Internet Engineering Task Force Juha Heinanen INTERNET DRAFT Telia Finland Expires August 2000 February, 2000 Soft Permanent LSPs for CR-LDP Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. 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. Distribution of this memo is unlimited. Abstract This document extends CR-LDP with capability to establish Soft Permanent LSPs (SPLSPs). A SPLSP is an LSP which originates or terminates at a label switched interface of an MPLS node. 1. Introduction A Soft Permanent LSP (SPLSP) is an LSP, which originates, terminates, or both originates and terminates at a label switched interface of an MPLS node. SPLSPs are useful, for example, in cases where an MPLS domain does not want to dynamically exchange MPLS control information with another MPLS domain or where an MPLS node, such as a CPE node, does not implement an MPLS control protocol. SPLSPs are also useful for the dynamic reestablishment of LSPs following node or trunk failures if the MPLS network does not support other protection Heinanen Soft Permanent LSPs for CR-LDP [Page 1] INTERNET DRAFT February, 2000 mechanisms. In this case, the originating MPLS node would detect when an established SPLSP fails, and would then automatically reissue the required Label Request Message to reestablish the SPLSP. This document defines the SPLSP capability for CR-LDP [1]. 2. Messages The MPLS node where an SPLSP originates from "owns" the SPLSP and is responsible for establishing and (in case of failure) reestablishing it. If an SPLSP terminates at an interface of an MPLS node, the originating MPLS node initiates the SPLSP establishment by a CR-LDP Label Request Message. In the Label Request Message the terminating interface is identified by an IP host address carried in the last ER- Hop of the ER-TLV, whereas the label to be used at that interface for the SPLSP is carried in the Label TLV. If an SPLSP terminates at an MPLS node itself, the originating MPLS node initiates the SPLSP establishment using a normal CR-LDP Label Request Message, where the terminating MPLS node is identified by an IP host address carried in the last ER-Hop of the ER-TLV. In the originating MPLS node the method of identifying the origin of the SPLSP (the node itself or one of its interfaces as well as the label to be used for the SPLSP at the possible interface) is a local matter and thus outside the scope of this document. 3. Procedures If a CR-LDP Label Request Message includes a Label TLV, it is a Label Request Message for SPLSP establishment. The procedures of Label Request Message for SPLSP establishment are as follows. A Label Request Message for SPLSP establishment is processed at the originating MPLS node and at all intermediate nodes according to normal CR-LDP rules except that the normally nonexistent Label TLV is forwarded opaquely. At the terminating MPLS node, a Label Request Message for SPLSP establishment is processed according to the normal CR-LDP rules except that the last ER-Hop of the ER-TLV identifies the interface where the SPLSP terminates and the Label TLV contains the value of the label to be used for the SPLSP at that interface. If the requested label value is not available at the terminating interface, the terminating MPLS node sends a Notification message to the originating MPLS node with Status Code "Label Value Not Available". Heinanen Soft Permanent LSPs for CR-LDP [Page 2] INTERNET DRAFT February, 2000 4. Security Considerations SPLSPs share the security concerns of regular CR-LDP LSPs. It is also worth noting that when an SPLSP originates or terminates at an interface of an MPLS node, the entity using the SPLSP at that interface is dependent on the provider of the SPLSP for routing of the SPLSP to or from the correct other entity. 5. Acknowledgements The author thanks Eric Gray and Andrew Malis both from Lucent for their comments on an earlier version of this document. 5. Author Address Juha Heinanen Telia Finland, Inc. Myyrmaentie 2 01600 Vantaa, Finland Email: jh@telia.fi Heinanen Soft Permanent LSPs for CR-LDP [Page 3]