6tisch S. Anamalamudi Internet-Draft M. Zhang Intended status: Standards Track AR. Sangi Expires: February 4, 2017 Huawei Technologies C. Perkins Futurewei S.V.R.Anand Indian Institute of Science August 03, 2016 Scheduling Function One (SF1) for hop-by-hop Scheduling in 6tisch Networks draft-satish-6tisch-6top-sf1-02 Abstract This document defines a 6top Scheduling Function called "Scheduling Function One" (SF1) to reserve, label and schedule the end-to-end resources hop-by-hop through distributed Resource Reservation Protocol(RSVP). SF1 uses the 6P signaling messages with a global TrackID to add/delete cells in end-to-end L2-bundles of isolated instance. 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 February 4, 2017. Copyright Notice Copyright (c) 2016 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 Anamalamudi, et al. Expires February 4, 2017 [Page 1] Internet-Draft draft-satish-6tisch-6top-sf1 August 2016 (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. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Operation of Scheduling Function one (SF1) . . . . . . . . . 3 2.1. Resource Reservation Protocol(RSVP-lite) . . . . . . . . 4 2.2. RSVP-PATH message . . . . . . . . . . . . . . . . . . . . 4 2.3. RSVP-RESV message . . . . . . . . . . . . . . . . . . . . 5 2.4. Reroute and Bandwidth Increase mechanism . . . . . . . . 8 2.5. Error Codes . . . . . . . . . . . . . . . . . . . . . . . 8 3. Scheduling Function Identifier . . . . . . . . . . . . . . . 8 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 5. Security Considerations . . . . . . . . . . . . . . . . . . . 8 6. References . . . . . . . . . . . . . . . . . . . . . . . . . 8 6.1. References . . . . . . . . . . . . . . . . . . . . . . . 8 6.2. Informative References . . . . . . . . . . . . . . . . . 9 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9 1. Introduction With Scheduling Function Zero (SF0) [I-D.dujovne-6tisch-6top-sf0], on-the-fly cell scheduling (ADD/DELETE) to 1-hop neighbors can be achieved for aggregated (best-effort) traffic flows. In other words, all the instances from nodeA to nodeB in Fig. 1 are scheduled in a single L3-bundle (IP link). L3-bundle(Instance-1,Instance-2,...Instance-n) -------------------------------------------------> nodeA<------------------------------------------------- nodeB L3-bundle(Instance-1,Instance-2,...Instance-n) Figure 1: L3-bundle for aggregated traffic flows in 1-hop with SF0. Some applications (e.g. Industrial M2M) require end-to-end dedicated L2-bundles to protect the control/data streams for time-critical applications [I-D.ietf-detnet-use-cases]. For such applications, per-instance based L2-bundles need to be scheduled hop-by-hop in between application sender and receiver nodes [I-D.ietf-6tisch-architecture]. In addition, cells in the scheduled end-to-end L2-bundles of each instance have to be dynamically adapted for bursty time-critical traffic flows. To achieve, end-to-end track Anamalamudi, et al. Expires February 4, 2017 [Page 2] Internet-Draft draft-satish-6tisch-6top-sf1 August 2016 has to be installed with a global TrackID that is associated with the L2-bundles of each instance. With 1-hop based SF0 cell scheduling, it is difficult to schedule dedicated end-to-end cells for isolated traffic flows. In addition, global bandwidth estimation through Resource Reservation protocol is required for bandwidth allocation in multi-hop cell scheduling. This draft proposes a Scheduling Function One (SF1) to schedule end-to-end dedicated L2-bundles for each instance, and to dynamically adapt the cells in scheduled L2-bundles of ongoing instance through RSVP protocol(see Fig. 2). L2-bundle(Instance-1) L2-bundle(Instance-1) -----------------------> ------------------> <------------------------ <------------------- L2-bundle(Instance-1) L2-bundle(Instance-1) L2-bundle(Instance-2) L2-bundle(Instance-2) ----------------------> -----------------> Sender<-----------------------nodeB <----------------- Receiver L2-bundle(Instance-2) L2-bundle(Instance-2) . . . . L2-bundle(Instance-n) L2-bundle(Instance-n) -----------------------> --------------------> <------------------------ <-------------------- L2-bundle(Instance-n) L2-bundle(Instance-n) Figure 2: Dedicated L2-bundles for end-to-end isolated traffic flows with SF1 2. Operation of Scheduling Function one (SF1) With SF1, Sender determines when to reserve the end-to-end resources, support implicit label switching(GMPLS), schedule the labeled L2-bundles hop-by-hop, associate the global TrackID for labeled L2-bundles, and dynamically adapt the cells in ongoing instance through distributed Resource Reservation Protocol (RSVP-lite). The triggering events in SF1 are as follows : 1. If Sender has any Outgoing Bandwidth Requirement for new instance to transmit data to Receiver. 2. If Sender has a New Outgoing Bandwidth Requirement for Ongoing Instance to transmit data to Receiver. In both cases, distributed RSVP-lite (explained in Section .2.1) is triggered to provide end-to-end resource reservations along with scheduling operations. Anamalamudi, et al. Expires February 4, 2017 [Page 3] Internet-Draft draft-satish-6tisch-6top-sf1 August 2016 2.1. Resource Reservation Protocol(RSVP-lite) In this specification, an end-to-end route path is assumed to be available with reactive P2P-RPL (Storing or non-storing mode) protocols. A distributed Resource Reservation Protocol (RSVP-lite) with 6tisch scheduling capability is designed to schedule the labeled reserved resources hop-by-hop for isolated instance. SF1 of application sender will trigger the RSVP-lite operation, whenever it has time critical traffic flow towards the receiver. The RSVP-lite has two messages namely (1) RSVP-PATH message(Sender to Receiver) and (2) RSVP-RESV message(Receiver to Sender). 2.2. RSVP-PATH message The basic RSVP-PATH message [RFC2205] is used to carry the "Sender Traffic Specification" along with "characterization parameters" from sender to receiver. Since RSVP treat objects as opaque data, it is valid to assume other protocol(eg., GMPLS, 6P) as an object in RSVP- PATH messages. The format of PATH message with the support of 6tisch scheduling capabilities (6P and SF1) is as follows : ::= [ ] [ [ | ] ... ] [ ] [ ] [ ] [ ... ] [] [<6P OPERATION REQUEST>] [ ] [ ] [ ] [ ... ] "SF1 OPERATION REQUEST" and "6P OPERATION REQUEST" are added in the PATH message to check for 6tisch scheduling capabilities within the intermediate nodes from sender to receiver. "Timeslot Switching Capability(TSC)" is used as an implicit labels to switch the cell at intermediate nodes [RFC3473]. The message format of the "TSC" is out-of-scope in this specification. "LABEL_REQUEST" in path message should set to "Timeslot Switching Capability". "RPLInstanceID" is added in the "SENDER_TEMPLATE" to create Global TrackID during 6P Anamalamudi, et al. Expires February 4, 2017 [Page 4] Internet-Draft draft-satish-6tisch-6top-sf1 August 2016 transactions of RSVP-RESV message. Whenever the intermediate node won't support the "Timeslot switching Capability" or "6P transactions" or "SF1 operation" then it needs to send a "PathErr" message back to application sender. 2.3. RSVP-RESV message The basic RSVP-RESV messages [RFC2205] are transmitted upstream from receiver to sender to provide resource reservation along with "Label Distribution". In this specification, hop-by-hop scheduling is extended to support both resource reservation and label distribution. The current specification is only defined for unicast point-to-point traffic flows, i.e., Fixed Filter (FF) reservation style. The format of RESV message with the support of 6tisch scheduling capabilities (6P and SF1) is as follows : ::= [ ] [ [ | ] ... ] [ ]