Network Working Group A. Kern Internet-Draft A. Takacs Intended status: Standards Track Ericsson Expires: September 3, 2012 March 2, 2012 GMPLS RSVP-TE Extensions for SONET/SDH and OTN OAM Configuration draft-ietf-ccamp-rsvp-te-sdh-otn-oam-ext-04 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 September 3, 2012 [Page 1] Internet-Draft GMPLS Based OTN and SDH OAM Configuration March 2012 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]. Status of this Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. 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." This Internet-Draft will expire on September 3, 2012. Copyright Notice Copyright (c) 2012 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 (http://trustee.ietf.org/license-info) 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. Kern & Takacs Expires September 3, 2012 [Page 2] Internet-Draft GMPLS Based OTN and SDH OAM Configuration March 2012 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 . . . . . . . . . . . . . . . . 6 2.3.1. SONET/SDH . . . . . . . . . . . . . . . . . . . . . . 6 2.3.2. OTN . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.4. Delay measurement . . . . . . . . . . . . . . . . . . . . 6 3. RSVP-TE signaling extensions . . . . . . . . . . . . . . . . . 7 3.1. Operation overview . . . . . . . . . . . . . . . . . . . . 7 3.1.1. Continuity Check supervision . . . . . . . . . . . . . 7 3.1.2. Connectivity Monitoring supervision . . . . . . . . . 8 3.1.2.1. SDH/SONET . . . . . . . . . . . . . . . . . . . . 8 3.1.2.2. OTN . . . . . . . . . . . . . . . . . . . . . . . 8 3.1.3. Signal quality supervision . . . . . . . . . . . . . . 9 3.2. Signaling support of Virtual Concatenation Groups (VCG) . 9 3.3. OAM types and functions . . . . . . . . . . . . . . . . . 10 3.4. SONET/SDH OAM Configuration sub-TLV . . . . . . . . . . . 10 3.5. OTN OAM Configuration sub-TLV . . . . . . . . . . . . . . 11 3.6. TTI Configuration Sub-TLV . . . . . . . . . . . . . . . . 11 3.6.1. SDH TTI Configuration Sub-TLV . . . . . . . . . . . . 11 3.6.2. OTN TTI Configuration Sub-TLV . . . . . . . . . . . . 12 3.7. Degraded signal thresholds Sub-TLV . . . . . . . . . . . . 14 4. Error handling . . . . . . . . . . . . . . . . . . . . . . . . 16 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17 6. Security Considerations . . . . . . . . . . . . . . . . . . . 18 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 19 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 20 8.1. Normative References . . . . . . . . . . . . . . . . . . . 20 8.2. Informative References . . . . . . . . . . . . . . . . . . 20 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 22 Kern & Takacs Expires September 3, 2012 [Page 3] Internet-Draft GMPLS Based OTN and SDH OAM Configuration March 2012 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 SONET/ SDH [RFC4606], OTN [RFC4328] and OTNv3 [OTNv3_SIG] 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 for end-to-end monitoring. Kern & Takacs Expires September 3, 2012 [Page 4] Internet-Draft GMPLS Based OTN and SDH OAM Configuration March 2012 2. Overview of SONET/SDH and OTN OAM related functions SONET/SDH [G.707] and OTN [G.709v3] provide a variety of supervision functions. Among these functions we consider continuity, connectivity and signal quality supervision functions, as these are the candidates for GMPLS based configuration. We also consider delay measurement management function of OTN. 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]. Kern & Takacs Expires September 3, 2012 [Page 5] Internet-Draft GMPLS Based OTN and SDH OAM Configuration March 2012 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 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. 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. 2.4. Delay measurement [G.709v3] introduced a tool for measuring round-trip delay of a bidirectional ODU path or tandem connection. For implementing delay measurement a one-bit delay measurement (DM) signal is defined in the ODUk header. That signal is constant value (either 0 or 1). One endpoint initiates a delay measurement by inverting the bit emitted in the DM signal. The remote endpoint loops back the DM signal; therefore, the delay measurement initiating node will receive the inverted signal from the remote endpoint. This way the initiating endpoint will determine the round trip delay. Kern & Takacs Expires September 3, 2012 [Page 6] Internet-Draft GMPLS Based OTN and SDH OAM Configuration March 2012 3. RSVP-TE signaling extensions 3.1. Operation overview RFC 4606 and RFC 4328 define the RSVP-TE extensions necessary to manage SDH/SONET and OTN optical and digital hierarchy connections. Connections for recent version of OTN, the OTNv3 are configured according to [OTNv3_SIG]. The monitoring functions associated to these connections may be configured together with configuring the connection itself. The LSP Attribute Flag "OAM MEP entities desired" [GMPLS-OAM-FWK] is used to signal that the monitoring functions at the endpoints must be established. The "OAM MIP entities desired" flag must be set to 0 and must be ignored. To configure OAM parameters the OAM Configuration TLV can be included in the LSP_ATTRIBUTES object. The TLV identifies which OAM technology ("OAM Type" field) to be used as well as which OAM functions are to be enabled (OAM Function Flags sub-TLV). For SONET/ SDH and OTN the "Continuity Check" and "Connectivity Verification" flags control the Continuity and Connectivity supervision functions, while the "Performance Monitoring/Loss" flag enables the Signal Quality supervision function. Recent release of OTN [G.709v3] introduced delay measurement for paths. Such node enables delay measurement by setting "Performance Monitoring/Delay" flag. By setting that flag the node also indicates that it will initiate the delay measurement proactively; therefore, the remote endpoint node should not initate delay measurement over the configured connection proactively. Equipments designed according to earlier version of G709 must clear "Performance Monitoring/Loss" flag and upon receiving OAM configuration message with "Performance Monitoring/Delay" flag set must generate "OAM Problem/Unsupported OAM Function" error. The "Performance Monitoring/Delay" flag must be cleared for SONET/SDH as it is not supported by SONET/SDH. For additional details the appropriate technology specific sub-TLV can be carried in the OAM Configuration TLV. 3.1.1. Continuity Check supervision In case of both discussed technologies, setting up continuity supervision function for a connection does not need further configuration besides enabling it. Therefore, by setting the "Connectivity Monitoring" Flag of OAM Function implicitly enables the continuity supervision function as well. Kern & Takacs Expires September 3, 2012 [Page 7] Internet-Draft GMPLS Based OTN and SDH OAM Configuration March 2012 3.1.2. Connectivity Monitoring supervision 3.1.2.1. SDH/SONET [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. The source node emits this stream and the destination node matches it with an expected one. When the destination detects mismatch, defect state will be declared. Since these streams encode an identifier defined for the source node, different stream will to be emitted in the upstream and downstream directions for bidirectional connections. 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. 3.1.2.2. OTN [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 Kern & Takacs Expires September 3, 2012 [Page 8] Internet-Draft GMPLS Based OTN and SDH OAM Configuration March 2012 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 3.1.3. Signal quality supervision Signal quality supervision function is implemented in MS, HOVC, LOVC layers of SDH/SONET. 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. The 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. Furthermore, as only one level is allowed a single Signal quality supervision TLV is added to the OTN OAM Configuration TLV. 3.2. 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. [RFC6344] summarises GMPLS signaling capabilities to support virtual concatenation and proposes extensions to that. A Virtual Concatenated Group (VCG) is constructed from several individual data Kern & Takacs Expires September 3, 2012 [Page 9] Internet-Draft GMPLS Based OTN and SDH OAM Configuration March 2012 plane signals. The co-routed signals of a VCG could be provisioned together using a single RSVP-TE session (co-signaled). As different OAM configuration may be applied to each of these individual signals, the OAM configuration extension is applied as follows. We assume that the same OAM type and the same set of OAM functions apply to every individual signal of the VCG. A single OAM Configuration TLV is carried in the LSP_ATTRIBUTES Object, while multiple instances of technology specific OAM configuration sub-TLVs are added: one instance per individual signal. The order of these TLVs refers to the logical order of the basic signals (as they are listed in the Label Object). [RFC6344] 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 updated the contents of the OAM Configuration TLV needs to be updated accordingly. 3.3. OAM types and functions This document defines two new code points for the "OAM Type" field of the OAM Configuration TLV, defined in [GMPLS-OAM-FWK]: SONET/SDH OAM and OTN Digital Hierarchy OAM. OAM Type Description ------------ ------------------ 3 SONET/SDH OAM 4 OTN Digital Hierarchy OAM The "OAM Function Flags sub-TLV", defined in [GMPLS-OAM-FWK]. SONET/ SDH and OTN supervision functions are defined in this document for the following flags: "Continuity Check", "Connectivity Verification", "Performance Monitoring/Loss" and "Performance Monitoring/Delay". 3.4. SONET/SDH OAM Configuration sub-TLV SONET/SDH OAM Configuration sub-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 (4) (IANA) | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | ~ sub TLVs ~ | | Kern & Takacs Expires September 3, 2012 [Page 10] Internet-Draft GMPLS Based OTN and SDH OAM Configuration March 2012 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type: indicates a new type: the SONET/SDH OAM Configuration TLV (IANA to define). Length: indicates the total length including sub-TLVs 3.5. 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. 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 (5) (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 3.6. TTI Configuration Sub-TLV 3.6.1. SDH TTI Configuration Sub-TLV This sub-TLV is carried in the SONET/SDH OAM Configuration sub-TLV, if the Connectivity Verification OAM Function Flag is set. In every supporting layers 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. Kern & Takacs Expires September 3, 2012 [Page 11] Internet-Draft GMPLS Based OTN and SDH OAM Configuration March 2012 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 not supported by the referred SONET/SDH layer, error must be generated: "OAM Problem/TTI Length Mismatch". 3.6.2. OTN TTI Configuration Sub-TLV This sub-TLV is carried in the OTN OAM Configuration sub-TLV, if the Connectivity Verification OAM Function Flag is set. Kern & Takacs Expires September 3, 2012 [Page 12] Internet-Draft GMPLS Based OTN and SDH OAM Configuration March 2012 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 = 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) 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 Kern & Takacs Expires September 3, 2012 [Page 13] Internet-Draft GMPLS Based OTN and SDH OAM Configuration March 2012 direction (See Figure 2). 3 - Invalid. 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" 3.7. 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. This sub-TLV can be carried in both the SONET/SDH OAM Configuration sub-TLV or OTN OAM Configuration sub- TLV, if the PerformanceMonitoring/Loss OAM Function Flag is set. 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 = 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, 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 Kern & Takacs Expires September 3, 2012 [Page 14] Internet-Draft GMPLS Based OTN and SDH OAM Configuration March 2012 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 September 3, 2012 [Page 15] Internet-Draft GMPLS Based OTN and SDH OAM Configuration March 2012 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 In case of SONET/SDH if Performance Measurement/Delay flag is set in the OAM Functions Flag sub-TLV, an error must be generated "OAM Problem/Unsupported OAM Function". o In case of OTN if the equipment does not support delay measurement and the Performance Measurement/Delay flag is set in the received OAM Functions Flag sub-TLV, an error must be generated "OAM Problem/Unsupported OAM Function". o In case of SONET/SDH OAM when the length or format of the TTI to be configured is not supported by the referred SONET/SDH layer, an 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". Kern & Takacs Expires September 3, 2012 [Page 16] Internet-Draft GMPLS Based OTN and SDH OAM Configuration March 2012 5. IANA Considerations This document specifies two new sub-TLVs to be carried in the OAM Configuration TLV in the LSP_ATTRIBUTES or LSP_REQUIRED_ATTRIBUTES Objects in Path and Resv messages. The document assigns values 3 and 4 from the "OAM Type" field of the OAM Configuration TLV. The following error values need to be assigned under "OAM Problem" error code: "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". Kern & Takacs Expires September 3, 2012 [Page 17] Internet-Draft GMPLS Based OTN and SDH OAM Configuration March 2012 6. Security Considerations Security aspects are addressed in the OAM configuration framework document [GMPLS-OAM-FWK] Kern & Takacs Expires September 3, 2012 [Page 18] Internet-Draft GMPLS Based OTN and SDH OAM Configuration March 2012 7. Acknowledgements The authors would like to thank Francesco Fondelli for his useful comments. Kern & Takacs Expires September 3, 2012 [Page 19] Internet-Draft GMPLS Based OTN and SDH OAM Configuration March 2012 8. References 8.1. Normative References [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. 8.2. Informative 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.709v3] International Telecommunications Union, "Interfaces for the Optical Transport Network (OTN)", ITU-T Recommendation G.709, December 2009. [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. [OTNv3_SIG] Zhang, F., Zhang, G., Belotti, S., Ceccarelli, D., and K. Pithewan, "Operating Virtual Concatenation (VCAT) and the Link Capacity Adjustment Scheme (LCAS) with Generalized Multi-Protocol Label Switching (GMPLS)", draft-ietf-ccamp-gmpls-signaling-g709v3-01 (work in progress), October 2011. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC4328] Papadimitriou, D., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Extensions for G.709 Optical Transport Networks Control", RFC 4328, January 2006. Kern & Takacs Expires September 3, 2012 [Page 20] Internet-Draft GMPLS Based OTN and SDH OAM Configuration March 2012 [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. [RFC6344] Bernstein, G., Caviglia, D., Rabbat, R., and H. Helvoort, "Operating Virtual Concatenation (VCAT) and the Link Capacity Adjustment Scheme (LCAS) with Generalized Multi- Protocol Label Switching (GMPLS)", RFC 6344, August 2011. Kern & Takacs Expires September 3, 2012 [Page 21] Internet-Draft GMPLS Based OTN and SDH OAM Configuration March 2012 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 September 3, 2012 [Page 22]