Requirements for Very Fast Setup of GMPLS LSPs
draft-malis-ccamp-fast-lsps-00

Internet Engineering Task Force (IETF)                     A. Malis, Ed.
Internet-Draft                                       Huawei Technologies
Intended status: Informational                                  R. Skoog
Expires: July 27, 2014                                      H. Kobrinski
                                          Applied Communication Sciences
                                                                G. Clapp
                                                      AT&T Labs Research
                                                               V. Shukla
                                                  Verizon Communications
                                                        January 23, 2014

             Requirements for Very Fast Setup of GMPLS LSPs
                     draft-malis-ccamp-fast-lsps-00

Abstract

   The Defense Advanced Research Projects Agency (DARPA) Core Optical
   Networks (CORONET) program has laid out a vision for the next
   evolution of IP and optical commercial and government networks, with
   a focus on highly dynamic and resilient multi-terabit core networks.
   It anticipates the need for rapid (sub-second) setup and SONET/SDH-
   like restoration times for high-churn (up to tens of requests per
   second network-wide and one second to one minute holding times) on-
   demand wavelength, sub-wavelength and packet services for a variety
   of applications (e.g., grid computing, cloud computing, data
   visualization, fast data transfer, etc.).  This must be done while
   meeting stringent call blocking requirements, and while minimizing
   the use of resources such as time slots, switch ports, wavelength
   conversion and wavelength-km.

   This document discusses the requirements for extensions to
   Generalized Multi-Protocol Label Switching (GMPLS) signaling for
   expediting the control of Label Switched Paths (LSPs), including sub-
   wavelengths (e.g., OTN ODUs) and full wavelengths, in order to
   satisfy application requirements laid out in this program.

Status of This Memo

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Scope and Motivation  . . . . . . . . . . . . . . . . . . . .   4
   3.  Requirements for Very Fast Setup of GMPLS LSPs  . . . . . . .   5
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   6
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   6
   6.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   6
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   6
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .   6
     7.2.  Informative References  . . . . . . . . . . . . . . . . .   7
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   7

1.  Introduction

   The Defense Advanced Research Projects Agency (DARPA) Core Optical
   Networks (CORONET) program [Chiu] has laid out a vision for the next
   evolution of IP and optical commercial and government networks, with
   a focus on highly dynamic and resilient multi-terabit core networks.
   The program anticipates an environment where there are multiple
   Bandwidth-on-Demand service requests per second, such as might arise
   as cloud services proliferate.  It includes dynamic services with
   connection setup requirements that are two to three orders of
   magnitude faster than possible with current connection setup
   protocols.  The aggregate traffic demand, which is composed of both
   packet (IP) and circuit (wavelength and sub-wavelength) services,

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   represents a five to twenty-fold increase over today's traffic levels
   for the largest of any individual carrier.  It is the desired goal of
   the program to achieve transition of these advances to commercial and
   government networks in the next few years.  Thus, the aggressive
   requirements must be met with solutions that are scalable, cost
   effective, and power efficient, while providing the desired quality
   of service (QoS).

   Thus, CORONET anticipates the need for rapid (sub-second) setup and
   restoration times for high-churn (up to tens of requests per second
   network-wide and one second to one minute holding times) on-demand
   wavelength, sub-wavelength and packet services for a variety of
   applications (e.g., grid computing, cloud computing, data
   visualization, fast data transfer, etc.).  This must be done while
   meeting stringent call blocking requirements, and while minimizing
   the use of resources such as time slots, switch ports, wavelength
   conversion and wavelength-km.

   GMPLS protocols and procedures have been developed to enable
   automated control of Label Switched Paths (LSPs), including setup,
   teardown, modification, and restoration, for switching technologies
   extending from layer 2 and layer 3 packets, to time division
   multiplexing, to wavelength, and to fiber.

   However, while the current GMPLS constituent protocols are geared for
   a wide scope of applications and robust performance, they have not
   specifically addressed the more aggressive characteristics envisioned
   here, e.g., applications requiring low connection setup times while
   maintaining a high success ratio (i.e., low blocking) in a high-churn
   environment.  For example, in Internet2, a network which provides
   CORONET-like high bandwidth circuit services for the Research &
   Education community, a circuit is currently established, on average,
   roughly at a rate of one per hour.  In contrast, the CORONET vision
   is a churn rate of up to tens of circuits per second, over four
   orders of magnitude greater.

   Furthermore, scenarios with highly dynamic connection request
   activity, where the connection request arrival rate is higher than
   the TE update rate allowed by OSPF-TE, could lead to unacceptable
   blocking ratios or low resource utilization.  The purpose of this
   draft is to determine the requirements to augment the GMPLS framework
   to allow specific applications, or users, to rapidly set up
   connections over GMPLS networks with minimal delays and a high
   probability of success.

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2.  Scope and Motivation

   [RFC6163] provides the framework, basic elements, and terminology of
   wavelength switched optical networks (WSON) and wavelength-based
   LSPs.  These basic elements generally apply to other GMPLS
   technologies as well, e.g., spectral switching (SSON), sub-wavelength
   TDM, and L2 LSPs.  This draft refers to the same general framework
   and technologies, but addresses an extension of the general problem
   space addressed in [RFC6163].  Specifically, this draft addresses the
   requirements of expediting LSP setup, under heavy connection churn
   scenarios, while achieving low blocking, under an overall distributed
   control plane.  Once there is agreement on the requirements, further
   drafts will describe the procedures and signaling contents required
   to meet the requirements (potentially more than one if separate
   standard track drafts are found necessary for wavelength and sub-
   wavelength LSPs).  Both single-domain and multi-domain network
   scenarios are addressed.  A connection setup delay is defined here as
   the time between the arrival of a connection request at an ingress
   edge switch - or more generally a Label Switch Router (LSR) - and the
   time at which information can start flowing from that ingress switch
   over that connection.  Note that this definition is more inclusive
   than the LSP setup time defined in [RFC5814] and [RFC6777], which do
   not include PCE path computation delays.

   The motivation for GMPLS extensions as described here is the
   anticipated need for rapid setup while maintaining low blocking, on-
   demand, of large bandwidth connections (in the form of sub-
   wavelengths, e.g., OTN ODUx, and wavelengths, e.g., OTN OCh) for a
   variety of applications including grid computing, cloud computing,
   data visualization, and intra- and inter-datacenter communications.
   The ability to setup circuit-like LSPs for large bandwidth flows and
   with low setup delays provides an alternative to packet-based
   solutions implemented over static circuits that may require tying up
   more expensive and power-consuming resources (e.g., router ports).
   Reducing the LSP setup delay will reduce the minimum bandwidth
   threshold at which a GMPLS approach is preferred over a layer 3
   (e.g., IP) approach.  Dynamic circuit and virtual circuit switching
   intrinsically provide guaranteed bandwidth, guaranteed low-latency
   and jitter, and faster restoration, all of which are very hard to
   provide in a packet-only networks.  Again, a key element in achieving
   these benefits is enabling the fastest possible circuit setup times.

   Future applications are expected to require setup times as fast as
   100 ms in highly dynamic, national-scale network environments while
   meeting stringent blocking requirements and minimizing the use of
   resources such as switch ports, wavelength converters/regenerators,
   wavelength-km, and other network design parameters.  Of course, the

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   benefits of low setup delay diminish for connections with long
   holding times.

   The need for rapid setup for specific applications may override and
   thus get traded off against some other features currently provided in
   GMPLS, e.g., robustness against setup errors.

   With the advent of data centers, cloud computing, video, gaming,
   mobile and other broadband applications, it is anticipated that
   connection request rates may increase, even for connections with
   longer holding times, either during limited time periods (such as
   during the restoration from a data center failure) or over the longer
   term, to the point where the current GMPLS maximum frequency of TE
   information updates is not sufficient to provide adequate path
   computation and resource allocation, as network conditions and
   resource attributes may be changing faster than can be reflected in
   OSPF-TE updates.

   Thus, GMPLS and routing protocol traffic engineering (e.g. OSPF-TE)
   extensions are also needed to address heavy churn of connection
   requests (i.e., high connection request arrival rate) in networks
   with high traffic loads, even for connections with relatively longer
   holding times.

3.  Requirements for Very Fast Setup of GMPLS LSPs

   This section lists the requirements for very fast setup of GMPLS LSPs
   in order to provide the services described in the previous sections.
   They will be the basis for future standards-track drafts to satisfy
   these requirements.  Some of these requirements may be
   implementation-dependent to some extent, but they may also have LSP
   signaling protocol dependencies as well.

   R1  Protocol extensions must be backward compatible with existing
       GMPLS control plane protocols.

   R2  Use of GMPLS protocol extensions for this application must be
       selectable by provisioning or configuration.

   R3  Must support the use of PCE for path computation, and in
       particular the PCE-based approach for multi-domain LSPs in
       [RFC5441].

   R4  Must have an LSP setup time less than or equal to 100 ms for
       intra-continental LSPs, and less than or equal to 250 ms for
       transcontinental LSPs, including PCE path computation delays.

   R5  Must support LSP holding times of one second to one minute.

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   R6  While there are implementation-dependent aspects of supporting
       high LSP setup rates, the protocol aspects of LSP signaling must
       not preclude LSP request rates of tens per second.  A possible
       example of a protocol aspect is the ability to update the IGP TE
       database to accurately reflect resource availability at all
       times.  Note that LSP request rates may be dependent on LSP
       bandwidth, where very high bandwidth LSPs (such as for an entire
       wavelength) could be less frequent than lower-rate LSPs (such as
       an ODUx connection).

   R7  Must support restoration for all cases of single node or link
       failures.

   R8  At most one blocked LSP setup request per 1000 requests.

4.  IANA Considerations

   This memo includes no request to IANA.

5.  Security Considerations

   Being able to support very fast setup and a high churn rate of GMPLS
   LSPs is not expected to adversely affect the underlying security
   issues associated with existing GMPLS signaling, and potentially
   could improve GMPLS' resistance against denial of service attacks
   that attempt to deny service through the use of a high frequency of
   GMPLS LSP setup requests.

6.  Acknowledgements

   The authors would like to thank Ann Von Lehmen, Joe Gannett, and
   Brian Wilson of Applied Communication Sciences for their comments and
   assistance on this document.

7.  References

7.1.  Normative References

   [RFC5441]  Vasseur, JP., Zhang, R., Bitar, N., and JL. Le Roux, "A
              Backward-Recursive PCE-Based Computation (BRPC) Procedure
              to Compute Shortest Constrained Inter-Domain Traffic
              Engineering Label Switched Paths", RFC 5441, April 2009.

   [RFC5814]  Sun, W. and G. Zhang, "Label Switched Path (LSP) Dynamic
              Provisioning Performance Metrics in Generalized MPLS
              Networks", RFC 5814, March 2010.

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   [RFC6163]  Lee, Y., Bernstein, G., and W. Imajuku, "Framework for
              GMPLS and Path Computation Element (PCE) Control of
              Wavelength Switched Optical Networks (WSONs)", RFC 6163,
              April 2011.

   [RFC6777]  Sun, W., Zhang, G., Gao, J., Xie, G., and R. Papneja,
              "Label Switched Path (LSP) Data Path Delay Metrics in
              Generalized MPLS and MPLS Traffic Engineering (MPLS-TE)
              Networks", RFC 6777, November 2012.

7.2.  Informative References

   [Chiu]     A. Chiu, et al, "Architectures and Protocols for Capacity
              Efficient, Highly Dynamic and Highly Resilient Core
              Networks", Journal of Optical Communications and
              Networking vol. 4, No. 1, pp. 1-14, January 2012,
              <http://dx.doi.org/10.1364/JOCN.4.000001>.

Authors' Addresses

   Andrew G. Malis (editor)
   Huawei Technologies

   Email: agmalis@gmail.com

   Ronald A. Skoog
   Applied Communication Sciences

   Email: rskoog@appcomsci.com

   Haim Kobrinski
   Applied Communication Sciences

   Email: hkobrinski@appcomsci.com

   George Clapp
   AT&T Labs Research

   Email: clapp@research.att.com

   Vishnu Shukla
   Verizon Communications

   Email: vishnu.shukla@verizon.com

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