tewg S.Wright Internet Draft BellSouth Document: draft-wright-load-distribution-00.txt R.Jaeger Category: Informational LTS, U.Maryland F.Reichmeyer IP Highway July 2000 Traffic Engineering of Load Distribution Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026 [1]. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet- Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. 1. Abstract Online traffic load distribution for a single class of service has been explored extensively given that extensions to IGP can provide loading information to network nodes. To perform traffic engineering of load distribution for multi-service networks, or off line traffic engineering of single service networks, a control mechanism for provisioning bandwidth according to some policy must be provided. This draft identifies the mechanisms that affect load distribution and the controls for mechanisms that affect load distribution to enable policy based traffic engineering of the load distribution to be performed. This draft identifies the mechanisms that affect load distribution and the control for those mechanisms to enable policy based traffic engineering of load distribution. This draft also presents guidelines for the use of these load distribution mechanisms in the context of single IP network administration. 2. Conventions used in this document Wright Informational - Expires January 2001 1 Traffic Engineering Of Load Distribution July 2000 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 RFC-2119 [2]. 3. Introduction The traffic load that an IP network supports may be distributed in various ways within the constraints of the topology of the network ( i.e. avoiding routing loops). The default mechanism for load distribution is to rely on an IGP (e.g. IS-IS, OSPF) to identify a single "shortest" path between any two endpoints of the network. "Shortest" is typically defined in terms of a minimization of an administrative weight (e.g. hop count) assigned to each link of the network topology. Having identified a single shortest path, all traffic between those endpoints then follows that path until the IGP detects a topology change. While often called dynamic routing, (since it changes in response to topology changes) this might be better characterized as topology driven route determination. This default IGP mechanism works well in a wide variety of operational contexts. Nonetheless, there are operational environments in which network operators may wish to use additional controls to affect the distribution of traffic within their networks. These may include: a) service specific routing (e.g. voice service may utilize delay sensitive routing, but best effort service may not) b) customer specific routing (e.g. VPNs) c) tactical route changes where peak traffic demands exceed single link capacity d) tactical route changes for fault avoidance This draft assumes the existence of some rationale for greater control of the load distribution than that provided by the default mechanisms The main objectives of this draft include identifying (within the context of a single IP network administration) : 1. mechanisms that affect load distribution 2. controls for mechanisms that affect load distribution 3. engineering guidelines in the use of these controls (future) This document has evolved from a previous draft [3] in an effort to meet comments from the interim tewg for a broader discussion of load distribution. The intention is for this document to evolve toward a working group informational RFC. Further comments and suggestions towards that objective are requested. Wright Informational - Expires January 2001 2 Traffic Engineering Of Load Distribution July 2000 This document is structured as follows. Section 4 provides an overview of load distribution within the context of a single IP network administration. Route determination is discussed in section 5. Traffic classification in multipath routing configurations is considered in section 6. section 7 discusses traffic engineered load balancing in MPLS. Security considerations are provided in section 8. 4. Load Distribution The traffic load distribution may be considered on a service- specific basis or aggregated across multiple services. In considering the load distribution, one should also distinguish between a snapshot of the network's state (i.e. a measurement) and the (hypothetical) network state, that may result from some (projected) traffic demand. Measurement of the traffic load distribution is discussed further in section 4.1 Load distribution has two main components - the identification of the routes over which traffic flows, and, in the case of multipath routing configurations (where multiple acyclic paths exist between common endpoints), the classification of flows determines the distribution of flows among those routes. Control of the load distribution is discussed in section 4.2. The traffic engineering of the load distribution within the context of the traffic engineering framework is considered in section 4.3 4.1 Traffic Load Definition and Measurement With modern node equipment supporting wire speed forwarding, in this draft we assume traffic load is a link measurement, although in some cases node constraints (e.g. packet forwarding capacity) may be more relevant. Traffic load is measured in units of network capacity. Network capacity is typically measured in units of bandwidth (e.g. with a magnitude dimensioned bits/second or packets/second). However, bandwidth should be considered a vector quantity providing both a magnitude and a direction. Bandwidth magnitude measurements are typically made at some specific (but often implicit) point in the network where traffic is flowing, in a specific direction, (e.g. between two points of a unicast transmission). The significance comes in distinguishing between bandwidth measurements made on a link basis and bandwidth demands between end-points of a network. A snapshot of the current load distribution may be identified through relevant measurements available on the network. The available traffic metrics for determining the load distribution include, e.g. generic IP traffic metrics (see e.g. RFC 2679 [4] or RFC 2722 [5]). The measurements of network capacity utilization can be combined with the information from the routing database to provide an overall perspective on the traffic Wright Informational - Expires January 2001 3 Traffic Engineering Of Load Distribution July 2000 distribution within the network. This information may be combined at the routers (and then reported back) or aggregated in the management system for dynamic traffic engineering. A peak demand value of the traffic load magnitude (over some time interval, and in the context of a specific traffic direction) may be used for network capacity planning purposes (beyond the scope of this document). Considering the increasing deployment of asymmetric host interfaces (e.g. ADSL) and application software architectures (e.g. client-server), the traffic load distribution is not necessarily symmetric between the opposite directions of transmission for any two endpoints of the network. 4.2 Load Distribution Controls In order for a traffic engineering process to impact the network, there must be adequate controls within the network to implement the results of the offline traffic engineering processes. In this draft, we generally assume the physical topology (links and nodes) to be fixed, while considering the traffic engineering options for affecting the distribution of a traffic load over that topology. The addition of new nodes and links is considered a network capacity planning problem beyond the scope of this draft. The fundamental load affecting mechanisms are: (1) the identification of suitable routes and (2) (in the case of multipath routing) the allocation of traffic to a specific path. For traffic engineering purposes, the control mechanisms available can affect either of these mechanisms. 4.3 Control of the Load Distribution in the context of the traffic Engineering Framework Given the assumption of the existence of a need for control of the load distribution, it follows that the values of the control parameters are unlikely to be static. Within the TE Framework's taxonomy [6] of traffic engineering systems, (control of) load distribution may be: a) dependent on time or network state ( either local or global state)- (e.g. based on IGP topology information) b) based on algorithms executed offline or online c) impacted by open or closed loop network control d) centralized or distributed control of the distributed route set and traffic classification functions e) prescriptive ( i.e a control function) rather than simply descriptive of network state. We assume network feedback to be an important part of the dynamic control of load distribution within the network. While the offline Wright Informational - Expires January 2001 4 Traffic Engineering Of Load Distribution July 2000 algorithms to compute a set of paths between ingress and egress points in the administrative domain may rely on historic load data, online adjustments to the traffic engineered paths will rely in part on this load information reported by the nodes. The traffic engineering framework identifies process model components for : 1. measurement 2. modeling, analysis, and simulation 3. optimization. Traffic load distribution measurment was discussed in section 4.1. Modeling, analysis and simulation of the load distribution expected in the network is typically performed offline. Such analyses typically produce individual results of limited scope (e.g. valid for a specific demanded traffic load, or fault condition etc.). However the accumulation of a number of such results can provide an indication of the robustness of a particular network configuration. The notion of optimization of the load distribution implies the existence of some objective optimization criteria and constraints. Load distribution optimization objectives may include: I. elimination of overload conditions on links / nodes II. equalization of load on links / nodes A variety of load distribution constraints may be derived from equipment, network topology, operational practices, service agreements etc. Load distribution constraints may include: a) current topology / route database b) current planned changes to topology / route database c) capacity allocations for planned traffic demand d) capacity allocations for network protection purposes e) service level agreements (SLAs) for bandwidth and delay sensitivity of flows Within the context of the traffic-engineering framework, control of the load distribution is a core capability for enabling traffic engineering of the network. 5. Route Determination Routing protocols have been studied extensively in the IETF and elsewhere. This section is not intended to replicate existing specifications, but rather to focus on specific operational aspects of controlling those routing protocols towards a traffic-engineered load distribution. in thsi draft , we assume that a traffic engineered load distribution typically relies on something other than a default IGP rout set, and typically requires support for multiple path configurations. Wright Informational - Expires January 2001 5 Traffic Engineering Of Load Distribution July 2000 The set of routes deployed for use within a network is not necessarily monolithic. Not all routes in the network may be determined by the same system. Routes may be static or dynamic. Routes may be determined by: 1. topology driven IGP 2. explicitly specified 3. capacity constraints (e.g. link / node / service bandwidth) 4. constraints on other desired route characteristics, (e.g. delay, diversity / affinity with other routes etc.) Combinations of the methods are possible: - partial explicit routes where some of the links are selected by the topology driven IGP - some routes may be automatically generated by the IGP. Others may be explicitly set by some management system. Explicit routes are not necessarily static. Consider that explicit routes may be generated periodically by an offline traffic engineering tool and provisioned into the network. MPLS provides efficient mechanisms for explicit routing and bandwidth reservation. Note that link capacity may be reserved for a variety of protection strategies as well as for planned traffic load demands and in response to signaled bandwidth requests (e.g. RSVP). When allocating capacity, there may be issues in the sequence with which capacity on specific routes is allocated affecting the overall traffic load capacity. It is important during path selection to chose paths that have a minimal effect on future path setups (see e.g. [7]). Aggregate capacity required for some paths may exceed the capacities of one or more links along the path, forcing the selection of an alternative path for that traffic. Constraint based routing approaches may also provide mechanisms to support additional constraints ( other than capacity based constraints) IGPs (e.g. IS-IS, OSPF) have had enhancement proposals to support to additional network state information for traffic engineering purposes (e.g. available link capacity). Alternatively, routers can report relevant network state information, both raw and processed, directly to the management system. In other networks (e.g. PSTN), some symmetry in the routing of traffic flows and aggregate demand may be assumed. In the case of the public Internet, symmetry is unlikely to be achieved in routing (e.g. due to peering policies sending responses to different peering points than queries). Controls over the determination of routes form an important aspect of traffic engineering for load distribution. Since the routing operates over a specific topology, any control of the topology abstraction used provides some control of the set of possible routes. 5.1 Control of the topology abstraction Wright Informational - Expires January 2001 6 Traffic Engineering Of Load Distribution July 2000 There are two major controls available on the topology abstraction - the use of hierarchical routing and link bundling concepts. 5.1.1 Hierarchical Routing Hierarchical routing provides a mechanism to abstract portions of the network in order to simplify the topology over which routes are being selected. Hierarchical routing examples in IP networks include: a) use of an EGP (e.g. BGP) and an IGP (e.g.ISIS) b) MPLS Label stacks Such hierarchies provide both a simplified topology and a coarse classification of traffic. 5.1.2 Link Bundling In some cases a pair of LSRs may be connected by several (parallel) links. From the MPLS Traffic Engineering point of view, for the purpose of scalability, it may be desirable to treat all these links as a single IP link - an operation known as Link Bundling (e.g. ref. [8]). With load balancing, the load to be balanced is spread across multiple LSPs that in general does not require physical topology adjacency for the LSRs. The techniques are complementary. Link bundling provides a local optimization that is particularly suited for aggregating low speed links. Load Balancing is targeted at larger scale network optimizations. 5.2 Operational controls over route determination The default topology driven IGP provides the least administrative control over route determination. The main control available in this case is the ability to modify the administrative weights. This has network wide effects and may result in unanticipated traffic shifts. A route set comprised entirely of completely-specified explicit- routes is the opposite extreme i.e. complete offline operational control of the routing. A disadvantage of using explicit routes is the administrative burden and potential for human induced errors from using this approach on a large scale. Management systems (e.g. policy-based management) may be deployed to ease these operational concerns, while still providing more precise control over the routes deployed in the network. In MPLS enabled networks, explicit route specification is feasible and a finer grained approach is possible for classification, including service differentiation. 6. Traffic Classification in Multipath Routing Configurations Given multiple paths between two endpoints, there is a choice to be made of which traffic to send down a particular path. This choice could be affected by: Wright Informational - Expires January 2001 7 Traffic Engineering Of Load Distribution July 2000 1. traffic source preferences (e.g. expressed as marking - DSCPs) 2. traffic destination preferences ( e.g. peering arrangements) 3. network operator preferences (e.g. time of day routing, scheduled facility maintenance, policy) 4. network state ( e.g. link congestion avoidance) There are a number of potential issues related to the use of multi- path routing [9] including: a) variable path MTU b) variable latencies c) increased difficulty in debugging d) sequence integrity These issues may be of particular concern when traffic from a single "flow" is routed over multiple paths, or during the transition of traffic flow between paths. Some effort [10] has been made to consider these effects in the development of hashing algorithms for use in multipath routing. However, the transient effects of flow migration for other than best-effort flows have not been resolved. The choice of traffic classification algorithm can be delegated to the network (e.g. load balancing - which may be done based on some hash of packet headers and/or random numbers). This approach is taken in Equal Cost Multipath [ECMP] and Optimized Multipath [11]. Alternatively, a policy-based approach has the advantage of permitting greater flexibility in the packet classification and path selection. This flexibility can be used for more sophisticated load balancing algorithms, or to meet churn in the network optimization objectives from new service requirements. Multipath routing, in the absence of explicit routes, is difficult to traffic engineer as it devolves to the problem of adjusting the administrative weights. MPLS networks provide a convenient and realistic context for multipath classification examples using explicit routes. One LSP could be established along the default IGP path. An additional LSP could be provisioned (in various ways)to meet different traffic engineering objectives. 7. Traffic Engineered Load Distribution in Multipath MPLS networks In this section we focus mainly on load balancing as a specific sub- problem within the topic of load distribution. Load-balancing essentially provides a partition of the traffic load across the multiple paths in the MPLS network. The basis for partitioning the traffic can be static or dynamic. Dynamic load balancing can be based on a dynamic administrative control (e.g. Time of Day), or it can form a closed control loop with some measured network parameter. Static partitioning of the load can be based on information carried within the packet header (e.g. source / destination addresses, Wright Informational - Expires January 2001 8 Traffic Engineering Of Load Distribution July 2000 Source / destination port numbers, packet size, protocol ID, DSCP, etc.). Static partitioning can also be based on other information available at the LSR (e.g. the arriving physical interface). A control-loop based load-balancing scheme seeks to balance the load close to some objective, subject to error in the measurements and delays in the feedback loop etc. The objective may be based on a fraction of the input traffic to be sent down a link (e.g. 20% down LSP (abd) and 80% down LSP (acd)in Figure 1) in which case some measurement of the input traffic is required. The objective may also be based on avoiding congestion loss in which case some loss metric is required. The metrics required for control loop load balancing may be derived from information available locally at the upstream LSR, or may be triggered by events distributed elsewhere in the network. In the latter case, the metrics must be delivered to the Policy Decision Point. Obviously, locally derived trigger conditions would be expected to avoid the propagation delays etc. associated with the general distributed case. Frequent notification of the state of these metrics increases network traffic which may be undesirable. This draft does not seek to provide guidance on the appropriate rate of notification for metric updates. Consider the case of a single large flow that must be load balanced across a set of links. In this case policies based solely on the packet headers may be inadequate and some other approach (e.g. based on a random number generated within the router) may be required. Note that sequence integrity of the aggregate FEC forwarded over a set of load balancing LSPs may not be preserved under such a regime. ECMP and OMP embed the load balancing optimization problem in the IGP implementation. This may be appropriate in the context of a single service if the optimization objectives and constraints can be agreed. ECMP approaches apply equal cost routes, but do not provide guidance on allocating load between routes with different capacities. OMP attempts a network wide routing optimization (considering capacities) but assumes that all network services can be reduced to a single dimension of capacity. For networks requiring greater flexibility in the optimization objectives and constraints, policy based approaches may be appropriate. 7.1 Policy-Based MPLS Network Context for Load Balancing Figure 1 illustrates a generic policy based network architecture in the context of an MPLS network. In this example, we have two LSPs established : LSP #1 that follows the path(abd) LSP #2 that follows the path(acd). In this draft we do not consider the problems of establishing the LSPs. We assume that a variety of mechanisms may be used for either manual(e.g. LSPs provision explicit routes) or automated (e.g. LSPs Wright Informational - Expires January 2001 9 Traffic Engineering Of Load Distribution July 2000 based on topology driven or data driven shortest path routes) establishment of the LSPs. Future versions of this or another draft may address the issue of establishing LSPs via policy mechanisms (e.g. using COPS). ++++++++++++++ + Policy + + Management + + Tool + ++++++++++++++ |\ |\ | | | | (E.g., JAVA, LDAP) | ++++++++++++++ | + Policy + | + Repository + | + + | ++++++++++++++ | |\ | | | | (e.g. LDAP) ++++++++++++++ + Policy + + Decision + + Point + ++++++++++++++ / / | \ / / | +-------+ / / | \ (e.g. COPS, SNMP) +++++++++++++++ | ++++++++++++++ +++++++++++++++ + ELSR(a) +----+ LSR (b) +---+ ELSR (d) + +++++++++++++++ | ++++++++++++++ +++++++++++++++ \ | / \ +--\ / \ ++++++++++++++ / \-+ LSR (c) +--/ ++++++++++++++ Figure 1 LSR as PEP The load balancing operation is performed at the LSR containing the ingress of the LSPs to be load balanced. This LSR ((a) in Figure 1) is acting as the Policy Enforcement Point for load-balancing policies related to these LSPs. In this context the load-balancing problem concerns the selection of suitable policies to control the classification and admission of packets and/or of flows to both LSPs. The admission decision for an LSP is reflected in the placement of that LSP as the Next Hop Forwarding Label Entry (NHFLE) within the appropriate routing tables within the LSR. Normally, there is only Wright Informational - Expires January 2001 10 Traffic Engineering Of Load Distribution July 2000 one NHLFE corresponding to each FEC, however there are some circumstances where multiple NHLFEs may exist for an FEC. The conditions for the policies applying to the set of LSPs to be load balanced should be consistent. For example, if the condition used to allocate flows between LSPs is the source address range, then the set of policies applied to the set of LSPs should account for the disposition of the entire source address range. For policy-based MPLS networks, traffic engineering policies would also be able to utilize for both conditions and actions the parameters available in the standard MPLS MIBs i.e. MPLS Traffic Engineering MIB [12], MPLS LSR MIB [13] MPLS Packet Classifier MIB [14] MIB elements for additional traffic metrics are for further study beyond the scope of this internet draft. 7.2 Load Balancing at Edge of MPLS Domain Flows admitted to an LSP at the edge of an MPLS domain are described by the set of Forwarding Equivalence Classes (FECs) that are mapped to the LSPs in the FEC to NHLFE (FTN) table. The load-balancing operation may be considered as redefining the FECs to send traffic along the appropriate path. Rather than sending all the traffic along a single LSP, the load balancing policy operation results in the creation of new FECs which effectively partition the traffic flow among the LSPs in order to achieve some load balance objective. Consider as an example, two simple point-to-point LSPs, (a) and (b), with the same source and destination LSRs, over which we are to load balance some aggregate FEC (z). The aggregate FEC (z) is the union of FEC (a) and FEC (b). The load balancing policy may adjust the FEC (a) and FEC (b) definitions such that the aggregate FEC (z) is preserved. 7.3 Load Balancing at interior of MPLS Domain Flows admitted to an LSP at the interior of an MPLS domain are described by the set of labels that are mapped to the LSPs in the Incoming label Map (ILM). A Point-to-Point LSP that simply transits an LSR at the interior of an MPLS domain does not have an LSP ingress at this transit LSR. Merge points of a Multipoint-to-Point LSP may be considered as ingress points for the next link of the LSP. Wright Informational - Expires January 2001 11 Traffic Engineering Of Load Distribution July 2000 A label stacking operation may be considered as an ingress point to a new LSP. The above conditions, which put multiple LSPs onto different LSPs, may require load balancing at the interior node. The FEC of an incoming flow may be inferred from its label. Hence load-balancing policies may operate based on incoming labels to segregate traffic rather than requiring the ability to walk up the incoming label stack to the packet header in order to reclassify the packet. The result is a coarse load balancing of LSPs (not flows) onto one of a number of LSPs from the LSR to the egress LSR. 7.4 MPLS Policies for Load Balancing MPLS load balancing partitions an incoming stream of traffic across multiple LSPs. The load balancing policy, as well as the ingress LSR where the policy is enforced, must be able to distinctly identify LSPs that will deliver flows towards the destination. We do not, in this draft, address the issue of how LSPs are established. It is assumed, however, that the PDP that installs the load balancing policy, has knowledge of the existing LSPs and is able to identify them in policy rules. One way to achieve this is through the binding of a label to an LSP. An example MPLS load-balancing policy may state, for the simple case of balancing across two LSPs, ôIf traffic matches classifier æCÆ, then forward on LSP æL1Æ, else forward on LSP æL2Æö. Classification can be done on a number of parameters, such as packet header fields, incoming labels, etc. The classification conditions of an MPLS load- balancing policy are thus effectively constrained to be able to specify the FEC in terms that can be resolved into MPLS packet classification MIB parameters. Forwarding traffic on an LSP can be achieved by tagging the traffic with the appropriate label corresponding to the LSP. MPLS load- balancing policy actions typically result in the definition of an alternative FEC to be forwarded down a specific LSP. This would typically be achieved by appropriate provisioning of the FEC and routing tables (the FTN and ILM tables in the MPLS architecture) - e.g. via the appropriate MIBs. 8. Security Considerations The policy system and the MPLS system both have their inherent security issues, which this document does not attempt to resolve. The policy system provides a mechanism to configure the LSPs within LSRs. Any thing that can be configured can also be incorrectly configured with potentially disastrous results. The policy system can help to secure the MPLS system by providing appropriate controls Wright Informational - Expires January 2001 12 Traffic Engineering Of Load Distribution July 2000 on the LSP life cycle. Conversely, if the security of the Policy system is compromised, then this may impact any MPLS systems controlled by that policy system. The MPLS network is not expected to impact the security of the Policy system. Further security considerations of Policy-Enabled MPLS networks is for further study. 9. References [1] Bradner, S., "The Internet Standards Process -- Revision 3", BCP 9, RFC 2026, October 1996. [2] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997 [3] Wright, S., Reichmeyer, F., Jaeger, R., Gibson, M., "Policy Based load balancing in Traffic Engineered MPLS Networks", work- in-progress, draft-wright-mpls-te-policy-00.txt, June 2000. [4] Almes, G., Kaldindi, A., Zekauskas, M., "A One-way Delay metric for IPPM", RFC 2679, September 1999 [5] Brownlee, N., Mills, C., Ruth, G., "Traffic flow Measurement: Architecture", RFC 2722, October 1999. [6] Awduche, D., Chiu, A., Elwalid, A., Widjaja, I., Xiao, X., "A Framework for Internet Traffic Engineering", draft-ietf-tewg- framework-01.txt, work in progress, May 2000. [7] Kodialam, M., Lakshman, T.V., ôMinimum Interference Routing with Applications to MPLS Traffic Engineering,ö Proc. INFOCOM, Mar.2000 [8] Kompella, K., Rekhter, Y., " Link Bundling in MPLS Traffic Engineering", work-in-progress, draft-kompella-mpls-bundle- 00.txt, February 2000. [9] Thaler, D., Hopps, C., "Multipath Issues in Unicast and Multicast Next-Hop Selection", draft-thaler-multipath-05.txt, work in progress, February 2000. [10] Hopps, C., "Analysis of Equal-cost Multi-path Algorithm", draft-hopps-ecmp-algo-analysis-04.txt, work-in-progress, February 2000. [11] Villamizar, C. "MPLS Optimized OMP", work in progress, 1999. available at http://www.fictitious.org Wright Informational - Expires January 2001 13 Traffic Engineering Of Load Distribution July 2000 [12] Srinivasan, C., Viswanathan, A., Nadeau, T., "MPLS Traffic Engineering Management Information Base Using SMIv2", work-in- progress, draft-ietf-mpls-te-mib-03.txt, March 2000. [13] Srinivasan, C., Viswanathan,A., Nadeau,T.,"MPLS Label Switch Router Management Information Base Using SMIv2", work-in- progress, draft-ietf-mpls-lsr-mib-04.txt, April 2000. [14] Nadeau,T., Srinivasan, C., Viswanathan,A., "Multiprotocol label Switching Packet Classification Management Information Base Using SMIv2", work-in-progress, draft-nadeau-mpls-packet-classifier- mib-00.txt, March 2000. 10. Acknowledgments 11. Author's Addresses Steven Wright Science & Technology BellSouth Telecommunications 41G70 BSC 675 West Peachtree St. NE. Atlanta, GA 30375 Phone +1 (404) 332-2194 Email: steven.wright@snt.bellsouth.com Robert Jaeger Laboratory for Telecommunications Science, 2800 Powder Mill Road, Bldg 601, Room 131 Adelphi, MD 20783 Phone +1 (301) 688-1420 Email: rob@lts.ncsc.mil Francis Reichmeyer IPHighway, Inc. 55 New York Avenue Framingham, MA 01701 Phone +1 (201) 655-8714 Email: franr@iphighway.com Wright Informational - Expires January 2001 14 Traffic Engineering Of Load Distribution July 2000 Full Copyright Statement "Copyright (C) The Internet Society (date). All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implmentation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns. This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE Wright Informational - Expires January 2001 15