< draft-enghardt-panrg-path-properties-01.txt   draft-enghardt-panrg-path-properties-02.txt >
PANRG T. Enghardt PANRG T. Enghardt
Internet-Draft TU Berlin Internet-Draft TU Berlin
Intended status: Informational C. Kraehenbuehl Intended status: Informational C. Kraehenbuehl
Expires: September 12, 2019 ETH Zuerich Expires: January 9, 2020 ETH Zuerich
March 11, 2019 July 08, 2019
A Vocabulary of Path Properties A Vocabulary of Path Properties
draft-enghardt-panrg-path-properties-01 draft-enghardt-panrg-path-properties-02
Abstract Abstract
This document defines and categorizes information about Internet This document defines and categorizes information about Internet
paths that an entity, such as an endpoint, might have or want to paths that an entity, such as a host, might have or want to have.
have. This information is expressed as properties of paths between This information is expressed as properties of paths between two
two endpoints. hosts.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/. Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on September 12, 2019. This Internet-Draft will expire on January 9, 2020.
Copyright Notice Copyright Notice
Copyright (c) 2019 IETF Trust and the persons identified as the Copyright (c) 2019 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of (https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
skipping to change at page 2, line 15 skipping to change at page 2, line 15
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Domain Properties . . . . . . . . . . . . . . . . . . . . . . 5 3. Domain Properties . . . . . . . . . . . . . . . . . . . . . . 5
4. Backbone Properties . . . . . . . . . . . . . . . . . . . . . 6 4. Backbone Properties . . . . . . . . . . . . . . . . . . . . . 6
5. Dynamic Properties . . . . . . . . . . . . . . . . . . . . . 7 5. Dynamic Properties . . . . . . . . . . . . . . . . . . . . . 7
6. Security Considerations . . . . . . . . . . . . . . . . . . . 8 6. Security Considerations . . . . . . . . . . . . . . . . . . . 8
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
8. Informative References . . . . . . . . . . . . . . . . . . . 8 8. Informative References . . . . . . . . . . . . . . . . . . . 8
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 8 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 9
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9
1. Introduction 1. Introduction
Because the current Internet provides an IP-based best-effort bit Because the current Internet provides an IP-based best-effort bit
pipe, endpoints have little information about paths to other pipe, hosts have little information about paths to other hosts. A
endpoints. A Path Aware Network exposes information about one or Path Aware Network exposes information about one or multiple paths
multiple paths through the network to endpoints or the network through the network to hosts or the network infrastructure.
infrastructure.
It is impossible to provide an exhaustive list of path properties, as It is impossible to provide an exhaustive list of path properties, as
with every new technology and protocol, novel properties might become with every new technology and protocol, novel properties might become
relevant. In this document, we specify a set of path properties relevant. In this document, we specify a set of path properties
which might be useful in the following use cases: Traffic policies, which might be useful in the following use cases: Traffic policies,
network monitoring, and path selection. network monitoring, and path selection.
o Traffic policies: Entities such as network operators or end users o Traffic policies: Entities such as network operators or end users
may want to define traffic policies leveraging path awareness. may want to define traffic policies leveraging path awareness.
Such policies can allow or disallow sending traffic over specific Such policies can allow or disallow sending traffic over specific
networks or nodes, select an appropriate protocol depending on the networks or nodes, select an appropriate protocol depending on the
capabilities of the on-path devices, or adjust protocol parameters capabilities of the on-path devices, or adjust protocol parameters
to an existing path. An example of a traffic policy is a video to an existing path. An example of a traffic policy is a video
streaming application choosing an (initial) video quality based on streaming application choosing an (initial) video quality based on
the achievable data rate, or the monetary cost of the link using a the achievable data rate, or the monetary cost of the link using a
volume-based or flat-rate cost model. Another example is an volume-based or flat-rate cost model. Another example is an
enterprise network where all traffic has to go through a firewall, enterprise network where all traffic has to go through a firewall,
in which case the endpoint needs to be aware of on-path firewalls. in which case the host needs to be aware of on-path firewalls.
o Network monitoring: Network operators can use path properties o Network monitoring: Network operators can use path properties
(e.g., measured by on-path devices), to observe Quality of Service (e.g., measured by on-path devices), to observe Quality of Service
(QoS) characteristics of recent end-user traffic, and identify (QoS) characteristics of recent end-user traffic, and identify
potential problems with their network early on, before the end- potential problems with their network early on, before the end-
user complains. user complains.
o Path selection: In some cases, entities can choose to use a o Path selection: In some cases, entities can choose to use a
certain path (or subset of paths) from a set of paths to achieve a certain path (or subset of paths) from a set of paths to achieve a
specific goal. As the possible benefits of a well chosen path specific goal. As the possible benefits of a well chosen path
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large file in a peer-to-peer network requires paths with high large file in a peer-to-peer network requires paths with high
achievable data rate. Additionally, there may be trade-offs achievable data rate. Additionally, there may be trade-offs
between path properties (e.g., latency and data rate), and between path properties (e.g., latency and data rate), and
entities may influence these trade-offs with their choices. A entities may influence these trade-offs with their choices. A
network (e.g., an AS) can adjust its path selection for internal network (e.g., an AS) can adjust its path selection for internal
or external routing based on the path properties. In BGP, the or external routing based on the path properties. In BGP, the
Multi Exit Discriminator (MED) attribute decides which path to Multi Exit Discriminator (MED) attribute decides which path to
choose if other attributes are equal; in a path aware network, choose if other attributes are equal; in a path aware network,
instead of using this single MED value, other properties such as instead of using this single MED value, other properties such as
maximum or available/expected data rate could additionally be used maximum or available/expected data rate could additionally be used
to improve load balancing. An endpoint might be able to select to improve load balancing. A host might be able to select between
between a set of paths, either if there are several paths to the a set of paths, either if there are several paths to the same
same destination (e.g., if the endpoint is a mobile device with destination (e.g., if the host is a mobile device with two
two wireless interfaces, both providing a path), or if there are wireless interfaces, both providing a path), or if there are
several destinations, and thus several paths, providing the same several destinations, and thus several paths, providing the same
service (e.g., Application-Layer Traffic Optimization (ALTO) service (e.g., Application-Layer Traffic Optimization (ALTO)
[RFC5693], an application layer peer-to-peer protocol allowing [RFC5693], an application layer peer-to-peer protocol allowing
endpoints a better-than-random peer selection). Care needs to be hosts a better-than-random peer selection). Care needs to be
taken when selecting paths based on path properties, as path taken when selecting paths based on path properties, as path
properties that were previously measured may have become outdated properties that were previously measured may have become outdated
and, thus, useless to predict the path properties of packets sent and, thus, useless to predict the path properties of packets sent
now. now.
Such path properties may be relatively dynamic, e.g. current Round Such path properties may be relatively dynamic, e.g. current Round
Trip Time, close to the origin, e.g. nature of the access technology Trip Time, close to the origin, e.g. nature of the access technology
on the first hop, or far from the origin, e.g. list of ASes on the first hop, or far from the origin, e.g. list of ASes
traversed. traversed.
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dynamic properties. The merit of a momentary measurement of a dynamic properties. The merit of a momentary measurement of a
dynamic path property diminishes greatly as time goes on, e.g. the dynamic path property diminishes greatly as time goes on, e.g. the
merit of an RTT measurement from a few seconds ago is quite small, merit of an RTT measurement from a few seconds ago is quite small,
while a non-dynamic path property might stay relevant, e.g. a NAT can while a non-dynamic path property might stay relevant, e.g. a NAT can
be assumed to stay on a path during the lifetime of a connection, as be assumed to stay on a path during the lifetime of a connection, as
the removal of the NAT would break the connection. the removal of the NAT would break the connection.
Non-dynamic properties are further separated into (local) domain Non-dynamic properties are further separated into (local) domain
properties related to the first few hops of the connection, and properties related to the first few hops of the connection, and
backbone properties related to the remaining hops. Domain properties backbone properties related to the remaining hops. Domain properties
expose a high amount of information to endpoints and strongly expose a high amount of information to hosts and strongly influence
influence the connection behavior while there is little influence and the connection behavior while there is little influence and
information about backbone properties. information about backbone properties.
Dynamic properties are not separated into domain and backbone Dynamic properties are not separated into domain and backbone
properties, since most of these properties are defined for a complete properties, since most of these properties are defined for a complete
path and it is difficult and seldom useful to define them on part of path and it is difficult and seldom useful to define them on part of
the path. There are exceptions such as dynamic wireless access the path. There are exceptions such as dynamic wireless access
properties, but these do not justify separation into different properties, but these do not justify separation into different
categories. categories.
This document addresses the first of the questions in Path-Aware This document addresses the first of the questions in Path-Aware
Networking [I-D.irtf-panrg-questions], which is a product of the Networking [I-D.irtf-panrg-questions], which is a product of the
PANRG in the IRTF. PANRG in the IRTF.
2. Terminology 2. Terminology
Path element: A path element is a device (including the endpoints), Node: An entity which processes packets, e.g., sends, receives,
or link used to connect two devices and transmit information on a forwards, or modifies them.
specific layer. Path elements may exist on multiple layers (e.g.,
the endpoint corresponds to a path element on every layer), may be
hidden on higher layers (e.g., a layer 2 switch in the local
network), or a path element may be an aggregation of several path
elements on a lower layer (e.g., the link connecting the endpoints
on the transport layer being an aggregation of all network layer
path elements).
Path segment: A path segment is an ordered set of path elements at Host: A node that processes packets that are explicitly addressed to
the network layer that can be traversed by a packet. itself.
Path: A path is defined as an ordered set of path elements at the Router: A node that processes packets that are not explicitly
network layer between two endpoints. A path can be traversed by a addressed to itself.
packet.
Flow: Several packets traversing the same path elements can be Link: A medium or communication facility that connects two or more
combined into a flow (e.g., all packets sent within a UDP session nodes with each other and enables them to exchange packets. A
which traverse the same path elements). As a special case, a flow link can be physical, e.g., a WiFi network which connects an
can consist of just one packet. Access Point to stations, or virtual, e.g., a virtual switch which
connects two virtual machines hosted on the same physical machine.
Property: A property describes a trait of a set of path elements Path element: Either a node or a link.
(e.g., capacity of a link, is device X a firewall, one-way maximum
data rate which is the minimum of all links' maximum data rates),
or a trait of a flow being sent on a set of path elements (e.g.,
RTT, one-way delay). A property is thus described by a tuple
containing the ordered set of path elements, the set of packets
traversing the path (the flow) or an empty set if no packets are
relevant for the property, the name of the trait (e.g., maximum
data rate), and the value of the trait (e.g., 100mbps).
Aggregated Property: A property can be aggregated over a set of path Path: A sequence of adjacent path elements, alternating between
elements (e.g., MTU in the network backbone as the minimum MTU of nodes and links, starting and ending with a host. A path can be
the individual path elements), or over a set of packets (e.g., viewed as an abstraction on a specific layer, omitting lower layer
median one-way latency of all packets during the last second), or path elements. For example, a router implementing IPv6 may be a
over both (e.g., average time a packets spends in buffers outside path element on a path when considering the network layer. If
the local network). Aggregation can be numerical (average, sum, this router does not implement transport layer functionality, it
min, ...), logical (true if all are true, true if at least X are is hidden when a higher layer, such as the transport or
true, ...), or an arbitrary function which maps a set of input application layer, is considered. In the case of multicast or
properties to an output property. broadcast, a single packet may be sent over multiple paths at once
- one path for each combination of sending and receiving host.
Measured & Potential Property: A property can be classified by Subpath: Given a path, a subpath is a sequence of adjacent path
timescale into a measured property, based on concrete previous and elements of this path, starting and ending with a node.
current measurements, and a potential property, which is a
property with predicted characteristics, possibly including the Flow: One or multiple packets which are traversing the same subpath
reliability of such predictions. An example of a potential or path. For example, a flow can consist of all packets sent
property with a high reliability is the maximum data rate of an within a TCP session with the same five-tuple between two hosts,
ethernet link in the local network during the next day, while a or it can consist of all packets sent on the same physical link.
potential property with a lower reliability is the expected one-
way latency of packets sent to an endpoint on the other side of Property: A trait of one or a sequence of path elements, or a trait
the planet during the next second. The notion of reliability of a flow with respect to one or a sequence of path elements. An
depends on the property, it might be the confidence level and example of a link property is the maximum data rate that can be
sent over the link. An example of a node property is the
administrative domain that the node belongs to. An example of a
property of a flow with respect to a subpath is the aggregated
one-way delay of the flow being sent from one node to another node
over a subpath. A property is thus described by a tuple
containing the sequence of path elements, the flow or an empty set
if no packets are relevant for the property, the name of the
property (e.g., maximum data rate), and the value of the property
(e.g., 1Gbps).
Aggregated property: A collection of multiple values of a property
into a single value, according to a function. A property can be
aggregated over multiple path elements (i.e., a path), e.g., the
MTU of a path as the minimum MTU of all links on the path, over
multiple packets (i.e., a flow), e.g., the median one-way latency
of all packets between two nodes, or over both, e.g., the mean of
the queueing delays of a flow on all nodes along a path. The
aggregation function can be numerical, e.g., median, sum, minimum,
it can be logical, e.g., "true if all are true", "true if at least
50\% of values are true", or an arbitrary function which maps
multiple input values to an output value.
Measured property: A property that is observed for a specific path
element or path, e.g., using measurements. For example, the one-
way delay of a specific packet can be measured.
Estimated property: An approximate calculation or judgment of the
value of a property. For example, an estimated property may
describe the expected median one-way latency of packets sent on a
path within the next second. An estimated property includes the
reliability of the estimate. The notion of reliability depends on
the property. For example, it may be the confidence level and
interval for numerical properties or the likelihood that a interval for numerical properties or the likelihood that a
property holds for non-numerical properties. property holds for non-numerical properties.
3. Domain Properties 3. Domain Properties
Domain path properties relate to path elements within the first hop Domain path properties relate to path elements within the first hop
or the first few hops, which are usually in the same administrative or the first few hops, which are usually in the same administrative
domain as an endpoint considering them. domain as a host considering them.
Due to the potential physical proximity and pre-existing trust or Due to the potential physical proximity and pre-existing trust or
contractual relationships between endpoints and path elements within contractual relationships between hosts and path elements within the
the same domain, domain properties may be more accessible to the same domain, domain properties may be more accessible to the host
endpoint than other properties. than other properties.
Furthermore, endpoints may be able to influence both which domain Furthermore, hosts may be able to influence both which domain they
they are in and which path elements in this domain to connect to, and are in and which path elements in this domain to connect to, and they
they may be able to influence the properties of path elements within may be able to influence the properties of path elements within this
this domain. For example, a user might select between multiple domain. For example, a user might select between multiple potential
potential adjacent path elements by selecting between multiple adjacent links by selecting between multiple available WiFi Access
available WiFi Access Points. Or when connected to an Access Point, Points. Or when connected to an Access Point, the user may move
the user may move closer to enable their device to use a different closer to enable their device to use a different access technology,
access technology, potentially increasing the data rate available to potentially increasing the data rate available to the device.
the device. Another example is a user changing their data plan to Another example is a user changing their data plan to reduce the
reduce the Monetary Cost to transmit a given amount of data across a Monetary Cost to transmit a given amount of data across a network.
network.
Access Technology: The physical or link layer technology used for Access Technology: The physical or link layer technology used for
transmitting or receiving a flow on one or multiple path elements transmitting or receiving a flow on one or multiple path elements
in the same domain. The Access Technology may be given in an in the same domain. The Access Technology may be given in an
abstract way, e.g., as a WiFi, Wired Ethernet, or Cellular link. abstract way, e.g., as a WiFi, Wired Ethernet, or Cellular link.
It may also be given as a specific technology, e.g., as a 2G, 3G, It may also be given as a specific technology, e.g., as a 2G, 3G,
4G, or 5G cellular link, or an 802.11a, b, g, n, or ac WiFi link. 4G, or 5G cellular link, or an 802.11a, b, g, n, or ac WiFi link.
Other path elements relevant to the access technology may include Other path elements relevant to the access technology may include
on-path devices, such as elements of a cellular backbone network. on-path devices, such as elements of a cellular backbone network.
Note that there is no common registry of possible values for this Note that there is no common registry of possible values for this
property. property.
Monetary Cost: The price to be paid to transmit a specific flow Monetary Cost: The price to be paid to transmit a specific flow
across a path segment. across a subpath.
4. Backbone Properties 4. Backbone Properties
Backbone path properties relate to path elements not within the same Backbone path properties relate to path elements not within the same
domain as an endpoint considering them, thus, in the backbone from domain as a host considering them, thus, in the backbone from the
the endpoint's point of view. host's point of view.
Typically, backbone properties are less accessible to an endpoint Typically, backbone properties are less accessible to a host than
than domain properties, due to the potential increased distance and domain properties, due to the potential increased distance and the
the lack of pre-existing trust or contractual relationship. lack of pre-existing trust or contractual relationship.
Additionally, endpoints are less likely to be able to influence which Additionally, hosts are less likely to be able to influence which
path elements form their path in the backbone, as well as their path elements form their path in the backbone, as well as their
properties. properties.
Some path properties relate to the entire path, part of which often Some path properties relate to the entire path or to subpaths, part
lies outside of an endpoint's domain. Thus, such properties are of which often lies outside of a host's domain. Thus, such
listed as Backbone Properties. properties are listed as Backbone Properties.
Presence of a certain network function on the path: Indicates that a Presence of a certain network function on the path: Indicates that a
certain path element performs a certain network function on a node performs a certain network function on a flow, e.g., whether
flow, e.g., whether the path element acts as a proxy, as a the node acts as a proxy, as a firewall, or performs Network
firewall, or performs Network Address Translation (NAT). This Address Translation (NAT). This node may be either in the same
path element may be either in the same domain as the endpoint or domain as the host or in a different domain, i.e., the backbone.
in a different domain, i.e., the backbone.
Administrative Entity: The administrative entity, e.g., the AS, to Administrative Entity: The administrative entity, e.g., the AS, to
which a path element or path segment belongs. which a path element or subpath belongs.
Disjointness: For a set of two paths, the number of shared path Disjointness: For a set of two paths, the number of shared path
elements can be a measure of intersection (e.g., Jaccard elements can be a measure of intersection (e.g., Jaccard
coefficient, which is the number of shared elements divided by the coefficient, which is the number of shared elements divided by the
total number of elements). Conversely, the number of non-shared total number of elements). Conversely, the number of non-shared
path elements can be a measure of disjointness (e.g., 1 - Jaccard path elements can be a measure of disjointness (e.g., 1 - Jaccard
coefficient). A multipath protocol might use disjointness of coefficient). A multipath protocol might use disjointness of
paths as a metric to reduce the number of single points of paths as a metric to reduce the number of single points of
failure. failure.
Path MTU: The maximum size, in octets, of an IP packet that can be Path MTU: The maximum size, in octets, of an IP packet that can be
transmitted without fragmentation on a path segment. transmitted without fragmentation on a subpath.
Transport Protocols available: Whether a specific transport protocol Transport Protocols available: Whether a specific transport protocol
can be used to establish a connection over a path or path segment. can be used to establish a connection over a path or subpath. A
An endpoint may cache its knowledge about recent successfully host may cache its knowledge about recent successfully established
established connections using specific protocols, e.g., a QUIC connections using specific protocols, e.g., a QUIC connection, or
connection, or an MPTCP subflow, over a specific path. an MPTCP subflow.
Protocol Features available: Whether a specific protocol feature is Protocol Features available: Whether a specific protocol feature is
available over this path, e.g., Explicit Congestion Notification available over a path or subpath, e.g., Explicit Congestion
(ECN), or TCP Fast Open. Notification (ECN), or TCP Fast Open.
5. Dynamic Properties 5. Dynamic Properties
Dynamic path properties relate to a path segment with respect to the Dynamic path properties relate to the transmission of an individual
transmission of an individual packet or of a flow over this path packet or of a flow over a subpath. Properties related to a path
segment. Properties related to a path element which constitutes a element which constitutes a single layer 2 domain are abstracted from
single layer 2 domain are abstracted from the used physical and link the used physical and link layer technology, similar to [RFC8175].
layer technology, similar to [RFC8175].
Typically, Dynamic Properties can only be approximated and sampled, Typically, Dynamic Properties can be measured or approximated, and
and might be made available in an aggregated form, such as averages might be made available in an aggregated form, such as averages or
or minimums. Dynamic Path Properties can be measured by the endpoint minimums. Dynamic Path Properties can be measured by the host itself
itself or somethere in the network. See [ANRW18-Metrics] for a or by a different entity. See [ANRW18-Metrics] for a discussion of
discussion of how to measure some dynamic path properties at the how to measure some dynamic path properties at the host.
endpoint.
Some dynamic properties are defined in different directions for the Some dynamic properties are defined in different directions for the
same path element, e.g., for transmitting and receiving packets. same path element, e.g., for transmitting and receiving packets.
Maximum Data Rate (Transmit/Receive): The theoretical maximum data Maximum Data Rate (Transmit/Receive): The theoretical maximum data
rate, in bits per second, that can be achieved on a link, path rate, in bits per second, that can be achieved on a link, subpath,
segment, or path, for receiving or transmitting traffic. or path, for receiving or transmitting traffic.
Current Data Rate (Transmit/Receive): The data rate, in bits per Current Data Rate (Transmit/Receive): The data rate, in bits per
second, at which a link is currently receiving or transmitting second, at which a link is currently receiving or transmitting
traffic. traffic.
Latency: The time delay between sending a packet on a path element Latency: The time delay between a node sending a packet and a
and receiving the same packet on a different path element. different node on the same path receiving the same packet.
Latency variation: The variation of the Latency within a flow. Latency variation: The variation of the latency within a flow.
Packet Loss: The percentage of packets within a flow which are sent Packet Loss: The percentage of packets within a flow which are sent
by one path element, but not received by a different path element. by one node, but not received by a different node.
Congestion: Whether a protocol feature such as ECN has provided Congestion: Whether a protocol feature such as ECN has provided
information that there currently is congestion on a path. information that there currently is congestion on a path.
6. Security Considerations 6. Security Considerations
If devices are basing policy or path selection decisions on path If nodes are basing policy or path selection decisions on path
properties, they need to rely on the accuracy of path properties that properties, they need to rely on the accuracy of path properties that
other devices communicate to them. In order to be able to trust such other devices communicate to them. In order to be able to trust such
path properties, devices may need to establish a trust relationship path properties, nodes may need to establish a trust relationship or
or be able to verify the authenticity, integrity, and correctness of be able to verify the authenticity, integrity, and correctness of
path properties received from another device. path properties received from another node.
7. IANA Considerations 7. IANA Considerations
This document has no IANA actions. This document has no IANA actions.
8. Informative References 8. Informative References
[ANRW18-Metrics] [ANRW18-Metrics]
Enghardt, T., Tiesel, P., and A. Feldmann, "Metrics for Enghardt, T., Tiesel, P., and A. Feldmann, "Metrics for
access network selection", Proceedings of the Applied access network selection", Proceedings of the Applied
Networking Research Workshop on - ANRW '18, Networking Research Workshop on - ANRW '18,
DOI 10.1145/3232755.3232764, 2018. DOI 10.1145/3232755.3232764, 2018.
[I-D.irtf-panrg-questions] [I-D.irtf-panrg-questions]
Trammell, B., "Open Questions in Path Aware Networking", Trammell, B., "Open Questions in Path Aware Networking",
draft-irtf-panrg-questions-01 (work in progress), October draft-irtf-panrg-questions-02 (work in progress), May
2018. 2019.
[RFC5693] Seedorf, J. and E. Burger, "Application-Layer Traffic [RFC5693] Seedorf, J. and E. Burger, "Application-Layer Traffic
Optimization (ALTO) Problem Statement", RFC 5693, Optimization (ALTO) Problem Statement", RFC 5693,
DOI 10.17487/RFC5693, October 2009, DOI 10.17487/RFC5693, October 2009,
<https://www.rfc-editor.org/info/rfc5693>. <https://www.rfc-editor.org/info/rfc5693>.
[RFC8175] Ratliff, S., Jury, S., Satterwhite, D., Taylor, R., and B. [RFC8175] Ratliff, S., Jury, S., Satterwhite, D., Taylor, R., and B.
Berry, "Dynamic Link Exchange Protocol (DLEP)", RFC 8175, Berry, "Dynamic Link Exchange Protocol (DLEP)", RFC 8175,
DOI 10.17487/RFC8175, June 2017, DOI 10.17487/RFC8175, June 2017,
<https://www.rfc-editor.org/info/rfc8175>. <https://www.rfc-editor.org/info/rfc8175>.
Acknowledgments Acknowledgments
Thanks to the Path-Aware Networking Research Group for the discussion Thanks to the Path-Aware Networking Research Group for the discussion
and feedback. Thanks to Adrian Perrig for the feedback. Thanks to and feedback. Thanks to Adrian Perrig and Matthias Rost for the
Paul Hoffman for the editorial changes. feedback. Thanks to Paul Hoffman for the editorial changes.
Authors' Addresses Authors' Addresses
Theresa Enghardt Theresa Enghardt
TU Berlin TU Berlin
Email: theresa@inet.tu-berlin.de Email: theresa@inet.tu-berlin.de
Cyrill Kraehenbuehl Cyrill Kraehenbuehl
ETH Zuerich ETH Zuerich
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