SPRING Working Group R. Gandhi, Ed.Internet-Draft C. FilsfilsIntended Status: Standards Track Cisco Systems, Inc.Expires: March 18, 2019 D. Voyer Bell Canada S. Salsano Universita di Roma "Tor Vergata" P. L. Ventre CNIT M. Chen Huawei September 14, 2018UDP Path for In-bandPerformance Measurement for Segment Routing Networksdraft-gandhi-spring-udp-pm-02Abstract Segment Routing (SR) is applicable to both Multiprotocol Label Switching (SR-MPLS) and IPv6 (SRv6) data planes. This document specifies procedures for using UDP path for sending and processing in-band probe query and response messages for Performance Measurement. The procedure uses theRFC 6374 defined mechanisms for Delay and Loss performance measurement. The procedure specified is applicable to SR-MPLS and SRv6 data planes for both links and end-to-end measurement for SR Policies. This document also defines mechanisms for handling Equal Cost Multipaths (ECMPs) for SR Policies. In addition, this document defines Return Path Segment List TLV for two-way performance measurement and Block Number TLV for loss measurement.Status of This Memo This Internet-Draft is submitted in full conformance with the provisions ofBCP 78 andBCP 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 athttp://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."Gandhi, et al. Expires March 18, 2019 [Page 1]
Internet-Draft UDP Path for PM in Segment Routing September 14, 2018Copyright Notice Copyright (c) 2018 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject toBCP 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.Table of Contents1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . .32. Conventions Used in This Document . . . . . . . . . . . . . .42.1. Requirements Language . . . . . . . . . . . . . . . . . .42.2. Abbreviations . . . . . . . . . . . . . . . . . . . . . .42.3. Reference Topology . . . . . . . . . . . . . . . . . . . .53. Probe Messages . . . . . . . . . . . . . . . . . . . . . . . .63.1. Probe Query Message . . . . . . . . . . . . . . . . . . .63.1.1. Delay Measurement Probe Query Message . . . . . . . .63.1.2. Loss Measurement Probe Query Message . . . . . . . . .73.1.2.1. Block Number TLV . . . . . . . . . . . . . . . . .83.1.3. In-band Probe Query for SR Links . . . . . . . . . . .8 3.1.4. In-band Probe Query for End-to-end Measurement of SR Policy . . . . . . . . . . . . . . . . . . . . . . . .83.1.4.1. In-band Probe Query Message for SR-MPLS Policy . .83.1.4.2. In-band Probe Query Message for SRv6 Policy . . .93.2. Probe Response Message . . . . . . . . . . . . . . . . . .9 3.2.1. One-way Measurement for SR Link and end-to-end SR Policy . . . . . . . . . . . . . . . . . . . . . . . .103.2.1.1. Probe Response Message to Controller . . . . . . .113.2.2. Two-way Measurement for SR Links . . . . . . . . . . .113.2.3. Two-way End-to-end Measurement of SR Policy . . . . .113.2.3.1. Return Path Segment List TLV . . . . . . . . . . .11 3.2.3.2. In-band Probe Response Message for SR-MPLS Policy . . . . . . . . . . . . . . . . . . . . . .133.2.3.3. In-band Probe Response Message for SRv6 Policy . .134. Performance Measurement for P2MP SR Policies . . . . . . . . .145. ECMP Support . . . . . . . . . . . . . . . . . . . . . . . . .146. Sequence Number TLV . . . . . . . . . . . . . . . . . . . . .147. Security Considerations . . . . . . . . . . . . . . . . . . .158. IANA Considerations . . . . . . . . . . . . . . . . . . . . .15Gandhi, et al. Expires March 18, 2019 [Page 2]
Internet-Draft UDP Path for PM in Segment Routing September 14, 20189. References . . . . . . . . . . . . . . . . . . . . . . . . . .169.1. Normative References . . . . . . . . . . . . . . . . . . .169.2. Informative References . . . . . . . . . . . . . . . . . .16 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . .19 Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . .19 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . .191. Introduction Segment Routing (SR) technology greatly simplifies network operations for Software Defined Networks (SDNs). SR is applicable to both Multiprotocol Label Switching (SR-MPLS) and IPv6 (SRv6) data planes. SR takes advantage of the Equal-Cost Multipaths (ECMPs) between source, transit and destination nodes. SR Policies as defined in [I-D.spring-segment-routing-policy] are used to steer traffic through a specific, user-defined path using a stack of Segments. Built-in SR Performance Measurement (PM) is one of the essential requirements to provide Service Level Agreements (SLAs). The One-Way Active Measurement Protocol (OWAMP) defined in [RFC4656] and Two-Way Active Measurement Protocol (TWAMP) defined in [RFC5357] provide capabilities for the measurement of various performance metrics in IP networks. These protocols rely on control channel signaling to establish a test channel over an UDP path. These protocols lack support for IEEE 1588 timestamp [IEEE1588] format and direct-mode Loss Measurement (LM), which are required in SR networks [RFC6374]. The Simple Two-way Active Measurement Protocol (STAMP) [I-D.ippm-stamp] alleviates the control channel signaling by using configuration data model to provision test channels. In addition, the STAMP supports IEEE 1588 timestamp format for Delay Measurement (DM). The TWAMP Light from broadband forum [BBF.TR-390] provides simplified mechanisms for active performance measurement in Customer Edge IP networks. [RFC6374] specifies protocol mechanisms to enable the efficient and accurate measurement of performance metrics and can be used in SR networks with MPLS data plane [I-D.spring-sr-mpls-pm]. [RFC6374] addresses the limitations of the IP based performance measurement protocols as specified inSection 1 of [RFC6374]. The [RFC6374] requires data plane to support MPLS Generic Associated Channel Label (GAL) and Generic Associated Channel (G-Ach), which may not be supported on all nodes in the network. [RFC7876] specifies the procedures to be used when sending and processing out-of-band performance measurement probe response messages over an UDP return path forRFC 6374 based probe queries.Gandhi, et al. Expires March 18, 2019 [Page 3]
Internet-Draft UDP Path for PM in Segment Routing September 14, 2018 [RFC7876] can be used to send out-of-band PM probe responses in both SR-MPLS and SRv6 networks for one-way performance measurement. For SR Policies, there are ECMPs between the source and transit nodes, between transit nodes and between transit and destination nodes. Existing PM protocols (e.g.RFC 6374) do not define handling for ECMP forwarding paths in SR networks. For two-way measurements for SR Policies, there is a need to specify a return path in the form of a Segment List in PM probe query messages without requiring any SR Policy state on the destination node. Exiting protocols do not have such mechanisms to specify return path in the PM probe query messages. This document specifies a procedure for using UDP path for sending and processing in-band probe query and response messages for Performance Measurement that does not require to bootstrap PM sessions. The procedure usesRFC 6374 defined mechanisms for Delay and Loss PM and unless otherwise specified, the procedures fromRFC6374 are not modified. The procedure specified is applicable to both SR-MPLS and SRv6 data planes. The procedure does not require to bootstrap PM sessions and can be used for both SR links and end-to-end performance measurement for SR Policies. This document also defines mechanisms for handling Equal Cost Multipaths (ECMPs) for SR Policies. In addition, this document defines Return Path Segment List (RPSL) TLV for two-way performance measurement and Block Number TLV for loss measurement.2. Conventions Used in This Document2.1. 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 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.2.2. Abbreviations ACH: Associated Channel Header. BSID: Binding Segment ID. DFLag: Data Format Flag. DM: Delay Measurement.Gandhi, et al. Expires March 18, 2019 [Page 4]
Internet-Draft UDP Path for PM in Segment Routing September 14, 2018 ECMP: Equal Cost Multi-Path. G-ACh: Generic Associated Channel (G-ACh). GAL: Generic Associated Channel (G-ACh) Label. LM: Loss Measurement. MPLS: Multiprotocol Label Switching. NTP: Network Time Protocol. OWAMP: One-Way Active Measurement Protocol. PM: Performance Measurement. PTP: Precision Time Protocol. RPSL: Return Path Segment List. SID: Segment ID. SL: Segment List. SR: Segment Routing. SR-MPLS: Segment Routing with MPLS data plane. SRv6: Segment Routing with IPv6 data plane. STAMP: Simple Two-way Active Measurement Protocol. TC: Traffic Class. TWAMP: Two-Way Active Measurement Protocol. URO: UDP Return Object.2.3. Reference Topology In the reference topology, the querier node R1 initiates a probe query for performance measurement and the responder node R5 sends a probe response for the query message received. The probe response may be sent to the querier node R1 or to a controller node R100. The nodes R1 and R5 may be directly connected via a link enabled with Segment Routing or there exists a Point-to-Point (P2P) SR Policy [I-D.spring-segment-routing-policy] on node R1 with destination toGandhi, et al. Expires March 18, 2019 [Page 5]
Internet-Draft UDP Path for PM in Segment Routing September 14, 2018 node R5. In case of Point-to-Multipoint (P2MP), SR Policy originating from source node R1 may terminate on multiple destination leaf nodes [I-D.spring-sr-p2mp-policy]. ------ |R100| ------ ^ | Response | +-------+ Query +-------+ | | - - - - - - - - - ->| | | R1 |---------------------| R5 | | |<- - - - - - - - - - | | +-------+ Response +-------+ Reference Topology Both Delay and Loss performance measurement is performed in-band for the traffic traversing between node R1 and node R5. One-way delay and two-way delay measurements are defined inSection 2.4 of [RFC6374]. Transmit and Receive packet loss measurements are defined inSection 2.2 andSection 2.6 of [RFC6374]. One-way loss measurement provides receive packet loss whereas two-way loss measurement provides both transmit and receive packet loss.3. Probe Messages3.1. Probe Query Message In this document, UDP path is defined for sending and processing PM probe query messages for Delay and Loss measurements for SR links and end-to-end SR Policies as described in the following Sections. As well-known UDP port is used for identifying PM probe packets, bootstrapping of the PM session [RFC5357] is not required. The TTL / Hop Limit field of the IP header MUST be set to 1.3.1.1. Delay Measurement Probe Query Message The message content for Delay Measurement probe query message using UDP header [RFC768] is shown in Figure 1. As shown, the DM probe query message is sent with Destination UDP port number TBA1 defined in this document. The Source UDP port may optionally be set to TBA1 for two-way delay measurement. The DM probe query message contains the payload for delay measurement defined inSection 3.2 of [RFC6374].Gandhi, et al. Expires March 18, 2019 [Page 6]
Internet-Draft UDP Path for PM in Segment Routing September 14, 2018 +---------------------------------------------------------------+ | IP Header | . Source IP Address = Querier IPv4 or IPv6 Address . . Destination IP Address = Responder IPv4 or IPv6 Address . . Protocol = UDP . . IP TTL = 1 . . Router Alert Option Not Set . . . +---------------------------------------------------------------+ | UDP Header | . Source Port = As chosen by Querier . . Destination Port = TBA1 by IANA for Delay Measurement . . . +---------------------------------------------------------------+ | Payload = Message as specified inSection 3.2 of RFC 6374 | . . +---------------------------------------------------------------+ Figure 1: DM Probe Query Message3.1.2. Loss Measurement Probe Query Message The message content for Loss measurement probe query message using UDP header [RFC768] is shown in Figure 2. As shown, the LM probe query message is sent with Destination UDP port number TBA2 defined in this document. The Source UDP port may optionally be set to TBA2 for two-way loss measurement. The LM probe query message contains the payload for loss measurement defined inSection 3.1 of [RFC6374]. +---------------------------------------------------------------+ | IP Header | . Source IP Address = Querier IPv4 or IPv6 Address . . Destination IP Address = Responder IPv4 or IPv6 Address . . Protocol = UDP . . IP TTL = 1 . . Router Alert Option Not Set . . . +---------------------------------------------------------------+ | UDP Header | . Source Port = As chosen by Querier . . Destination Port = TBA2 by IANA for Loss Measurement . . . +---------------------------------------------------------------+ | Payload = Message as specified inSection 3.1 of RFC 6374 | . . +---------------------------------------------------------------+Gandhi, et al. Expires March 18, 2019 [Page 7]
Internet-Draft UDP Path for PM in Segment Routing September 14, 2018 Figure 2: LM Probe Query Message The path segment identifier [I-D.spring-mpls-path-segment] [I-D.pce-sr-path-segment] of the SR Policy is required for accounting received traffic on the egress node for loss measurement.3.1.2.1. Block Number TLV The Loss Measurement using Alternate-Marking method defined in [RFC8321] requires to identify the Block Number (color) of the traffic counters carried by the probe query and response messages. Probe query and response messages specified in [RFC6374] for Loss Measurement do not define any means to carry the Block Number. [RFC6374] defines probe query and response messages that can include one or more optional TLVs. New TLV Type (value TBA8) is defined in this document to carry Block Number (32-bit) for the traffic counters in the probe query and response messages for loss measurement. The format of the Block Number TLV is shown in Figure 11: 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 TBA8 | Length | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Block Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 11: Block Number TLV The Block Number TLV is optional. The PM querier node SHOULD only insert one Block Number TLV in the probe query message and the responder node in the probe response message SHOULD return the first Block Number TLV from the probe query messages and ignore other Block Number TLVs if present. In both probe query and response messages, the counters MUST belong to the same Block Number.3.1.3. In-band Probe Query for SR Links The probe query message as defined in Figure 1 is sent in-band for Delay measurement. The probe query message as defined in Figure 2 is sent in-band for Loss measurement.3.1.4. In-band Probe Query for End-to-end Measurement of SR Policy3.1.4.1. In-band Probe Query Message for SR-MPLS Policy The message content for in-band probe query message using UDP headerGandhi, et al. Expires March 18, 2019 [Page 8]
Internet-Draft UDP Path for PM in Segment Routing September 14, 2018 for end-to-end performance measurement of SR-MPLS Policy is shown in Figure 3. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Segment List(0) | EXP |S| TTL | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ . . . . . . +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Segment List(n) | EXP |S| TTL | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Message as shown in Figure 1 for DM or Figure 2 for LM | . . +---------------------------------------------------------------+ Figure 3: In-band Probe Query Message for SR-MPLS Policy The Segment List (SL) can be empty to indicate Implicit NULL label case.3.1.4.2. In-band Probe Query Message for SRv6 Policy The in-band probe query messages using UDP header for end-to-end performance measurement of an SRv6 Policy is sent using SRv6 Segment Routing Header (SRH) and Segment List of the SRv6 Policy as defined in [I-D.6man-segment-routing-header] and is shown in Figure 4. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SRH | . . +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Message as shown in Figure 1 for DM or Figure 2 for LM | . . +---------------------------------------------------------------+ Figure 4: In-band Probe Query Message for SRv6 Policy3.2. Probe Response Message When the received probe query message does not contain any UDP Return Object (URO) TLV [RFC7876], the probe response message is sent using the IP/UDP information from the probe query message. The content ofGandhi, et al. Expires March 18, 2019 [Page 9]
Internet-Draft UDP Path for PM in Segment Routing September 14, 2018 the probe response message is shown in Figure 5. +---------------------------------------------------------------+ | IP Header | . Source IP Address = Responder IPv4 or IPv6 Address . . Destination IP Address = Source IP Address from Query . . Protocol = UDP . . Router Alert Option Not Set . . . +---------------------------------------------------------------+ | UDP Header | . Source Port = As chosen by Responder . . Destination Port = Source Port from Query . . . +---------------------------------------------------------------+ | Message as specified inSection 3.2 of RFC 6374 for DM, or | . Message as specified inSection 3.1 of RFC 6374 for LM . . . +---------------------------------------------------------------+ Figure 5: Probe Response Message When the received probe query message contains UDP Return Object (URO) TLV [RFC7876], the probe response message the message uses the IP/UDP information from the URO in the probe query message. The content of the probe response message is shown in Figure 6. +---------------------------------------------------------------+ | IP Header | . Source IP Address = Responder IPv4 or IPv6 Address . . Destination IP Address = URO.Address . . Protocol = UDP . . Router Alert Option Not Set . . . +---------------------------------------------------------------+ | UDP Header | . Source Port = As chosen by Responder . . Destination Port = URO.UDP-Destination-Port . . . +---------------------------------------------------------------+ | Message as specified inSection 3.2 of RFC 6374 for DM, or | . Message as specified inSection 3.1 of RFC 6374 for LM . . . +---------------------------------------------------------------+ Figure 6: Probe Response Message Using URO from Probe Query Message3.2.1. One-way Measurement for SR Link and end-to-end SR PolicyGandhi, et al. Expires March 18, 2019 [Page 10]
Internet-Draft UDP Path for PM in Segment Routing September 14, 2018 For one-way performance measurement, the probe response message as defined in Figure 5 or Figure 6 is sent out-of-band for both SR links and SR Policies. The PM querier node can receive probe response message back by properly setting its own IP address as Source Address of the header or by adding URO TLV in the probe query message and setting its own IP address in the IP Address in the URO TLV (Type=131) [RFC7876]. In addition, the "control code" in the probe query message is set to "out-of-band response requested". The "Source Address" TLV (Type 130), and "Return Address" TLV (Type 1), if present in the probe query message, are not used to send probe response message.3.2.1.1. Probe Response Message to Controller As shown in the Reference Topology, if the querier node requires the probe response message to be sent to the controller R100, it adds URO TLV in the probe query message and sets the IP address of R100 in the IP Address field and UDP port TBA1 for DM and TBA2 for LM in the UDP-Destination-Port field of the URO TLV (Type=131) [RFC7876].3.2.2. Two-way Measurement for SR Links For two-way performance measurement, when using a bidirectional channel, the probe response message as defined in Figure 5 or Figure 6 is sent back in-band to the querier node for SR links. In this case, the "control code" in the probe query message is set to "in-band response requested" [RFC6374].3.2.3. Two-way End-to-end Measurement of SR Policy For two-way performance measurement, when using a bidirectional channel, the probe response message is sent back in-band to the querier node for end-to-end measurement of SR Policies. In this case, the "control code" in the probe query message is set to "in-band response requested" [RFC6374]. The path segment identifier [I-D.spring-mpls-path-segment] [I-D.pce-sr-path-segment] of the forward SR Policy can be used to find the reverse SR Policy to send the probe response message in the absence of RPSL TLV defined in the following Section.3.2.3.1. Return Path Segment List TLV For two-way performance measurement, the responder node needs to send the probe response message in-band on a specific reverse SR path. This way the destination node does not require any additional SR Policy state. The querier node can request in the probe queryGandhi, et al. Expires March 18, 2019 [Page 11]
Internet-Draft UDP Path for PM in Segment Routing September 14, 2018 message to the responder node to send a response back on a given reverse path (typically co-routed path for two-way measurement). [RFC6374] defines DM and LM probe query messages that can include one or more optional TLVs. New TLV Types are defined in this document for Return Path Segment List (RPSL) to carry reverse SR path for probe response messages. The format of the RPSL TLV is shown in Figure 7: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | RPSL Type | Length | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Segment List(0) | . . +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ . . . . . . +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Segment List(n) | . . +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 7: Return Path Segment List TLV The RPSL can be one of following Types: o RPSL Type (value TBA3): SR-MPLS Label Stack of the Reverse SR Policy o RPSL Type (value TBA4): SRv6 Segment List of the Reverse SR Policy o RPSL Type (value TBA5): SR-MPLS Binding SID [I-D.pce-binding-label-sid] of the Reverse SR Policy o RPSL Type (value TBA6): SRv6 Binding SID [I-D.pce-binding-label-sid] of the Reverse SR Policy The Segment List(0) can be used by the responder node to compute the next-hop IP address and outgoing interface to send the probe response messages. The RPSL TLV is optional. The PM querier node MUST only insert one RPSL TLV in the probe query message and the responder node MUST only process the first RPSL TLV in the probe query message and ignoreGandhi, et al. Expires March 18, 2019 [Page 12]
Internet-Draft UDP Path for PM in Segment Routing September 14, 2018 other RPSL TLVs if present. The responder node MUST send probe response message back on the reverse path specified in the RPSL TLV and MUST NOT add RPSL TLV in the probe response message.3.2.3.2. In-band Probe Response Message for SR-MPLS Policy The message content for sending probe response message in-band using UDP header for two-way end-to-end performance measurement of an SR-MPLS Policy is shown in Figure 8. The SR-MPLS label stack in the packet header is built using the Segment List received in the RPSL TLV in the probe query message. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Segment List(0) | EXP |S| TTL | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ . . . . . . +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Segment List(n) | EXP |S| TTL | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Message as shown in Figure 5 or 6 | . IP TTL = 1 . . . +---------------------------------------------------------------+ Figure 8: In-band Probe Response Message for SR-MPLS Policy3.2.3.3. In-band Probe Response Message for SRv6 Policy The message content for sending probe response message in-band using UDP header for two-way end-to-end performance measurement of an SRv6 Policy is shown in Figure 9. For SRv6 Policy, the SRv6 SID list in the SRH of the probe response message is built using the SRv6 Segment List received in the RPSL TLV in the probe query message. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SRH | . . +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Message as shown in Figure 5 or 6 | . IP TTL = 1 . . . +---------------------------------------------------------------+Gandhi, et al. Expires March 18, 2019 [Page 13]
Internet-Draft UDP Path for PM in Segment Routing September 14, 2018 Figure 9: In-band Probe Response Message for SRv6 Policy4. Performance Measurement for P2MP SR Policies The procedures for delay and loss measurement described in this document for Point-to-Point (P2P) SR-MPLS Policies are also equally applicable to the Point-to-Multipoint (P2MP) SR Policies.5. ECMP Support An SR Policy can have ECMPs between the source and transit nodes, between transit nodes and between transit and destination nodes. The PM probe messages can be sent to traverse different ECMP paths to measure performance of an SR Policy. Forwarding plane has various hashing functions available to forward packets on specific ECMP paths. Following mechanisms can be used in PM probe messages to take advantage of the hashing function in forwarding plane to influence the path taken by them. o The mechanisms described in [RFC8029] [RFC5884] for handling ECMPs are also applicable to the performance measurement. In the IP/UDP header of the PM probe messages, Destination Addresses in 127/8 range for IPv4 or 0:0:0:0:0:FFFF:7F00/104 range for IPv6 can be used to exercise a particular ECMP path. In addition, different Source Addresses or different Source UDP ports can be used for this purpose. As specified in [RFC6437], 3-tuple of Flow Label, Source Address and Destination Address fields in the IPv6 header can also be used. o For SR-MPLS, entropy label [RFC6790] in the PM probe messages can be used. o For SRv6, Flow Label in SRH [I-D.6man-segment-routing-header] of the PM probe messages can be used.6. Sequence Number TLV The message formats for DM and LM [RFC6374] do not contain sequence number for probe query packets. Sequence numbers can be useful when some probe query messages are lost or they arrive out of order. [RFC6374] defines DM and LM probe query and response messages that can include one or more optional TLVs. New TLV Type (value TBA7) is defined in this document to carry sequence number for probe query and response messages for delay and loss measurement. The format of theGandhi, et al. Expires March 18, 2019 [Page 14]
Internet-Draft UDP Path for PM in Segment Routing September 14, 2018 Sequence Number TLV is shown in Figure 10: 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 TBA7 | Length | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sequence Number | . . +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 10: Sequence Number TLV The sequence numbers start with 0 and are incremented by one for each subsequent probe query packet. The sequence number can be of any length determined by the querier node. The Sequence Number TLV is optional. The PM querier node SHOULD only insert one Sequence Number TLV in the probe query message and the responder node in the probe response message SHOULD return the first Sequence Number TLV from the probe query message and ignore other Sequence Number TLVs if present.7. Security Considerations The performance measurement is intended for deployment in well-managed private and service provider networks. The security considerations described inSection 8 of [RFC6374] are applicable to this specification, and particular attention should be paid to the last two paragraphs. Cryptographic measures may be enhanced by the correct configuration of access-control lists and firewalls.8. IANA Considerations IANA is requested to allocate following UDP ports for performance measurements: o UDP Port TBA1: Delay Performance Measurement o UDP Port TBA2: Loss Performance Measurement IANA is also requested to allocate values for the following Return Path Segment List TLV Types forRFC 6374 to be carried in PM probe query messages: o Type TBA3: SR-MPLS Label Stack of the Reverse SR PolicyGandhi, et al. Expires March 18, 2019 [Page 15]
Internet-Draft UDP Path for PM in Segment Routing September 14, 2018 o Type TBA4: SRv6 Segment List of the Reverse SR Policy o Type TBA5: SR-MPLS Binding SID of the Reverse SR Policy o Type TBA6: SRv6 Binding SID of the Reverse SR Policy IANA is also requested to allocate a value for the following Sequence Number TLV Type forRFC 6374 to be carried in the PM probe query and response messages for delay and loss measurement: o Type TBA7: Sequence Number TLV IANA is also requested to allocate a value for the following Block Number TLV Type forRFC 6374 to be carried in the PM probe query and response messages for loss measurement: o Type TBA8: Block Number TLV9. References9.1. Normative References [RFC768] Postel, J., "User Datagram Protocol", STD 6,RFC 768, August 1980. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels",RFC 2119, March 1997. [RFC6374] Frost, D. and S. Bryant, "Packet Loss and Delay Measurement for MPLS networks',RFC 6374, September 2011. [RFC7876] Bryant, S., Sivabalan, S., and Soni, S., "UDP Return Path for Packet Loss and Delay Measurement for MPLS Networks",RFC 7876, July 2016. [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase inRFC2119 Key Words",RFC 8174, May 2017.9.2. Informative References [IEEE1588] IEEE, "1588-2008 IEEE Standard for a Precision Clock Synchronization Protocol for Networked Measurement and Control Systems", March 2008.Gandhi, et al. Expires March 18, 2019 [Page 16]
Internet-Draft UDP Path for PM in Segment Routing September 14, 2018 [RFC4656] Shalunov, S., Teitelbaum, B., Karp, A., Boote, J., and M. Zekauskas, "A One-way Active Measurement Protocol (OWAMP)",RFC 4656, September 2006. [RFC5357] Hedayat, K., Krzanowski, R., Morton, A., Yum, K., and J. Babiarz, "A Two-Way Active Measurement Protocol (TWAMP)",RFC 5357, October 2008. [RFC5884] Aggarwal, R., Kompella, K., Nadeau, T., and G. Swallow, "Bidirectional Forwarding Detection (BFD) for MPLS Label Switched Paths (LSPs)",RFC 5884, DOI 10.17487/RFC5884, June 2010. [RFC6437] Amante, S., Carpenter, B., Jiang, S., and J. Rajahalme, "IPv6 Flow Label Specification",RFC 6437, November 2011. [RFC6790] Kompella, K., Drake, J., Amante, S., Henderickx, W., and L. Yong, "The Use of Entropy Labels in MPLS Forwarding",RFC 6790, November 2012. [RFC8029] Kompella, K., Swallow, G., Pignataro, C., Kumar, N., Aldrin, S. and M. Chen, "Detecting Multiprotocol Label Switched (MPLS) Data-Plane Failures",RFC 8029, March 2017. [RFC8321] Fioccola, G. Ed., "Alternate-Marking Method for Passive and Hybrid Performance Monitoring",RFC 8321, January 2018. [I-D.spring-segment-routing-policy] Filsfils, C., et al., "Segment Routing Policy Architecture",draft-ietf-spring-segment-routing-policy, work in progress. [I-D.spring-sr-p2mp-policy] Voyer, D. Ed., et al., "SR Replication Policy for P2MP Service Delivery",draft-voyer-spring-sr-p2mp-policy, work in progress. [I-D.6man-segment-routing-header] Filsfils, C., et al., "IPv6 Segment Routing Header (SRH)",draft-ietf-6man-segment-routing-header, work in progress. [I-D.spring-sr-mpls-pm] Filsfils, C., Gandhi, R. Ed., et al. "Performance Measurement in Segment Routing Networks with MPLS Data Plane",draft-gandhi-spring-sr-mpls-pm, work in progress. [I-D.pce-binding-label-sid] Filsfils, C., et al., "Carrying BindingGandhi, et al. Expires March 18, 2019 [Page 17]
Internet-Draft UDP Path for PM in Segment Routing September 14, 2018 Label Segment-ID in PCE-based Networks",draft-sivabalan-pce-binding-label-sid, work in progress. [I-D.spring-mpls-path-segment] Cheng, W., et al., "Path Segment in MPLS Based Segment Routing Network",draft-cheng-spring-mpls-path-segment, work in progress. [I-D.pce-sr-path-segment] Li, C., et al., "Path Computation Element Communication Protocol (PCEP) Extension for Path Identification in Segment Routing (SR)",draft-li-pce-sr-path-segment, work in progress. [I-D.ippm-stamp] Mirsky, G. et al. "Simple Two-way Active Measurement Protocol",draft-ietf-ippm-stamp, work in progress. [BBF.TR-390] "Performance Measurement from IP Edge to Customer Equipment using TWAMP Light", BBF TR-390, May 2017.Gandhi, et al. Expires March 18, 2019 [Page 18]
Internet-Draft UDP Path for PM in Segment Routing September 14, 2018Acknowledgments The authors would like to thank Nagendra Kumar and Carlos Pignataro for the discussion on SRv6 Performance Measurement.Contributors Sagar Soni Cisco Systems, Inc. Email: sagsoni@cisco.com Patrick Khordoc Cisco Systems, Inc. Email: pkhordoc@cisco.com Zafar Ali Cisco Systems, Inc. Email: zali@cisco.com Daniel Bernier Bell Canada Email: daniel.bernier@bell.ca Dirk Steinberg Steinberg Consulting Germany Email: dws@dirksteinberg.deAuthors' Addresses Rakesh Gandhi (editor) Cisco Systems, Inc. Canada Email: rgandhi@cisco.com Clarence Filsfils Cisco Systems, Inc. Email: cfilsfil@cisco.com Daniel VoyerGandhi, et al. Expires March 18, 2019 [Page 19]
Internet-Draft UDP Path for PM in Segment Routing September 14, 2018 Bell Canada Email: daniel.voyer@bell.ca Stefano Salsano Universita di Roma "Tor Vergata" Italy Email: stefano.salsano@uniroma2.it Pier Luigi Ventre CNIT Italy Email: pierluigi.ventre@cnit.it Mach(Guoyi) Chen Huawei Email: mach.chen@huawei.comGandhi, et al. Expires March 18, 2019 [Page 20] draft-gandhi-spring-udp-pm-02
Replaced Internet-Draft (individual)
| Document | Document type | Replaced Internet-Draft (individual) Expired & archived This document is an Internet-Draft (I-D). Anyone may submit an I-D to the IETF. This I-D isnot endorsed by the IETF and hasno formal standing in theIETF standards process. | |
|---|---|---|---|
| Select version | |||
| Compare versions | |||
| Authors | Rakesh Gandhi,Clarence Filsfils,Daniel Voyer,Stefano Salsano,Pier Luigi Ventre,Mach Chen Email authors | ||
| Replaced by | draft-gandhi-spring-rfc6374-srpm-udp | ||
| RFC stream | (None) | ||
| Intended RFC status | (None) | ||
| Other formats |