Network Working Group W. Sun, Ed. Internet-Draft SJTU Intended status: Standards Track G. Zhang, Ed. Expires: January 10, 2010 CATR July 9, 2009 Label Switched Path (LSP) Dynamic Provisioning Performance Metrics in Generalized MPLS Networks draft-ietf-ccamp-lsp-dppm-06.txt Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. This document may contain material from IETF Documents or IETF Contributions published or made publicly available before November 10, 2008. The person(s) controlling the copyright in some of this material may not have granted the IETF Trust the right to allow modifications of such material outside the IETF Standards Process. 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The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on January 10, 2010. Copyright Notice Copyright (c) 2009 IETF Trust and the persons identified as the document authors. All rights reserved. Sun & Zhang Expires January 10, 2010 [Page 1] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents in effect on the date of publication of this document (http://trustee.ietf.org/license-info). Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Sun & Zhang Expires January 10, 2010 [Page 2] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 Abstract Generalized Multi-Protocol Label Switching (GMPLS) is one of the most promising candidate technologies for future data transmission network. GMPLS has been developed to control and operate different kinds of network elements, such as conventional routers, switches, Dense Wavelength Division Multiplexing (DWDM) systems, Add- Drop Multiplexers (ADMs), photonic cross-connects (PXCs), optical cross- connects (OXCs), etc. Dynamic provisioning ability of these physically diverse devices differs from each other drastically. At the same time, the need for dynamically provisioned connections is increasing because optical networks are being deployed in metro areas. As different applications have varied requirements in the provisioning performance of optical networks, it is imperative to define standardized metrics and procedures such that the performance of networks and application needs can be mapped to each other. This document provides a series of performance metrics to evaluate the dynamic LSP provisioning performance in GMPLS networks, specifically the dynamic LSP setup/release performance. These metrics can depict the features of GMPLS networks in LSP dynamic provisioning. They can also be used in operational networks for carriers to monitor the control plane performance in realtime. Sun & Zhang Expires January 10, 2010 [Page 3] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 7 2. Conventions Used in This Document . . . . . . . . . . . . . . 8 3. Overview of Performance Metrics . . . . . . . . . . . . . . . 9 4. A Singleton Definition for Single Uni-directional LSP Setup Delay . . . . . . . . . . . . . . . . . . . . . . . . . 10 4.1. Motivation . . . . . . . . . . . . . . . . . . . . . . . . 10 4.2. Metric Name . . . . . . . . . . . . . . . . . . . . . . . 10 4.3. Metric Parameters . . . . . . . . . . . . . . . . . . . . 10 4.4. Metric Units . . . . . . . . . . . . . . . . . . . . . . . 11 4.5. Definition . . . . . . . . . . . . . . . . . . . . . . . . 11 4.6. Discussion . . . . . . . . . . . . . . . . . . . . . . . . 11 4.7. Methodologies . . . . . . . . . . . . . . . . . . . . . . 12 5. A Singleton Definition for multiple Uni-directional LSP Setup Delay . . . . . . . . . . . . . . . . . . . . . . . . . 13 5.1. Motivation . . . . . . . . . . . . . . . . . . . . . . . . 13 5.2. Metric Name . . . . . . . . . . . . . . . . . . . . . . . 13 5.3. Metric Parameters . . . . . . . . . . . . . . . . . . . . 13 5.4. Metric Units . . . . . . . . . . . . . . . . . . . . . . . 13 5.5. Definition . . . . . . . . . . . . . . . . . . . . . . . . 13 5.6. Discussion . . . . . . . . . . . . . . . . . . . . . . . . 14 5.7. Methodologies . . . . . . . . . . . . . . . . . . . . . . 15 6. A Singleton Definition for Single Bi-directional LSP Setup Delay . . . . . . . . . . . . . . . . . . . . . . . . . 16 6.1. Motivation . . . . . . . . . . . . . . . . . . . . . . . . 16 6.2. Metric Name . . . . . . . . . . . . . . . . . . . . . . . 16 6.3. Metric Parameters . . . . . . . . . . . . . . . . . . . . 17 6.4. Metric Units . . . . . . . . . . . . . . . . . . . . . . . 17 6.5. Definition . . . . . . . . . . . . . . . . . . . . . . . . 17 6.6. Discussion . . . . . . . . . . . . . . . . . . . . . . . . 17 6.7. Methodologies . . . . . . . . . . . . . . . . . . . . . . 18 7. A Singleton Definition for multiple Bi-directional LSPs Setup Delay . . . . . . . . . . . . . . . . . . . . . . . . . 19 7.1. Motivation . . . . . . . . . . . . . . . . . . . . . . . . 19 7.2. Metric Name . . . . . . . . . . . . . . . . . . . . . . . 19 7.3. Metric Parameters . . . . . . . . . . . . . . . . . . . . 19 7.4. Metric Units . . . . . . . . . . . . . . . . . . . . . . . 19 7.5. Definition . . . . . . . . . . . . . . . . . . . . . . . . 19 7.6. Discussion . . . . . . . . . . . . . . . . . . . . . . . . 20 7.7. Methodologies . . . . . . . . . . . . . . . . . . . . . . 21 Sun & Zhang Expires January 10, 2010 [Page 4] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 8. A Singleton Definition for LSP Graceful Release Delay . . . . 22 8.1. Motivation . . . . . . . . . . . . . . . . . . . . . . . . 22 8.2. Metric Name . . . . . . . . . . . . . . . . . . . . . . . 22 8.3. Metric Parameters . . . . . . . . . . . . . . . . . . . . 22 8.4. Metric Units . . . . . . . . . . . . . . . . . . . . . . . 22 8.5. Definition . . . . . . . . . . . . . . . . . . . . . . . . 22 8.6. Discussion . . . . . . . . . . . . . . . . . . . . . . . . 23 8.7. Methodologies . . . . . . . . . . . . . . . . . . . . . . 24 9. A Definition for Samples of Single Uni-directional LSP Setup Delay . . . . . . . . . . . . . . . . . . . . . . . . . 26 9.1. Metric Name . . . . . . . . . . . . . . . . . . . . . . . 26 9.2. Metric Parameters . . . . . . . . . . . . . . . . . . . . 26 9.3. Metric Units . . . . . . . . . . . . . . . . . . . . . . . 26 9.4. Definition . . . . . . . . . . . . . . . . . . . . . . . . 26 9.5. Discussion . . . . . . . . . . . . . . . . . . . . . . . . 27 9.6. Methodologies . . . . . . . . . . . . . . . . . . . . . . 27 9.7. Typical testing cases . . . . . . . . . . . . . . . . . . 27 9.7.1. With no LSP in the Network . . . . . . . . . . . . . . 28 9.7.2. With a number of LSPs in the Network . . . . . . . . . 28 10. A Definition for Samples of Multiple Uni-directional LSPs Setup Delay . . . . . . . . . . . . . . . . . . . . . . . . . 29 10.1. Metric Name . . . . . . . . . . . . . . . . . . . . . . . 29 10.2. Metric Parameters . . . . . . . . . . . . . . . . . . . . 29 10.3. Metric Units . . . . . . . . . . . . . . . . . . . . . . . 29 10.4. Definition . . . . . . . . . . . . . . . . . . . . . . . . 29 10.5. Discussion . . . . . . . . . . . . . . . . . . . . . . . . 30 10.6. Methodologies . . . . . . . . . . . . . . . . . . . . . . 30 10.7. Typical testing cases . . . . . . . . . . . . . . . . . . 30 10.7.1. With No LSP in the Network . . . . . . . . . . . . . . 31 10.7.2. With a Number of LSPs in the Network . . . . . . . . . 31 11. A Definition for Samples of Single Bi-directional LSP Setup Delay . . . . . . . . . . . . . . . . . . . . . . . . . 32 11.1. Metric Name . . . . . . . . . . . . . . . . . . . . . . . 32 11.2. Metric Parameters . . . . . . . . . . . . . . . . . . . . 32 11.3. Metric Units . . . . . . . . . . . . . . . . . . . . . . . 32 11.4. Definition . . . . . . . . . . . . . . . . . . . . . . . . 32 11.5. Discussion . . . . . . . . . . . . . . . . . . . . . . . . 33 11.6. Methodologies . . . . . . . . . . . . . . . . . . . . . . 33 11.7. Typical testing cases . . . . . . . . . . . . . . . . . . 34 11.7.1. With No LSP in the Network . . . . . . . . . . . . . . 34 11.7.2. With a Number of LSPs in the Network . . . . . . . . . 34 12. A Definition for Samples of Multiple Bi-directional LSPs Setup Delay . . . . . . . . . . . . . . . . . . . . . . . . . 35 12.1. Metric Name . . . . . . . . . . . . . . . . . . . . . . . 35 Sun & Zhang Expires January 10, 2010 [Page 5] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 12.2. Metric Parameters . . . . . . . . . . . . . . . . . . . . 35 12.3. Metric Units . . . . . . . . . . . . . . . . . . . . . . . 35 12.4. Definition . . . . . . . . . . . . . . . . . . . . . . . . 35 12.5. Discussion . . . . . . . . . . . . . . . . . . . . . . . . 36 12.6. Methodologies . . . . . . . . . . . . . . . . . . . . . . 36 12.7. Typical testing cases . . . . . . . . . . . . . . . . . . 36 12.7.1. With No LSP in the Network . . . . . . . . . . . . . . 37 12.7.2. With a Number of LSPs in the Network . . . . . . . . . 37 13. A Definition for Samples of LSP Graceful Release Delay . . . . 38 13.1. Metric Name . . . . . . . . . . . . . . . . . . . . . . . 38 13.2. Metric Parameters . . . . . . . . . . . . . . . . . . . . 38 13.3. Metric Units . . . . . . . . . . . . . . . . . . . . . . . 38 13.4. Definition . . . . . . . . . . . . . . . . . . . . . . . . 38 13.5. Discussion . . . . . . . . . . . . . . . . . . . . . . . . 38 13.6. Methodologies . . . . . . . . . . . . . . . . . . . . . . 39 14. Some Statistics Definitions for Metrics to Report . . . . . . 40 14.1. The Minimum of Metric . . . . . . . . . . . . . . . . . . 40 14.2. The Median of Metric . . . . . . . . . . . . . . . . . . . 40 14.3. The percentile of Metric . . . . . . . . . . . . . . . . . 40 14.4. Failure statistics of Metric . . . . . . . . . . . . . . . 40 14.4.1. Failure Count . . . . . . . . . . . . . . . . . . . . 41 14.4.2. Failure Ratio . . . . . . . . . . . . . . . . . . . . 41 15. Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . 42 16. Security Considerations . . . . . . . . . . . . . . . . . . . 43 17. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 44 18. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 45 19. References . . . . . . . . . . . . . . . . . . . . . . . . . . 46 19.1. Normative References . . . . . . . . . . . . . . . . . . . 46 19.2. Informative References . . . . . . . . . . . . . . . . . . 46 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 48 Sun & Zhang Expires January 10, 2010 [Page 6] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 1. Introduction Generalized Multi-Protocol Label Switching (GMPLS) is one of the most promising control plane solutions for future transport and service network. GMPLS has been developed to control and operate different kinds of network elements, such as conventional routers, switches, Dense Wavelength Division Multiplexing (DWDM) systems, Add-Drop Multiplexors (ADMs), photonic cross-connects (PXCs), optical cross- connects (OXCs), etc. Dynamic provisioning ability of these physically diverse devices differs from each other drastically. The introduction of a control plane into optical circuit switching networks automates the provisioning of connections and drastically reduces connection provision delay. As more and more services and applications are seeking to use GMPLS controlled networks as their underlying transport network, and increasingly in a dynamic way, the need is growing for measuring and characterizing the performance of LSP provisioning in GMPLS networks, such that requirement from applications and the provisioning capability of the network can be mapped to each other. This draft defines performance metrics and methodologies that can be used to depict the dynamic LSP provisioning performance of GMPLS networks, more specifically, performance of the signaling protocol. The metrics defined in this document can on the one hand be used to depict the average performance of GMPLS implementations. On the other hand, it can also be used in operational environments for carriers to monitor the control plane operation in real-time. For example, a new object can be added to GMPLS TE STD MIB [RFC4802] so that the current and past control plane performance can be monitored through network management systems. The extension of TE-MIB to support the defined metrics is outside the scope of this document. Sun & Zhang Expires January 10, 2010 [Page 7] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 2. 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]. Sun & Zhang Expires January 10, 2010 [Page 8] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 3. Overview of Performance Metrics In this memo, to depict the dynamic LSP provisioning performance of a GMPLS network, we define 3 performance metrics: uni-directional LSP setup delay, bi-directional LSP setup delay, and LSP graceful release delay. The latency of the LSP setup/release signal is similar to the Round-trip Delay in IP networks. So we refer the structures and notions introduced and discussed in the IPPM Framework document, [RFC2330] [RFC2679] [RFC2681]. The reader is assumed to be familiar with the notions in those documents. Note that data path related metrics, for example, the time between the reception of RESV message by ingress node and forward data path becomes operational, are defined in another document [I-D.sun-ccamp-dpm]. An implementation MAY choose whether to implement metrics in the two documents together. However, it is RECOMMENDED that both measurements are performed to complement each other. Sun & Zhang Expires January 10, 2010 [Page 9] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 4. A Singleton Definition for Single Uni-directional LSP Setup Delay This part defines a metric for single uni-directional Label Switched Path setup delay across a GMPLS network. 4.1. Motivation Single uni-directional Label Switched Path setup delay is useful for several reasons: o Single LSP setup delay is an important metric that depicts the provisioning performance of a GMPLS network. Longer LSP setup delay will incur higher overhead for the requesting application, especially when the LSP duration is comparable to the LSP setup delay. o The minimum value of this metric provides an indication of the delay that will likely be experienced when the LSP traversed the shortest route at the lightest load in the control plane. As the delay itself consists of several components, such as link propagation delay and nodal processing delay, this metric also reflects the status of control plane. For example, for LSPs traversing the same route, longer setup delays may suggest congestion in the control channel or high control element load. For this reason, this metric is useful for testing and diagnostic purposes. o LSP setup delay variance has different impact on applications. Erratic variation in LSP setup delay makes it difficult to support applications that have stringent setup delay requirement. The measurement of single uni-directional LSP setup delay instead of bi-directional LSP setup delay is motivated by the following factors: o Some applications may use only uni-directional LSPs rather than bi-directional ones. For example, content delivery services with multicasting may use only uni-directional LSPs. 4.2. Metric Name single uni-directional LSP setup delay 4.3. Metric Parameters o ID0, the ingress LSR ID o ID1, the egress LSR ID Sun & Zhang Expires January 10, 2010 [Page 10] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 o T, a time when the setup is attempted 4.4. Metric Units The value of single uni-directional LSP setup delay is either a real number, or an undefined number of milliseconds. 4.5. Definition The single uni-directional LSP setup delay from the ingress node ID0 to the egress node ID1 [RFC3945] at T is dT means that ingress node ID0 sends the first bit of a PATH message packet to egress node ID1 at wire-time T, and that the ingress node ID0 received the last bit of responding RESV message packet from the egress node ID1 at wire- time T+dT in the uni-directional LSP setup case. The single uni-directional LSP setup delay from the ingress node ID0 to the egress node ID1 at T is undefined, means that ingress node ID0 sends the first bit of PATH message packet to egress node ID1 at wire-time T and that ingress node ID0 does not receive the corresponding RESV message within a reasonable period of time. The undefined value of this metric indicates an event of Single Uni- directional LSP Setup Failure, and would be used to report a count or an percentage of Single Uni-directional LSP Setup failures. See section Section 14.4 for definitions of LSP setup/release failures. 4.6. Discussion The following issues are likely to come up in practice: o The accuracy of uni-directional LSP setup delay at time T depends on the clock resolution in the ingress node; but synchronization between the ingress node and egress node is not required since uni-directional LSP setup uses two-way signaling. o A given methodology will have to include a way to determine whether a latency value is infinite or whether it is merely very large. Simple upper bounds MAY be used. But GMPLS networks may accommodate many kinds of devices. For example, some photonic cross-connects (PXCs) have to move micro mirrors. This physical motion may take several milliseconds. But the common electronic switches can finish the nodal processing within several microseconds. So the uni-directional LSP setup delay varies drastically from one network to another. In practice, the upper bound should be chosen carefully and the value MUST be reported. Sun & Zhang Expires January 10, 2010 [Page 11] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 o If ingress node sends out the PATH message to set up LSP, but never receives the corresponding RESV message, uni-directional LSP setup delay MUST be set to undefined. o If ingress node sends out the PATH message to set up LSP but receives PathErr message, uni-directional LSP setup delay MUST be set to undefined. There are many possible reasons for this case. For example, the PATH message has invalid parameters or the network does not have enough resource to set up the requested LSP, etc. 4.7. Methodologies Generally the methodology would proceed as follows: o Make sure that the network has enough resource to set up the requested LSP. o At the ingress node, form the PATH message according to the LSP requirements. A timestamp (T1) may be stored locally on the ingress node when the PATH message packet is sent towards the egress node. o If the corresponding RESV message arrives within a reasonable period of time, take the timestamp (T2) as soon as possible upon receipt of the message. By subtracting the two timestamps, an estimate of uni-directional LSP setup delay (T2 -T1) can be computed. o If the corresponding RESV message fails to arrive within a reasonable period of time, the uni-directional LSP setup delay is deemed to be undefined. Note that the 'reasonable' threshold is a parameter of the methodology. o If the corresponding response message is PathErr, the uni- directional LSP setup delay is deemed to be undefined. Sun & Zhang Expires January 10, 2010 [Page 12] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 5. A Singleton Definition for multiple Uni-directional LSP Setup Delay This part defines a metric for multiple uni-directional Label Switched Paths setup delay across a GMPLS network. 5.1. Motivation Multiple uni-directional Label Switched Paths setup delay is useful for several reasons: o Upon traffic interruption caused by network failure or network upgrade, carriers may require a large number of LSPs be set up during a short time period. o The time needed to setup a large number of LSPs during a short time period can not be deduced by single LSP setup delay. 5.2. Metric Name Multiple uni-directional LSPs setup delay 5.3. Metric Parameters o ID0, the ingress LSR ID o ID1, the egress LSR ID o Lambda_m, a rate in reciprocal milliseconds o X, the number of LSPs to setup o T, a time when the first setup is attempted 5.4. Metric Units The value of multiple uni-directional LSPs setup delay is either a real number, or an undefined number of milliseconds. 5.5. Definition Given Lambda_m and X, the multiple uni-directional LSPs setup delay from the ingress node to the egress node [RFC3945] at T is dT means: o ingress node ID0 sends the first bit of the first PATH message packet to egress node ID1 at wire-time T o all subsequent (X-1) PATH messages are sent according to the specified Poisson process with arrival rate Lambda_m Sun & Zhang Expires January 10, 2010 [Page 13] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 o ingress node ID0 receives all corresponding RESV message packets from egress node ID1, and o ingress node ID0 receives the last RESV message packet at wire- time T+dT The multiple uni-directional LSPs setup delay at T is undefined, means that ingress node ID0 sends all the PATH messages toward the egress node ID1 and the first bit of the first PATH message packet is sent at wire-time T and that ingress node ID0 does not receive the one or more of the corresponding RESV messages within a reasonable period of time. The undefined value of this metric indicates an event of Multiple Uni-directional LSP Setup Failure, and would be used to report a count or an percentage of Multiple Uni-directional LSP Setup failures. See section Section 14.4 for definitions of LSP setup/ release failures. 5.6. Discussion The following issues are likely to come up in practice: o The accuracy of multiple uni-directional LSPs setup delay at time T depends on the clock resolution in the ingress node; but synchronization between the ingress node and egress node is not required since uni-directional LSP setup uses two-way signaling. o A given methodology will have to include a way to determine whether a latency value is infinite or whether it is merely very large. Simple upper bounds MAY be used. But GMPLS networks may accommodate many kinds of devices. For example, some photonic cross-connects (PXCs) have to move micro mirrors. This physical motion may take several milliseconds. But electronic switches can finish the nodal processing within several microseconds. So the multiple uni-directional LSP setup delay varies drastically from one network to another. In practice, the upper bound should be chosen carefully and the value MUST be reported. o If ingress node sends out the multiple PATH messages to set up the LSPs, but never receives one or more of the corresponding RESV messages, multiple uni-directional LSP setup delay MUST be set to undefined. o If ingress node sends out the PATH messages to set up the LSPs but receives one or more PathErr messages, multiple uni-directional LSPs setup delay MUST be set to undefined. There are many possible reasons for this case. For example, one of the PATH Sun & Zhang Expires January 10, 2010 [Page 14] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 messages has invalid parameters or the network has not enough resource to set up the requested LSPs, etc. o The arrival rate of the Poisson process Lambda_m should be chosen carefully such that in the one hand the control plane is not overburdened. On the other hand, the arrival rate is large enough to meet the requirements of applications or services. 5.7. Methodologies Generally the methodology would proceed as follows: o Make sure that the network has enough resource to set up the requested LSPs. o At the ingress node, form the PATH messages according to the LSPs' requirements. o At the ingress node, select the time for each of the PATH messages according to the specified Poisson process. o At the ingress node, send out the PATH messages according to the selected time. o Store a timestamp (T1) locally on the ingress node when the first PATH message packet is sent towards the egress node. o If all of the corresponding RESV messages arrive within a reasonable period of time, take the final timestamp (T2) as soon as possible upon the receipt of all the messages. By subtracting the two timestamps, an estimate of multiple uni-directional LSPs setup delay (T2 -T1) can be computed. o If one or more of the corresponding RESV messages fail to arrive within a reasonable period of time, the multiple uni-directional LSPs setup delay is deemed to be undefined. Note that the 'reasonable' threshold is a parameter of the methodology. o If one or more of the corresponding response messages are PathErr, the multiple uni-directional LSPs setup delay is deemed to be undefined. Sun & Zhang Expires January 10, 2010 [Page 15] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 6. A Singleton Definition for Single Bi-directional LSP Setup Delay GMPLS allows establishment of bi-directional symmetric LSPs (not of asymmetric LSPs). This part defines a metric for single bi- directional LSP setup delay across a GMPLS network. 6.1. Motivation Single bi-directional Label Switched Path setup delay is useful for several reasons: o LSP setup delay is an important metric that depicts the provisioning performance of a GMPLS network. Longer LSP setup delay will incur higher overhead for the requesting application, especially when the LSP duration is comparable to the LSP setup delay. Thus, measuring the setup delay is important for application scheduling. o The minimum value of this metric provides an indication of the delay that will likely be experienced when the LSP traversed the shortest route at the lightest load in the control plane. As the delay itself consists of several components, such as link propagation delay and nodal processing delay, this metric also reflects the status of control plane. For example, for LSPs traversing the same route, longer setup delays may suggest congestion in the control channel or high control element load. For this reason, this metric is useful for testing and diagnostic purposes. o LSP setup delay variance has different impact on applications. Erratic variation in LSP setup delay makes it difficult to support applications that have stringent setup delay requirement. The measurement of single bi-directional LSP setup delay instead of uni-directional LSP setup delay is motivated by the following factors: o Bi-directional LSPs are seen as a requirement for many GMPLS networks. Its provisioning performance is important to applications that generate bi-directional traffic. 6.2. Metric Name Single bi-directional LSP setup delay Sun & Zhang Expires January 10, 2010 [Page 16] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 6.3. Metric Parameters o ID0, the ingress LSR ID o ID1, the egress LSR ID o T, a time when the setup is attempted 6.4. Metric Units The value of single bi-directional LSP setup delay is either a real number, or an undefined number of milliseconds. 6.5. Definition For a real number dT, the single bi-directional LSP setup delay from ingress node ID0 to egress node ID1 at T is dT, means that ingress node ID0 sends out the first bit of a PATH message including an Upstream Label [RFC3473] heading for egress node ID1 at wire-time T, egress node ID1 receives that packet, then immediately sends a RESV message packet back to ingress node ID0, and that ingress node ID0 receives the last bit of the RESV message packet at wire-time T+dT. The single bi-directional LSP setup delay from ingress node ID0 to egress node ID1 at T is undefined, means that ingress node ID0 sends the first bit of PATH message to egress node ID1 at wire-time T and that ingress node ID0 does not receive that response packet within a reasonable period of time. The undefined value of this metric indicates an event of Single Bi- directional LSP Setup Failure, and would be used to report a count or an percentage of Single Bi-directional LSP Setup failures. See section Section 14.4 for definitions of LSP setup/release failures. 6.6. Discussion The following issues are likely to come up in practice: o The accuracy of single bi-directional LSP setup delay depends on the clock resolution in the ingress node; but synchronization between the ingress node and egress node is not required since single bi-directional LSP setup uses two-way signaling. o A given methodology will have to include a way to determine whether a latency value is infinite or whether it is merely very large. Simple upper bounds MAY be used. But GMPLS networks may accommodate many kinds of devices. For example, some photonic cross-connects (PXCs) have to move micro mirrors. This physical Sun & Zhang Expires January 10, 2010 [Page 17] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 motion may take several milliseconds. But electronic switches can finish the nodal processing within several microseconds. So the bi-directional LSP setup delay varies drastically from one network to another. In the process of bi-directional LSP setup, if the downstream node overrides the label suggested by the upstream node, the setup delay may also increase. Thus, in practice, the upper bound should be chosen carefully and the value MUST be reported. o If the ingress node sends out the PATH message to set up the LSP, but never receives the corresponding RESV message, single bi- directional LSP setup delay MUST be set to undefined. o If the ingress node sends out the PATH message to set up the LSP, but receives PathErr message, single bi-directional LSP setup delay MUST be set to undefined. There are many possible reasons for this case. For example, the PATH message has invalid parameters or the network has not enough resource to set up the requested LSP. 6.7. Methodologies Generally the methodology would proceed as follows: o Make sure that the network has enough resource to set up the requested LSP. o At the ingress node, form the PATH message (including the Upstream Label or suggested label) according to the LSP requirements. A timestamp (T1) may be stored locally on the ingress node when the PATH message packet is sent towards the egress node. o If the corresponding RESV message arrives within a reasonable period of time, take the final timestamp (T2) as soon as possible upon the receipt of the message. By subtracting the two timestamps, an estimate of bi-directional LSP setup delay (T2 -T1) can be computed. o If the corresponding RESV message fails to arrive within a reasonable period of time, the single bi-directional LSP setup delay is deemed to be undefined. Note that the 'reasonable' threshold is a parameter of the methodology. o If the corresponding response message is PathErr, the single bi- directional LSP setup delay is deemed to be undefined. Sun & Zhang Expires January 10, 2010 [Page 18] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 7. A Singleton Definition for multiple Bi-directional LSPs Setup Delay This part defines a metric for multiple bi-directional LSPs setup delay across a GMPLS network. 7.1. Motivation multiple bi-directional LSPs setup delay is useful for several reasons: o Upon traffic interruption caused by network failure or network upgrade, carriers may require a large number of LSPs be set up during a short time period o The time needed to setup a large number of LSPs during a short time period can not be deduced by single LSP setup delay 7.2. Metric Name Multiple bi-directional LSPs setup delay 7.3. Metric Parameters o ID0, the ingress LSR ID o ID1, the egress LSR ID o Lambda_m, a rate in reciprocal milliseconds o X, the number of LSPs to setup o T, a time when the first setup is attempted 7.4. Metric Units The value of multiple bi-directional LSPs setup delay is either a real number, or an undefined number of milliseconds. 7.5. Definition Given Lambda_m and X, for a real number dT, the multiple bi- directional LSPs setup delay from ingress node to egress node at T is dT, means that: o ingress node ID0 sends the first bit of the first PATH message heading for egress node ID1 at wire-time T Sun & Zhang Expires January 10, 2010 [Page 19] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 o all subsequent (X-1) PATH messages are sent according to the specified Poisson process with arrival rate Lambda_m o ingress node ID1 receives all corresponding RESV message packets from egress node ID1, and o ingress node ID0 receives the last RESV message packet at wire- time T+dT The multiple bi-directional LSPs setup delay from ingress node to egress node at T is undefined, means that ingress node sends all the PATH messages to egress node and that the ingress node fails to receive one or more of the response RESV messages within a reasonable period of time. The undefined value of this metric indicates an event of Multiple Bi- directional LSP Setup Failure, and would be used to report a count or an percentage of Multiple Bi-directional LSP Setup failures. See section Section 14.4 for definitions of LSP setup/release failures. 7.6. Discussion The following issues are likely to come up in practice: o The accuracy of multiple bi-directional LSPs setup delay depends on the clock resolution in the ingress node; but synchronization between the ingress node and egress node is not required since bi- directional LSP setup uses two-way signaling. o A given methodology will have to include a way to determine whether a latency value is infinite or whether it is merely very large. Simple upper bounds MAY be used. But GMPLS networks may accommodate many kinds of devices. For example, some photonic cross-connects (PXCs) have to move micro mirrors. This physical motion may take several milliseconds. But electronic switches can finish the nodal process within several microseconds. So the multiple bi-directional LSPs setup delay varies drastically from a network to another. In the process of multiple bi-directional LSPs setup, if the downstream node overrides the label suggested by the upstream node, the setup delay may also increase. Thus, in practice, the upper bound should be chosen carefully and the value MUST be reported. o If the ingress node sends out the PATH messages to set up the LSPs, but never receives all the corresponding RESV messages, the multiple bi-directional LSPs setup delay MUST be set to undefined. Sun & Zhang Expires January 10, 2010 [Page 20] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 o If the ingress node sends out the PATH messages to set up the LSPs, but receives one or more responding PathErr messages, the multiple bi-directional LSPs setup delay MUST be set to undefined. There are many possible reasons for this case. For example, one or more of the PATH messages have invalid parameters or the network has not enough resource to set up the requested LSPs. o The arrival rate of the Poisson process Lambda_m should be carefully chosen such that on the one hand the control plane is not overburdened. On the other hand, the arrival rate is large enough to meet the requirements of applications or services. 7.7. Methodologies Generally the methodology would proceed as follows: o Make sure that the network has enough resource to set up the requested LSPs. o At the ingress node, form the PATH messages (including the Upstream Label or suggested label) according to the LSPs' requirements. o At the ingress node, select the time for each of the PATH messages according to the specified Poisson process. o At the ingress node, send out the PATH messages according to the selected time. o Store a timestamp (T1) locally in the ingress node when the first PATH message packet is sent towards the egress node. o If all of the corresponding RESV messages arrive within a reasonable period of time, take the final timestamp (T2) as soon as possible upon the receipt of all the messages. By subtracting the two timestamps, an estimate of multiple bi-directional LSPs setup delay (T2 -T1) can be computed. o If one or more of the corresponding RESV messages fail to arrive within a reasonable period of time, the multiple bi-directional LSPs setup delay is deemed to be undefined. Note that the 'reasonable' threshold is a parameter of the methodology. o If one or more of the corresponding response messages are PathErr, the multiple bi-directional LSPs setup delay is deemed to be undefined. Sun & Zhang Expires January 10, 2010 [Page 21] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 8. A Singleton Definition for LSP Graceful Release Delay There are two different kinds of LSP release mechanisms in GMPLS networks: graceful release and forceful release. This document does not take forceful LSP release procedure into account. 8.1. Motivation LSP graceful release delay is useful for several reasons: o The LSP graceful release delay is part of the total cost of dynamic LSP provisioning. For some short duration applications, the LSP release time can not be ignored o The LSP graceful release procedure is more preferred in a GMPLS controlled network, particularly the optical networks. Since it doesn't trigger restoration/protection, it is "alarm-free connection deletion" in [RFC4208]. 8.2. Metric Name LSP graceful release delay 8.3. Metric Parameters o ID0, the ingress LSR ID o ID1, the egress LSR ID o T, a time when the release is attempted 8.4. Metric Units The value of LSP graceful release delay is either a real number, or an undefined number of milliseconds. 8.5. Definition There are two different LSP graceful release procedures, one is initiated by the ingress node, and another is initiated by the egress node. The two procedures are depicted in [RFC3473]. We define the graceful LSP release delay for these two procedures separately. For a real number dT, the LSP graceful release delay from ingress node ID0 to egress node ID1 at T is dT, means that ingress node ID0 sends the first bit of a PATH message including Admin Status Object with the Reflect (R) and Delete (D) bits set to the egress node at wire-time T, that the egress node ID1 receives that packet, then Sun & Zhang Expires January 10, 2010 [Page 22] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 immediately sends a RESV message including Admin Status Object with the Delete (D) bit set back to the ingress node. The ingress node ID0 sends out PathTear downstream to remove the LSP, and egress node ID1 receives the last bit of PathTear packet at wire-time T+dT. Also as an option, upon receipt of the PATH message including Admin Status Object with the Reflect (R) and Delete (D) bits set, the egress node ID1 may respond with PathErr message with the Path_State_Removed flag set. The LSP graceful release delay from ingress node ID0 to egress node ID1 at T is undefined, means that ingress node ID0 sends the first bit of PATH message to egress node ID1 at wire-time T and that (either egress node does not receive the PATH packet, egress node does not send corresponding RESV message packet in response, or ingress node does not receive that RESV packet, and) the egress node ID1 does not receive the PathTear within a reasonable period of time. The LSP graceful release delay from egress node ID1 to ingress node ID0 at T is dT, means that egress node ID1 sends the first bit of a RESV message including Admin Status Object with setting the Reflect (R) and Delete (D) bits to ingress node at wire-time T. The ingress node ID0 sends out PathTear downstream to remove the LSP, and egress node ID1 receives the last bit of PathTear packet at wire-time T+dT. The LSP graceful release delay from egress node ID1 to ingress node ID0 at T is undefined, means that egress node ID1 sends the first bit of RESV message including Admin Status Object with setting the Reflect (R) and Delete (D) bits to ingress node ID0 at wire-time T and that (either ingress node does not receive the RESV packet, or ingress node does not send PathTear message packet in response, and) the egress node ID1 does not receive the PathTear within a reasonable period of time. The undefined value of this metric indicates an event of LSP Graceful Release Failure, and would be used to report a count or an percentage of LSP Graceful Release failures. See section Section 14.4 for definitions of LSP setup/release failures. 8.6. Discussion The following issues are likely to come up in practice: o In the first (second) circumstance, the accuracy of LSP graceful release delay at time T depends on the clock resolution in the ingress (egress) node. In the first circumstance, synchronization between the ingress node and egress node is required; but not in the second circumstance; Sun & Zhang Expires January 10, 2010 [Page 23] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 o A given methodology has to include a way to determine whether a latency value is infinite or whether it is merely very large. Simple upper bounds MAY be used. But the upper bound should be chosen carefully in practice and the value MUST be reported; o In the first circumstance, if the ingress node sends out PATH message including Admin Status Object with the Reflect (R) and Delete (D) bits set to initiate LSP graceful release, but the egress node never receives the corresponding PathTear message, LSP graceful release delay MUST be set to undefined. o In the second circumstance, if the egress node sends out the RESV message including Admin Status Object with the Reflect (R) and Delete (D) bits set to initiate LSP graceful release, but never receives the corresponding PathTear message, LSP graceful release delay MUST be set to undefined. 8.7. Methodologies In the first circumstance, the methodology may proceed as follows: o Make sure the LSP to be deleted is set up; o At the ingress node, form the PATH message including Admin Status Object with the Reflect (R) and Delete (D) bits set. A timestamp (T1) may be stored locally on the ingress node when the PATH message packet is sent towards the egress node; o Upon receiving the PATH message including Admin Status Object with the Reflect (R) and Delete (D) bits set, the egress node sends a RESV message including Admin Status Object with the Delete (D) and Reflect (R) bits set. Alternatively, the egress node sends a PathErr message with the Path_State_Removed flag set upstream; o When the ingress node receive the RESV message or the PathErr message, it sends a PathTear message to remove the LSP; o The egress node takes a timestamp (T2) once it receives the last bit of the PathTear message. The LSP graceful release delay is then (T2-T1). o If the ingress node sends the PATH message downstream, but the egress node fails to receive the PathTear message within a reasonable period of time, the LSP graceful release delay is deemed to be undefined. Note that the 'reasonable' threshold is a parameter of the methodology. In the second circumstance, the methodology would proceed as follows: Sun & Zhang Expires January 10, 2010 [Page 24] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 o Make sure the LSP to be deleted is set up; o On the egress node, form the RESV message including Admin Status Object with the Reflect (R) and Delete (D) bits set. A timestamp may be stored locally on the egress node when the RESV message packet is sent towards the ingress node; o Upon receiving the Admin Status Object with the Reflect (R) and Delete (D) bits set in the RESV message, the ingress node sends a PathTear message downstream to remove the LSP; o Egress node takes a timestamp (T2) once it receives the last bit of the PathTear message. The LSP graceful release delay is then (T2-T1). o If the egress node sends the RESV message upstream, but it fails to receive the PathTear message within a reasonable period of time, the LSP graceful release delay is deemed to be undefined. Note that the 'reasonable' threshold is a parameter of the methodology. Sun & Zhang Expires January 10, 2010 [Page 25] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 9. A Definition for Samples of Single Uni-directional LSP Setup Delay In Section 4, we have defined the singleton metric of Single uni- directional LSP setup delay. Now we define how to get one particular sample of Single uni-directional LSP setup delay. Sampling is to select a particular potion of singleton values of the given parameters. Like in [RFC2330], we use Poisson sampling as an example. 9.1. Metric Name Single uni-directional LSP setup delay sample 9.2. Metric Parameters o ID0, the ingress LSR ID o ID1, the egress LSR ID o T0, a time o Tf, a time o Lambda, a rate in the reciprocal milliseconds o Th, LSP holding time o Td, the maximum waiting time for successful setup 9.3. Metric Units A sequence of pairs; the elements of each pair are: o T, a time when setup is attempted o dT, either a real number or an undefined number of milliseconds. 9.4. Definition Given T0, Tf, and lambda, compute a pseudo-random Poisson process beginning at or before T0, with average arrival rate lambda, and ending at or after Tf. Those time values greater than or equal to T0 and less than or equal to Tf are then selected. At each of the times in this process, we obtain the value of uni-directional LSP setup delay sample at this time. The value of the sample is the sequence made up of the resulting pairs. If there are no such pairs, the sequence is of length zero and the sample is said to be empty. Sun & Zhang Expires January 10, 2010 [Page 26] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 9.5. Discussion The parameter lambda should be carefully chosen. If the rate is too high, too frequent LSP setup/release procedure will result in high overhead in the control plane. In turn, the high overhead will increase uni-directional LSP setup delay. On the other hand if the rate is too low, the sample could not completely reflect the dynamic provisioning performance of the GMPLS network. The appropriate lambda value depends on the given network. The parameters Td should be carefully chosen. Different switching technologies may vary significantly in performing a cross-connect operation. At the same time, the time needed in setting up an LSP under different traffic may also vary significantly. In the case of active measurement, the parameters Th should be carefully chosen. The combination of lambda and Th reflects the load of the network. The selection of Th should take into account that the network has sufficient resource to perform subsequent tests. The value of Th MAY be constant during one sampling process for simplicity considerations. Note that for online or passive measurements, the arrival rate and LSP holding time are determined by actual traffic, hence in this case Lambda and Th are not input parameters. 9.6. Methodologies o Select the times using the specified Poisson arrival process, and o Set up the LSP as the methodology for the singleton uni- directional LSP setup delay, and obtain the value of uni- directional LSP setup delay o Release the LSP after Th, and wait for the next Poisson arrival event Note that: it is possible that before the previous LSP release procedure completes, the next Poisson arrival event arrives and the LSP setup procedure is initiated. If there is resource contention between the two LSPs, the LSP setup may fail. Ways to avoid such contention are outside the scope of this document. 9.7. Typical testing cases Sun & Zhang Expires January 10, 2010 [Page 27] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 9.7.1. With no LSP in the Network 9.7.1.1. Motivation Single uni-directional LSP setup delay with no LSP in the network is important because this reflects the inherent delay of an RSVP-TE implementation. The minimum value provides an indication of the delay that will likely be experienced when an LSP traverses the shortest route with the lightest load in the control plane. 9.7.1.2. Methodologies Make sure that there is no LSP in the network, and proceed with the methodologies described in Section 9.6. 9.7.2. With a number of LSPs in the Network 9.7.2.1. Motivation Single uni-directional LSP setup delay with a number of LSPs in the network is important because it reflects the performance of an operational network with considerable load. This delay may vary significantly as the number of existing LSPs vary. It can be used as a scalability metric of an RSVP-TE implementation. 9.7.2.2. Methodologies Setup the required number of LSPs, and wait until the network reaches a stable state, then proceed with the methodologies described in Section 9.6. Sun & Zhang Expires January 10, 2010 [Page 28] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 10. A Definition for Samples of Multiple Uni-directional LSPs Setup Delay In Section 5, we have defined the singleton metric of multiple uni- directional LSPs setup delay. Now we define how to get one particular sample of multiple uni-directional LSP setup delay. Sampling is to select a particular potion of singleton values of the given parameters. Like in [RFC2330], we use Poisson sampling as an example. 10.1. Metric Name Multiple uni-directional LSPs setup delay sample 10.2. Metric Parameters o ID0, the ingress LSR ID o ID1, the egress LSR ID o T0, a time o Tf, a time o Lambda_m, a rate in the reciprocal milliseconds o Lambda, a rate in the reciprocal milliseconds o X, the number of LSPs to setup o Th, LSP holding time o Td, the maximum waiting time for successful multiple uni- directional LSPs setup 10.3. Metric Units A sequence of pairs; the elements of each pair are: o T, a time when the first setup is attempted o dT, either a real number or an undefined number of milliseconds. 10.4. Definition Given T0, Tf, and lambda, compute a pseudo-random Poisson process beginning at or before T0, with average arrival rate lambda, and ending at or after Tf. Those time values greater than or equal to T0 Sun & Zhang Expires January 10, 2010 [Page 29] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 and less than or equal to Tf are then selected. At each of the time in this process, we obtain the value of multiple uni-directional LSP setup delay sample at this time. The value of the sample is the sequence made up of the resulting pairs. If there are no such pairs, the sequence is of length zero and the sample is said to be empty. 10.5. Discussion The parameter lambda is used as arrival rate of "bacth uni- directional LSPs setup" operation. It regulates the interval in between each batch operation. The parameter lambda_m is used within each batch operation, as described in Section 5. The parameters lambda and lambda_m should be carefully chosen. If the rate is too high, too frequent LSP setup/release procedure will result in high overhead in the control plane. In turn, the high overhead will increase uni-directional LSP setup delay. On the other hand if the rate is too low, the sample could not completely reflect the dynamic provisioning performance of the GMPLS network. The appropriate lambda and lambda_m value depends on the given network. The parameters Td should be carefully chosen. Different switching technologies may vary significantly in performing a cross-connect operation. At the same time, the time needed in setting up an LSP under different traffic may also vary significantly. 10.6. Methodologies o Select the times using the specified Poisson arrival process, and o Set up the LSP as the methodology for the singleton multiple uni- directional LSPs setup delay, and obtain the value of multiple uni-directional LSPs setup delay o Release the LSP after Th, and wait for the next Poisson arrival event Note that: it is possible that before the previous LSP release procedure completes, the next Poisson arrival event arrives and the LSP setup procedure is initiated. If there is resource contention between the two LSPs, the LSP setup may fail. Ways to avoid such contention are outside the scope of this document. 10.7. Typical testing cases Sun & Zhang Expires January 10, 2010 [Page 30] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 10.7.1. With No LSP in the Network 10.7.1.1. Motivation Multiple uni-directional LSP setup delay with no LSP in the network is important because this reflects the inherent delay of an RSVP-TE implementation. The minimum value provides an indication of the delay that will likely be experienced when LSPs traverse the shortest route with the lightest load in the control plane. 10.7.1.2. Methodologies Make sure that there is no LSP in the network, and proceed with the methodologies described in Section 10.6. 10.7.2. With a Number of LSPs in the Network 10.7.2.1. Motivation Multiple uni-directional LSPs setup delay with a number of LSPs in the network is important because it reflects the performance of an operational network with considerable load. This delay can vary significantly as the number of existing LSPs vary. It can be used as a scalability metric of an RSVP-TE implementation. 10.7.2.2. Methodologies Setup the required number of LSPs, and wait until the network reaches a stable state, then proceed with the methodologies described in Section 10.6.. Sun & Zhang Expires January 10, 2010 [Page 31] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 11. A Definition for Samples of Single Bi-directional LSP Setup Delay In Section 6, we have defined the singleton metric of Single Bi- directional LSP setup delay. Now we define how to get one particular sample of Single Bi-directional LSP setup delay. Sampling is to select a particular potion of singleton values of the given parameters. Like in [RFC2330], we use Poisson sampling as an example. 11.1. Metric Name Single Bi-directional LSP setup delay sample with no LSP in the network 11.2. Metric Parameters o ID0, the ingress LSR ID o ID1, the egress LSR ID o T0, a time o Tf, a time o Lambda, a rate in the reciprocal milliseconds o Th, LSP holding time o Td, the maximum waiting time for successful setup 11.3. Metric Units A sequence of pairs; the elements of each pair are: o T, a time when setup is attempted o dT, either a real number or an undefined number of milliseconds. 11.4. Definition Given T0, Tf, and lambda, compute a pseudo-random Poisson process beginning at or before T0, with average arrival rate lambda, and ending at or after Tf. Those time values greater than or equal to T0 and less than or equal to Tf are then selected. At each of the times in this process, we obtain the value of Bi-directional LSP setup delay sample at this time. The value of the sample is the sequence made up of the resulting pairs. If there are no such pairs, the sequence is of length zero and the sample is said Sun & Zhang Expires January 10, 2010 [Page 32] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 to be empty. 11.5. Discussion The parameters lambda should be carefully chosen. If the rate is too high, too frequent LSP setup/release procedure will result in high overhead in the control plane. In turn, the high overhead will increase Bi-directional LSP setup delay. On the other hand if the rate is too low, the sample could not completely reflect the dynamic provisioning performance of the GMPLS network. The appropriate lambda value depends on the given network. The parameters Td should be carefully chosen. Different switching technologies may vary significantly in performing a cross-connect operation. At the same time, the time needed in setting up an LSP under different traffic may also vary significantly. In the case of active measurement, the parameters Th should be carefully chosen. The combination of lambda and Th reflects the load of the network. The selection of Th SHOULD take into account that the network has sufficient resource to perform subsequent tests. The value of Th MAY be constant during one sampling process for simplicity considerations. Note that for online or passive measurements, the arrival rate and the LSP holding time are determined by actual traffic, hence in this case Lambda and Th are not an input parameter. 11.6. Methodologies o Select the times using the specified Poisson arrival process, and o Set up the LSP as the methodology for the singleton bi-directional LSP setup delay, and obtain the value of bi-directional LSP setup delay o Release the LSP after Th, and wait for the next Poisson arrival event Note that: it is possible that before the previous LSP release procedure completes, the next Poisson arrival event arrives and the LSP setup procedure is initiated. If there is resource contention between the two LSPs, the LSP setup may fail. Ways to avoid such contention are outside the scope of this document. Sun & Zhang Expires January 10, 2010 [Page 33] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 11.7. Typical testing cases 11.7.1. With No LSP in the Network 11.7.1.1. Motivation Single bi-directional LSP setup delay with no LSP in the network is important because this reflects the inherent delay of an RSVP-TE implementation. The minimum value provides an indication of the delay that will likely be experienced when an LSP traverses the shortest route with the lightest load in the control plane. 11.7.1.2. Methodologies Make sure that there is no LSP in the network, and proceed with the methodologies described in Section 11.6. 11.7.2. With a Number of LSPs in the Network 11.7.2.1. Motivation Single bi-directional LSP setup delay with a number of LSPs in the network is important because it reflects the performance of an operational network with considerable load. This delay can vary significantly as the number of existing LSPs varies. It can be used as a scalability metric of an RSVP-TE implementation. 11.7.2.2. Methodologies Setup the required number of LSPs, and wait until the network reaches a stable state, then proceed with the methodologies described in Section 11.6. . Sun & Zhang Expires January 10, 2010 [Page 34] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 12. A Definition for Samples of Multiple Bi-directional LSPs Setup Delay In Section 7, we have defined the singleton metric of multiple bi- directional LSPs setup delay. Now we define how to get one particular sample of multiple bi-directional LSP setup delay. Sampling is to select a particular potion of singleton values of the given parameters. Like in [RFC2330], we use Poisson sampling as an example. 12.1. Metric Name Multiple bi-directional LSPs setup delay sample 12.2. Metric Parameters o ID0, the ingress LSR ID o ID1, the egress LSR ID o T0, a time o Tf, a time o Lambda_m, a rate in the reciprocal milliseconds o Lambda, a rate in the reciprocal milliseconds o X, the number of LSPs to setup o Th, LSP holding time o Td, the maximum waiting time for successful multiple uni- directional LSPs setup 12.3. Metric Units A sequence of pairs; the elements of each pair are: o T, a time when the first setup is attempted o dT, either a real number or an undefined number of milliseconds. 12.4. Definition Given T0, Tf, and lambda, compute a pseudo-random Poisson process beginning at or before T0, with average arrival rate lambda, and ending at or after Tf. Those time values greater than or equal to T0 Sun & Zhang Expires January 10, 2010 [Page 35] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 and less than or equal to Tf are then selected. At each of the times in this process, we obtain the value of multiple uni-directional LSP setup delay sample at this time. The value of the sample is the sequence made up of the resulting pairs. If there are no such pairs, the sequence is of length zero and the sample is said to be empty. 12.5. Discussion The parameter lambda is used as arrival rate of "bacth bi-directional LSPs setup" operation. It regulates the interval in between each batch operation. The parameter lambda_m is used within each batch operation, as described in Section 7. The parameters lambda and lambda_m should be carefully chosen. If the rate is too high, too frequent LSP setup/release procedure will result in high overhead in the control plane. In turn, the high overhead will increase uni-directional LSP setup delay. On the other hand if the rate is too low, the sample could not completely reflect the dynamic provisioning performance of the GMPLS network. The appropriate lambda and lambda_m value depends on the given network. The parameters Td should be carefully chosen. Different switching technologies may vary significantly in performing a cross-connect operation. At the same time, the time needed in setting up an LSP under different traffic may also vary significantly. 12.6. Methodologies o Select the times using the specified Poisson arrival process, and o Set up the LSP as the methodology for the singleton multiple bi- directional LSPs setup delay, and obtain the value of multiple uni-directional LSPs setup delay o Release the LSP after Th, and wait for the next Poisson arrival event Note that: it is possible that before the previous LSP release procedure completes, the next Poisson arrival event arrives and the LSP setup procedure is initiated. If there is resource contention between the two LSPs, the LSP setup may fail. Ways to avoid such contention are outside the scope of this document. 12.7. Typical testing cases Sun & Zhang Expires January 10, 2010 [Page 36] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 12.7.1. With No LSP in the Network 12.7.1.1. Motivation Multiple bi-directional LSPs setup delay with no LSP in the network is important because this reflects the inherent delay of an RSVP-TE implementation. The minimum value provides an indication of the delay that will likely be experienced when an LSPs traverse the shortest route with the lightest load in the control plane. 12.7.1.2. Methodologies Make sure that there is no LSP in the network, and proceed with the methodologies described in Section 10.6. 12.7.2. With a Number of LSPs in the Network 12.7.2.1. Motivation multiple bi-directional LSPs setup delay with a number of LSPs in the network is important because it reflects the performance of an operational network with considerable load. This delay may vary significantly as the number of existing LSPs vary. It may be used as a scalability metric of an RSVP-TE implementation. 12.7.2.2. Methodologies Setup the required number of LSPs, and wait until the network reaches a stable state, then proceed with the methodologies described in Section 12.6.. Sun & Zhang Expires January 10, 2010 [Page 37] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 13. A Definition for Samples of LSP Graceful Release Delay In Section 8, we have defined the singleton metric of LSP graceful release delay. Now we define how to get one particular sample of LSP graceful release delay. We also use Poisson sampling as an example. 13.1. Metric Name LSP graceful release delay sample 13.2. Metric Parameters o ID0, the ingress LSR ID o ID1, the egress LSR ID o T0, a time o Tf, a time o Lambda, a rate in reciprocal milliseconds o Td, the maximum waiting time for successful LSP release 13.3. Metric Units A sequence of pairs; the elements of each pair are: o T, a time, and o dT, either a real number or an undefined number of milliseconds. 13.4. Definition Given T0, Tf, and lambda, we compute a pseudo-random Poisson process beginning at or before T0, with average arrival rate lambda, and ending at or after Tf. Those time values greater than or equal to T0 and less than or equal to Tf are then selected. At each of the times in this process, we obtain the value of LSP graceful release delay sample at this time. The value of the sample is the sequence made up of the resulting pairs. If there are no such pairs, the sequence is of length zero and the sample is said to be empty. 13.5. Discussion The parameter lambda should be carefully chosen. If the rate is too large, too frequent LSP setup/release procedure will result in high Sun & Zhang Expires January 10, 2010 [Page 38] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 overhead in the control plane. In turn, the high overhead will increase uni-directional LSP setup delay. On the other hand if the rate is too small, the sample could not completely reflect the dynamic provisioning performance of the GMPLS network. The appropriate lambda value depends on the given network. 13.6. Methodologies Generally the methodology would proceed as follows: o Setup the LSP to be deleted o Select the times using the specified Poisson arrival process, and o Release the LSP as the methodology for the singleton LSP graceful release delay, and obtain the value of LSP graceful release delay o Setup the LSP, and restart the Poisson arrival process, wait for the next Poisson arrival event Sun & Zhang Expires January 10, 2010 [Page 39] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 14. Some Statistics Definitions for Metrics to Report Given the samples of the performance metric, we now offer several statistics of these samples to report. From these statistics, we can draw some useful conclusions of a GMPLS network. The value of these metrics is either a real number, or an undefined number of milliseconds. In the following discussion, we only consider the finite values. 14.1. The Minimum of Metric The minimum of metric is the minimum of all the dT values in the sample. In computing this, undefined values SHOULD be treated as infinitely large. Note that this means that the minimum could thus be undefined if all the dT values are undefined. In addition, the metric minimum SHOULD be set to undefined if the sample is empty. 14.2. The Median of Metric Metric median is the median of the dT values in the given sample. In computing the median, the undefined values MUST NOT be counted in. 14.3. The percentile of Metric Given a metric and a percent X between 0% and 100%, the Xth percentile of all the dT values in the sample. In addition, the percentile is undefined if the sample is empty. Example: suppose we take a sample and the results are: Stream1 = < , , , , > Then the 50th percentile would be 110 msec, since 90 msec and 100 msec are smaller, and 110 and 500 msec are larger (undefined values are not counted in). 14.4. Failure statistics of Metric In the process of LSP setup/release, it may fail due to various reasons. For example, setup/release may fail when the control plane is overburdened or when there is resource shortage in one of the intermediate nodes. Since the setup/release failure may have significant impact on network operation, it is worthwhile to report each failure cases, so that appropriate operations can be performed to check the possible implementation,configuration or other deficiencies. Five types of failure events are defined in previous sections: Sun & Zhang Expires January 10, 2010 [Page 40] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 o Single Uni-directional LSP Setup Failure o Multiple Uni-directional LSP Setup Failure o Single Bi-directional LSP Setup Failure o Multiple Bi-directional LSP Setup Failure o LSP graceful release failure Given the samples of the performance metric, we now offer two statistics of failure events of these samples to report. 14.4.1. Failure Count Failure Count is defined as the number of the undefined value of the corresponding performance metric (failure events) in a sample. The unit of Failure Count is numerical. 14.4.2. Failure Ratio Failure Ratio is the percentage of the number of failure events to the total number of requests in a sample. The calculation for Failure Ratio is defined as follows: X type failure ratio = Number of X type failure events/(Number of valid X type metric values + Number of X type failure events) * 100%. Sun & Zhang Expires January 10, 2010 [Page 41] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 15. Discussion It is worthwhile to point out that: o The uni-directional/bi-directional LSP setup delay is one ingress- egress round trip time plus processing time. But in this document, uni-directional/bi-directional LSP setup delay has not taken the processing time in the end nodes (ingress or/and egress) into account. The timestamp T2 is taken after the endpoint node receives it. Actually, the last node has to take some time to process local procedure. Similarly, in the LSP graceful release delay, the memo has not considered the processing time in the end node. o This document assumes that the correct procedures for installing the data plane are followed as described in [RFC3209], [RFC3471], and [RFC3473]. That is, by the time the egress receives and processes a Path message, it is safe for the egress to transmit data on the reverse path, and by the time the ingress receives and processes a RESV message it is safe for the ingress to transmit data on the forward path. See [I-D.shiomoto-ccamp-switch-programming] for detailed explanations. This document does not include any verification that the implementations of the control plane software are conformant, although such tests MAY be constructed with the use of suitable signal generation test equipment. In [I-D.sun-ccamp-dpm], we defined a series of metrics to do such verifications. However, it is RECOMMENDED that both the measurements defined in this document and the measurements defined in [I-D.sun-ccamp-dpm] are performed to complement each other. o Note that, in implementing the tests described in this document a tester should be sure to measure the time taken for the control plane messages including the processing of those messages by the nodes under test. o Bi-directional LSPs may be setup using three way signalling, where the initiating node will send a RESV_CONF message downsteam upon receiving the RESV message. The RESV_CONF message is used to notify the terminate node that it can transfer data upstream. Actually, both direction should be ready to transfer data when the RESV message is received by the initiate node. Therefore, the bi- directional LSP setup delay defined in this document does not take the confirmation procedure into account. Sun & Zhang Expires January 10, 2010 [Page 42] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 16. Security Considerations Samples of the metrics can be obtained in either active or passive manners. In active measurement, ingress nodes inject probing messages into the control plane. The measurement parameters must be carefully selected so that the measurements inject trivial amounts of additional traffic into the networks they measure. If they inject "too much" traffic, they can skew the results of the measurement, and in extreme cases cause congestion and denial of service. When samples of the metrics are collected in a passive manner, e.g., by monitoring the operations on real-life LSPs, the implementation of the monitoring and reporting mechanism must be careful so that they will not be used to attack the control plane. Besides, the security considerations pertaining to the original RSVP protocol [RFC2205] and its TE extensions [RFC3209] also remain relevant. Sun & Zhang Expires January 10, 2010 [Page 43] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 17. IANA Considerations This document makes no requests for IANA action. Sun & Zhang Expires January 10, 2010 [Page 44] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 18. Acknowledgements We wish to thank Dan Li, Fang Liu (Christine), Zafar Ali, Monique Morrow, Al Morton, Henk Uijterwaal, Adrian Farrel, Deborah Brungard, Lou Berger, Thomas D. Nadeau for their comments and helps. This document contains ideas as well as text that have appeared in existing IETF documents. The authors wish to thank G. Almes, S. Kalidindi and M. Zekauskas. We also wish to thank Weisheng Hu, Yaohui Jin and Wei Guo in the state key laboratory of advanced optical communication systems and networks for the valuable comments. We also wish to thank the support from NSFC and 863 program of China. Sun & Zhang Expires January 10, 2010 [Page 45] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 19. References 19.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2205] Braden, B., Zhang, L., Berson, S., Herzog, S., and S. Jamin, "Resource ReSerVation Protocol (RSVP) -- Version 1 Functional Specification", RFC 2205, September 1997. [RFC2679] Almes, G., Kalidindi, S., and M. Zekauskas, "A One-way Delay Metric for IPPM", RFC 2679, September 1999. [RFC2681] Almes, G., Kalidindi, S., and M. Zekauskas, "A Round-trip Delay Metric for IPPM", RFC 2681, September 1999. [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V., and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP Tunnels", RFC 3209, December 2001. [RFC3471] Berger, L., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Functional Description", RFC 3471, January 2003. [RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource ReserVation Protocol-Traffic Engineering (RSVP-TE) Extensions", RFC 3473, January 2003. [RFC3945] Mannie, E., "Generalized Multi-Protocol Label Switching (GMPLS) Architecture", RFC 3945, October 2004. [RFC4208] Swallow, G., Drake, J., Ishimatsu, H., and Y. Rekhter, "Generalized Multiprotocol Label Switching (GMPLS) User- Network Interface (UNI): Resource ReserVation Protocol- Traffic Engineering (RSVP-TE) Support for the Overlay Model", RFC 4208, October 2005. [RFC4802] Nadeau, T. and A. Farrel, "Generalized Multiprotocol Label Switching (GMPLS) Traffic Engineering Management Information Base", RFC 4802, February 2007. 19.2. Informative References [I-D.shiomoto-ccamp-switch-programming] Shiomoto, K. and A. Farrel, "Advice on When It is Safe to Start Sending Data on Label Switched Paths Established Using RSVP-TE", draft-shiomoto-ccamp-switch-programming-00 Sun & Zhang Expires January 10, 2010 [Page 46] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 (work in progress), February 2009. [I-D.sun-ccamp-dpm] Sun, W., Zhang, G., Gao, J., Xie, G., Papneja, R., Gu, B., Wei, X., Otani, T., and R. Jing, "Label Switched Path (LSP) Data Path Delay Metric in Generalized MPLS/ MPLS-TE Networks", draft-sun-ccamp-dpm-00 (work in progress), June 2009. [RFC2330] Paxson, V., Almes, G., Mahdavi, J., and M. Mathis, "Framework for IP Performance Metrics", RFC 2330, May 1998. Sun & Zhang Expires January 10, 2010 [Page 47] Internet-Draft LSP Dynamic PPM in GMPLS Networks July 2009 Authors' Addresses Weiqiang Sun Shanghai Jiao Tong University 800 Dongchuan Road Shanghai 200240 CN Phone: +86 21 3420 5359 Email: sunwq@mit.edu Guoying Zhang China Academy of Telecommunication Research,MIIT,China. No.11 YueTan South Street Beijing 100045 CN Phone: +86 1068094272 Email: zhangguoying@mail.ritt.com.cn Jianhua Gao Huawei Technologies Co., LTD. CN Phone: +86 755 28973237 Email: gjhhit@huawei.com Guowu Xie University of California, Riverside 900 University Ave. Riverside, CA 92521 USA Phone: +1 951 237 8825 Email: xieg@cs.ucr.edu Rajiv Papneja Isocore 12359 Sunrise Valley Drive, STE 100 Reston, VA 20190 USA Phone: +1 703 860 9273 Email: rpapneja@isocore.com Sun & Zhang Expires January 3, 2010 [Page 48] Internet-Draft LSP Dynamic PPM in GMPLS Networks January 2009 Bin Gu IXIA Oriental Kenzo Plaza 8M,48 Dongzhimen Wai Street,Dongcheng District Beijing 200240 CN Phone: +86 13611590766 Email: BGu@ixiacom.com Xueqin Wei Fiberhome Telecommunicaiton Technology Co.,Ltd. Wuhan CN Phone: +86 13871127882 Email: xqwei@fiberhome.com.cn Tomohiro Otani KDDI R&D Laboratories, Inc. 2-1-15 Ohara Kamifukuoka Saitama 356-8502 Japan Phone: +81-49-278-7357 Email: otani@kddilabs.jp Ruiquan Jing China Telecom Beijing Research Institute 118 Xizhimenwai Avenue Beijing 100035 CN Phone: +86-10-58552000 Email: jingrq@ctbri.com.cn Sun & Zhang Expires January 3, 2010 [Page 49]