Network Working Group N. Bahadur Internet-Draft R. Aggarwal Intended status: Standards Track Juniper Networks, Inc. Expires: April 28, 2011 S. Boutros Cisco Systems, Inc. E. Gray Ericsson October 25, 2010 MPLS On-demand Connectivity Verification and Route Tracing draft-ietf-mpls-tp-on-demand-cv-01 Abstract LSP-Ping is an existing and widely deployed OAM mechanism for MPLS LSPs. This document describes extensions to LSP-Ping so that LSP- Ping can be used for On-demand Connectivity Verification of MPLS-TP LSPs. This document also clarifies procedures to be used for processing the related OAM packets. Further, it describes procedures for using LSP-Ping to perform Connectivity Verification and Route Tracing functions in MPLS-TP networks. 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 April 28, 2011. Copyright Notice Copyright (c) 2010 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 Bahadur, et al. Expires April 28, 2011 [Page 1] Internet-Draft MPLS On-demand Connectivity Verification October 2010 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 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Conventions used in this document . . . . . . . . . . . . 3 1.2. On-demand CV for MPLS-TP LSPs using IP encapsulation . . . 3 1.3. On-demand CV for MPLS-TP LSPs using non-IP encapsulation . . . . . . . . . . . . . . . . . . . . . . 4 2. LSP-Ping Extensions . . . . . . . . . . . . . . . . . . . . . 4 2.1. New address type for Downstream Mapping TLV . . . . . . . 4 2.2. Source Address TLV . . . . . . . . . . . . . . . . . . . . 4 2.3. MEP and MIP Identifier . . . . . . . . . . . . . . . . . . 5 2.4. Identifying Statically provisioned LSPs and PWs . . . . . 5 2.4.1. Static LSP Sub-TLV . . . . . . . . . . . . . . . . . . 5 2.4.2. Static Pseudowire Sub-TLV . . . . . . . . . . . . . . 6 3. Performing On-demand CV over MPLS-TP LSPs . . . . . . . . . . 7 3.1. LSP-Ping with IP encapsulation . . . . . . . . . . . . . . 7 3.2. On-demand CV with IP encapsulation, over ACH . . . . . . . 7 3.3. Non-IP based On-demand CV, using ACH . . . . . . . . . . . 8 3.4. Reverse path Connectivity verification . . . . . . . . . . 8 3.5. P2MP Considerations . . . . . . . . . . . . . . . . . . . 9 3.6. Operation of On-demand CV with Static MPLS-TP . . . . . . 9 4. Performing on-demand Route Tracing over MPLS-TP LSPs . . . . . 9 4.1. On-demand LSP Route Tracing with IP encapsulation . . . . 10 4.2. Non-IP based On-demand LSP Route Tracing, using ACH . . . 10 4.2.1. Ingress node procedure for sending echo request packets . . . . . . . . . . . . . . . . . . . . . . . 10 4.2.2. Ingress node procedure for receiving echo response packets . . . . . . . . . . . . . . . . . . . . . . . 10 4.2.3. Transit and egress node procedure . . . . . . . . . . 10 4.3. P2MP Considerations . . . . . . . . . . . . . . . . . . . 11 4.4. ECMP Considerations . . . . . . . . . . . . . . . . . . . 11 5. Applicability . . . . . . . . . . . . . . . . . . . . . . . . 11 6. Security Considerations . . . . . . . . . . . . . . . . . . . 11 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 8. Contributing Authors . . . . . . . . . . . . . . . . . . . . . 12 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 12 9.1. Normative References . . . . . . . . . . . . . . . . . . . 12 9.2. Informative References . . . . . . . . . . . . . . . . . . 12 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 13 Bahadur, et al. Expires April 28, 2011 [Page 2] Internet-Draft MPLS On-demand Connectivity Verification October 2010 1. Introduction LSP-Ping [RFC4379] is an OAM mechanism for MPLS LSPs. This document describes extensions to LSP-Ping so that LSP-Ping can be used for on- demand monitoring of MPLS-TP LSPs. It also clarifies the procedures to be used for processing the OAM packets. This document describes how LSP-Ping can be used for on-demand Connectivity Verification (Section 3) and Route Tracing (Section 4) functions required in [RFC5860] and specified in [I-D.ietf-mpls-tp-oam-framework]. 1.1. Conventions used in this document The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. In addition, there is considerable opportunity for confusion in use of the terms "on-demand connectivity verification" (CV), "on-demand route tracing" and "LSP-Ping." In this document, we try to use the terms consistently as follows: LSP-Ping: refers to the mechanism - particularly as defined and used in referenced material; On-demand CV: refers to on-demand connectivity verification and - where both apply equally - on-demand route tracing as implemmented using the LSP-Ping mechanism as extended for support of MPLS-TP; On-demand route tracing: used in those cases where the LSP-Ping mechanism (as extended) is used exclusively for route tracing. 1.2. On-demand CV for MPLS-TP LSPs using IP encapsulation LSP-Ping requires IP addressing on the egress and transit LSRs for performing OAM on MPLS signaled LSPs and pseudowires. In particular, in these cases the LSP-Ping packets generated by an ingress LSR are encapsulated in an IP/UDP header with the destination address from the 127/8 range and then encapsulated in the MPLS label stack ([RFC4379] , [RFC5884]). Egress LSRs use the presence of the 127/8 destination address to identify the OAM packets and rely further on the UDP port number to determine whether the packet is a LSP-Ping packet. It is to be noted that this determination does not require IP forwarding capabilities. It requires the presence of an IP host stack which enables egress LSRs to process packets with a destination address from the 127/8 range. [RFC1122] allocates the 127/8 range as "Internal host loopback address" and [RFC1812] states that "a router SHOULD NOT forward, except over a loopback interface, any packet that has a destination address on network 127". Bahadur, et al. Expires April 28, 2011 [Page 3] Internet-Draft MPLS On-demand Connectivity Verification October 2010 1.3. On-demand CV for MPLS-TP LSPs using non-IP encapsulation In certain MPLS-TP deployment scenarios IP addressing might not be available or it may be preferred to use some form of non-IP encapsulation for On-demand CV, route tracing and BFD packets. In such scenarios, On-demand CV and/or route tracing SHOULD be run without IP addressing, using the ACH channel type specified in [I-D.ietf-mpls-tp-lsp-ping-bfd-procedures]. Section 3.3 and Section 4.2 describe the theory of operation for performing On-demand CV over MPLS-TP LSPs with any non-IP encapsulation. 2. LSP-Ping Extensions 2.1. New address type for Downstream Mapping TLV [RFC4379] defines the Downstream Mapping TLV. This document defines the following new Address type which is added to the Downstream Mapping TLV: Type # Address Type K Octets ------ -------------- -------- 0 Not Applicable 8 Figure 1: Downstream Mapping TLV new address type The new address type indicates that no address is present in the Downstream Mapping TLV. Multipath type SHOULD be set to 0 (no multipath) when using this address type. When this address type is used, on receipt of a LSP-Ping echo request, interface verification MUST be bypassed. Thus the receiving node SHOULD only perform mpls label control-plane/data-plane consistency checks. The new address type is also applicable to the Detailed Downstream Mapping TLV defined in [I-D.ietf-mpls-lsp-ping-enhanced-dsmap]. 2.2. Source Address TLV When sending On-demand CV packets using ACH, without IP encapsulation, there MAY be a need to identify the source address of the packet. This source address will be specified via the Source Address TLV, being defined in [I-D.ietf-mpls-tp-ach-tlv]. A On- demand CV packet MUST NOT include more than 1 source address TLV. Bahadur, et al. Expires April 28, 2011 [Page 4] Internet-Draft MPLS On-demand Connectivity Verification October 2010 The source address MUST specify the address of the originator of the packet. If more than 1 such TLV is present in a On-demand CV request packet, then an error of 1 (Malformed echo request received, Section 3.1 [RFC4379]) MUST be returned, if it is possible to unambiguously identify the source of the packet. 2.3. MEP and MIP Identifier When sending On-demand CV packets using ACH, there MAY be a need to identify the maintenance end point (MEP) and/or the maintenance intermediate point (MIP) targetted for the transport path monitored (see [I-D.ietf-mpls-tp-rosetta-stone]). MEP/MIP identifiers defined in [I-D.ietf-mpls-tp-identifiers] MAY be included in the ACH for this purpose. The ACH TLV (see [I-D.ietf-mpls-tp-ach-tlv]) MUST NOT include more than one targetted MEP/MIP identifier. The MEP/MIP identifier associated with the packet MUST be checked for the MPLS-TP transport path that is being monitored. If the identifier does not match, then the packet MUST be dropped. 2.4. Identifying Statically provisioned LSPs and PWs [RFC4379] specifies how an MPLS LSP under test may be identified in an echo request. A Target FEC Stack TLV is used to identify the LSP. In order to identify a statically provisioned LSP and PW, new target FEC stack sub-TLVs are being defined. The new sub-TLVs are assigned sub-type identifiers as follows, and are described in the following sections. Type # Sub-Type # Length Value Field ------ ---------- ------ ----------- 1 17 24 Static LSP 1 18 24 Static Pseudowire Figure 2: New target FEC sub-types 2.4.1. Static LSP Sub-TLV The format of the Static LSP sub-TLV value field is specified in the following figure. The value fields are taken from the definitions in [I-D.ietf-mpls-tp-identifiers]. Bahadur, et al. Expires April 28, 2011 [Page 5] Internet-Draft MPLS On-demand Connectivity Verification October 2010 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Source Global ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Source Node ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Source Tunnel Number | LSP Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Destination Global ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Destination Node ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Destination Tunnel Number | Must be Zero | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 3: Static LSP FEC Sub-TLV The Source global ID and Destination Global ID MAY be set to 0. When set to zero, the field is not applicable. 2.4.2. Static Pseudowire Sub-TLV The format of the Static PW sub-TLV value field is specified in the following figure. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Source Global ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Source Node ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Source AC-ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Destination Global ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Destination Node ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Destination AC-ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 4: Static PW FEC Sub-TLV The Source global ID and Destination Global ID MAY be set to 0. When set to zero, the field is not applicable. The Global ID and Node ID Bahadur, et al. Expires April 28, 2011 [Page 6] Internet-Draft MPLS On-demand Connectivity Verification October 2010 fields are taken from the definitions in [I-D.ietf-mpls-tp-identifiers]. The AC-ID definitions are taken from [RFC5003]. 3. Performing On-demand CV over MPLS-TP LSPs This section specifies how On-demand CV can be used in the context of MPLS-TP LSPs. The On-demand CV function meets the On-demand Connectivity Verification requirements specified in [RFC5860], section 2.2.3. This function SHOULD NOT be performed except in the on-demand mode. This function SHOULD be performed between End Points (MEPs) and Intermediate Points (MIPs) of PWs and LSPs, and between End Points of PWs, LSPs and Sections. In order for the On-demand CV packet to be processed at the desired MIP, the TTL of the MPLS label should be set such that it expires at the MIP to be probed. 3.1. LSP-Ping with IP encapsulation LSP-Ping packets, as specified in [RFC4379], are sent over the MPLS LSP for which OAM is being performed and contain an IP/UDP packet within them. The IP header is not used for forwarding (since LSP forwarding is done using MPLS label switching). The IP header is used mainly for addressing and can be used in the context of MPLS-TP LSPs. This form of On-demand CV OAM MUST be supported for MPLS-TP LSPs when IP addressing is in use. The On-demand CV echo response message MUST be sent on the reverse path of the LSP. The reply MUST contain IP/UDP headers followed by the On-demand CV payload. The destination address in the IP header MUST be set to that of the sender of the echo request message. The source address in the IP address MUST be set to a valid address of the replying node. 3.2. On-demand CV with IP encapsulation, over ACH IP encapsulated On-demand CV packets MAY be sent over the MPLS LSP using control channel (ACH) ([I-D.ietf-mpls-tp-lsp-ping-bfd-procedures]). IP ACH type specified in [RFC4385] MUST be used in such a case. The IP header is used mainly for addressing and can be used in the context of MPLS-TP LSPs. The On-demand CV echo response message SHOULD be sent on the reverse path of the LSP using ACH and SHOULD be IP encapsulated. The destination address in the IP header MUST be set to that of the sender of the echo request message. The source address in the IP address MUST be set to a valid address of the replying node. Bahadur, et al. Expires April 28, 2011 [Page 7] Internet-Draft MPLS On-demand Connectivity Verification October 2010 3.3. Non-IP based On-demand CV, using ACH The OAM procedures defined in [RFC4379] require the use of IP addressing, and in some cases IP routing, to perform OAM functions. When the ACH header is used, IP addressing and routing is not needed. This section describes procedures for performing on-demand CV without a dependency on IP addressing and routing. When using On-demand CV via LSP-Ping with the ACH header ([I-D.ietf-mpls-tp-lsp-ping-bfd-procedures]), the LSP-Ping Reply mode [RFC4379] in the LSP-Ping echo request MUST be set to 4 (Reply via application level control channel). Note that the application level control channel in this case is the reverse path of the LSP (or Pseudowire) using ACH. The requesting node MAY attach a Source Address TLV (Section 2.2) to identify the node originating the request. The On-demand CV reply message MUST be sent on the reverse path of the LSP using ACH. The On-demand CV payload MUST directly follow the ACH header (and any ACH TLVs) and no IP and/or UDP headers MUST be attached. The responding node MAY attach a Source Address TLV to identify the node sending the response. If a node receives an MPLS echo request packet over ACH, without IP/ UDP headers, with a reply mode of 4, and if that node does not have a return MPLS LSP path to the echo request source, then the node SHOULD drop the echo request packet and not attempt to send a response. If a node receives an MPLS echo request with a reply mode other than 4 (reply via application level control channel), and if the node supports that reply mode, then it MAY respond using that reply mode. If the node does not suppor the reply mode requested, or is unable to reply using the requested reply mode in any specific instance, the it MUST drop the echo request packet and not attempt to send a response. 3.4. Reverse path Connectivity verification TODO: Need a couple of things here: Firstly, we need a flag to tell the egress to send back reverse path FEC info. Secondly, we need a new TLV type to indicate that the FEC is the reverse-path FEC. Also need a new error code for the egress to indicate that there is no reverse path for the LSP. For bi-directional LSPs, when the egress sends the echo response, the egress MAY attach the target FEC stack TLV [RFC4379] in the echo response. The requesting node (on receipt of the response) can use Bahadur, et al. Expires April 28, 2011 [Page 8] Internet-Draft MPLS On-demand Connectivity Verification October 2010 the FEC stack TLV to perform reverse path connectivity verification. For co-routed bi-directional LSPs, the target FEC stack used for On- demand CV will be the same in both the forward and reverse path of the LSP. For associated bi-directional LSPs, the target FEC stack will be different for the reverse path. On receipt of the echo response, the requesting node MUST perform the following checks: 1. Perform interface and label-stack validation to ensure that the packet is received on the reverse path of the bi-directional LSP 2. If the target FEC stack is present in the echo response, then perform FEC validation. If any of the validations fail, then the requesting node MUST drop the echo response and report an error. 3.5. P2MP Considerations [I-D.ietf-mpls-p2mp-lsp-ping] describes how LSP-Ping can be used for OAM on P2MP LSPs with IP encapsulation. This MUST be supported for MPLS-TP P2MP LSPs when IP addressing is used. When IP addressing is not used, then the procedures described in Section 3.3 can be applied to P2MP MPLS-TP LSPs as well. 3.6. Operation of On-demand CV with Static MPLS-TP Support for static MPLS-TP LSP, or Pseudowire, usage and on-demand CV, requires manageable objects necessary to, for instance, configure operating parameters such as duration and periodicity of an on-demand connectivity test. The specifics of this manageability requirement are out-of-scope in this document and SHOULD be addressed in an appropriate management specification. 4. Performing on-demand Route Tracing over MPLS-TP LSPs This section specifies how On-demand CV traceroute can be used in the context of MPLS-TP LSPs. The On-demand CV traceroute function meets the Route Tracing requirement specified in [RFC5860], section 2.2.4. This function SHOULD be performed on-demand. This function SHOULD be performed between End Points and Intermediate Points of PWs and LSPs, and between End Points of PWs, LSPs and Sections. When performing On-demand CV traceroute, the requesting node inserts a Downstream Mapping TLV to get the downstream node information and to enable LSP verification along the transit nodes. The Downstream Bahadur, et al. Expires April 28, 2011 [Page 9] Internet-Draft MPLS On-demand Connectivity Verification October 2010 Mapping TLV can be used as is for performing the traceroute. If IP addressing is not in use, then the Address Type field in the Downstream Mapping TLV can be set to "Not applicable" (Section 2.1). The Downstream Mapping TLV address type field can be extended to include other address types as need be. 4.1. On-demand LSP Route Tracing with IP encapsulation The mechanics of On-demand CV traceroute are similar to those described for ping in Section 3.1. On-demand Route Tracing packets sent by the LSP ingress MUST follow procedures described in [RFC4379]. This form of On-demand CV OAM MUST be supported for MPLS-TP LSPs, when IP addressing is used. 4.2. Non-IP based On-demand LSP Route Tracing, using ACH This section describes procedures for performing LSP traceroute when using LSP-Ping with the ACH header ([I-D.ietf-mpls-tp-lsp-ping-bfd-procedures]) and without any dependency on IP addressing. The procedures specified in Section 3.3 with regards to Source Address TLV, MEP/MIP identifiers apply to LSP traceroute as well. 4.2.1. Ingress node procedure for sending echo request packets On-demand Route Tracing packets sent by the LSP ingress MUST adhere to the format described in Section 3.3. MPLS-TTL expiry (as described in [RFC4379]) will be used to direct the packets to specific nodes along the LSP path. 4.2.2. Ingress node procedure for receiving echo response packets The On-demand CV traceroute responses will be received on the LSP itself and the presence of an ACH header with channel type of On- demand CV is an indicator that the packet contains On-demand CV payload. 4.2.3. Transit and egress node procedure When a echo request reaches the transit or egress, the presence of the ACH channel type of On-demand CV will indicate that the packet contains On-demand CV data. The On-demand CV data, the label stack and the MEP/MIP identifier should be sufficient to identify the LSP associated with the echo request packet. If there is an error and the node is unable to identify the LSP on which the echo response would to be sent, the node MUST drop the echo request packet and not send any response back. All responses MUST always be sent on a LSP path using the ACH header and ACH channel type of On-demand CV. Bahadur, et al. Expires April 28, 2011 [Page 10] Internet-Draft MPLS On-demand Connectivity Verification October 2010 4.3. P2MP Considerations [I-D.ietf-mpls-p2mp-lsp-ping] describes how LSP-Ping can be used for OAM on P2MP LSPs. This MUST be supported for MPLS-TP P2MP LSPs when IP addressing is used. When IP addressing is not used, then the procedures described in Section 4.2 can be applied to P2MP MPLS-TP LSPs as well. 4.4. ECMP Considerations On-demand CV using ACH SHOULD NOT be used when there is ECMP (equal cost multiple paths) for a given LSP. The addition of the additional ACH header may modify the hashing behavior for OAM packets which may result in incorrect monitoring of path taken by data traffic. 5. Applicability The procedures specified in this document for non-IP encapsulation apply only to MPLS-TP Transport paths. This includes LSPs and PWs when IP encapsulation is not desired. However, when IP addressing is used, as in non MPLS-TP LSPs, procedures specified in [RFC4379] MUST be used. 6. Security Considerations The draft does not introduce any new security considerations. Those discussed in [RFC4379] are also applicable to this document. 7. IANA Considerations Section 2.4 defines 2 new sub-TLV types for inclusion within the LSP Ping [RFC4379] Target FEC Stack TLV. IANA is requested to assign sub-type values to the following sub-TLVs from the "Multiprotocol Label Switching Architecture (MPLS) Label Switched Paths (LSPs) Parameters - TLVs" registry, "TLVs and sub- TLVs" sub-registry. - Static LSP (temporarily assigned 17) - Static Pseudowire (temporarily assigned 18) Bahadur, et al. Expires April 28, 2011 [Page 11] Internet-Draft MPLS On-demand Connectivity Verification October 2010 8. Contributing Authors The following individuals also contributed to this document: o Thomas D. Nadeau, BT o Nurit Sprecher, Nokia Siemens Networks o Yaacov Weingarten, Nokia Siemens Networks 9. References 9.1. Normative References [I-D.ietf-mpls-tp-lsp-ping-bfd-procedures] Bahadur, N., Aggarwal, R., Ward, D., Nadeau, T., Sprecher, N., and Y. Weingarten, "LSP-Ping and BFD encapsulation over ACH", draft-ietf-mpls-tp-lsp-ping-bfd-procedures-01 (work in progress), August 2010. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC4379] Kompella, K. and G. Swallow, "Detecting Multi-Protocol Label Switched (MPLS) Data Plane Failures", RFC 4379, February 2006. [RFC4385] Bryant, S., Swallow, G., Martini, L., and D. McPherson, "Pseudowire Emulation Edge-to-Edge (PWE3) Control Word for Use over an MPLS PSN", RFC 4385, February 2006. 9.2. Informative References [I-D.ietf-mpls-lsp-ping-enhanced-dsmap] Bahadur, N., Kompella, K., and G. Swallow, "Mechanism for performing LSP-Ping over MPLS tunnels", draft-ietf-mpls-lsp-ping-enhanced-dsmap-07 (work in progress), October 2010. [I-D.ietf-mpls-p2mp-lsp-ping] Yasukawa, S., Farrel, A., Ali, Z., Swallow, G., Nadeau, T., and S. Saxena, "Detecting Data Plane Failures in Point-to-Multipoint Multiprotocol Label Switching (MPLS) - Extensions to LSP Ping", draft-ietf-mpls-p2mp-lsp-ping-12 (work in progress), October 2010. [I-D.ietf-mpls-tp-ach-tlv] Boutros, S., Bryant, S., Sivabalan, S., Swallow, G., Ward, D., and V. Manral, "Definition of ACH TLV Structure", draft-ietf-mpls-tp-ach-tlv-02 (work in progress), Bahadur, et al. Expires April 28, 2011 [Page 12] Internet-Draft MPLS On-demand Connectivity Verification October 2010 March 2010. [I-D.ietf-mpls-tp-identifiers] Bocci, M. and G. Swallow, "MPLS-TP Identifiers", draft-ietf-mpls-tp-identifiers-02 (work in progress), July 2010. [I-D.ietf-mpls-tp-oam-framework] Allan, D., Busi, I., Niven-Jenkins, B., Fulignoli, A., Hernandez-Valencia, E., Levrau, L., Sestito, V., Sprecher, N., Helvoort, H., Vigoureux, M., Weingarten, Y., and R. Winter, "Operations, Administration and Maintenance Framework for MPLS- based Transport Networks", draft-ietf-mpls-tp-oam-framework-09 (work in progress), October 2010. [I-D.ietf-mpls-tp-rosetta-stone] Sprecher, N., "A Thesaurus for the Terminology used in Multiprotocol Label Switching Transport Profile (MPLS-TP) drafts/RFCs and ITU-T's Transport Network Recommendations.", draft-ietf-mpls-tp-rosetta-stone-02 (work in progress), May 2010. [RFC1122] Braden, R., "Requirements for Internet Hosts - Communication Layers", STD 3, RFC 1122, October 1989. [RFC1812] Baker, F., "Requirements for IP Version 4 Routers", RFC 1812, June 1995. [RFC5003] Metz, C., Martini, L., Balus, F., and J. Sugimoto, "Attachment Individual Identifier (AII) Types for Aggregation", RFC 5003, September 2007. [RFC5860] Vigoureux, M., Ward, D., and M. Betts, "Requirements for Operations, Administration, and Maintenance (OAM) in MPLS Transport Networks", RFC 5860, May 2010. [RFC5884] Aggarwal, R., Kompella, K., Nadeau, T., and G. Swallow, "Bidirectional Forwarding Detection (BFD) for MPLS Label Switched Paths (LSPs)", RFC 5884, June 2010. Bahadur, et al. Expires April 28, 2011 [Page 13] Internet-Draft MPLS On-demand Connectivity Verification October 2010 Authors' Addresses Nitin Bahadur Juniper Networks, Inc. 1194 N. Mathilda Avenue Sunnyvale, CA 94089 US Phone: +1 408 745 2000 Email: nitinb@juniper.net URI: www.juniper.net Rahul Aggarwal Juniper Networks, Inc. 1194 N. Mathilda Avenue Sunnyvale, CA 94089 US Phone: +1 408 745 2000 Email: rahul@juniper.net URI: www.juniper.net Sami Boutros Cisco Systems, Inc. 3750 Cisco Way San Jose, CA 95134 US Phone: Fax: Email: sboutros@cisco.com URI: Eric Gray Ericsson 900 Chelmsford Street Lowell, MA 01851 US Phone: +1 978 275 7470 Fax: Email: eric.gray@ericsson.com URI: Bahadur, et al. Expires April 28, 2011 [Page 14]