Benchmarking Working Group H. Berkowitz
Internet-Draft Gett Communications
Expires: September 1, 2003 E. Davies (ed.)
Nortel Networks
S. Hares
Nexthop Technologies
P. Krishnaswamy
SAIC
M. Lepp
Consultant
A. Retano
Cisco Systems, Inc.
March 3, 2003
Terminology for Benchmarking BGP Device Convergence in the Control
Plane
draft-ietf-bmwg-conterm-04.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
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.
This Internet-Draft will expire on September 1, 2003.
Copyright Notice
Copyright (C) The Internet Society (2003). All Rights Reserved.
Abstract
This draft establishes terminology to standardize the description of
benchmarking methodology for measuring eBGP convergence in the
Berkowitz, et al. Expires September 1, 2003 [Page 1]
Internet-Draft Terminology for Benchmarking BGP March 2003
control plane of a single BGP device. Future documents will address
iBGP convergence, the initiation of forwarding based on converged
control plane information and multiple interacting BGP devices. This
terminology is applicable to both IPv4 and IPv6. Illustrative
examples of each version are included where relevant.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1 Overview and Roadmap . . . . . . . . . . . . . . . . . . . . 4
1.2 Definition Format . . . . . . . . . . . . . . . . . . . . . 5
2. Components and characteristics of Routing information . . . 6
2.1 (Network) Prefix . . . . . . . . . . . . . . . . . . . . . . 6
2.2 Network Prefix Length . . . . . . . . . . . . . . . . . . . 6
2.3 Route . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.4 BGP Route . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.5 Network Level Reachability Information (NLRI) . . . . . . . 8
2.6 BGP UPDATE message . . . . . . . . . . . . . . . . . . . . . 8
3. Routing Data Structures and Route Categories . . . . . . . . 9
3.1 Routing Information Base (RIB) . . . . . . . . . . . . . . . 9
3.1.1 Adj-RIB-In and Adj-RIB-Out . . . . . . . . . . . . . . . . . 9
3.1.2 Loc-RIB . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.2 Routing Policy . . . . . . . . . . . . . . . . . . . . . . . 10
3.3 Routing Policy Information Base . . . . . . . . . . . . . . 10
3.4 Forwarding Information Base (FIB) . . . . . . . . . . . . . 11
3.5 BGP Instance . . . . . . . . . . . . . . . . . . . . . . . . 12
3.6 BGP Device . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.7 BGP Session . . . . . . . . . . . . . . . . . . . . . . . . 13
3.8 Active BGP Session . . . . . . . . . . . . . . . . . . . . . 13
3.9 BGP Peer . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.10 BGP Neighbor . . . . . . . . . . . . . . . . . . . . . . . . 14
3.11 MinRouteAdvertisementInterval (MRAI) . . . . . . . . . . . . 14
3.12 MinASOriginationInterval (MAOI) . . . . . . . . . . . . . . 15
3.13 Active Route . . . . . . . . . . . . . . . . . . . . . . . . 15
3.14 Unique Route . . . . . . . . . . . . . . . . . . . . . . . . 16
3.15 Non-Unique Route . . . . . . . . . . . . . . . . . . . . . . 16
3.16 Route Instance . . . . . . . . . . . . . . . . . . . . . . . 16
4. Constituent elements of a router or network of routers. . . 18
4.1 Default Route, Default Free Table, and Full Table . . . . . 18
4.1.1 Default Route . . . . . . . . . . . . . . . . . . . . . . . 18
4.1.2 Default Free Routing Table . . . . . . . . . . . . . . . . . 18
4.1.3 Full Default Free Table . . . . . . . . . . . . . . . . . . 19
4.1.4 Default-Free Zone . . . . . . . . . . . . . . . . . . . . . 19
4.1.5 Full Provider-Internal Table . . . . . . . . . . . . . . . . 20
4.2 Classes of BGP-Speaking Routers . . . . . . . . . . . . . . 20
4.2.1 Provider Edge Router . . . . . . . . . . . . . . . . . . . . 20
4.2.2 Subscriber Edge Router . . . . . . . . . . . . . . . . . . . 21
4.2.3 Inter-provider Border Router . . . . . . . . . . . . . . . . 21
Berkowitz, et al. Expires September 1, 2003 [Page 2]
Internet-Draft Terminology for Benchmarking BGP March 2003
4.2.4 Core Router . . . . . . . . . . . . . . . . . . . . . . . . 22
5. Characterization of sets of update messages . . . . . . . . 23
5.1 Route Packing . . . . . . . . . . . . . . . . . . . . . . . 23
5.2 Route Mixture . . . . . . . . . . . . . . . . . . . . . . . 23
5.3 Update Train . . . . . . . . . . . . . . . . . . . . . . . . 24
5.4 Randomness in Update Trains . . . . . . . . . . . . . . . . 25
5.5 Route Flap . . . . . . . . . . . . . . . . . . . . . . . . . 26
6. Route Changes and Convergence . . . . . . . . . . . . . . . 27
6.1 Route Change Events . . . . . . . . . . . . . . . . . . . . 27
6.2 Device Convergence in the Control Plane . . . . . . . . . . 28
7. BGP Operation Events . . . . . . . . . . . . . . . . . . . . 30
7.1 Hard reset . . . . . . . . . . . . . . . . . . . . . . . . . 30
7.2 Soft reset . . . . . . . . . . . . . . . . . . . . . . . . . 30
8. Factors that impact the performance of the convergence
process . . . . . . . . . . . . . . . . . . . . . . . . . . 32
8.1 General factors affecting device convergence . . . . . . . . 32
8.1.1 Number of peers . . . . . . . . . . . . . . . . . . . . . . 32
8.1.2 Number of routes per peer . . . . . . . . . . . . . . . . . 32
8.1.3 Policy processing/reconfiguration . . . . . . . . . . . . . 32
8.1.4 Interactions with other protocols . . . . . . . . . . . . . 32
8.1.5 Flap Damping . . . . . . . . . . . . . . . . . . . . . . . . 33
8.1.6 Churn . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
8.2 Implementation-specific and other factors affecting BGP
convergence . . . . . . . . . . . . . . . . . . . . . . . . 33
8.2.1 Forwarded traffic . . . . . . . . . . . . . . . . . . . . . 34
8.2.2 Timers . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
8.2.3 TCP parameters underlying BGP transport . . . . . . . . . . 34
8.2.4 Authentication . . . . . . . . . . . . . . . . . . . . . . . 34
9. Security Considerations . . . . . . . . . . . . . . . . . . 35
10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . 36
Normative References . . . . . . . . . . . . . . . . . . . . 37
Informative References . . . . . . . . . . . . . . . . . . . 38
For Internet Draft consistency purposes only . . . . . . . . 39
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 39
Intellectual Property and Copyright Statements . . . . . . . 41
Berkowitz, et al. Expires September 1, 2003 [Page 3]
Internet-Draft Terminology for Benchmarking BGP March 2003
1. Introduction
This document defines terminology for use in characterizing the
convergence performance of BGP processes in routers or other devices
that instantiate BGP functionality (see RFC1771 [1]). It is the first
part of a two document series, of which the subsequent document will
contain the associated tests and methodology. This terminology is
applicable to both IPv4 and IPv6. Illustrative examples of each
version are included where relevant. Although IPv6 will require the
use of MP-BGP, we will not deal with issues related to RFC 2283 [17]
in this draft.
The following observations underlie the approach adopted in this, and
the companion document:
o The principal objective is to derive methodologies to standardize
conducting and reporting convergence-related measurements for BGP.
o It is necessary to remove ambiguity from many frequently used
terms that arise in the context of such measurements.
o As convergence characterization is a complex process, it is
desirable to restrict the initial focus in this set of documents
to specifying how to take basic control plane measurements as a
first step to characterizing BGP convergence.
For path vector protocols, such as BGP, the primary initial focus
will therefore be on network and system control-plane activity
consisting of the arrival, processing, and propagation of routing
information.
We note that for testing purposes all optional parameters should be
turned off. All variable parameters should be in their default
setting unless specified by the test.
Subsequent drafts will explore the more intricate aspects of
convergence measurement, such as the impacts of the presence of
Multiprotocol Extensions for BGP-4, policy processing, simultaneous
traffic on the control and data paths within the DUT, and other
realistic performance modifiers. Convergence of Interior Gateway
Protocols will also be considered in separate drafts.
1.1 Overview and Roadmap
Characterizations of the BGP convergence performance of a device must
take into account all distinct stages and aspects of BGP
functionality. This requires that the relevant terms and metrics be
as specifically defined as possible. Such definition is the goal of
Berkowitz, et al. Expires September 1, 2003 [Page 4]
Internet-Draft Terminology for Benchmarking BGP March 2003
this document.
The necessary definitions are classified into separate categories:
o Components and characteristics of routing information
o Routing data structures and route categories
o Descriptions of the constituent elements of a network or a router
that is undergoing convergence
o Characterization of sets of update messages, types of route change
events, as well as some events specific to BGP operation
o Descriptions of factors that impact the performance of
convergence processes
1.2 Definition Format
The definition format is equivalent to that defined in [3], and is
repeated here for convenience:
X.x Term to be defined. (e.g., Latency)
Definition:
One or more sentences forming the body of the definition.
Discussion:
A brief discussion of the term, its application and any
restrictions that there might be on measurement procedures.
Measurement units:
The units used to report measurements of this term, if applicable.
Issues:
List of issues or conditions that could affect this term.
See Also:
List of related terms that are relevant to the definition or
discussion of this term.
Berkowitz, et al. Expires September 1, 2003 [Page 5]
Internet-Draft Terminology for Benchmarking BGP March 2003
2. Components and characteristics of Routing information
2.1 (Network) Prefix
Definition:
"A network prefix is a contiguous set of bits at the more
significant end of the address that collectively designates the
set of systems within a network; host numbers select among those
systems." (This definition is taken directly from section 2.2.5.2,
"Classless Inter Domain Routing (CIDR)", in [3].)
Discussion:
In the CIDR context, the network prefix is the network component
of an IP address.
Measurement Units: N.A.
Issues:
See Also:
2.2 Network Prefix Length
Definition:
The network prefix length is the number of bits out of the total
available in the address field, used to define the network prefix.
Discussion:
A common alternative to using a bit-wise mask to communicate this
component is the use of "slash (/) notation." Slash notation binds
the notion of network prefix length in bits to an IP address.
E.g., 141.184.128.0/17 indicates the network component of this
IPv4 address is 17 bits wide. Similar notation is used for IPv6
network prefixes e.g. :FF02:20::/24
When referring to groups of addresses, the network prefix length
is often used as a means of describing groups of addresses as an
equivalence class. For example, 'one hundred /16 addresses'
refers to 100 addresses whose network prefix length is 16 bits.
Measurement units: bits
Issues:
See Also: network prefix
Berkowitz, et al. Expires September 1, 2003 [Page 6]
Internet-Draft Terminology for Benchmarking BGP March 2003
2.3 Route
Definition:
In general, a 'route' is the n-tuple
<prefix, nexthop, other routing or non-routing protocol
attributes]>
A route is not end-to-end, but is defined with respect to a
specific next hop that will move traffic closer to the destination
defined by the prefix. In this usage, a route is the basic unit of
information about a target destination distilled from routing
protocols.
Discussion:
This term refers to the concept of a route common to all routing
protocols. With reference to the definition above, typical
non-routing-protocol attributes would be associated with diffserv
or traffic engineering.
Measurement Units: N.A.
Issues: None.
See Also: BGP route
2.4 BGP Route
Definition:
A BGP route is an n-tuple
<prefix, nexthop, ASpath [, other BGP attributes]>.
Discussion:
BGP Attributes, such as Nexthop or AS path are defined in RFC
1771[1], where they are known as Path Attributes, and are the
qualifying data that define the route.
From RFC 1771: "For purposes of this protocol a route is defined
as a unit of information that pairs a destination with the
attributes of a path to that destination"
Measurement Units: N.A.
Issues:
See Also: Route, prefix, Adj-RIB-in, NLRI.
Berkowitz, et al. Expires September 1, 2003 [Page 7]
Internet-Draft Terminology for Benchmarking BGP March 2003
2.5 Network Level Reachability Information (NLRI)
Definition:
The NRLI consists of one or more network prefixes with the same
set of path attributes.
Discussion:
Each prefix in the NLRI is combined with the (common) path
attributes to form a BGP route. The NLRI encapsulates a set of
destinations to which packets can be routed (from this point in
the network) along a common route described by the path
attributes.
Measurement Units: N.A.
Issues:
See Also: Route Packing, Network Prefix, BGP Route, NLRI
2.6 BGP UPDATE message
Definition:
An UPDATE message contains an advertisement of a single NLRI
field, possibly containing multiple prefixes, and multiple
withdrawals of unfeasible routes. See RFC 1771 ([1]) for details.
Discussion:
From RFC 1771: "A variable length sequence of path attributes is
present in every UPDATE. Each path attribute is a triple
<attribute type, attribute length, attribute value> of variable
length."
Measurement Units: N.A.
See Also
Berkowitz, et al. Expires September 1, 2003 [Page 8]
Internet-Draft Terminology for Benchmarking BGP March 2003
3. Routing Data Structures and Route Categories
3.1 Routing Information Base (RIB)
The RIB collectively consists of a set of logically (not necessarily
physically) distinct databases, each of which is enumerated below.
The RIB contains all destination prefixes to which the router may
forward, and one or more currently reachable next hop addresses for
them.
Routes included in this set potentially have been selected from
several sources of information, including hardware status, interior
routing protocols, and exterior routing protocols. RFC 1812 contains
a basic set of route selection criteria relevant in an all-source
context. Many implementations impose additional criteria. A common
implementation-specific criterion is the preference given to
different routing information sources.
3.1.1 Adj-RIB-In and Adj-RIB-Out
Definition:
Adj-RIB-In and Adj-RIB-Out are "views" of routing information from
the perspective of individual peer routers.
The Adj-RIB-In contains information advertised to the DUT by a
specific peer. The Adj-RIB-Out contains the information the DUT
will advertise to the peer.
See RFC 1771[1].
Discussion:
Issues:
Measurement Units: Number of route instances
See Also:
Route, BGP Route, Route Instance, Loc-RIB, FIB
3.1.2 Loc-RIB
Definition:
The Loc-RIB contains the set of best routes selected from the
various Adj-RIBs, after applying local policies and the BGP route
selection algorithm.
Berkowitz, et al. Expires September 1, 2003 [Page 9]
Internet-Draft Terminology for Benchmarking BGP March 2003
Discussion:
The separation implied between the various RIBs is logical. It
does not necessarily follow that these RIBs are distinct and
separate entities in any given implementation.
Types of routes can include internal BGP, external BGP, interface,
static and IGP routes.
Issues:
Measurement Units: Number of routes
See Also:
Route, BGP Route, Route Instance, Adj-RIB-in, Adj-RIB-out,FIB
3.2 Routing Policy
Definition:
Routing Policy is "the ability to define conditions for accepting,
rejecting, and modifying routes received in advertisements"[9].
Discussion:
RFC 1771 [1] further constrains policy to be within the hop-by-hop
routing paradigm. Policy is implemented using filters and
associated policy actions. Many AS's formulate and document their
policies using the Routing Policy Specification Language (RPSL)
[6] and then automatically generate configurations for the BGP
processes in their routers from the RPSL specifications.
Measurement Units: Number of policies; length of policies
Issues:
See Also: Routing Policy Information Base.
3.3 Routing Policy Information Base
Definition:
A routing policy information base is the set of incoming and
outgoing policies.
Discussion:
All references to the phase of the BGP selection process below are
made with respect to RFC 1771 [1] definition of these phases.
Berkowitz, et al. Expires September 1, 2003 [Page 10]
Internet-Draft Terminology for Benchmarking BGP March 2003
Incoming policies are applied in Phase 1 of the BGP selection
process [1] to the Adj-RIB-In routes to set the metric for the
Phase 2 decision process. Outgoing Policies are applied in Phase
3 of the BGP process to the Adj-RIB-Out routes preceding route
(prefix and path attribute tuple) announcements to a specific
peer.
Policies in the Policy Information Base have matching and action
conditions. Common information to match include route prefixes,
AS paths, communities, etc. The action on match may be to drop
the update and not pass it to the Loc-RIB, or to modify the update
in some way, such as changing local preference (on input) or MED
(on output), adding or deleting communities, prepending the
current AS in the AS path, etc.
The amount of policy processing (both in terms of route maps and
filter/access lists) will impact the convergence time and
properties of the distributed BGP algorithm. The amount of policy
processing may vary from a simple policy which accepts all routes
and sends all routes to complex policy with a substantial fraction
of the prefixes being filtered by filter/access lists.
Measurement Units: Number and length of policies
Issues:
See Also:
3.4 Forwarding Information Base (FIB)
Definition:
As according to the definition in Appendix B of [4]: "The table
containing the information necessary to forward IP Datagrams is
called the Forwarding Information Base. At minimum, this contains
the interface identifier and next hop information for each
reachable destination network prefix."
Discussion:
The forwarding information base describes a database indexing
network prefixes versus router port identifiers.
The forwarding information base is distinct from the "routing
table" (the Routing Information Base or RIB), which holds all
routing information received from routing peers. It is a data
plane construct and used for the forwarding of each packet. The
Forwarding Information Base is generated from the RIB. For the
purposes of this document, the FIB is effectively the subset of
Berkowitz, et al. Expires September 1, 2003 [Page 11]
Internet-Draft Terminology for Benchmarking BGP March 2003
the RIB used by the forwarding plane to make per-packet forwarding
decisions.
Most current implementations have full, non-cached FIBs per router
interface. All the route computation and convergence occurs before
entries are downloaded into a FIB.
Measurement units: N.A.
Issues:
See Also: Route, RIB
3.5 BGP Instance
Definition:
A BGP instance is a process with a single Loc-RIB.
Discussion:
For example, a BGP instance would run in routers or test
equipment. A test generator acting as multiple peers will
typically run more than one instance of BGP. A router would
typically run a single instance.
Measurement units: N/A
Issues:
See Also:
3.6 BGP Device
Definition:
A BGP device is a system that has one or more BGP instances
running on it, each of which is responsible for executing the BGP
state machine.
Discussion:
We have chosen to use "device" as the general case, to deal with
the understood [e.g. [9]] and yet-to-be-invented cases where the
control processing may be separate from forwarding [12]. A BGP
device may be a traditional router, a route server, a BGP-aware
traffic steering device or a non forwarding route reflector. BGP
instances such as route reflectors or servers, for example, never
forwards traffic, so forwarding-based measurements would be
meaningless for it.
Berkowitz, et al. Expires September 1, 2003 [Page 12]
Internet-Draft Terminology for Benchmarking BGP March 2003
Measurement units: N/A
Issues:
See Also:
3.7 BGP Session
Definition:
A BGP session is a session between two BGP instances.
Discussion:
Measurement units: N/A
Issues:
See Also:
3.8 Active BGP Session
Definition:
An active BGP session is one which is in the established state.
(See RFC 1771 [1]).
Discussion:
Measurement units: N/A
Issues:
See Also:
3.9 BGP Peer
Definition:
A BGP peer is another BGP instance to which the Device Under Test
(DUT) is in the Established state. (See RFC 1771 [1]).
Discussion:
In the test scenarios in the methodology discussion that will
follow this draft, peers send BGP advertisements to the DUT and
receive DUT-originated advertisements. We recommend that the
peering relation be established before tests are begun. It might
also be interesting to measure the time required to reach the
Berkowitz, et al. Expires September 1, 2003 [Page 13]
Internet-Draft Terminology for Benchmarking BGP March 2003
established state.
This is a protocol-specific definition, not to be confused with
another frequent usage, which refers to the business/economic
definition for the exchange of routes without financial
compensation.
It is worth noting that a BGP peer, by this definition is
associated with a BGP peering session, and there may be more than
one such active session on a router or on a tester. The peering
sessions referred to here may exist between various classes of BGP
routers (see Section 4.2).
Measurement units: number of BGP peers
Issues:
See Also:
3.10 BGP Neighbor
Definition:
A BGP neighbor is a device that can be configured as a BGP peer.
Discussion:
Measurement units:
Issues:
See Also:
3.11 MinRouteAdvertisementInterval (MRAI)
Definition:
(Paraphrased from 1771[1]) The MRAI timer determines the minimum
time between advertisements of routes to a particular destination
(prefix) from a single BGP device. The timer is applied on a
pre-prefix basis, although the timer is set on a per BGP device
basis.
Discussion:
Given that a BGP instance may manage in excess of 100,000 routes,
RFC 1771 allows for a degree of optimization in order to limit the
number of timers needed. The MRAI does not apply to routes
received from BGP speakers in the same AS or to explicit
Berkowitz, et al. Expires September 1, 2003 [Page 14]
Internet-Draft Terminology for Benchmarking BGP March 2003
withdrawals.
RFC 1771 also recommends that random jitter is applied to MRAI in
an attempt to avoid synchronization effects between the BGP
instances in a network.
In this document we define routing plane convergence by measuring
the time an NLRI is advertised to the DUT to the time it is
advertised from the DUT. Clearly any delay inserted by the MRAI
will have a significant effect on this measurement.
Measurement Units: seconds.
Issues:
See Also: NLRI, BGP route
3.12 MinASOriginationInterval (MAOI)
Definition:
The MAOI specifies the minimum interval between advertisements of
locally originated routes from this BGP instance.
Discussion:
Random jitter is applied to MAOI in an attempt to avoid
synchronization effects between BGP instances in a network.
Measurement Units: seconds
Issues:
It is not known what, if any relationship exists between the
settings of MRAI and MAOI.
See Also: MRAI, BGP route
3.13 Active Route
Definition:
Route for which there is a FIB entry corresponding to a RIB entry.
Discussion:
Measurement Units: Number of routes.
Berkowitz, et al. Expires September 1, 2003 [Page 15]
Internet-Draft Terminology for Benchmarking BGP March 2003
Issues:
See also: RIB.
3.14 Unique Route
Definition:
A unique route is a prefix for which there is just one route
instance across all Adj-Ribs-In.
Discussion:
Measurement Units: N.A.
Issues:
See Also: route, route instance
3.15 Non-Unique Route
Definition:
A Non-unique route is a prefix for which there is at least one
other route in a set including more than one Adj-RIB-in.
Discussion:
Measurement Units: N.A.
Issues:
See Also:
route, route instance, unique active route.
3.16 Route Instance
Definition:
A route instance is one of several possible occurrences of a route
for a particular prefix.
Discussion:
When a router has multiple peers from which it accepts routes,
routes to the same prefix may be received from several peers. This
is then an example of multiple route instances.
Berkowitz, et al. Expires September 1, 2003 [Page 16]
Internet-Draft Terminology for Benchmarking BGP March 2003
Each route instance is associated with a specific peer. The BGP
selection algorithm may reject a specific route instance due to
local policy.
Measurement Units: Number of route instances
Issues:
The number of route instances in the Adj-RIB-in bases will vary
based on the function to be performed by a router. An
inter-provider border router, located in the default free zone
(not defined) will likely receive more route instances than a
provider edge router, located closer to the end-users of the
network.
See Also:
Berkowitz, et al. Expires September 1, 2003 [Page 17]
Internet-Draft Terminology for Benchmarking BGP March 2003
4. Constituent elements of a router or network of routers.
Many terms included in this list of definitions were originally
described in previous standards or papers. They are included here
because of their pertinence to this discussion. Where relevant,
reference is made to these sources. An effort has been made to keep
this list complete with regard to the necessary concepts without over
definition.
4.1 Default Route, Default Free Table, and Full Table
An individual router's routing table may not necessarily contain a
default route. Not having a default route, however, is not
synonymous with having a full default-free table(DFT).
It should be noted that the references to number of routes in this
section document are to routes installed in the loc-RIB and are
therefore unique routes, not route instances, and that the total
number of route instances may be 4 to 10 times the number of routes.
4.1.1 Default Route
Definition:
A Default Route can match any destination address. If a router
does not have a more specific route for a particular packet's
destination address, it forwards this packet to the next hop in
the default route entry, provided its Forwarding Table (Forwarding
Information Base (FIB) contains one. The notation for a default
route for IPv4 is 0.0.0.0/0 and for IPv6 it is 0:0:0:0:0:0:0:0 or
::/0.
Discussion:
Measurement units: N.A.
Issues:
See Also: default free routing table, route, route instance
4.1.2 Default Free Routing Table
Definition:
A default free routing table has no default routes and is
typically seen in routers in the core or top tier of routers in
the network.
Berkowitz, et al. Expires September 1, 2003 [Page 18]
Internet-Draft Terminology for Benchmarking BGP March 2003
Discussion:
The term originates from the concept that routers at the core or
top tier of the Internet will not be configured with a default
route (Notation in IPv4 0.0.0.0/0 and in IPv6 0:0:0:0:0:0:0:0 or
::/0). Thus they will forward every packet to a specific next hop
based on the longest match between the destination IP addresse
and the routes in the forwarding table.
Default free routing table size is commonly used as an indicator
of the magnitude of reachable Internet address space. However,
default free routing tables may also include routes internal to
the router's AS.
Measurement Units: The number of routes
See Also: Full Default Free, Default Route
4.1.3 Full Default Free Table
Definition:
A full default free table is the union of all sets of default free
BGP routes collectively announced by the complete set of
autonomous systems making up the public Internet. Due to the
dynamic nature of the Internet, the exact size and composition of
this table may vary slightly depending where and when it is
observed.
Discussion:
It is generally accepted that a full table, in this usage, does
not contain the infrastructure routes or individual sub-aggregates
of routes that are otherwise aggregated by the provider before
announcement to other autonomous systems.
Measurement Units: number of routes
Issues:
See Also: Routes, Route Instances, Default Route
4.1.4 Default-Free Zone
Definition:
The default-free zone is that part of the Internet backbone that
does not have a default route.
Berkowitz, et al. Expires September 1, 2003 [Page 19]
Internet-Draft Terminology for Benchmarking BGP March 2003
Discussion:
Measurement Units:
Issues:
See Also: Default Route
4.1.5 Full Provider-Internal Table
Definition:
A full provider-internal table is a superset of the full routing
table that contains infrastructure and non- aggregated routes.
Discussion:
Experience has shown that this table can contain 1.3 to 1.5 times
the number of routes in the externally visible full table. Tables
of this size, therefore, are a real-world requirement for key
internal provider routers.
Measurement Units: number of routes
Issues:
See Also: Routes, Route Instances, Default Route
4.2 Classes of BGP-Speaking Routers
A given router may perform more than one of the following functions,
based on its logical location in the network.
4.2.1 Provider Edge Router
Definition:
A provider edge router is a router at the edge of a provider's
network that speaks eBGP to a BGP speaker in another AS.
Discussion:
The traffic that transits this router may be destined to, or
originate from non-contiguous autonomous systems.
Such a router will always speak eBGP and may speak iBGP.
Measurement units:
Berkowitz, et al. Expires September 1, 2003 [Page 20]
Internet-Draft Terminology for Benchmarking BGP March 2003
Issues:
See Also:
4.2.2 Subscriber Edge Router
Definition:
A subscriber edge router is router at the edge of the subscriber's
network that speaks eBGP to its provider's AS(s).
Discussion:
The router belongs to an end user organization that may be multi-
homed, and which carries traffic only to and from that end user
AS.
Such a router will always speak eBGP and may speak iBGP.
Measurement units:
Issues:
See Also:
4.2.3 Inter-provider Border Router
Definition:
An inter-provider border router is a BGP speaking router which
maintains BGP sessions with otherBGP speaking routers in other
providers' ASs.
Discussion:
Traffic transiting this router may be originated in or destined
for another AS that has no direct connectivity with this
provider's AS.
Such a router will always speak eBGP and may speak iBGP.
Measurement units:
Issues:
See Also:
Berkowitz, et al. Expires September 1, 2003 [Page 21]
Internet-Draft Terminology for Benchmarking BGP March 2003
4.2.4 Core Router
Definition:
An core router is a provider router Internal to the provider's
net, speaking iBGP to that provider's edge routers, other intra-
provider core routers, or the provider's inter-provider border
routers.
Discussion:
Such a router will always speak iBGP and may speak eBGP.
Measurement units:
Issues:
Then by this definition they aren't core routers.
See Also:
Berkowitz, et al. Expires September 1, 2003 [Page 22]
Internet-Draft Terminology for Benchmarking BGP March 2003
5. Characterization of sets of update messages
This section contains a sequence of definitions that build up to the
definition of an Update Train. The Packet train concept was
originally introduced by Jain and Routhier [11]. It is here adapted
to refer to a train of packets of interest in BGP performance
testing.
This is a formalization of the sort of test stimulus that is expected
as input to a DUT running BGP. This data could be a
well-characterized, ordered and timed set of hand-crafted BGP UPDATE
packets. It could just as well be a set of BGP UPDATE packets that
have been captured from a live router.
Characterization of route mixtures and Update Trains is an open area
of research. The particular question of interest for this work is
the identification of suitable Update Trains, modeled or taken from
live traces that reflect realistic sequences of UPDATEs and their
contents.
5.1 Route Packing
Definition:
Route packing is the number of route prefixes accommodated in a
single Routing Protocol UPDATE Message either as updates
(additions or modifications) or withdrawals.
Discussion:
In general, a routing protocol update may contain more than one
prefix. In BGP, a single UPDATE may contain two sets of multiple
network prefixes: one set of additions and updates with identical
attributes (the NLRI) and one set of unfeasible routes to be
withdrawn.
Measurement Units:
Number of prefixes.
Issues:
See Also:
route, BGP route, route instance, update train, NLRI.
5.2 Route Mixture
Berkowitz, et al. Expires September 1, 2003 [Page 23]
Internet-Draft Terminology for Benchmarking BGP March 2003
Definition:
A route mixture is the demographics of a set of routes.
Discussion:
A route mixture is the input data for the benchmark. The
particular route mixture used as input must be selected to suit
the question being asked of the benchmark. Data containing simple
route mixtures might be suitable to test the performance limits of
the BGP device.
Using live data, or input that simulates live data, should improve
understanding of how the BGP device will operate in a live
network. The data for this kind of test must be route mixtures
that model the patterns of arriving control traffic in the live
Internet.
To accomplish that kind of modeling it is necessary to identify
the key parameters that characterize a live Internet route
mixture. The parameters and how they interact is an open research
problem. However, we identify the following as affecting the
route mixture:
* Path length distribution
* Attribute distribution
* Prefix length distribution
* Packet packing
* Probability density function of inter-arrival times of
UPDATES
Each of the items above is more complex than a single number. For
example, one could consider the distribution of prefixes by AS or
distribution of prefixes by length.
Measurement Units: Probability density functions
Issues:
See Also: NLRI, RIB.
5.3 Update Train
Berkowitz, et al. Expires September 1, 2003 [Page 24]
Internet-Draft Terminology for Benchmarking BGP March 2003
Definition:
An update train is a set of Routing Protocol UPDATE messages sent
by a router to a BGP peer.
Discussion:
The arrival pattern of UPDATEs can be influenced by many things,
including TCP parameters, hold-down timers, upsteam processing, a
peer coming up or multiple peers sending at the same time.
Network conditions such as a local or remote peer flapping a link
can also affect the arrival pattern.
Measurement units:
Probability density function for the inter-arrival times of UPDATE
packets in the train.
Issues:
Characterizing the profiles of real world UPDATE trains is a
matter for future research. In order to generate realistic UPDATE
trains as test stimuli a formal mathematical scheme or a proven
heuristic is needed to drive the selection of prefixes. Whatever
mechanism is selected it must generate Update trains that have
similar characteristics to those measured in live networks.
See Also: Route Mixture, MRAI, MAOI
5.4 Randomness in Update Trains
As we have seen from the previous sections, an update train used as a
test stimulus has a considerable number of parameters that can be
varied, to a greater or lesser extent, randomly and independently.
A random Update Train will contain:
o A route mixture randomized across
* NLRIs
* updates and withdrawals
* prefixes
* inter-arrival times of the UPDATEs
and possibly across other variables.
This is intended to simulate the unpredictable asynchronous nature of
the network, whereby UPDATE packets may have arbitrary contents and
Berkowitz, et al. Expires September 1, 2003 [Page 25]
Internet-Draft Terminology for Benchmarking BGP March 2003
be delivered at random times.
It is important that the data set be randomized sufficiently to avoid
favoring one vendor's implementation over another's. Specifically,
the distribution of prefixes could be structured to favor the
internal organization of the routes in a particular vendor's
databases. This is to be avoided.
5.5 Route Flap
Definition:
A route flap ia a change of state (withdrawal, announcement,
attribute change) for a route.
Discussion:
Route flapping can be considered a special and pathological case
of update trains. A practical interpretation of what may be
considered excessively rapid is the RIPE 229 [7], which contains
current guidelines on flap damping parameters.
Measurement units: Flapping events per unit time.
Issues:
Specific Flap events can be found in Section 6.1. A bench-marker
should use a mixture of different route change events in testing.
See Also: Route change events, flap damping, packet train
Berkowitz, et al. Expires September 1, 2003 [Page 26]
Internet-Draft Terminology for Benchmarking BGP March 2003
6. Route Changes and Convergence
The following two definitions are central to the benchmarking of
external routing convergence, and so are singled out for more
extensive discussion.
6.1 Route Change Events
A taxonomy characterizing routing information changes seen in
operational networks is proposed in [4] as well as Labovitz et al[5].
These papers describe BGP protocol-centric events, and event
sequences in the course of an analysis of network behavior. The
terminology in the two papers categorizes similar but slightly
different behaviors with some overlap. We would like to apply these
taxonomies to categorize the tests under definition where possible,
because these tests must tie in to phenomena that arise in actual
networks. We avail ourselves of, or may extend, this terminology as
necessary for this purpose.
A route can be changed implicitly by replacing it with another route
or explicitly by withdrawal followed by the introduction of a new
route. In either case the change may be an actual change, no change,
or a duplicate. The notation and definition of individual
categorizable route change events is adopted from [5] and given
below.
1. AADiff: Implicit withdrawal of a route and replacement by a route
different in some path attribute.
2. AADup: Implicit withdrawal of a route and replacement by route
that is identical in all path attributes.
3. WADiff: Explicit withdrawal of a route and replacement by a
different route.
4. WADup: Explicit withdrawal of a route and replacement by a route
that is identical in all path attributes.
To apply this taxonomy in the benchmarking context, we need both
terms to describe the sequence of events from the update train
perspective, as listed above, and event indications in the time
domain so as to be able to measure activity from the perspective of
the DUT. With this in mind, we incorporate and extend the definitions
of [5] to the following:
1. Tup (TDx): Route advertised to the DUT by Test Device x
2. Tdown(TDx): Route being withdrawn by Device x
Berkowitz, et al. Expires September 1, 2003 [Page 27]
Internet-Draft Terminology for Benchmarking BGP March 2003
3. Tupinit(TDx): The initial announcement of a route to a unique
prefix
4. TWF(TDx): Route fail over after an explicit withdrawal.
But we need to take this a step further. Each of these events can
involve a single route, a "short" packet train, or a "full" routing
table. We further extend the notation to indicate how many routes are
conveyed by the events above:
1. Tup(1,TDx) means Device x sends 1 route
2. Tup(S,TDx) means Device x sends a train, S, of routes
3. Tup(DFT,TDx) means Device x sends an approximation of a full
default-free table.
The basic criterion for selecting a "better" route is the final
tiebreaker defined in RFC1771, the router ID. As a consequence, this
memorandum uses the following descriptor events, which are routes
selected by the BGP selection process rather than simple updates:
1. Tbest -- The current best path.
2. Tbetter -- Advertise a path that is better than Tbest.
3. Tworse -- Advertise a path that is worse than Tbest.
6.2 Device Convergence in the Control Plane
Definition:
A routing device is said to have converged at the point in time
when the DUT has performed all actions in the control plane needed
to react to changes in topology in the context of the test
condition.
Discussion:
For example, when considering BGP convergence, the convergence
resulting from a change that alters the best route instance for a
single prefix at a router would be deemed to have occurred when
this route is advertised to its downstream peers. By way of
contrast, OSPF convergence concludes when SPF calculations have
been performed and the required link states advertised onwards.
The convergence process, in general, can be subdivided into three
distinct phases:
Berkowitz, et al. Expires September 1, 2003 [Page 28]
Internet-Draft Terminology for Benchmarking BGP March 2003
* convergence across the entire Internet,
* convergence within an Autonomous System,
* convergence with respect to a single device.
Convergence with respect to a single device can be
* convergence with regard to data forwarding process(es)
* convergence with regard to the routing process(es), the focus
of this document.
It is the latter, convergence with regard to the routing process,
that we describe in this and the methodology documents.
Because we are trying to benchmark the routing protocol
performance which is only a part of the device overall, this
definition is intended (so far as is possible) to exclude any
additional time such as is needed to download and install the
forwarding information base in the data plane. This definition
should be usable for different families of protocols.
It is of key importance to benchmark the performance of each phase
of convergence separately before proceeding to a composite
characterization of routing convergence, where
implementation-specific dependencies are allowed to interact.
The time resolution needed to measure the device convergence
depends to some extent on the types of the interfaces on the
router. For modern routers with gigabit or faster interfaces, an
individual UPDATE may be processed and re-advertised in very much
less than a millisecond so that time measurements must be made to
a resolution of hundreds to tens of microseconds or better.
Measurement Units:
Time period.
Issues:
See Also:
Berkowitz, et al. Expires September 1, 2003 [Page 29]
Internet-Draft Terminology for Benchmarking BGP March 2003
7. BGP Operation Events
The BGP process(es) in a device might restart because operator
intervention or a power failure caused a complete shut-down. In this
case a hard reset is needed. A peering session could be lost, for
example, because of action on the part of the peer or a dropped tcp
session. A device can reestablish its peers and re-advertise all
relevant routes in a hard reset. However, if a peer is lost, but
the BGP process has not failed, BGP has mechanisms for a "soft
reset."
7.1 Hard reset
Definition:
An event which triggers a complete re-initialization of the
routing tables on one or more BGP sessions, resulting in exchange
of a full routing table on one or more links to the router.
Discussion:
Measurement Units: N/A
Issues:
See Also:
7.2 Soft reset
Definition:
A soft reset is performed on a per-neighbor basis; it does not
clear the BGP session while re-establishing the peering relation
and does not stop the flow of traffic.
Discussion:
There are two methods of performing a soft reset: Graceful restart
[13] where the BGP device that has lost a peer but continues to
forward traffic for a period of time before tearing down the
peer's routes. The alternative method is soft refresh [12], where
a BGP device can request a peer's Adj-RIB-Out.
Measurement Units: N/A
Issues:
See Also:
Berkowitz, et al. Expires September 1, 2003 [Page 30]
Internet-Draft Terminology for Benchmarking BGP March 2003
Berkowitz, et al. Expires September 1, 2003 [Page 31]
Internet-Draft Terminology for Benchmarking BGP March 2003
8. Factors that impact the performance of the convergence process
While this is not a complete list, all of the items discussed below
have a significant affect on BGP convergence. Not all of them can be
addressed in the baseline measurements described in this document.
8.1 General factors affecting device convergence
These factors are conditions of testing external to the router Device
Under Test (DUT).
8.1.1 Number of peers
As the number of peers increases, the BGP route selection algorithm
is increasingly exercised. In addition, the phasing and frequency of
updates from the various peers will have an increasingly marked
effect on the convergence process on a router as the number of peers
grows. Increasing the number of peers also increases the processing
workload for TCP and BGP keepalives.
8.1.2 Number of routes per peer
The number of routes per BGP peer is an obvious stressor to the
convergence process. The number, and relative proportion, of multiple
route instances and distinct routes being added or withdrawn by each
peer will affect the convergence process, as will the mix of
overlapping route instances, and IGP routes.
8.1.3 Policy processing/reconfiguration
The number of routes and attributes being filtered, and set, as a
fraction of the target route table size is another parameter that
will affect BGP convergence.
Extreme examples are
o Minimal Policy: receive all, send all,
o Extensive policy: up to 100% of the total routes have applicable
policy.
8.1.4 Interactions with other protocols
There are interactions in the form of precedence, synchronization,
duplication and the addition of timers, and route selection criteria.
Ultimately, understanding BGP4 convergence must include understanding
of the interactions with both the IGPs and the protocols associated
Berkowitz, et al. Expires September 1, 2003 [Page 32]
Internet-Draft Terminology for Benchmarking BGP March 2003
with the physical media, such as Ethernet, SONET, DWDM.
8.1.5 Flap Damping
A router can use flap damping to respond to route flapping. Use of
flap damping is not mandatory, so the decision to enable the feature,
and to change parameters associated with it, can be considered a
matter of routing policy.
The timers are defined by RFC 2439 [2] and discussed in RIPE-229 [7].
If this feature is in effect, it requires that the device keep
additional state to carry out the damping, which can have a direct
impact on the control plane due to increased processing. In
addition, flap damping may delay the arrival of real changes in a
route, and affect convergence times
8.1.6 Churn
In theory, a BGP device could receive a set of updates that
completely defined the Internet, and could remain in a steady state,
only sending appropriate keepalives. In practice, the Internet will
always be changing.
Churn refers to control plane processor activity caused by
announcements received and sent by the router. It does not include
keepalives and TCP processing.
Churn is caused by both normal and pathological events. For example,
if an interface of the local router goes down and the associated
prefix is withdrawn, that withdrawal is a normal activity, although
it contributes to churn. If the local device receives a withdrawal
of a route it already advertises, or an announcement of a route it
did not previously know, and re-advertises this information, again
these are normal constituents of churn. Routine updates can range
from single announcement or withdrawals, to announcements of an
entire default-free table. The latter is completely reasonable as an
initialization condition.
Flapping routes are a pathological contributor to churn, as is MED
oscillation [16]. The goal of flap damping is to reduce the
contribution of flapping to churn.
The effect of churn on overall convergence depends on the processing
power available to the control plane, and whether the same
processor(s) are used for forwarding and for control.
8.2 Implementation-specific and other factors affecting BGP convergence
Berkowitz, et al. Expires September 1, 2003 [Page 33]
Internet-Draft Terminology for Benchmarking BGP March 2003
These factors are conditions of testing internal to the Device Under
Test (DUT), although they may affect its interactions with test
devices.
8.2.1 Forwarded traffic
The presence of actual traffic in the device may stress the control
path in some fashion if both the offered load due to data and the
control traffic (FIB updates and downloads as a consequence of
flaps)are excessive. The addition of data traffic presents a more
accurate reflection of realistic operating scenarios than if only
control traffic is present.
8.2.2 Timers
Settings of delay and hold-down timers at the link level as well as
for BGP4, can introduce or ameliorate delays. As part of a test
report, all relevant timers should be reported if they use non-
default value.
8.2.3 TCP parameters underlying BGP transport
Since all BGP traffic and interactions occur over TCP, all relevant
parameters characterizing the TCP sessions should be provided: e.g.
Slow start, max window size, maximum segment size, or timers.
8.2.4 Authentication
Authentication in BGP is currently done using the TCP MD5 Signature
Option [8]. The processing of the MD5 hash, particularly in devices
with a large number of BGP peers and a large amount of update traffic
can have an impact on the control plane of the device.
Berkowitz, et al. Expires September 1, 2003 [Page 34]
Internet-Draft Terminology for Benchmarking BGP March 2003
9. Security Considerations
The document explicitly considers authentication as a performance-
affecting feature, but does not consider the overall security of the
routing system.
Berkowitz, et al. Expires September 1, 2003 [Page 35]
Internet-Draft Terminology for Benchmarking BGP March 2003
10. Acknowledgments
Thanks to Francis Ovenden for review and Abha Ahuja for
encouragement. Much appreciation to Jeff Haas, Matt Richardson, and
Shane Wright at Nexthop for comments and input. Debby Stopp and Nick
Ambrose contributed the concept of route packing.
Berkowitz, et al. Expires September 1, 2003 [Page 36]
Internet-Draft Terminology for Benchmarking BGP March 2003
Normative References
[1] Rekhter, Y. and T. Li, "A Border Gateway Protocol 4 (BGP-4)",
RFC 1771, March 1995.
[2] Villamizar, C., Chandra, R. and R. Govindan , "BGP Route Flap
Damping", RFC 2439, November 1998.
[3] Baker, F., "Requirements for IP Version 4 Routers", RFC 1812,
June 1995.
[4] Ahuja, A., Jahanian, F., Bose, A. and C. Labovitz, "An
Experimental Study of Delayed Internet Routing Convergence",
RIPE-37 Presentation to Routing WG, June 2000, <http://
www.ripe.net/ripe/meetings/archive/ripe-37/presentations/
RIPE-37-convergence/>.
[5] Labovitz, C., Malan, G. and F. Jahanian, "Origins of Internet
Routing Instability", Infocom 99, August 1999.
[6] Alaettinoglu, C., Villamizar, C., Gerich, E., Kessens, D.,
Meyer, D., Bates, T., Karrenberg, D. and M. Terpstra, "Routing
Policy Specification Language (RPSL)", RFC 2622, June 1999.
[7] Panigl , C., Schmitz , J., Smith , P. and C. Vistoli, "RIPE
Routing-WG Recommendation for coordinated route-flap damping
parameters, version 2", RIPE 229, October 2001.
[8] Heffernan, A., "Protection of BGP Sessions via the TCP MD5
Signature Option", RFC 2385, August 1998.
[9] Juniper Networks, "Junos(tm) Internet Software Configuration
Guide Routing and Routing Protocols, Release 4.2", Junos 4.2
and other releases, September 2000, <http://www.juniper.net/
techpubs/software/junos42/swconfig-routing42/html/
glossary.html#1013039>.
[10] Rosen, E. and Y. Rekhter, "BGP/MPLS VPNs", RFC 2547, March
1999.
[11] Jain, R. and S. Routhier, "Packet trains -- measurement and a
new model for computer network traffic", IEEE Journal on
Selected Areas in Communication 4(6), September 1986.
Berkowitz, et al. Expires September 1, 2003 [Page 37]
Internet-Draft Terminology for Benchmarking BGP March 2003
Informative References
[12] Chen, E., "Route Refresh for BGP-4", RFC 2918, September 2000.
[13] Sangli, S., Rekhter, Y., Fernando, R., Scudder, J. and E. Chen,
"Graceful Restart Mechanism for BGP", draft-ietf-idr-restart-06
(work in progress), January 2003.
[14] Chen, E. and Y. Rekhter, "Cooperative Route Filtering
Capability for BGP-4", draft-ietf-idr-route-filter-08 (work in
progress), January 2003.
[15] Anderson, T. and H. Khosravi, "Requirements for Separation of
IP Control and Forwarding", draft-ietf-forces-requirements-08
(work in progress), January 2003.
[16] McPherson, D., Gill, V., Walton, D. and A. Retana, "Border
Gateway Protocol (BGP) Persistent Route Oscillation Condition",
RFC 3345, August 2002.
[17] Bates, T., Rekhter, Y., Chandra, R. and D. Katz,
"Multiprotocol Extensions for BGP-4", RFC 2283.
Berkowitz, et al. Expires September 1, 2003 [Page 38]
Internet-Draft Terminology for Benchmarking BGP March 2003
For Internet Draft consistency purposes only
[18] Bradner, S., "The Internet Standards Process -- Revision 3",
RFC 2026, BCP 9, October 1996.
Authors' Addresses
Howard Berkowitz
Gett Communications
5012 S. 25th St
Arlington, VA 22206
USA
Phone: +1 703 998-5819
Fax: +1 703 998-5058
EMail: hcb@gettcomm.com
Elwyn B. Davies
Nortel Networks
Harlow Laboratories
London Road
Harlow, Essex CM17 9NA
UK
Phone: +44 1279 405 498
EMail: elwynd@nortelnetworks.com
Susan Hares
Nexthop Technologies
517 W. William
Ann Arbor, MI 48103
USA
EMail: skh@nexthop.com
Padma Krishnaswamy
SAIC
331 Newman Springs Road
Red Bank, New Jersey 07701
USA
EMail: kri1@earthlink.net
Berkowitz, et al. Expires September 1, 2003 [Page 39]
Internet-Draft Terminology for Benchmarking BGP March 2003
Marianne Lepp
Consultant
EMail: mlepp@lepp.com
Alvaro Retana
Cisco Systems, Inc.
7025 Kit Creek Rd.
Research Triangle Park, NC 27709
USA
EMail: aretana@cisco.com
Berkowitz, et al. Expires September 1, 2003 [Page 40]
Internet-Draft Terminology for Benchmarking BGP March 2003
Intellectual Property Statement
The IETF takes no position regarding the validity or scope of any
intellectual property or other rights that might be claimed to
pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights
might or might not be available; neither does it represent that it
has made any effort to identify any such rights. Information on the
IETF's procedures with respect to rights in standards-track and
standards-related documentation can be found in BCP-11. Copies of
claims of rights made available for publication and any assurances of
licenses to be made available, or the result of an attempt made to
obtain a general license or permission for the use of such
proprietary rights by implementors or users of this specification can
be obtained from the IETF Secretariat.
The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights which may cover technology that may be required to practice
this standard. Please address the information to the IETF Executive
Director.
Full Copyright Statement
Copyright (C) The Internet Society (2003). 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 implementation 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 assignees.
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
Berkowitz, et al. Expires September 1, 2003 [Page 41]
Internet-Draft Terminology for Benchmarking BGP March 2003
HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Acknowledgement
Funding for the RFC Editor function is currently provided by the
Internet Society.
Berkowitz, et al. Expires September 1, 2003 [Page 42]