specific meanings such as "link mile" metric,
   "probability of failure" metric, etc.
<span class="h3"><a class="selflink" id="section-6.6" href="#section-6.6">6.6</a>. Port Label Restrictions</span>
   Port label restrictions could be applied generally to any label types
   in GMPLS by adding new kinds of restrictions.  Wavelength is a type
   of label.
   Port label (wavelength) restrictions (PortLabelRestriction) model the
   label (wavelength) restrictions that the link and various optical
   devices, such as Optical Cross-Connects (OXCs), ROADMs, and waveband
   multiplexers, may impose on a port.  These restrictions tell us what
   wavelength may or may not be used on a link and are relatively
   static.  This plays an important role in fully characterizing a WSON
   switching device [<a href="#ref-Switch" title=""Modeling WDM Wavelength Switching Systems for Use in GMPLS and Automated Path Computation"">Switch</a>].  Port wavelength restrictions are
   specified relative to the port in general or to a specific
   connectivity matrix (<a href="#section-4.1">Section 4.1</a>).  [<a href="#ref-Switch" title=""Modeling WDM Wavelength Switching Systems for Use in GMPLS and Automated Path Computation"">Switch</a>] gives an example where
   both switch and fixed connectivity matrices are used and both types
   of constraints occur on the same port.
   <PortLabelRestriction> ::= <MatrixID>
                              <RestrictionType>
                              <Restriction parameters list>
   <Restriction parameters list> ::=
                        <Simple label restriction parameters> |
                        <Channel count restriction parameters> |
                        <Label range restriction parameters> |
                        <Simple+channel restriction parameters> |
                        <Exclusive label restriction parameters>
<span class="grey">Lee, et al.                   Informational                    [Page 15]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-16" ></span>
<span class="grey"><a href="./rfc7446">RFC 7446</a>                 WSON Information Model            February 2015</span>
   <Simple label restriction parameters> ::= <LabelSet> ...
   <Channel count restriction parameters> ::= <MaxNumChannels>
   <Label range restriction parameters> ::= <MaxLabelRange>
                                            (<LabelSet> ...)
   <Simple+channel restriction parameters> ::= <MaxNumChannels>
                                               (<LabelSet> ...)
   <Exclusive label restriction parameters> ::= <LabelSet> ...
   Where
   MatrixID is the ID of the corresponding connectivity matrix (<a href="#section-4.1">Section</a>
   <a href="#section-4.1">4.1</a>).
   The RestrictionType parameter is used to specify general port
   restrictions and matrix-specific restrictions.  It can take the
   following values and meanings:
      SIMPLE_LABEL:   Simple label (wavelength) set restriction; the
         LabelSet parameter is required.
      CHANNEL_COUNT: The number of channels is restricted to be less
         than or equal to the MaxNumChannels parameter (which is
         required).
      LABEL_RANGE:  Used to indicate a restriction on a range of labels
         that can be switched.  For example, a waveband device with a
         tunable center frequency and passband.  This constraint is
         characterized by the MaxLabelRange parameter, which indicates
         the maximum range of the labels, e.g., which may represent a
         waveband in terms of channels.  Note that an additional
         parameter can be used to indicate the overall tuning range.
         Specific center frequency tuning information can be obtained
         from information about the dynamic channel in use.  It is
         assumed that both center frequency and bandwidth (Q) tuning can
         be done without causing faults in existing signals.
<span class="grey">Lee, et al.                   Informational                    [Page 16]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-17" ></span>
<span class="grey"><a href="./rfc7446">RFC 7446</a>                 WSON Information Model            February 2015</span>
      SIMPLE LABEL and CHANNEL COUNT: In this case, the accompanying
         label set and MaxNumChannels indicate labels permitted on the
         port and the maximum number of labels that can be
         simultaneously used on the port.
      LINK LABEL_EXCLUSIVITY: A label (wavelength) can be used at most
         once among a given set of ports.  The set of ports is specified
         as a parameter to this constraint.
   Restriction-specific parameters are used with one or more of the
   previously listed restriction types.  The currently defined
   parameters are:
      LabelSet is a conceptual set of labels (wavelengths).
      MaxNumChannels is the maximum number of channels that can be
         simultaneously used (relative to either a port or a matrix).
      LinkSet is a conceptual set of ports.
   MaxLabelRange indicates the maximum range of the labels.  For
   example, if the port is a "colored" drop port of a ROADM, then there
   are two restrictions: (a) CHANNEL_COUNT, with MaxNumChannels = 1, and
   (b) SIMPLE_WAVELENGTH, with the wavelength set consisting of a single
   member corresponding to the frequency of the permitted wavelength.
   See [<a href="#ref-Switch" title=""Modeling WDM Wavelength Switching Systems for Use in GMPLS and Automated Path Computation"">Switch</a>] for a complete waveband example.
   This information model for port wavelength (label) restrictions is
   fairly general in that it can be applied to ports that have label
   restrictions only or to ports that are part of an asymmetric switch
   and have label restrictions.  In addition, the types of label
   restrictions that can be supported are extensible.
<span class="h4"><a class="selflink" id="section-6.6.1" href="#section-6.6.1">6.6.1</a>.  Port-Wavelength Exclusivity Example</span>
   Although there can be many different ROADM or switch architectures
   that can lead to the constraint where a lambda (label) maybe used at
   most once on a set of ports, Figure 3 shows a ROADM architecture
   based on components known as Wavelength Selective Switches (WSSes)
   [<a href="#ref-OFC08" title=""Evolution to Colorless and Directionless ROADM Architectures"">OFC08</a>].  This ROADM is composed of splitters, combiners, and WSSes.
   This ROADM has 11 output ports, which are numbered in the diagram.
   Output ports 1-8 are known as drop ports and are intended to support
   a single wavelength.  Drop ports 1-4 output from WSS 2, which is fed
   from WSS 1 via a single fiber.  Due to this internal structure, a
   constraint is placed on the output ports 1-4 that a lambda can be
   used only once over the group of ports (assuming unicast and not
   multicast operation).  The output ports 5-8 have a similar constraint
   due to the internal structure.
<span class="grey">Lee, et al.                   Informational                    [Page 17]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-18" ></span>
<span class="grey"><a href="./rfc7446">RFC 7446</a>                 WSON Information Model            February 2015</span>
                            |               A
                            v            10 |
                        +-------+        +-------+
                        | Split |        |WSS  6 |
                        +-------+        +-------+
     +----+              | | | |          | | | |
     | W  |              | | | |          | | | +-------+   +----+
     | S  |--------------+ | | |    +-----+ | +----+    |   | S  |
   9 | S  |----------------|---|----|-------|------|----|---| p  |
   --|    |----------------|---|----|-------|----+ |    +---| l  |<
     | 5  |--------------+ |   |    | +-----+    | |     +--| i  |
     +----+              | |   |    | |   +------|-|-----|--| t  |
                +--------|-+   +----|-|---|------|----+  |  +----+
     +----+     |        |          | |   |      | |  |  |
     | S  |-----|--------|----------+ |   |      | |  |  |  +----+
     | p  |-----|--------|------------|---|------|----|--|--| W  |
   ->| l  |-----|-----+  | +----------+   |      | |  +--|--| S  |11
     | i  |---+ |     |  | | +------------|------|-------|--| S  |->
     | t  |   | |     |  | | |            |      | | +---|--|    |
     +----+   | | +---|--|-|-|------------|------|-|-|---+  | 7  |
              | | |   +--|-|-|--------+ | |      | | |      +----+
              | | |      | | |        | | |      | | |
             +------+   +------+     +------+   +------+
             | WSS 1|   | Split|     | WSS 3|   | Split|
             +--+---+   +--+---+     +--+---+   +--+---+
                |          A            |          A
                v          |            v          |
             +-------+  +--+----+    +-------+  +--+----+
             | WSS 2 |  | Comb. |    | WSS 4 |  | Comb. |
             +-------+  +-------+    +-------+  +-------+
             1|2|3|4|    A A A A     5|6|7|8|    A A A A
              v v v v    | | | |      v v v v    | | | |
   Figure 3: A ROADM Composed from Splitter, Combiners, and WSSes
<span class="h2"><a class="selflink" id="section-7" href="#section-7">7</a>.  Dynamic Components of the Information Model</span>
   In the previously presented information model, there are a limited
   number of information elements that are dynamic, i.e., subject to
   change with subsequent establishment and teardown of connections.
   Depending on the protocol used to convey this overall information
   model, it may be possible to send this dynamic information separately
   from the relatively larger amount of static information needed to
   characterize WSONs and their network elements.
<span class="grey">Lee, et al.                   Informational                    [Page 18]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-19" ></span>
<span class="grey"><a href="./rfc7446">RFC 7446</a>                 WSON Information Model            February 2015</span>
<span class="h3"><a class="selflink" id="section-7.1" href="#section-7.1">7.1</a>.  Dynamic Link Information (General)</span>
   For WSON links, the wavelength availability and which wavelengths are
   in use for shared backup purposes can be considered dynamic
   information and hence are grouped with the dynamic information in the
   following set:
   <DynamicLinkInfo> ::=  <LinkID>
                          <AvailableLabels>
                          [<SharedBackupLabels>]
   AvailableLabels is a set of labels (wavelengths) currently available
   on the link.  Given this information and the port wavelength
   restrictions, one can also determine which wavelengths are currently
   in use.  This parameter could potentially be used with other
   technologies that GMPLS currently covers or may cover in the future.
   SharedBackupLabels is a set of labels (wavelengths) currently used
   for shared backup protection on the link.  An example usage of this
   information in a WSON setting is given in [<a href="#ref-Shared" title=""Shared Backup Mesh Protection in PCE-based WSON Networks"">Shared</a>].  This parameter
   could potentially be used with other technologies that GMPLS
   currently covers or may cover in the future.
   Note that the above does not dictate a particular encoding or
   placement for available label information.  In some routing
   protocols, it may be advantageous or required to place this
   information within another information element such as the Interface
   Switching Capability Descriptor (ISCD).  Consult the extensions that
   are specific to each routing protocol for details of placement of
   information elements.
<span class="h3"><a class="selflink" id="section-7.2" href="#section-7.2">7.2</a>.  Dynamic Node Information (WSON Specific)</span>
   Currently the only node information that can be considered dynamic is
   the resource pool state, and it can be isolated into a dynamic node
   information element as follows:
   <DynamicNodeInfo> ::=  <NodeID> [<ResourcePool>]
<span class="h2"><a class="selflink" id="section-8" href="#section-8">8</a>.  Security Considerations</span>
   This document discusses an information model for RWA computation in
   WSONs.  From a security standpoint, such a model is very similar to
   the information that can be currently conveyed via GMPLS routing
   protocols.  Such information includes network topology, link state
   and current utilization, as well as the capabilities of switches and
<span class="grey">Lee, et al.                   Informational                    [Page 19]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-20" ></span>
<span class="grey"><a href="./rfc7446">RFC 7446</a>                 WSON Information Model            February 2015</span>
   routers within the network.  As such, this information should be
   protected from disclosure to unintended recipients.  In addition, the
   intentional modification of this information can significantly affect
   network operations, particularly due to the large capacity of the
   optical infrastructure to be controlled.  A general discussion on
   security in GMPLS networks can be found in [<a href="./rfc5920" title=""Security Framework for MPLS and GMPLS Networks"">RFC5920</a>].
<span class="h2"><a class="selflink" id="section-9" href="#section-9">9</a>.  References</span>
<span class="h3"><a class="selflink" id="section-9.1" href="#section-9.1">9.1</a>.  Normative References</span>
   [<a id="ref-G.7715">G.7715</a>]  ITU-T, "Architecture and requirements for routing in the
             automatically switched optical networks", ITU-T
             Recommendation G.7715, June 2002.
   [<a id="ref-RBNF">RBNF</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>, April 2009,
             <<a href="http://www.rfc-editor.org/info/rfc5511">http://www.rfc-editor.org/info/rfc5511</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>, January 2003,
             <<a href="http://www.rfc-editor.org/info/rfc3471">http://www.rfc-editor.org/info/rfc3471</a>>.
   [<a id="ref-RFC3630">RFC3630</a>] van der Meer, J., Mackie, D., Swaminathan, V., Singer, D.,
             and P. Gentric, "RTP Payload Format for Transport of MPEG-4
             Elementary Streams", <a href="./rfc3640">RFC 3640</a>, November 2003,
             <<a href="http://www.rfc-editor.org/info/rfc3640">http://www.rfc-editor.org/info/rfc3640</a>>.
   [<a id="ref-RFC4202">RFC4202</a>] Kompella, K., Ed., and Y. Rekhter, Ed., "Routing Extensions
             in Support of Generalized Multi-Protocol Label Switching
             (GMPLS)", <a href="./rfc4202">RFC 4202</a>, October 2005,
             <<a href="http://www.rfc-editor.org/info/rfc4202">http://www.rfc-editor.org/info/rfc4202</a>>.
   [<a id="ref-RFC4203">RFC4203</a>] Kompella, K., Ed., and Y. Rekhter, Ed., "OSPF Extensions in
             Support of Generalized Multi-Protocol Label Switching
             (GMPLS)", <a href="./rfc4203">RFC 4203</a>, October 2005,
             <<a href="http://www.rfc-editor.org/info/rfc4203">http://www.rfc-editor.org/info/rfc4203</a>>.
   [<a id="ref-RFC4328">RFC4328</a>] Papadimitriou, D., Ed., "Generalized Multi-Protocol Label
             Switching (GMPLS) Signaling Extensions for G.709 Optical
             Transport Networks Control", <a href="./rfc4328">RFC 4328</a>, January 2006,
             <<a href="http://www.rfc-editor.org/info/rfc4328">http://www.rfc-editor.org/info/rfc4328</a>>.
   [<a id="ref-RFC5305">RFC5305</a>] Li, T. and H. Smit, "IS-IS Extensions for Traffic
             Engineering", <a href="./rfc5305">RFC 5305</a>, October 2008,
             <<a href="http://www.rfc-editor.org/info/rfc5305">http://www.rfc-editor.org/info/rfc5305</a>>.
<span class="grey">Lee, et al.                   Informational                    [Page 20]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-21" ></span>
<span class="grey"><a href="./rfc7446">RFC 7446</a>                 WSON Information Model            February 2015</span>
   [<a id="ref-RFC5307">RFC5307</a>] Kompella, K., Ed., and Y. Rekhter, Ed., "IS-IS Extensions
             in Support of Generalized Multi-Protocol Label Switching
             (GMPLS)", <a href="./rfc5307">RFC 5307</a>, October 2008,
             <<a href="http://www.rfc-editor.org/info/rfc5307">http://www.rfc-editor.org/info/rfc5307</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>, April 2011,
             <<a href="http://www.rfc-editor.org/info/rfc6163">http://www.rfc-editor.org/info/rfc6163</a>>.
   [<a id="ref-RFC7308">RFC7308</a>] Osborne, E., "Extended Administrative Groups in MPLS
             Traffic Engineering (MPLS-TE)", <a href="./rfc7308">RFC 7308</a>, July 2014,
             <<a href="http://www.rfc-editor.org/info/rfc7308">http://www.rfc-editor.org/info/rfc7308</a>>.
<span class="h3"><a class="selflink" id="section-9.2" href="#section-9.2">9.2</a>.  Informative References</span>
   [<a id="ref-OFC08">OFC08</a>]   Roorda, P., and B. Collings, "Evolution to Colorless and
             Directionless ROADM Architectures", Optical Fiber
             Communication / National Fiber Optic Engineers Conference
             (OFC/NFOEC), 2008, pp. 1-3.
   [<a id="ref-RFC5920">RFC5920</a>] Fang, L., Ed., "Security Framework for MPLS and GMPLS
             Networks", <a href="./rfc5920">RFC 5920</a>, July 2010,
             <<a href="http://www.rfc-editor.org/info/rfc5920">http://www.rfc-editor.org/info/rfc5920</a>>.
   [<a id="ref-Shared">Shared</a>]  Bernstein, G., and Y. Lee, "Shared Backup Mesh Protection
             in PCE-based WSON Networks", iPOP 2008.
   [<a id="ref-Switch">Switch</a>]  Bernstein, G., Lee, Y., Gavler, A., and J. Martensson,
             "Modeling WDM Wavelength Switching Systems for Use in GMPLS
             and Automated Path Computation", Journal of Optical
             Communications and Networking, vol. 1, June 2009, pp.
             187-195.
<span class="grey">Lee, et al.                   Informational                    [Page 21]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-22" ></span>
<span class="grey"><a href="./rfc7446">RFC 7446</a>                 WSON Information Model            February 2015</span>
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
   Lyndon Ong
   Ciena
   EMail: lyong@ciena.com
   Cyril Margaria
   EMail: cyril.margaria@gmail.com
<span class="grey">Lee, et al.                   Informational                    [Page 22]</span></pre>
<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-23" ></span>
<span class="grey"><a href="./rfc7446">RFC 7446</a>                 WSON Information Model            February 2015</span>
Authors' Addresses
   Young Lee (editor)
   Huawei Technologies
   5369 Legacy Drive, Building 3
   Plano, TX  75023
   United States
   Phone: (469) 277-5838
   EMail: leeyoung@huawei.com
   Greg M. Bernstein (editor)
   Grotto Networking
   Fremont, CA
   United States
   Phone: (510) 573-2237
   EMail: gregb@grotto-networking.com
   Dan Li
   Huawei Technologies Co., Ltd.
   F3-5-B R&D Center, Huawei Base,
   Bantian, Longgang District
   Shenzhen 518129
   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
Lee, et al.                   Informational                    [Page 23]
</pre>
 
     |