Internet DRAFT - draft-ambrose-routing-protocol-term

draft-ambrose-routing-protocol-term




                                                           Nick Ambrose 
Network Working Group                                       Debby Stopp 
INTERNET-DRAFT                                                     IXIA 
Expires: December 2001                                        June 2001 
    
    
                  Terminology for Router Protocol Testing 
                <draft-ambrose-routing-protocol-term-00.txt> 
    
    
Status of this Memo 
    
   This document is an Internet-Draft and is in full conformance 
   with all provisions of Section 10 of RFC2026. 
    
    
   Internet-Drafts are working documents of the Internet Engineering 
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Abstract 
    
   The purpose of this draft is to describe terminology specific to the 
   benchmarking of devices that support one or more routing protocols.  
   It builds upon the tenets set forth in RFC 2544 and other IETF 
   Benchmarking Methodology Working Group (BMWG) efforts.  This 
   document seeks to extend these efforts to the router benchmarking 
   paradigm.  
    
   The BMWG produces two major classes of documents: Benchmarking 
   Terminology documents and Benchmarking Methodology documents. The 
   Terminology documents present the benchmarks and other related 
   terms.  The Methodology documents define the procedures required to 
   collect the benchmarks cited in the corresponding Terminology 
   documents. 
 
 






     
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Table of Contents 
    

   1. Introduction...................................................3 

   2. Key Words to Reflect Requirements..............................3 

   3. Definition Format..............................................3 

 3.1.  Existing Terminology.........................................3 

   4. Table of Defined Terms.........................................4 

 4.1.  General Nomenclature.........................................4 

  4.1.1.  Forwarding Information Base (FIB).........................4 

  4.1.2.  Routing Information Base (RIB)............................4 

  4.1.3.  Route Key.................................................5 

  4.1.4.  FIB Entry.................................................5 

  4.1.5.  Unique FIB Entry..........................................6 

  4.1.6.  RIB Entry.................................................6 

  4.1.7.  Unique RIB Entry..........................................6 

 4.2.  Specific Nomenclature........................................6 

  4.2.1.  Peer......................................................6 

  4.2.2.  Routing Protocol Entry....................................7 

  4.2.3.  Routing Protocol Message..................................7 

  4.2.4.  Routing Protocol Update Message...........................7 

  4.2.5.  Routing Protocol Withdrawal Message.......................7 

  4.2.6.  Advertised Routing Protocol Entry.........................8 

  4.2.7.  Established Peer..........................................8 

  4.2.8.  Route Packing.............................................8 

  4.2.9.  Policy....................................................8 

  4.2.10. Policy Information Base...................................9 

  4.2.11. Route Flap................................................9 

  4.2.12. FIB EntryĂs Availability..................................9 

  4.2.13. RIB EntryĂs Availability.................................10 

  4.2.14. Capacity.................................................10 

  4.2.15. Performance..............................................11 

  4.2.16. Routing Protocol Entries accepted rate...................11 

  4.2.17. PeerĂs offered rate......................................12 

  4.2.18. PeerĂs accepted rate.....................................12 

  4.2.19. Convergence..............................................13 

   5. Security Considerations.......................................13 

   6. References....................................................14 

   7. Author's Addresses............................................14 











     
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 1.     Introduction 
    
    
 2.     Key Words to Reflect Requirements  
    
   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. 
    
    
 3.     Definition Format 
    
   This section cites the template suggested by RFC 1242 in the 
   specification of a term to be defined. 
    
   Term to be defined. 
    
   Definition: 
   The specific definition for the term. 
    
   Discussion: 
   A brief discussion of the term, its application, or other 
   information that would build understanding. 
    
   Measurement units: 
   Units used to record measurements of this term, if applicable. 
    
   [Issues:] 
   List of issues or conditions that affect this term. This field can 
   present items the may impact the term's related methodology or 
   otherwise restrict its measurement procedures.  This field is 
   optional in this document. 
    
   [See Also:] 
   List of other terms that are relevant to the discussion of this 
   term. This field is optional in this document. 
    
    
 3.1.   Existing Terminology 
    
   This document draws on existing terminology defined in other BMWG 
   work.  Examples include, but are not limited to: 
    
      Device Under Test (DUT)   [RFC 2285, section 3.1.1] 
      System Under Test (SUT)   [RFC 2285, section 3.1.2] 
    
   Note: "DUT/SUT" refers to a metric that may be applicable to a DUT 
   or SUT. 
    
    


     
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 4.     Table of Defined Terms 
    
 4.1.   General Nomenclature 
 
 4.1.1. Forwarding Information Base (FIB) 
    
   Definition: 
   ˘The table containing the information necessary to forward 
   Datagrams. At minimum, this contains the interface identifier and 
   next hop information for each Route.÷[4] 
    
   Discussion: 
    
   This is a generalization of the FIB concept defined in [4]. The 
   concept of a FIB is extended to support IPV6 and forwarding of 
   frames based on information other than IP addresses (e.g. MPLS 
   label). 
    
   When we take performance measurements at the Data Plane, we are 
   measuring the performance of the FIB of a particular DUT/SUT. 
    
    
 4.1.2. Routing Information Base (RIB) 
    
   Definition: 
    
   The table that contains all destinations to which the DUT may 
   forward frames. 
    
   Discussion: 
    
   Entries in the RIB can be used to populate the FIB based on some 
   selection criteria. These entries can also be used as a source to 
   re-advertise information.  
    
   It is quite common for the RIB to contain multiple paths to the same 
   destination (possibly with the same or different degree of 
   preference and possibly advertised from multiple sources).  
 
   The RIB can also be used to generate information to re-advertise. 
     
   When we take performance measurements at the Control Plane, we are 
   measuring performance of the RIB (capacity, rates of acceptance 
   etc.) 
    
   See Also: 
    
   FIB 





     
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 4.1.3. Route Key 
    
   Definition: 
    
   A data item used to identify a path in a network 
    
   Discussion: 
    
   A Route Key is a Protocol Specific data item that can be used as a 
   key or partial key for lookup in a FIB or RIB. (i.e. an IP Route Key 
   could be a CIDR Prefix, for MPLS, a pair(incoming interface, label) 
   ). 
    
   When used in a RIB, it MAY represent a network path that is not 
   available for forwarding of frames.  When used in a FIB, it 
   represents a network path that is available for forwarding frames. 
    
   This is a generalization of the term ˘Prefix÷ defined in [4] which 
   is intended to extend beyond pure IP routing (e.g. MPLS networks) 
    
   See Also: 
    
   RIB 
   FIB 
    
    
 4.1.4. FIB Entry 
    
   Definition: 
    
   An entry in a FIB consisting of at least a Pair(Route Key, Next Hop) 
    
   Discussion: 
    
   A FIB Entry contains enough information to allow for forwarding of 
   frames.  
    
   The Route key determines which incoming frames match this entry and 
   the Next Hop governs which interface the frames will be forwarded 
   and can potentially include information that modifies the frame 
   contents (e.g. MPLS label swapping). 
    
   Next Hop is Routing Protocol Specific (i.e. for IP a Next Hop could 
   be an IP Address, for MPLS, a pair (outgoing interface, outgoing 
   label). 
    
   This is intended as a generalization of an ˘IP Route÷  
 
See Also: 
FIB 
RIB 
Rib Entry 
     
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 4.1.5. Unique FIB Entry 
    
   Definition: 
    
   A FIB Entry such that, for a given FIB, there is only one match to 
   the Route Key. 
    
   See Also: 
   FIB Entry 
    
    
 4.1.6. RIB Entry 
    
   Definition: 
    
   An entry in a RIB consisting of at least a Pair(Route Key, 
   Attributes). 
    
   Discussion: 
    
   A Protocol-specific data item that associates certain attributes 
   (i.e. degree of preference, Community) with a Route Key. 
 
    
 4.1.7. Unique RIB Entry 
    
   Definition: 
    
   A RIB Entry such that for a given RIB, there is only one match to 
   the Route Key 
    
   Discussion: 
    
   See Also: 
   FIB Entry 
    
    
 4.2.   Specific Nomenclature 
    
 
 4.2.1. Peer 
    
   Definition: 
    
   Two entities are Peers for a given Routing Protocol if they have 
   established communication via that Protocol. 
    
   Discussion: 
    



     
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 4.2.2. Routing Protocol Entry 
    
   Definition: 
    
   A pair consisting of at least (Route Key, Attributes) 
    
   Discussion: 
    
   Attributes are Protocol-specific (i.e. Next Hop, Community etc.) 
    
   An advertised Routing Protocol Entry may cause a DUT to install a 
   new RIB Entry into its RIB (with a potentially different set of 
   Attributes than those advertised). 
 
 
    
 4.2.3. Routing Protocol Message 
    
   Definition: 
    
   A message containing Protocol-specific information, exchanged 
   between Peers. 
    
   Discussion: 
    
   Some messages are used for initiation (i.e. BGP OPEN, OSPF HELLO) 
   whereas some are used to advertise or withdraw information (BGP 
   UPDATE, OSPF LSA packets). 
    
    
 4.2.4. Routing Protocol Update Message 
    
   Definition: 
    
   A Routing Protocol Message that advertises Routing Protocol Entries 
   to a Peer. 
    
   Discussion: 
 
   Note: Each Update message MAY advertise multiple Routing Protocol 
   Entries to a Peer 
    
    
 4.2.5. Routing Protocol Withdrawal Message 
    
   Definition: 
    
   A Routing Protocol Message that removes Routing Protocol Entries 
   from a Peer 
    
   Discussion: 
    
     
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   Note: Each Withdrawal message may remove multiple Routing Protocol 
   Entries from a Peer 
    
 4.2.6. Advertised Routing Protocol Entry 
   Definition: 
   A Routing Protocol Entry that has last been sent to a DUT/SUT in a 
   Routing Protocol Update Message 
    
   Discussion: 
    
   See Also: 
    
   Routing Protocol Entry 
   Routing Protocol Update Message 
    
 4.2.7. Established Peer 
    
   Definition: 
    
   A peer that is in a state where it can accept Routing Protocol 
   Update or withdrawal messages. 
    
   Discussion: 
    
   A Peer may have a number of states. Some of these states may be used 
   for initiation (e.g. OSPF HELLO's, BGP OPEN) during which the 
   protocol may not be capable of exchanging routing information. 
    
 4.2.8. Route Packing 
    
   Definition: 
    
   Number of Routing Protocol Entries that exist in a single Routing 
   Protocol Update or Withdraw Message. 
    
   Discussion: 
    
   Certain protocols such as BGP, support this concept (i.e. a single 
   BGP UPDATE message can advertise multiple NLRI entries with common 
   attributes). This can affect convergence and performance metrics. 
    
   Protocols that do not support such a concept implicitly have a Route 
   Packing of 1. 
 
 
 4.2.9. Policy 
    
   Definition: 
    
   Policy is ˘the ability to define conditions for accepting, rejecting 
   and modifying Routing Protocol Entries received in Routing Protocol 
   Update Messages÷. 
    
     
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   Discussion: 
    
   Some Routing Protocols do not explicitly support policy (e.g. OSPF) 
   such Protocols can be viewed as having ˘Implicit Policies÷ ű i.e. 
   OSPF has an implicit policy of Accept(All), Re-advertise(All).  
    
 4.2.10. 
         Policy Information Base 
    
   Definition: 
    
   A collection of policies that are applied to incoming or outgoing 
   Routing Entries. 
    
   Discussion: 
    
   Policy can be applied to incoming Routing Protocol Entries before 
   they are added to the RIB, or to RIB entries before they are re-
   advertised. 
    
    
 4.2.11. 
         Route Flap 
    
   Definition: 
    
   The withdrawing of a currently advertised Routing Protocol Entry or 
   the advertise and withdrawal of a currently unadvertised Routing 
   Protocol Entry. 
    
   Discussion: 
    
   A route flap is either an existing Routing Protocol Entry 
   disappearing (either being explicitly withdrawn, or being deleted 
   due to a peer closing) or a Routing Protocol Entry being advertised 
   and then disappearing. 
 
    
 
 4.2.12. 
         FIB EntryĂs Availability 
    
   Definition: 
    
   The time at which a RIB Entry has been installed in a RIB/FIB and 
   can be re-advertised or can be used to forward frames. 

   Discussion: 
    
   A FIB Entry is available as soon as it is stored in the FIB (and so 
   is available to forward frames) 
    




     
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 4.2.13. 
         RIB EntryĂs Availability 
    
   The time at which a RIB Entry has been installed in a RIB and is 
   available to be re-advertised. 
    
   Discussion: 
    
   A RIB Entry may be available but not re-advertised if it is not the 
   best route to itĂs destination.  
    
   Issues: 
    
   It is very difficult to measure these timings, since they are events 
   internal to a DUT. In this case, we measure an externally visible 
   event as an approximation (i.e. for Control plane, we can measure 
   the re-advertisement of a Protocol Route Entry, for Control plane, 
   the receipt of a Data frame addressed to the Protocol Route Entries 
   Route Key) 
 
    
 4.2.14. 
         Capacity 
    
   This section defines metrics used to measure the capacity of a 
   DUT/SUT to establish peers and accept Routing Protocol Entries. 
   This is a 2-dimentional metric, which can be measured at either the 
   control plane or data plane. 
    
   The sections below break this into two metrics (Peer capacity and 
   Route capacity) but it is useful to measure as ˘Peer capacity at a 
   given number of RIB Entries.÷ 
    
    
 4.2.14.1.     Peer Capacity 
    
   Definition: 
    
   Number of peers a DUT can establish with zero Routing Protocol 
   Entries 
    
   Discussion: 
    
   Issues: 
    
   Certain Protocols may require advertising at least one Routing 
   Protocol Entry (i.e. a Link-state protocol might require advertising 
   at least one Routing Protocol Entry (e.g. to represent at least one 
   interface). 
    
 
 4.2.14.2.     Route Capacity 
    
   Definition: 
     
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   Number of Routing Protocol Entries that can be accepted from a 
   single peer. 
    
   Discussion: 
    
   When measuring at the control plane, we verify the number of Routing 
   Protocol Entries re-advertised by the DUT/SUT. 
    
   When measuring at the data plane, we measure that the DUT/SUT is 
   able to forward at least one frame addressed to each Route Key in 
   each Routing Protocol Entry advertised. 
 
    
   Issues: 
    
   Measuring at the control plane and data plane can often produce 
   different capacities as DUT/SUTĂs FIB resources may be more limited 
   than their RIBĂs as they are often implemented in hardware. 
    
    
 4.2.15. 
         Performance 
    
 4.2.15.1.     Routing Protocol Entries offered rate 
    
   Definition: 
    
   Rate at which a test device is capable of advertising Routing 
   Protocol Entries. 
    
    
   Discussion: 
    
   This measures how quickly a test device is able to advertise Routing 
   Protocol Entries to a DUT. It is important to measure this quantity 
   as the DUT may be able to accept Routing Protocol Entries more 
   quickly than the tester can advertise. 
    
   Issues: 
    
   Units: 
    
   RIB Routing Protocol Entries/sec 
    
    
 4.2.16. 
         Routing Protocol Entries accepted rate 
    
   Definition: 
    
   Rate at which a DUT is able to accept/withdraw Routing Protocol 
   Entries. 
    

     
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   Discussion: 
    
   This measures the rate at which a DUT is able to accept Routing 
   Protocol Entries in Routing Protocol Update or Withdraw messages and 
   insert or remove the corresponding RIB Entries from its RIB. 
    
    
   Issues: 
    
   This is a metric that is internal to a DUT and must usually be 
   measured indirectly.  
    
 
   A RIB Entry is accepted when it is available into the RIB. 
    
   We can measure the Routing Protocol Entries offered rate from the 
   tester to the DUT and then verify that the DUT is able to re-
   advertise all offered Routing Protocol Entries. 
    
    
   Units: 
    
   Routing Protocol Entries/sec 
 
    
 4.2.17. 
         PeerĂs offered rate 
    
   Definition: 
    
   Rate of peer establish/teardown attempts that a test device can 
   generate. 
    
   Discussion: 
    
   It is important to measure this quantity, as the DUT may be able to 
   establish Peers more quickly than the test device. 
    
   Issues: 
    
   Units: 
    
   Number of PeerĂs/sec 
    
    
 4.2.18. 
         PeerĂs accepted rate 
    
   Definition: 
    
   Rate a DUT is able to accept or tear-down peerĂs. 
    
   Discussion 
    
   This measures how quickly a DUT can establish peers. 
     
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   Issues: 
    
   This is a metric that is internal to a DUT, in order to measure it, 
   we can measure how many peers the test device can establish after a 
   given amount of time. This introduces the possibility that some 
   peers have timed out on the DUT but the test device has not yet 
   noticed this. In order to reduce this possibility, it is important 
   that the test measure the time the last peer was offered, but then 
   continues to run until all peerĂs keepalive timers have had a chance 
   to expire and then verify that all peers are actually established. 
   This could also be verified using a SNMP query to the DUT. 
    
   Units: 
    
   Number of peerĂs rate 
    
    
 4.2.19. 
         Convergence 
    
 4.2.19.1.     Route convergence 
    
   Definition: 
    
   The delay from the offering of a Routing Protocol Entry until the 
   Routing Protocol Entry is available at the DUT. 
    
   Discussion: 
    
   Issues: 
 
   Units: 
    
   Time in seconds. 
    
    
 5.     Security Considerations 
    
   As this document is solely for the purpose of providing metric 
   methodology and describes neither a protocol nor a protocol's 
   implementation, there are no security considerations associated with 
   this document.  
    
   Methodologies regarding the collection of the metrics described 
   within this document may need to cite security considerations.  This 
   document does not address methodological issues. 
    






     
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 6.     References 
    
   [1] Bradner, S., "Benchmarking Terminology for Network 
      Interconnection Devices", RFC 1242, July 1991.  
    
   [2] Bradner, S., and J. McQuaid, "Benchmarking Methodology for 
      Network Interconnect Devices", RFC 2544, March 1999.  
    
   [3] Bradner, S. "Use of Keywords in RFCs to Reflect Requirement 
      Levels, RFC 2119, March 1997 
    
   [4] Baker, F., ˘Requirements for IP Version 4 routers÷, RFC 1812, 
      June 1995 
    
    
    
 7.     Author's Addresses 
    
   Nick Ambrose 
   IXIA 
   26601 W. Agoura Rd.  
   Calabasas, CA  91302  
   USA 
    
   Phone: 818 871 1800  
   EMail: nick@ixiacom.com 
    
   Debby Stopp 
   IXIA 
   26601 W. Agoura Rd.  
   Calabasas, CA  91302  
   USA 
    
   Phone: 818 871 1800  
   EMail: debby@ixiacom.com 
    
















     
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