Network Working Group A. Kern Internet-Draft A. Takacs Intended status: Standards Track Ericsson Expires: April 29, 2010 October 26, 2009 GMPLS RSVP-TE Extensions for OTN and SONET/SDH OAM Configuration draft-kern-ccamp-rsvp-te-sdh-otn-oam-ext-01 Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on April 29, 2010. Copyright Notice Copyright (c) 2009 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents in effect on the date of publication of this document (http://trustee.ietf.org/license-info). Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Kern & Takacs Expires April 29, 2010 [Page 1] Internet-Draft GMPLS Based OTN and SDH OAM Configuration October 2009 Abstract GMPLS has been extended to support connection establishment in both SONET/SDH [RFC4606] and OTN [RFC4328] networks. However support for the configuration of the supervision functions is not specified. Both SONET/SDH and OTN implement supervision functions to qualify the transported signals. This document defines extensions to RSVP-TE for SONET/SDH and OTN OAM configuration based on the OAM Configuration Framework defined in [GMPLS-OAM-FWK]. Kern & Takacs Expires April 29, 2010 [Page 2] Internet-Draft GMPLS Based OTN and SDH OAM Configuration October 2009 Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119]. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Overview of SONET/SDH and OTN OAM related functions . . . . . 5 2.1. Continuity supervision . . . . . . . . . . . . . . . . . . 5 2.2. Connectivity supervision . . . . . . . . . . . . . . . . . 5 2.2.1. SONET/SDH . . . . . . . . . . . . . . . . . . . . . . 5 2.2.2. OTN . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.3. Signal quality supervision . . . . . . . . . . . . . . . . 5 2.3.1. SONET/SDH . . . . . . . . . . . . . . . . . . . . . . 6 2.3.2. OTN . . . . . . . . . . . . . . . . . . . . . . . . . 6 3. RSVP-TE signaling extensions . . . . . . . . . . . . . . . . . 7 3.1. OAM configuration of switching layers . . . . . . . . . . 7 3.2. OAM configuration of section layers . . . . . . . . . . . 7 3.3. SONET/SDH OAM configuration . . . . . . . . . . . . . . . 9 3.3.1. Generic procedures . . . . . . . . . . . . . . . . . . 9 3.3.2. Connectivity supervision configuration . . . . . . . . 9 3.3.3. Signal quality supervision configuration . . . . . . . 10 3.3.4. Tandem Connection Monitoring support . . . . . . . . . 10 3.3.5. Non intrusive Monitoring support . . . . . . . . . . . 10 3.4. OTN OAM configuration . . . . . . . . . . . . . . . . . . 10 3.4.1. Generic procedures . . . . . . . . . . . . . . . . . . 10 3.4.2. Connectivity monitoring supervision configuration . . 11 3.4.3. Signal quality supervision configuration . . . . . . . 12 3.4.4. Tandem connection monitoring . . . . . . . . . . . . . 12 3.4.5. Signaling support of non-intrusive monitoring . . . . 13 3.5. Signaling support of Virtual Concatenation Groups (VCG) . 13 3.6. OAM types and functions . . . . . . . . . . . . . . . . . 14 3.7. Extensions to LSP_TUNNEL_INTERFACE_ID objects . . . . . . 15 3.8. SONET/SDH OAM Configuration sub-TLV . . . . . . . . . . . 15 3.9. OTN OAM Configuration sub-TLV . . . . . . . . . . . . . . 15 3.10. TTI Configuration Sub-TLV . . . . . . . . . . . . . . . . 16 3.10.1. SDH TTI Configuration Sub-TLV . . . . . . . . . . . . 16 3.10.2. OTN TTI Configuration Sub-TLV . . . . . . . . . . . . 17 3.11. Degraded signal thresholds Sub-TLV . . . . . . . . . . . . 18 4. Error handling . . . . . . . . . . . . . . . . . . . . . . . . 20 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 21 6. Security Considerations . . . . . . . . . . . . . . . . . . . 22 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 23 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 26 Kern & Takacs Expires April 29, 2010 [Page 3] Internet-Draft GMPLS Based OTN and SDH OAM Configuration October 2009 1. Introduction Both SONET/SDH and OTN implement supervision functions to qualify the transported signals. Supervision functions include continuity, connectivity, signal quality, alignment and payload supervision. The ITU-T G.806 [G.806] recommendation defines the generic framework of the supervision functions, which are then further specified for SONET/SDH and OTN in technology specific documents. GMPLS has been extended to support connection establishment in both SONET/SDH [RFC4606] and OTN [RFC4328] networks. These documents however do not support the configuration of the respective supervision functions. [GMPLS-OAM-FWK] defines a technology-agnostic framework for GMPLS to support the establishment and configuration of the pro-active OAM functions of signalled connections. The properties of the OAM functions are exchanged during connection establishment and may be modified during the life of the connection. The technology specific parameters to be exchanged are to be described in accompanying documents. This document defines the extensions for SONET/SDH and OTN OAM configuration. Kern & Takacs Expires April 29, 2010 [Page 4] Internet-Draft GMPLS Based OTN and SDH OAM Configuration October 2009 2. Overview of SONET/SDH and OTN OAM related functions SONET/SDH [G.707] and OTN [G.709] provide a variety of supervision functions. Here we only consider continuity, connectivity and signal quality supervision functions, as these are the candidates for GMPLS based configuration. 2.1. Continuity supervision Continuity supervision provides methods monitoring the health of a connection (trail). 2.2. Connectivity supervision The connectivity supervision function provides a method to detect misconnections. The detection procedure is based on emitting a Trace Trail Identifier (TTI) known by both endpoints. The TTI is included by the source node as an overhead signal for each connection. The receiver node then compares the received TTI with the expected value and decides if a miss-connection occurred. 2.2.1. SONET/SDH In case of SONET/SDH, connectivity supervision is implemented in the Regeneration Section (RS) and in the lower and higher order path layers (LOVC and HOVC). In all layers the TTI encodes only the Access Point Identifier (API) of the source node. In the various layers the lengths of these TTIs are different. In RS the TTI (encoded in J0 octet) is either 1 or 16 octets long. In higher order paths the TTI (encoded in J1), is either 16 or 64 octet long. In lower order paths the TTI is transmitted in the J2 byte and is 16 octet long. 2.2.2. OTN In case of OTN, connectivity supervision is supported by the OTUk and ODUk digital hierarchy layers. In both layers, the length of the TTI is 64 octets, but only the first 32 octets are considered for connectivity supervision. This first part is further divided into a Source Access Point Identifier (SAPI) and a Destination Access Point Identifier (DAPI). Connectivity supervision may consider either the SAPI or DAPI only or both. The structure of the SAPI and DAPI is specified in [G.709]. 2.3. Signal quality supervision The quality of the transmitted signal is monitored as a ratio of bad frames. If the number of such frames reaches a threshold a defect Kern & Takacs Expires April 29, 2010 [Page 5] Internet-Draft GMPLS Based OTN and SDH OAM Configuration October 2009 state is declared. To detect the correctness of the frames an Error Detection Code (EDC), such as Bit Interleaved Parity (BIP), is used. The distribution of the errors is assumed to follow either Poisson or a bursty distribution. For Poisson distribution an EDC violation ratio is defined as the threshold; while for the bursty model the threshold is defined as a number of consecutive 1-second time intervals in which the EDC violation exceeds a predefined ratio. In case of Poisson error distribution two defect state levels are defined: the Excessive Error and Degraded Signal defect. In the case of the bursty model, only the Degraded Signal defect level is considered. 2.3.1. SONET/SDH SONET/SDH supports both Excessive Error and Degraded Signal defect levels and supports both Poisson and bursty error distribution models. These signal quality parameters are configured for the Multiplexing Section (MS) and the LOVC and HOVC path layers. Note, that Tandem Connection sub-layers support only bursty error distribution model with Degraded Signal defect level. 2.3.2. OTN For OTN, in the digital transport layers (OTUk and ODUk) only the bursty error distribution model errors with the Degraded Signal defect level is supported. Two parameters are defined: Ratio of the bad frames in a one second interval (0% to 100% or 0 to number of frames per 1-second interval) and Number of consecutive intervals (between 2 and 10). Signal quality supervision in the optical transport layers is not specified by [G.798], it is indicated to be for further study. Kern & Takacs Expires April 29, 2010 [Page 6] Internet-Draft GMPLS Based OTN and SDH OAM Configuration October 2009 3. RSVP-TE signaling extensions Both SONET/SDH and OTN define hierarchical transport technologies, where the transport functionalities are distributed between layers. These layers can be characterized based on whether switching is performed in that layer or not (See Table 1). +-------------+------------+----------------------------------------+ | Does | OTN | SONET/SDH | | switching? | | | +-------------+------------+----------------------------------------+ | yes | ODU, OCh, | Path (HOVC and LOVC), MS (in case of | | | OChr | transparent switching) | | | | | | no | OTU, OMS | RS, MS (in case of non-transparent | | | | switching) | +-------------+------------+----------------------------------------+ Table 1: SONET/SDH and OTN layer examples for switching and section layers 3.1. OAM configuration of switching layers Generally, the OAM related parameters of a signalled LSP refer to the switching layer connection. o If the flag "Connectivity monitoring" in the OAM Configuration TLV is set, one or two Connectivity Supervision TLVs are added. One TLV is added if the connection is either unidirectional or bidirectional but the same configuration data is used at both endpoints. Otherwise, two TLV are added, one for each direction. o If the flag "Performance Monitoring/Loss" in the OAM Configuration TLV is set, Signal Quality Supervision TLVs can be added. o Flag "Performance Monitoring/Delay" must be cleared. The egress node parses and interprets the OAM parameters while intermediate nodes do not process the information. The technology independent procedures are as per [GMPLS-OAM-FWK] while the technology specific steps are defined in Section 3.3 and Section 3.4 in this document. 3.2. OAM configuration of section layers In the point of view of OAM configuration of connections of a section layer, two cases can be differentiated: Kern & Takacs Expires April 29, 2010 [Page 7] Internet-Draft GMPLS Based OTN and SDH OAM Configuration October 2009 When the section layer connection models a link between two physically adjacent nodes, the related OAM parameters are configured either manually or by other means (e.g., as part of link property correlation function of LMP). Therefore, this case is out of scope of this document. When a section layer connection models a logical link, which is implemented with a connection of a server switching layer, the related OAM parameters are configured along with the signaling of the implementing server switching layer connection. In this latter case, if the [LSP-HIER-BIS] signaling is used to setup the server layer connection and institiate it as FA-LSP, the OAM Configuration TLV can be added to the LSP_TUNNEL_INTERFACE_ID object to configure the OAM of the client section layer. As a single link is monitored: OAM MEP entities are desired while MIP entities are not. Furthermore, Alarm Indication from server layer is desired as well. This information is originally encoded in the LSP Attributes Flags TLV. As fix values for these bits are provided this TLV does not need to be added to the LSP_TUNNEL_INTERFACE_ID object. Therefore, the ingress node performs the following steps during constructing a PATH message: o Add LSP_TUNNEL_INTERFACE_ID object where a new flag "O" is set indicating that OAM configuration for the client layer connection (FA) is desired. o Adds an OAM Configuration TLV to the LSP_TUNNEL_INDERFACE_ID object and set its fields appropriately. o Technology specific OAM Configuration TLV (e.g., SONET/SDH or OTN) is added and extended as follows: * If flag "Connectivity monitoring" in OAM Configuration TLV is set one or two Connectivity Supervision TLVs is added. One TLV is added if the connection is either unidirectional or bidirectional but the same configuration data is used on both endpoints. Otherwise, two TLV are added, one for each direction. * If flag "Performance Monitoring/Loss" in OAM Configuration TLV is set Signal Quality Supervision TLVs can be added. The egress node performs the following steps at the receipt of a PATH message: Kern & Takacs Expires April 29, 2010 [Page 8] Internet-Draft GMPLS Based OTN and SDH OAM Configuration October 2009 o Checks if LSP_TUNNEL_INTERFACE_ID object is added and flag "O" is set. o If the "Connectivity monitoring" OAM function is set in the OAM Configuration TLV, the egress expects one or two Connectivity Supervision TLVs. o If the "Performance Monitoring/Loss" OAM function is set in the OAM Configuration TLV, one or two Signal quality supervision TLVs can be added to define the parameters to be configured. If no TLVs are added the suggested default values are used. 3.3. SONET/SDH OAM configuration 3.3.1. Generic procedures The RS and MS layers of SONET/SDH define sections between two adjacent nodes. In the basic configuration the supervision parameters encoded in the signal are terminated and processed in the adjacent nodes, thus, their configuration depends on whether they run over a physical link or a logical link implemented by a lower layer network. In the first case their configuration is done manually or by other means (not discussed in this document). In the latter case the RS and MS layer configuration is done along with the configuration of the connection in the sever layer. This can be automated using FA-LSPs as described in Section 3.2 The HOVC and LOVC path layers, as well as the RS and MS layers in transpared forwarding, are configured as in Section 3.1. The layer to be configured with RSVP-TE is encoded in the signal type field of the SENDER_TSPEC object. The content of the OAM configuration TLV is relevant to that layer. 3.3.2. Connectivity supervision configuration [G.707] defines three bytes (signals) for connectivity supervision purposes: the J0 byte in RS layer, the J1 and J2 bytes in HOVC and LOVC layers. These bytes encode 1 octet, 16 octet or 64 octet long unstructured octet streams. These streams encode the Access Point Identifier of the source node. In the case of bidirectional connection, different TTIs have to be emitted in the upstream and downstream directions. During the configuration the egress node has to be configured with the TTI value to be expected in the downstream direction and the TTI value to be emitted in the upstream direction. Therefore the SONET/SDH OAM Configuration TLV carries two Connectivity Supervision TLVs. Kern & Takacs Expires April 29, 2010 [Page 9] Internet-Draft GMPLS Based OTN and SDH OAM Configuration October 2009 3.3.3. Signal quality supervision configuration Signal quality supervision function is implemented in MS, HOVC, LOVC layers. All three layers support exceeded error level with Poisson error distribution model and degraded signal defect level with both, Poisson and bursty error distribution model. Dedicated Signal quality supervision TLVs encode each level, therefore when the "Performance Monitoring/Loss" flag is set; several such TLVs can be added to the SONET/SDH OAM Configuration TLV. If a configuration TLV for a particular level is missing the default parameters for that level is to be applied. 3.3.4. Tandem Connection Monitoring support TBA 3.3.5. Non intrusive Monitoring support TBA 3.4. OTN OAM configuration 3.4.1. Generic procedures The optical transport hierarchy provides connectivity and continuity supervision functions with appropriate maintenance signals. The OTS and OMS layers are section layers describing physical links. RSVP-TE does not support the configuration of these layers [RFC4328], hence OTS and OMS related OAM parameters are also out of scope of this document. The OCh layer adds end-to-end management signals. Although the OCh/OChr transport layer is configured with GMPLS the related OAM functions do not need configuration. The digital transport hierarchy has supervision functions as well. Both OTUk and ODUk layers implement connectivity and signal quality supervision functions, respectively. The OAM configuration for these layers is supported by the extensions defined in this document. o For OTUk connections the OAM functions are provisioned together with the server OCh/OChr LSP as defined in Section 3.2. o For ODUk connections the procedure defined in Section 3.1 is used. If the client layer network has section layer OAM monitoring capabilities, then the parameters of this latter layer can be encoded as per Section 3.2. Kern & Takacs Expires April 29, 2010 [Page 10] Internet-Draft GMPLS Based OTN and SDH OAM Configuration October 2009 3.4.2. Connectivity monitoring supervision configuration [G.709] defines a 64 octet long TTI, where the first 32 octets have a generic structure: a zero octet, a 15 octet long SAPI, a second zero octet and finally the 15 octet long DAPI. For a unidirectional connection a single Connection Supervision TLV encodes elements of the TTI to be emitted. This TLV also specifies which parts of the TTI are compared to the expected values (only SAPI, only DAPI, both SAPI and DAPI). In case of a bidirectional connection an endpoint can use a common API value for SAPI (for transmitted signal) and DAPI (for received signal). (See Figure 1.) The TTI values used in downstream and upstream directions are derived from the two API values: the downstream TTI will have the form of [0, API_a, 0, API_z] while the upstream TTI will use the form of [0, API_z, 0 API_a]. Ingress Node Egress Node ( API_a ) TTI_upstream = [0, API_z, 0, API_a ] ( API_z ) | Rx port | -- < -- < -- < -- < -- < -- < -- < -- < -- | Tx Port | | Tx port | -- > -- > -- > -- > -- > -- > -- > -- > -- | Rx Port | TTI_downstream = [0, API_a, 0, API_z ] Figure 1: TTI construction when a single API identifies the receiver and transmitter interfaces Then, a single Connectivity Supervision TLV is defined. The SAPI field carries the API of the ingress node (API_a) that initiates the signaling, while the DAPI carries the API of the egress node (API_z). On the other hand, it is possible that the endpoints use different values as SAPI and DAPI to identify the transmitter and receiver ports of a bidirectional connection (See Figure 2). In this case the TTIs to be used in the two directions are independent, thus, they must be explicitly configured. Therefore, two Connectivity Supervision TLVs are added to the OTN OAM Configuration TLV. Each TLV encodes whether it defines the downstream or the upstream TTI. Ingress Node Egress Node ( API_a1 ) TTI_upstream = [0, API_z1, 0, API_a1 ] ( API_z1 ) | Rx port | -- < -- < -- < -- < -- < -- < -- < -- < -- | Tx Port | | Tx port | -- > -- > -- > -- > -- > -- > -- > -- > -- | Rx Port | ( API_a2 ) TTI_downstream = [0, API_a2, 0, API_z2 ] ( API_z2 ) Figure 2: TTI construction when dedicated APIs identify the receiver and transmitter interfaces Kern & Takacs Expires April 29, 2010 [Page 11] Internet-Draft GMPLS Based OTN and SDH OAM Configuration October 2009 3.4.3. Signal quality supervision configuration OTN supports only Degraded Signal defect with bursty error model in OTUk and ODUk layers. Thus, the only parameters to be encoded are: the threshold for bad frames in a 1-second interval and the number of consecutive 1-second intervals with excessive bad frames. 3.4.4. Tandem connection monitoring [GMPLS-OAM-FWK] provides a generic mechanism to configure Tandem Connection Monitoring: the endpoints of a TCM Entity as well as the relevant OAM attributes are encoded with two TCME Configuration TLVs carried in HOP_ATTRIBUTES subobjects in the ERO [HOP_ATTR]. In the optical hierarchy, the OCh connections do not support tandem connection monitoring. In the digital hierarchy, the ODUk header field implements six channels for Tandem Connection Monitoring features. This allows deploying up to six overlapping TCMEs, and disjoint TMCEs may use the same channels. The Level field defined in [GMPLS-OAM-FWK] with the limitation that its value must be an integer value from domain 1 to 6 provides a direct mapping to the TCM instance indefiers (TCM1,TCM2, ..., TCM6). To configure the connection monitoring supervision function for a TCME the TTIs of the end-to-end connection can be considered as well as new TTI values can be provisioned. Therefore the TCM ingress looks for the TCM egress and besides the procedures defined in [GMPLS-OAM-FWK] it performs the following steps: If no TTI Configuration TLVs are given at the TCME ingress but are given at the corresponding TCME egress an error must generated: "TMCE Problem/TTI Configuration mismatch". If one or more TTI Configuration TLVs are given the ingress must check if TTI values are specified at the TCME egress. If not, the ingress node extends the TCME Configuration TLV of the egress node with the proper TTI configuration parameters. Otherwise, it must generate an error: "TMCE Problem/TTI Configuration mismatch". For signal quality supervision the defect states and thresholds applicable at the monitoring entity can be specified. As default value, the treshold parameters used at the (end-to-end connection or the proper TC) egress are applicable. Kern & Takacs Expires April 29, 2010 [Page 12] Internet-Draft GMPLS Based OTN and SDH OAM Configuration October 2009 3.4.5. Signaling support of non-intrusive monitoring OTN supports non-intrusive monitoring of end-to-end optical connections and end-to-end and tandem connections in the digital hierarchy. To place and configure a non-intrusive monitoring element the OAM Configuration framework introduced the NIME Configuration TLV [GMPLS-OAM-FWK], which is carried in HOP_ATTRIBUTES subobjects in the ERO [HOP_ATTR]. The Level value of NIME Configuration TLV indicates what is monitored: either the end-to-end flow (0) or a particular tandem connection (1..6). As TCM is not supported by optical hierarchy, in case of monitoring OCh connections the Level value must be set to 0. For connectivity suppervision the expected TTI value must be determined. The ingress node of the monitored end-to-end or tandem connection can extend technology specific sub-TLV of the NIME Configuration TLV with one or two TTI Configuration TLVs: The end-to-end connection ingress extends all NIME Configuration TLVs with LEVEL attribute set to 0. The TCME ingress extends all NIME Configuration TLVs that are placed before the TCME egress and have the same Level value as the TCME ingress. In case of bidirectional connections with asymmetric TTIs, flags "U" and "D" selects which of the two TTI values are to be used. For signal quality supervision the defect states and thresholds applicable at the monitoring entity can be specified. As default value, the treshold parameters used at the (end-to-end connection or the proper TC) egress are applicable. For OCh connection [G.798] defines two kinds of non-intrusive monitoring functions. The first option is based on the OCh attributes, while the second one terminates the optical channel and processes the carried OTU frames as well. To make distinction between the two options, the OAM Type of the NIME Configuration TLV is used: OTN optical hierarchy indicates first option, and OTN digital hierarchy indicates the second. 3.5. Signaling support of Virtual Concatenation Groups (VCG) A key capability of both, SONET/SDH and OTN is the support of virtual concatenation. This inverse multiplexing method uses multiplicity of parallel basic signals. The supervision function parameters of these basic signals can be different. Kern & Takacs Expires April 29, 2010 [Page 13] Internet-Draft GMPLS Based OTN and SDH OAM Configuration October 2009 [GMPLS-VCAT-LCAS] summarises GMPLS signaling capabilities to support virtual concatenation and proposes extensions to that. A Virtual Concatenated Group (VCG) is constructed from several individual data plane signals. Several co-routed data plane signals can be provisioned together using a single RSVP-TE session (co-signaled). Multiple RSVP-TE sessions can be merged to form the VCG. These sessions are then associated using RSVP-TE Calls [RFC4974]. As the scope of a single RSVP-TE session covers the co-signaled elements of a VCG, the OAM configuration extension is only relevant for this case too. We assume that the same OAM type and the same set of OAM functions apply to every individual signal of the VCG. A single generic OAM Configuration TLV is added to define these common parameters while multiple instances of technology specific OAM Configuration TLVs are listed: one instance per individual signal. The order of these TLVs refers to logical order of the basic signals (as they are listed in the label object). [GMPLS-VCAT-LCAS] allows extension/pruning of a VCG. To achieve it the traffic descriptor, which encodes how the VCG is structured, in the RSVP-TE session is updated. If the VCG is extended a new OAM Configuration TLV is added to the LSP Attributes objects together with updating the traffic descriptor. Support of LCAS is FFS. 3.6. OAM types and functions This document defines three new OAM types [GMPLS-OAM-FWK]: SONET/SDH OAM, OTN Digital Hierarchy OAM and OTN Optical hierarchy OAM. OAM Type Description ------------ ------------------ 0 Reserved 1 Ethernet OAM 2 SONET/SDH OAM 3 OTN Digital Hierarchy OAM 4 OTN Optical hierarchy OAM 5-256 Reserved The OAM Configuration TLV defines three OAM functions: Connectivity Monitoring, Loss Measurement and Delay Measurement. SONET/SDH and OTN supervision functions support Connectivity Monitoring and Loss Measurement. Therefore, if Delay measurement function is requested the nodes must generate an error with value "OAM Problem/Unsupported Kern & Takacs Expires April 29, 2010 [Page 14] Internet-Draft GMPLS Based OTN and SDH OAM Configuration October 2009 OAM Function". 3.7. Extensions to LSP_TUNNEL_INTERFACE_ID objects To support the OAM configuration of dynamically configured FAs the following extension to the LSP_TUNNEL_INTERFACE_ID Object is defined. A new flag (O) (IANA to assign) is added to the actions field of the LSP_TUNNEL_INTERFACE_ID Object: this bit indicates whether OAM monitoring for the section is desired. The bit can be set independently from the other flags. When it is set, the following TLVs must be added to the LSP_TUNNEL_INTERFACE_ID object as sub-TLVs: o OAM Configuration TLV to declare desired OAM technology and functions. o Technology specific OAM Configuration TLVs if needed. 3.8. SONET/SDH OAM Configuration sub-TLV SONET/SDH OAM Configuration TLV is defined to encode the parameters of continuity, connectivity and signal quality supervision functions for SONET/SDH networks. 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 (2) (IANA) | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | ~ sub TLVs ~ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type: indicates a new type: the SONET/SDH OAM Configuration TLV (IANA to define). Length: indicates the total length including sub-TLVs 3.9. OTN OAM Configuration sub-TLV OTN OAM Configuration TLV is defined to encode the parameters of continuity, connectivity and signal quality supervision functions for OTN. Kern & Takacs Expires April 29, 2010 [Page 15] Internet-Draft GMPLS Based OTN and SDH OAM Configuration October 2009 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 (3) (IANA) | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | ~ sub TLVs ~ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type: indicates a new type: the OTN OAM Configuration TLV (IANA to define). Length: indicates the total length including sub-TLVs 3.10. TTI Configuration Sub-TLV 3.10.1. SDH TTI Configuration Sub-TLV Several SONET/SDH layers support connectivity supervision functions. In every layer the TTI identifies the source interface (SAPI); however, the length of this identifier varies layer-by-layer (See Section 2.2.1). Therefore, a generic TLV is defined supporting various TTI lengths. 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 (1) (IANA) | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |A|U| Reserved | TTI | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | ~ TTI cont ~ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Flag "A", when set enables the AIS insertion on detecting TTI mismatch. Flat "U" encodes if the TTI refers to the downstream TTI (U=0) or the upstream one (U=1). The TTI field carries the TTI to be transmitted by the source node and to be expected by the sink. The TLV is padded to 4-octets. If the specified length and format of the TTI carried in this TLV is Kern & Takacs Expires April 29, 2010 [Page 16] Internet-Draft GMPLS Based OTN and SDH OAM Configuration October 2009 not supported by the referred SONET/SDH layer, error must be generated: "OAM Problem/TTI Length Mismatch". 3.10.2. OTN TTI Configuration Sub-TLV 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 (2) (IANA) | Length = 32 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |A|S|D|APP| Reserved | SAPI | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SAPI cont | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SAPI cont | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SAPI cont | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SAPI | DAPI | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | DAPI cont | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | DAPI cont | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | DAPI cont | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Three control flags are defined. Flag "A" indicates that AIS insertion on detecting TTI mismatch (failing the connectivity verification) is required (A=1) or not (A=0). The next two flags define which parts of the received TTI are compared to the expected one. If flag "S" is set the TTI octets 1 to 15 are matched to the expected SAPI value. If the flag "D" is set the TTI octets 17 to 31 are matched to the expected DAPI value. If both "S" and "D" are set both parts of TTI are compared to SAPI and DAPI values. Setting both "S" and "D" bits to 0 is invalid, and if encountered error must be generated: "OAM Problem/Invalid CC/CV configuration". The next two bits "APP" encode the applicability of the TTI configuration and the following code points are defined: 0 - Single TTI configuration: the TTI configuration is done according only to this TLV and no further TTI configuration TLVs are expected. This code point is used for unidirectional connections and for bidirectional connections with common APIs (See Figure 1) Kern & Takacs Expires April 29, 2010 [Page 17] Internet-Draft GMPLS Based OTN and SDH OAM Configuration October 2009 1 - Downstream TTI for double TTI configuration: the current TLV instruct the configuration of the TTI to be used in downstream direction (See Figure 2). 2 - Upstream TTI for double TTI configuration: the current TLV instruct the configuration of the TTI to be used in upstream direction (See Figure 2). 3 - Invalid. This TLV is included only if the "Connection Monitoring" flag in the OAM Configuration TLV is set. If the APP is set to 1 and the next or the previous sub-TLV is not an OTN TTI Configuration TLV with APP code point 2, then an error must be generated "OAM Problem/Invalid OTN TTI Configuration/Missing Upstream TTI configuration". If the APP is set to 2 and the next or the previous sub-TLV is not an OTN TTI Configuration TLV with APP code point 1, then an error must be generated "OAM Problem/Invalid OTN TTI Configuration/Missing Downstream TTI configuration". If the APP is set to either 1 or 2 and the unidirectional LSP is signaled (no UPSTREAM_LABEL is added to the message) or the APP is set to 3, an error must be generated "OAM Problem/Invalid OTN TTI Configuration/Invalid applicability code" 3.11. Degraded signal thresholds Sub-TLV The Degraded signal thresholds Sub-TLV instructs the configuration of the signal quality supervision function. This sub-TLV is applicable in both SONET/SDH and OTN cases. 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 (3) (IANA) | Length = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |B|L| Reserved | DEG_THR | DEG_M | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Two flags are defined to encode the signal quality measurement. The bit "B" encodes if distribution of errors is either Poisson (B=0) or Bursty (B=1). In case of Poisson distribution of errors two levels of defects are defined and encoded with bit "L": excessive error (L=0) and degraded signal (L=1). Since in case of Bursty distribution of errors only degraded signal defect is to be detected, Kern & Takacs Expires April 29, 2010 [Page 18] Internet-Draft GMPLS Based OTN and SDH OAM Configuration October 2009 therefore, in this latter case (B=1) the "L" bit must be set. Otherwise error must be generated: "OAM Problem/Invalid Performance Monitoring/Loss configuration". The field "DEG_THR" defines the threshold for the bad frames (BIP-8 violations) in both, Poisson and bursty distributions of errors. In the first case (B=0) this field encodes the quotient of the threshold 10e-X. The possible values for excessive error are 3,4 and 5, while for degraded signal defect are 6,7,8 and 9. In the second case (B=1) it encodes ratio of the bad frames in a 1-second period and can be set between 0 and 100, interpreted as ratios in percentage. The field "DEG_M" defines monitoring time-frame in 1 second periods assuming bursty distribution of errors. The valid values are 2 to 10 periods. Kern & Takacs Expires April 29, 2010 [Page 19] Internet-Draft GMPLS Based OTN and SDH OAM Configuration October 2009 4. Error handling In addition to error values specified in [GMPLS-OAM-FWK] this document defines the following values for the "OAM Problem" Error Code. o If Delay measurement function is requested in the OAM Configuration TLV, an error must be generated "OAM Problem/ Unsupported OAM Function". o In case of SONET/SDH the length or format of the TTI to be configured is not supported by the referred SONET/SDH layer, error must be generated: "OAM Problem/TTI Length Mismatch". o If both "S" and "D" bits in OTN TTI Configuration TLV are set to 0, error must be generated: "OAM Problem/Invalid CC/CV configuration" o If the APP is set to 1 and the next or the previous sub-TLV is not an OTN TTI Configuration TLV with APP code point 2, then an error must be generated "OAM Problem/Invalid OTN TTI Configuration/ Missing Upstream TTI configuration". o If the APP is set to 2 and the next or the previous sub-TLV is not an OTN TTI Configuration TLV with APP code point 1, then an error must be generated "OAM Problem/Invalid OTN TTI Configuration/ Missing Downstream TTI configuration". o If the APP is set to either 1 or 2 and the unidirectional LSP is signaled (no UPSTREAM_LABEL is added to the message) or the APP is set to 3, an error must be generated "OAM Problem/Invalid OTN TTI Configuration/Invalid applicability code" o If flag "B" in Degraded signal thresholds Sub-TLV is set to 1 and flag "L" in the same sub-TLV is set to 0 error must be generated "OAM Problem/Invalid Performance Monitoring/Loss configuration". o If TTI configurations at TMCE ingress and egress nodes are not compatible an error must be generated: "TCME Problem/TTI Configuration mismatch" Kern & Takacs Expires April 29, 2010 [Page 20] Internet-Draft GMPLS Based OTN and SDH OAM Configuration October 2009 5. IANA Considerations This document specifies a new SONET/SDH OAM Configuration TLV and OTN OAM Configuration TLV to be carried in the OAM Configuration TLV in LSP_ATTRIBUTES and LSP_REQUIRED_ATTRIBUTES objects in Path messages. The document assigns OAM Types 2 and 3 to OAM Type field of the OAM Configuration TLV. The following values need to be assigned under the Error Codes "OAM Problem/Unsupported OAM Function", "OAM Problem/TTI Length Mismatch", "OAM Problem/Invalid CC/CV configuration", "OAM Problem/Invalid OTN TTI Configuration/Missing Upstream TTI configuration", "OAM Problem/ Invalid OTN TTI Configuration/Missing Downstream TTI configuration", "OAM Problem/Invalid OTN TTI Configuration/Invalid applicability code", "OAM Problem/Invalid Performance Monitoring/Loss configuration", "TMCE Problem/TTI Configuration mismatch" Kern & Takacs Expires April 29, 2010 [Page 21] Internet-Draft GMPLS Based OTN and SDH OAM Configuration October 2009 6. Security Considerations Security aspects are addressed in the OAM configuration framework document [GMPLS-OAM-FWK] Kern & Takacs Expires April 29, 2010 [Page 22] Internet-Draft GMPLS Based OTN and SDH OAM Configuration October 2009 7. Acknowledgements The authors would like to thank Francesco Fondelli for his useful comments. Kern & Takacs Expires April 29, 2010 [Page 23] Internet-Draft GMPLS Based OTN and SDH OAM Configuration October 2009 8. References [G.707] International Telecommunications Union, "Network node interface for the synchronous digital hierarchy (SDH)", ITU-T Recommendation G.707, January 2007. [G.709] International Telecommunications Union, "Interfaces for the Optical Transport Network (OTN)", ITU-T Recommendation G.709, March 2003. [G.783] International Telecommunications Union, "Characteristics of synchronous digital hierarchy (SDH) equipment functional blocks", ITU-T Recommendation G.783, December 2006. [G.798] International Telecommunications Union, "Characteristics of optical transport network hierarchy equipment functional blocks", ITU-T Recommendation G.798, December 2006. [G.806] International Telecommunications Union, "Characteristics of transport equipment - Description methodology and generic functionality", ITU-T Recommendation G.806, January 2009. [GMPLS-OAM-FWK] Takacs, A., Fedyk, D., and H. Jia, "OAM Configuration Framework and Requirements for GMPLS RSVP-TE", draft-ietf-ccamp-oam-configuration-fwk-01 (work in progress), March 2009. [GMPLS-VCAT-LCAS] Bernstein, G., Rabbat, R., and H. Helvoort, "Operating Virtual Concatenation (VCAT) and the Link Capacity Adjustment Scheme (LCAS) with Generalized Multi-Protocol Label Switching (GMPLS)", draft-ietf-ccamp-gmpls-vcat-lcas-07 (work in progress), December 2008. [HOP_ATTR] Kern, A. and A. Takacs, "Encoding of Attributes of LSP hops using RSVP-TE", Internet-draft Work in progress, October 2009. [LSP-HIER-BIS] Shiomoto, K., Farrel, A., Rabbat, R., Ayyangar, A., and Z. Ali, "Procedures for Dynamically Signaled Hierarchical Label Switched Paths", Kern & Takacs Expires April 29, 2010 [Page 24] Internet-Draft GMPLS Based OTN and SDH OAM Configuration October 2009 draft-ietf-ccamp-lsp-hierarchy-bis-06 (work in progress), December 2008. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource ReserVation Protocol-Traffic Engineering (RSVP-TE) Extensions", RFC 3473, January 2003. [RFC4328] Papadimitriou, D., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Extensions for G.709 Optical Transport Networks Control", RFC 4328, January 2006. [RFC4606] Mannie, E. and D. Papadimitriou, "Generalized Multi- Protocol Label Switching (GMPLS) Extensions for Synchronous Optical Network (SONET) and Synchronous Digital Hierarchy (SDH) Control", RFC 4606, August 2006. [RFC4974] Papadimitriou, D. and A. Farrel, "Generalized MPLS (GMPLS) RSVP-TE Signaling Extensions in Support of Calls", RFC 4974, August 2007. Kern & Takacs Expires April 29, 2010 [Page 25] Internet-Draft GMPLS Based OTN and SDH OAM Configuration October 2009 Authors' Addresses Andras Kern Ericsson Laborc u. 1. Budapest, 1037 Hungary Email: andras.kern@ericsson.com Attila Takacs Ericsson Laborc u. 1. Budapest, 1037 Hungary Email: attila.takacs@ericsson.com Kern & Takacs Expires April 29, 2010 [Page 26]