rfc9508.original.xml   rfc9508.xml 
<?xml version='1.0' encoding='utf-8'?> <?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type='text/xsl' href='rfc2629.xslt' ?>
<!-- <xi:strict="yes" ?>
<xi:compact="yes" ?>
<xi:subcompact="no" ?> -->
<rfc <!DOCTYPE rfc [
xmlns:xi="http://www.w3.org/2001/XInclude" <!ENTITY nbsp "&#160;">
<!ENTITY zwsp "&#8203;">
<!ENTITY nbhy "&#8209;">
<!ENTITY wj "&#8288;">
]>
<rfc xmlns:xi="http://www.w3.org/2001/XInclude"
submissionType="IRTF"
category="exp" category="exp"
consensus="true"
docName="draft-irtf-icnrg-icnping-12" docName="draft-irtf-icnrg-icnping-12"
number="9508"
ipr="trust200902" ipr="trust200902"
obsoletes="" obsoletes=""
updates="" updates=""
submissionType="IRTF"
xml:lang="en" xml:lang="en"
tocInclude="true" tocInclude="true"
tocDepth="4" tocDepth="4"
symRefs="true" symRefs="true"
sortRefs="true" sortRefs="true"
version="3"> version="3">
<front> <front>
<title abbrev="ICN Ping">ICN Ping Protocol Specification</title> <title abbrev="ICN Ping">Information-Centric Networking (ICN) Ping Protocol
<seriesInfo name="Internet-Draft" value="draft-irtf-icnrg-icnping-12"/> Specification</title>
<seriesInfo name="RFC" value="9508"/>
<author fullname="Spyridon Mastorakis" initials="S" surname="Mastorakis"> <author fullname="Spyridon Mastorakis" initials="S" surname="Mastorakis">
<organization>University of Notre Dame</organization> <organization>University of Notre Dame</organization>
<address> <address>
<postal> <postal>
<street/> <street/>
<city>South Bend</city> <city>South Bend</city>
<region>IN</region> <region>IN</region>
<code/> <code/>
<country>US</country> <country>United States of America</country>
</postal> </postal>
<email>smastor2@nd.edu</email> <email>smastor2@nd.edu</email>
</address> </address>
</author> </author>
<author fullname="Dave Oran" initials="D" surname="Oran"> <author fullname="Dave Oran" initials="D" surname="Oran">
<organization>Network Systems Research and Design</organization> <organization>Network Systems Research and Design</organization>
<address> <address>
<postal> <postal>
<street/> <street/>
<city>Cambridge</city> <city>Cambridge</city>
<region>MA</region> <region>MA</region>
<code/> <code/>
<country>US</country> <country>United States of America</country>
</postal> </postal>
<email>daveoran@orandom.net</email> <email>daveoran@orandom.net</email>
</address> </address>
</author> </author>
<author fullname="Jim Gibson" initials="J" surname="Gibson"> <author fullname="Jim Gibson" initials="J" surname="Gibson">
<organization>Unaffiliated</organization> <organization>Unaffiliated</organization>
<address> <address>
<postal> <postal>
<street/> <street/>
<city>Belmont</city> <city>Belmont</city>
<region>MA</region> <region>MA</region>
<code/> <code/>
<country>US</country> <country>United States of America</country>
</postal> </postal>
<email>jcgibson61@gmail.com</email> <email>jcgibson61@gmail.com</email>
</address> </address>
</author> </author>
<author fullname="Ilya Moiseenko" initials="I" surname="Moiseenko"> <author fullname="Ilya Moiseenko" initials="I" surname="Moiseenko">
<organization>Apple Inc</organization> <organization>Apple Inc.</organization>
<address> <address>
<postal> <postal>
<street/> <street/>
<city>Cupertino</city> <city>Cupertino</city>
<region>CA</region> <region>CA</region>
<code/> <code/>
<country>US</country> <country>United States of America</country>
</postal> </postal>
<email>iliamo@mailbox.org</email> <email>iliamo@mailbox.org</email>
<!-- uri and facsimile elements may also be added -->
</address> </address>
</author> </author>
<author fullname="Ralph Droms" initials="R" surname="Droms"> <author fullname="Ralph Droms" initials="R" surname="Droms">
<organization>Unaffiliated</organization> <organization>Unaffiliated</organization>
<address> <address>
<postal> <postal>
<street/> <street/>
<city>Hopkinton</city> <city>Hopkinton</city>
<region>MA</region> <region>MA</region>
<code/> <code/>
<country>US</country> <country>United States of America</country>
</postal> </postal>
<email>rdroms.ietf@gmail.com</email> <email>rdroms.ietf@gmail.com</email>
</address> </address>
</author> </author>
<date year="2023"/> <date year="2024" month="March" />
<!-- Meta-data Declarations -->
<area>IRTF</area> <workgroup>Information-Centric Networking</workgroup>
<workgroup>ICNRG</workgroup>
<keyword>ICN</keyword> <keyword>ICN</keyword>
<keyword>Network Management</keyword> <keyword>Network Management</keyword>
<abstract> <abstract>
<t>This document presents the design of an ICN Ping protocol. It includes the operations of both the client and the forwarder.</t> <t>This document presents the design of an Information-Centric Networking (ICN) Ping protocol. It includes the operations of both the client and the forwa rder.</t>
<t>This document is a product of the Information-Centric Networking Resear ch Group (ICNRG) of the IRTF.</t> <t>This document is a product of the Information-Centric Networking Resear ch Group (ICNRG) of the IRTF.</t>
</abstract> </abstract>
</front> </front>
<middle> <middle>
<section numbered="true" toc="default"> <section numbered="true" toc="default">
<name>Introduction</name> <name>Introduction</name>
<t>Ascertaining data plane reachability to a destination and taking <t>Ascertaining data plane reachability to a destination and taking
coarse performance measurements of round trip time are fundamental coarse performance measurements of Round-Trip Time (RTT) are fundamental
facilities for network administration and troubleshooting. In IP, facilities for network administration and troubleshooting. In IP,
where routing and forwarding are based on IP addresses, ICMP echo where routing and forwarding are based on IP addresses, ICMP Echo
and ICMP echo response are the protocol mechanisms used for this Request and ICMP Echo Reply packets are the protocol mechanisms used for
purpose, generally exercised through the familiar ping utility. In this
ICN, where routing and forwarding are based on name prefixes, the purpose, generally exercised through the familiar ping utility. In
ability to ascertain reachability of names is required.</t> Information-Centric Networking (ICN), where routing and forwarding are b
ased on name prefixes, the
ability to ascertain the reachability of names is required.</t>
<t> This document proposes protocol mechanisms for a ping equivalent in <t> This document proposes protocol mechanisms for a ping equivalent in
ICN (<xref target="RFC8609">CCNx</xref> and <xref target="NDNTLV">NDN</xr ICN networks (<xref target="RFC8609">Content-Centric Networking (CCNx)</
ef>) networks. A non-normative appendix suggests useful properties for an ICN xref> and <xref target="NDNTLV">Named Data Networking (NDN)</xref>). A non-norma
ping client application, analogous to IP ping, that originates echo reque tive section (<xref target="app-additional"/>) suggests useful properties for an
sts ICN
and processes echo replies.</t> Ping client application, analogous to IP ping, that originates Echo Requ
ests
and processes Echo Replies.</t>
<t> In order to carry out meaningful experimentation and deployment of IC <t> In order to carry out meaningful experimentation and deployment of I
N CN
protocols, tools to manage and debug the operation of ICN archite protocols, new tools analogous to ping and traceroute used for
ctures and TCP/IP are needed to manage and debug the operation of ICN
protocols are needed analogous to ping and traceroute used for TC architectures and protocols.
P/IP. This document describes the design of a management and debugging
This document describes the design of a management and debugging protocol
protocol analogous to the ping protocol of TCP/IP; this new management an
analogous to the ping protocol of TCP/IP, which will aid d debugging protocol will aid
the experimental deployment of ICN protocols. As the community co the experimental deployment of ICN protocols. As the community c
ntinues its ontinues its
experimentation with ICN architectures and protocols, the design experimentation with ICN architectures and protocols, the design
of ICN Ping of ICN Ping
might change accordingly. ICN Ping is designed as a "first line o might change accordingly. ICN Ping is designed as a "first line
f defense" of defense"
tool to troubleshoot ICN architectures and protocols. As such, th tool to troubleshoot ICN architectures and protocols. As such, t
is document is his document is
classified as an experimental RFC. Note that a measurement applic classified as an Experimental RFC.
ation is Note that a measurement application is needed to make proper use of ICN Ping in
needed to make proper use of ICN Ping in order to compute various order to compute various statistics, such as average, maximum, and minimum Round
statistics, -Trip Time (RTT) values, variance in RTTs, and loss rates.</t>
such as the variance, average, maximum and minimum RTT values as
well as loss rates.</t>
<t>This document is not an Internet Standards Track specification; it is <t>This RFC represents the consensus of the Information-Centric Networki
published for examination, experimental implementation, a ng Research Group (ICNRG) of the Internet Research Task Force (IRTF).</t>
nd evaluation.
This document defines an Experimental Protocol for the In
ternet
community. This document is a product of the Internet Res
earch Task
Force (IRTF). The IRTF publishes the results of Internet-
related
research and development activities. These results might
not be
suitable for deployment. This RFC represents the consensu
s of the
Information-Centric Networking Research Group of the Inte
rnet
Research Task Force (IRTF). Documents approved for public
ation by
the IRSG are not candidates for any level of Internet Sta
ndard; see
Section 2 of RFC 7841.</t>
<section numbered="true" toc="default"> <section numbered="true" toc="default">
<name>Requirements Language</name> <name>Requirements Language</name>
<t>The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", <t>The key words "<bcp14>MUST</bcp14>", "<bcp14>MUST NOT</bcp14>",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "<bcp14>REQUIRED</bcp14>", "<bcp14>SHALL</bcp14>",
document are to be interpreted as described in BCP 14 "<bcp14>SHALL NOT</bcp14>", "<bcp14>SHOULD</bcp14>",
<xref target="RFC2119"/> <xref target="RFC8174"/> when, and only "<bcp14>SHOULD NOT</bcp14>",
when, they appear in all capitals, as shown here.</t> "<bcp14>RECOMMENDED</bcp14>", "<bcp14>NOT RECOMMENDED</bcp14>",
"<bcp14>MAY</bcp14>", and "<bcp14>OPTIONAL</bcp14>" in this document
are to be interpreted as described in BCP&nbsp;14
<xref target="RFC2119"/> <xref target="RFC8174"/> when, and only
when, they appear in all capitals, as shown here.</t>
</section> </section>
<section numbered="true" toc="default"> <section numbered="true" toc="default">
<name>Terminology</name> <name>Terminology</name>
<t>This specification uses the terminology defined in <xref target="RFC8 <t>This specification uses the terminology defined in <xref target="RFC8
793"/>. To aid the understanding of readers, we additionally define the followin 793"/>. To aid the reader, we additionally define the following terms:</t>
g terms:</t> <dl spacing="normal">
<ul> <dt>Producer's Name:</dt><dd>The name prefix that a request must car
<li>Producer's name: The name prefix that a request must carry in or ry in order to reach a producer over an ICN network.</dd>
der to reach a producer over an ICN network.</li> <dt>Named Data:</dt><dd>A synonym for a Content Object.</dd>
<li>Named Data: A synonym for a content object.</li> <dt>Round-Trip Time (RTT):</dt><dd>The time between sending a reques
<li>Round Trip Time (RTT): The time between sending a request for a t for a specific piece of named data and receiving the corresponding piece of na
specific piece of named data and receiving the corresponding piece of named data med data.</dd>
.</li> <dt>Sender:</dt><dd>An entity that sends a request for named data or
<li>Sender: An entity that sends a request for named data or a piece a piece of named data.</dd>
of named data.</li> <dt>Name of a Sender:</dt><dd>An alias of a producer's name.</dd>
<li>Name of a sender: An alias of producer's name.</li> <dt>Border Forwarder:</dt><dd>The forwarder that is the border of a
<li>Border forwarder: The forwarder that is the border of a network network region where a producer's name is directly routable (i.e., the producer'
region where a producer's name is directly routable (i.e., the producer's name i s name is present in the FIB of forwarders within this network region).</dd>
s present in the FIB of forwarders within this network region).</li> </dl>
</ul>
</section> </section>
</section> </section>
<section numbered="true" toc="default"> <section numbered="true" toc="default">
<name>Background on IP-Based Ping Operation</name> <name>Background on IP-Based Ping Operation</name>
<t>In IP-based ping, an IP address is specified by the user either directl y, or via <t>In IP-based ping, an IP address is specified by the user either directl y or via
translation of a domain name through DNS. The ping client applicatio n translation of a domain name through DNS. The ping client applicatio n
sends a number of ICMP Echo Request packets with the specified IP sends a number of ICMP Echo Request packets with the specified IP
address as the IP destination address and an IP address from the cli ent's host address as the IP destination address and an IP address from the cli ent's host
as the IP source address.</t> as the IP source address.</t>
<t>Each ICMP Echo Request is forwarded across <t>Each ICMP Echo Request is forwarded across
the network based on its destination IP address. If it eventually re aches the the network based on its destination IP address. If it eventually re aches the
destination, the destination responds by sending back an ICMP Echo R eply destination, the destination responds by sending back an ICMP Echo R eply
packet to the IP source address from the ICMP Echo Request.</t> packet to the IP source address from the ICMP Echo Request.</t>
<t>If an ICMP Echo Request does not reach the destination or the <t>If an ICMP Echo Request does not reach the destination or the
Echo reply is lost, the ping client times out. Any ICMP error messag Echo Reply is lost, the ping client times out. Any ICMP error messag
es, es
such as "no route to destination", generated by the ICMP Echo Reques generated in response to the ICMP Echo Request message, such as "No
t message route to destination", are returned to the client and reported.</t>
are returned to the client and reported.</t>
</section> </section>
<section numbered="true" toc="default"> <section numbered="true" toc="default">
<name>Ping Functionality Challenges and Opportunities in ICN</name> <name>Ping Functionality Challenges and Opportunities in ICN</name>
<t> In ICN, the communication paradigm is based exclusively on named <t> In ICN, the communication paradigm is based exclusively on named
objects. An Interest is forwarded across the network based on the name pre objects. An Interest message is forwarded across the network based on the
fix that it carries. name prefix that it carries.
Eventually, a content object is retrieved either from a producer Eventually, a Content Object is retrieved from either a producer
application or some forwarder's Content Store (CS).</t> application or some forwarder's Content Store (CS).</t>
<t>IP-based ping was built as an add-on measurement and debugging tool on <t>IP-based ping was built as an add-on measurement and debugging tool on
top of an already existing network architecture. In ICN, we have the opportunity top of an already-existing network architecture. In ICN, we have the opportunity
to incorporate diagnostic to incorporate diagnostic
mechanisms directly in the network layer protocol, and hopefully provide m mechanisms directly in the network-layer protocol and, hopefully, provide
ore powerful more powerful
diagnostic capability than can be realized through the layered ICMP Echo a pproach.</t> diagnostic capability than can be realized through the layered ICMP Echo a pproach.</t>
<t>An ICN network differs from an IP network in at least 4 important ways: </t> <t>An ICN network differs from an IP network in at least four important wa ys (four of which are as follows):</t>
<ul spacing="normal"> <ul spacing="normal">
<li>IP identifies interfaces to an IP network with a fixed-length <li>IP identifies interfaces to an IP network with a fixed-length
address, and delivers IP packets to one or more of these interface address and delivers IP packets to one or more of these interfaces
s. ICN . ICN
identifies units of data in the network with a variable length nam identifies units of data in the network with a variable-length nam
e e
consisting of a hierarchical list of name components.</li> consisting of a hierarchical list of name components.</li>
<li>An IP-based network depends on the IP packets having source IP addr <li>An IP-based network depends on the IP packets having source IP addr
esses that are used as the destination address for replies. On the esses that are used as the destination address for replies. On the other hand, I
other hand, ICN Interests do not have source addresses and they are forwarded b CN Interests do not have source addresses, and they are forwarded based on names
ased on names, which do not refer to a unique end-point. Data packets follow the , which do not refer to a unique endpoint. Data packets follow the reverse path
reverse path of the Interests based on hop-by-hop state of the Interests based on hop-by-hop state
created during Interest forwarding.</li> created during Interest forwarding.</li>
<li>An IP network supports multi-path, single destination, stateless pac <li>An IP network supports multi-path, single-destination, stateless pac
ket ket
forwarding and delivery via unicast, a limited form of forwarding and delivery via unicast; a limited form of
multi-destination selected delivery with anycast, and group-based multi-destination selected delivery with anycast; and group-based
multi-destination delivery via multicast. In contrast, ICN support s multi-destination delivery via multicast. In contrast, ICN support s
multi-path and multi-destination stateful Interest forwarding and multi-path and multi-destination stateful Interest forwarding and
multi-destination delivery of named data. This single multi-destination delivery of named data. This single
forwarding semantic subsumes the functions of unicast, anycast, an d forwarding semantic subsumes the functions of unicast, anycast, an d
multicast. As a result, consecutive (or retransmitted) ICN Intere st multicast. As a result, consecutive (or retransmitted) ICN Intere st
messages may be forwarded through an ICN network along different messages may be forwarded through an ICN network along different
paths, and may be forwarded to different data sources (e.g., end-n paths and may be forwarded to different data sources (e.g., end-no
ode de
applications, in-network storage) holding a copy of the applications and in-network storage) holding a copy of the
requested unit of data. This can lead to a significant variance i n requested unit of data. This can lead to a significant variance i n
round-trip times, which while resulting in a more robust overall f orwarding architecture, has implications for a network RTTs; such variance, while resulting in a more robust overall forw arding architecture, has implications for a network
troubleshooting mechanism like ping.</li> troubleshooting mechanism like ping.</li>
<li>In the case of multiple Interests with the same name arriving <li>In the case of multiple Interests with the same name arriving
at a forwarder, a number of Interests may be aggregated in a commo n Pending at a forwarder, a number of Interests may be aggregated in a commo n Pending
Interest Table (PIT) entry and only one of them forwarded onward. Depending on the lifetime of a PIT entry, Interest Table (PIT) entry and only one of them forwarded onward. Depending on the lifetime of a PIT entry,
the round-trip time an Interest-Data exchange might significantly the RTT of an Interest-Data exchange might vary significantly
vary (e.g., it might be shorter than the full RTT to reach the
(e.g., it might be shorter than the full round-trip time to reach original content producer). To this end, the RTT experienced
the
original content producer). To this end, the round-trip time exper
ienced
by consumers might also vary.</li> by consumers might also vary.</li>
</ul> </ul>
<t>These differences introduce new challenges, new opportunities and new <t>These differences introduce new challenges, new opportunities, and new
requirements in the design of an ICN ping protocol. Following this communi requirements regarding the design of an ICN Ping protocol. Following this
cation communication
model, a ping client should be able to express ping echo requests model, a ping client should be able to express Ping Echo Requests
with some name prefix and receive responses.</t> with some name prefix and receive responses.</t>
<t>Our goals are the following:</t> <t>Our goals are as follows:</t>
<ul spacing="normal"> <ul spacing="normal">
<li>Test the reachability and the operational state of an ICN forwarder. </li> <li>Test the reachability and the operational state of an ICN forwarder. </li>
<li>Test the reachability of a producer or a data repository (in the sen se of whether <li>Test the reachability of a producer or a data repository (in the sen se of whether
Interests for a prefix that it serves can be forwarded to it) and discove Interests for a prefix that it serves can be forwarded to it), and disco
r the ver the
forwarder with local connectivity to (an instance of) this producer or re forwarder with local connectivity to (an instance of) this producer or r
pository.</li> epository.</li>
<li>Test whether a specific named object is cached in some on-path CS <li>Test whether a specific named object is cached in some on-path CS
(e.g., a video segment with a name "/vide (e.g., a video segment with the name "/v
o/_seq=1”), ideo/_seq=1"),
and, if so, return the administrative name of the corresponding forwarder and, if so, return the administrative name of the corresponding forwarde
(e.g., a forwarder with an administrative name "/ISP/forwarder1”).</li> r
(e.g., a forwarder with the administrative name "/ISP&wj;/forwarder1").<
/li>
<li>Perform some simple network performance measurements, such as RTT an d loss rate.</li> <li>Perform some simple network performance measurements, such as RTT an d loss rate.</li>
</ul> </ul>
<t>To this end, a ping name can represent:</t> <t>To this end, a ping name can represent:</t>
<ul spacing="normal"> <ul spacing="normal">
<li>An administrative name that has been assigned to a forwarder.</li> <li>An administrative name that has been assigned to a forwarder.</li>
<li>A name that includes an application's namespace as a prefix.</li> <li>A name that includes an application's namespace as a prefix.</li>
<li>A named object that might reside in some in-network storage.</li> <li>A named object that might reside in some in-network storage.</li>
</ul> </ul>
<t>In order to provide stable and reliable diagnostics, it is desirable th <t>In order to provide stable and reliable diagnostics, it is desirable th
at the at the packet encoding of a Ping Echo Request enable the forwarders to distingui
packet encoding of a ping echo request enable the forwarders to sh a ping from a normal Interest, while diverging as little as possible from the
distinguish a ping from a normal Interest, while also allowing for forwarding behavior for an Interest packet. In the same way, the encoding of a
forwarding behavior to be as similar as possible to that of an Ping Echo Reply should minimize any processing differences from those employed f
Interest packet. In the same way, the encoding of a ping echo reply or a data packet by the forwarders.</t>
should allow for forwarder processing as close as possible to that used fo
r data
packets.</t>
<t>The ping protocol should also enable relatively robust round-trip time <t>The ping protocol should also enable relatively robust RTT
measurements. To this end, it is valuable to have a mechanism to steer measurements. To this end, it is valuable to have a mechanism to steer
consecutive ping echo requests for the same name towards an individual pat h. Such a capability was initially published in <xref target="PATHSTEERING" for mat="default"/> and has been specified for CCNx and NDN in <xref target="I-D.irt f-icnrg-pathsteering"/>.</t> consecutive Ping Echo Requests for the same name towards an individual pat h. Such a capability was initially published in <xref target="PATHSTEERING" for mat="default"/> and has been specified for CCNx and NDN in <xref target="RFC9531 "/>.</t>
<t>It is also important, in the case of ping echo requests for the same na me from different sources to have a mechanism to avoid those requests being aggr egated in the PIT. To this end, we need some encoding in the ping echo requests <t>In the case of Ping Echo Requests for the same name from different sour ces, it is also important to have a mechanism to avoid those requests being aggr egated in the PIT. To this end, we need some encoding in the Ping Echo Requests
to make each request for a common name unique, hence avoiding PIT aggregat ion and to make each request for a common name unique, hence avoiding PIT aggregat ion and
further enabling the exact match of a response with a particular ping pack et. However, avoiding PIT aggregation could lead to PIT DoS attacks.</t> further enabling the exact match of a response with a particular ping pack et. However, avoiding PIT aggregation could lead to PIT DoS attacks.</t>
</section> </section>
<section numbered="true" toc="default"> <section numbered="true" toc="default">
<name>ICN Ping Echo CCNx Packet Formats</name> <name>ICN Ping Echo CCNx Packet Formats</name>
<t>In this section, we describe the Echo Packet Format according to the <t>In this section, we describe the Echo packet formats according to the
CCNx packet format <xref target="RFC8569" format="default"/>, where CCNx packet format <xref target="RFC8569" format="default"/>, where
messages exist within outermost containments (packets). messages exist within outermost containments (packets).
Specifically, we specify two types Specifically, we propose two types
of ping packets, an echo request and an echo reply packet type.</t> of ping packets: an Echo Request and an Echo Reply.</t>
<section numbered="true" toc="default"> <section numbered="true" toc="default">
<name>ICN Ping Echo Request CCNx Packet Format</name> <name>ICN Ping Echo Request CCNx Packet Format</name>
<t>The format of the ping echo request packet is presented below:</t> <t>The format of the Ping Echo Request packet is presented below:</t>
<figure align="center" anchor="ping-packet"> <figure align="center" anchor="ping-packet">
<name>Echo Request CCNx Packet Format</name> <name>Echo Request CCNx Packet Format</name>
<artwork align="left" name="" type="" alt=""><![CDATA[ <artwork align="left" name="" type="" alt=""><![CDATA[
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
| | | | | | | |
| Version |PT_ECHO_REQUEST| PacketLength | | Version |PT_ECHO_REQUEST| PacketLength |
| | | | | | | |
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
| | | | | | | | | |
| HopLimit | Reserved | Flags | HeaderLength | | HopLimit | Reserved | Flags | HeaderLength |
| | | | | | | | | |
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
/ / / /
/ Path label TLV / / Path Label TLV /
/ / / /
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
| | | |
| Echo Request Message TLVs | | Echo Request Message TLVs |
| | | |
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
]]></artwork> ]]></artwork>
</figure> </figure>
<t>The existing packet header fields have the same definition as the hea der fields of a CCNx Interest packet. The value of the packet type field is <em> PT_ECHO_REQUEST</em>. See <xref target="IANA"/> for the value assignments.</t> <t>The existing packet header fields have the same definition as the hea der fields of a CCNx Interest packet. The value of the packet type field is <em> PT_ECHO_REQUEST</em>. &nbsp;See <xref target="IANA"/> for the value assignment.< /t>
<t>Compared to the typical format of a CCNx packet header from <xref tar <t>Compared to the typical format of a CCNx packet header <xref target="
get="RFC8569" format="default"/>, in order to enable path steering of Echo Reque RFC8609" format="default"/>, there is a new optional fixed header
sts, there is an optional fixed header Path label TLV as specified in section 3. added to the packet header:</t>
1 of <xref target="I-D.irtf-icnrg-pathsteering"/> added to the packet header:</t
>
<t>The message format of an echo request is presented below:</t> <ul>
<li>A Path Steering hop-by-hop header TLV, which is constructed hop by hop in
the Ping Echo Reply and included in the Ping Echo Request to steer consecutive r
equests expressed by a client towards a common forwarding path or different forw
arding paths. The Path Label TLV is specified in <xref target="RFC9531" sectionF
ormat="of"/>.</li>
</ul>
<t>The message format of an Echo Request is presented below:</t>
<figure align="center" anchor="echo-request"> <figure align="center" anchor="echo-request">
<name>Echo Request Message Format</name> <name>Echo Request Message Format</name>
<artwork align="left" name="" type="" alt=""><![CDATA[ <artwork align="left" name="" type="" alt=""><![CDATA[
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
| | | | | |
| MessageType = 0x0005 | MessageLength | | MessageType = 0x05 | MessageLength |
| | | | | |
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
| | | |
| Name TLV | | Name TLV |
| | | |
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
]]></artwork> ]]></artwork>
</figure> </figure>
<t>The echo request message is of type T_DISCOVERY. The Name TLV <t>The Echo Request message is of type T_DISCOVERY. The Name TLV
has the structure described in <xref target="RFC8609"/>. has the structure described in <xref target="RFC8609"/>.
The name consists of the prefix that we would like to ping appended with The name consists of the prefix that we would like to ping appended with
a nonce typed name segment (T_NONCE) as its last segment. The nonce can b e encoded as a base64-encoded string with the URL-safe alphabet as defined in Se ction 5 of <xref target="RFC4648"/>, with padding omitted. See <xref target="IAN A"/> for the value assigned to this name segment type. The value of this TLV is a 64-bit nonce. a nonce typed name segment (T_NONCE) as its last segment. The nonce can b e encoded as a base64-encoded string with the URL-safe alphabet as defined in <x ref target="RFC4648" sectionFormat="of" section="5"/>, with padding omitted. See <xref target="IANA"/> for the value assigned to this name segment type. The val ue of this TLV is a 64-bit nonce.
The purpose of the nonce is to avoid Interest aggregation and allow clien t matching of replies with requests. As described below, the nonce is ignored fo r CS checking.</t> The purpose of the nonce is to avoid Interest aggregation and allow clien t matching of replies with requests. As described below, the nonce is ignored fo r CS checking.</t>
<figure align="center"> <figure align="center">
<name>T_NONCE Name Segment TLV for Echo Request messages</name> <name>T_NONCE Name Segment TLV for Echo Request Messages</name>
<artwork align="left" name="" type="" alt=""><![CDATA[ <artwork align="left" name="" type="" alt=""><![CDATA[
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
| | | | | |
| T_NONCE_Type | T_NONCE_Length = 8 | | T_NONCE_Type | T_NONCE_Length = 8 |
| | | | | |
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
| | | |
| | | |
| | | |
| T_NONCE_Value | | T_NONCE_Value |
| | | |
| | | |
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
]]></artwork> ]]></artwork>
</figure> </figure>
</section> </section>
<!-- This PI places the pagebreak correctly (before the section title) in the text output. -->
<section anchor="CCNxReply" numbered="true" toc="default"> <section anchor="CCNxReply" numbered="true" toc="default">
<name>Ping Echo Reply CCNx Packet Format</name> <name>ICN Ping Echo Reply CCNx Packet Format</name>
<t>The format of a ping echo reply packet is presented below:</t> <t>The format of a Ping Echo Reply packet is presented below:</t>
<figure align="center"> <figure align="center">
<name>Echo Reply CCNx Packet Format</name> <name>Echo Reply CCNx Packet Format</name>
<artwork align="left" name="" type="" alt=""><![CDATA[ <artwork align="left" name="" type="" alt=""><![CDATA[
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
| | | | | | | |
| Version | PT_ECHO_REPLY | PacketLength | | Version | PT_ECHO_REPLY | PacketLength |
| | | | | | | |
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
| | | | | | | |
| Reserved | Flags | HeaderLength | | Reserved | Flags | HeaderLength |
| | | | | | | |
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
/ / / /
/ Path label TLV / / Path Label TLV /
/ / / /
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
| | | |
| Echo Reply Message TLVs | | Echo Reply Message TLVs |
| | | |
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
]]></artwork> ]]></artwork>
</figure> </figure>
<t>The header of an echo reply consists of the header fields of a CCNx C <t>The header of an Echo Reply consists of the header fields of a CCNx C
ontent ontent
Object and a hop-by-hop Path label TLV. The value of the packet type Object and a hop-by-hop Path Label TLV. The value of the packet type
field is PT_ECHO_REPLY. See <xref target="IANA"/> for the value assignmen field is PT_ECHO_REPLY. See <xref target="IANA"/> for the value assignmen
ts. t.
The Path label header TLV from section 3.1 of <xref target="I-D.irtf-icnr The Path Label header TLV (<xref target="RFC9531" sectionFormat="of" sect
g-pathsteering"/> ion="3.1"/>)
is as defined for the echo request packet.</t> is as defined for the Echo Request packet.</t>
<t>A ping echo reply message is of type T_OBJECT, contains a Name TLV <t>A Ping Echo Reply message is of type T_OBJECT and contains a Name TLV
(name of the corresponding echo request), a PayloadType TLV and an (name of the corresponding Echo Request), a PayloadType TLV, and an
ExpiryTime TLV with a value of 0 to indicate that echo replies must ExpiryTime TLV with a value of 0 to indicate that Echo Replies must
not be returned from network caches.</t> not be returned from network caches.</t>
<figure align="center"> <figure align="center">
<name>Echo Reply Message Format</name> <name>Echo Reply Message Format</name>
<artwork align="left" name="" type="" alt=""><![CDATA[ <artwork align="left" name="" type="" alt=""><![CDATA[
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
| | | | | |
| MessageType = 0x0005 | MessageLength | | MessageType = 0x06 | MessageLength |
| | | | | |
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
| | | |
| Name TLV | | Name TLV |
| | | |
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
| | | |
| PayloadType TLV | | PayloadType TLV |
| | | |
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
| | | |
| ExpiryTime TLV | | ExpiryTime TLV |
| | | |
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
]]></artwork> ]]></artwork>
</figure> </figure>
<t>The PayloadType TLV is presented below. It is of type T_PAYLOADTYPE_D ATA, and <t>The PayloadType TLV is presented below. It is of type T_PAYLOADTYPE_D ATA, and
the data schema consists of 3 TLVs: 1) the name of the sender of this rep the data schema consists of three TLVs:</t>
ly <ol type="%d)">
(with the same structure as a CCNx Name TLV), 2) the sender's signature o <li>the name of the sender of this reply
f (with the same structure as a CCNx Name TLV),</li>
their own name (with the same structure as a CCNx ValidationPayload TLV), <li>the sender's signature of
3) a TLV with a return code to indicate what led to the generation of thi their own name (with the same structure as a CCNx ValidationPayload TLV),
s reply and</li>
(i.e., existence of a local application, a CS hit or a match with a forwa <li>a TLV with a return code to indicate what led to the generation of
rder's this reply
administrative name as specified in <xref target="forwarder" format="defa (i.e., the existence of a local application, a CS hit, or a match with a
ult"/>).</t> forwarder's
administrative name as specified in <xref target="forwarder" format="defa
ult"/>).</li>
</ol>
<figure align="center"> <figure align="center">
<name>Echo Reply Message Format</name> <name>Echo Reply PayloadType TLV Format</name>
<artwork align="left" name="" type="" alt=""><![CDATA[ <artwork align="left" name="" type="" alt=""><![CDATA[
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
| | | | | |
| T_PAYLOADTYPE_DATA | Length | | T_PAYLOADTYPE_DATA | Length |
| | | | | |
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
/ / / /
/ Sender's Name TLV / / Sender's Name TLV /
/ / / /
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
/ / / /
/ Sender's Signature TLV / / Sender's Signature TLV /
/ / / /
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
/ / / /
/ Echo Reply Code / / Echo Reply Code /
/ / / /
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
]]></artwork> ]]></artwork>
</figure> </figure>
<t>The goal of including the name of the sender in the echo reply is to enable the <t>The goal of including the name of the sender in the Echo Reply is to enable the
user to reach this entity directly to ask for further management/administr ative user to reach this entity directly to ask for further management/administr ative
information using generic Interest-Data exchanges or by employing a more c omprehensive management tool such as <xref target="RFC9344">CCNinfo</xref> information using generic Interest-Data exchanges or by employing a more c omprehensive management tool, such as <xref target="RFC9344">CCNinfo</xref>,
after a successful verification of the sender's name.</t> after a successful verification of the sender's name.</t>
<t>The types of the Echo Reply Code field are the following:</t> <t>The types of the Echo Reply Code field are as follows:</t>
<ul spacing="normal"> <dl spacing="normal">
<li>T_ECHO_RETURN_FORWARDER: Indicates that the target name matched th <dt>T_ECHO_RETURN_FORWARDER:</dt><dd>Indicates that the target name ma
e administrative name of a forwarder.</li> tched the administrative name of a forwarder.</dd>
<li>T_ECHO_RETURN_APPLICATION: Indicates that the target name matched <dt>T_ECHO_RETURN_APPLICATION:</dt><dd>Indicates that the target name
a prefix served by an application.</li> matched a prefix served by an application.</dd>
<li>T_ECHO_RETURN_OBJECT: Indicates that the target name matched the n <dt>T_ECHO_RETURN_OBJECT:</dt><dd>Indicates that the target name match
ame of an object in a forwarder's CS.</li> ed the name of an object in a forwarder's CS.</dd>
</ul> </dl>
</section> </section>
</section> </section>
<section numbered="true" toc="default"> <section numbered="true" toc="default">
<name>ICN Ping Echo NDN Packet Formats</name> <name>ICN Ping Echo NDN Packet Formats</name>
<t>In this section, we present the ICN Ping Echo Request and Reply Format according to the NDN packet specification <t>In this section, we present the ICN Ping Echo Request and Reply packet formats according to the NDN packet format specification
<xref target="NDNTLV" format="default"/>.</t> <xref target="NDNTLV" format="default"/>.</t>
<section numbered="true" toc="default"> <section numbered="true" toc="default">
<name>ICN Ping Echo Request NDN Packet Format</name> <name>ICN Ping Echo Request NDN Packet Format</name>
<t>An echo request is encoded as an NDN Interest packet. Its format is t he following:</t> <t>An Echo Request is encoded as an NDN Interest packet. Its format is a s follows:</t>
<figure align="center"> <figure align="center">
<name>Echo Request NDN Packet Format</name> <name>Echo Request NDN Packet Format</name>
<artwork align="left" name="" type="" alt=""><![CDATA[ <artwork align="left" name="" type="" alt=""><![CDATA[
EchoRequest = INTEREST-TYPE TLV-LENGTH EchoRequest = INTEREST-TYPE TLV-LENGTH
Name Name
MustBeFresh MustBeFresh
Nonce Nonce
ApplicationParameters? ApplicationParameters?
]]></artwork> ]]></artwork>
</figure> </figure>
<t>The name field of an echo request consists of the name prefix to be p inged, a nonce value (it can be the value of the Nonce field) and the suffix "pi ng" to denote that this Interest is a ping request (added as a KeywordNameCompon ent). When the "ApplicationParameters" element is present, a pa rametersSha256DigestComponent is added as the last name segment.</t> <t>The name field of an Echo Request consists of the name prefix to be p inged, a nonce value (it can be the value of the Nonce field), and the suffix "p ing" to denote that this Interest is a ping request (added as a KeywordNameCompo nent <xref target="NDNTLV"/>). When the "ApplicationParameters" element is prese nt, a ParametersSha256DigestComponent (<xref target="forwarder"/>) is added as t he last name segment.</t>
<t>An echo request MAY carry a Path label TLV in the <xref target="NDNLP v2">NDN Link Adaptation Protocol</xref> as specified in <xref target="I-D.irtf-i cnrg-pathsteering"/>.</t> <t>An Echo Request <bcp14>MAY</bcp14> carry a Path Label TLV in the <xre f target="NDNLPv2">NDN Link Adaptation Protocol</xref> as specified in <xref tar get="RFC9531"/>.</t>
<t>Since the NDN packet format does not provide a mechanism to prevent t he network from caching specific data packets, we use the MustBeFresh element fo r echo requests (in combination with a Freshness Period TLV of value 1 for echo replies) to avoid fetching cached echo replies with an expired freshness period <xref target="REALTIME" format="default"/>.</t> <t>Since the NDN packet format does not provide a mechanism to prevent t he network from caching specific data packets, we use the MustBeFresh TLV for Ec ho Requests (in combination with a FreshnessPeriod TLV with a value of 1 for Ech o Replies) to avoid fetching cached Echo Replies with an expired freshness perio d <xref target="REALTIME" format="default"/>.</t>
</section> </section>
<section numbered="true" toc="default"> <section numbered="true" toc="default">
<name>Ping Echo Reply NDN Packet Format</name> <name>ICN Ping Echo Reply NDN Packet Format</name>
<t>An echo reply is encoded as an NDN Data packet. Its format is the fol <t>An Echo Reply is encoded as an NDN Data packet. Its format is as foll
lowing:</t> ows:</t>
<figure align="center"> <figure align="center">
<name>Echo Reply NDN Packet Format</name> <name>Echo Reply NDN Packet Format</name>
<artwork align="left" name="" type="" alt=""><![CDATA[ <artwork align="left" name="" type="" alt=""><![CDATA[
EchoReply = DATA-TLV TLV-LENGTH EchoReply = DATA-TLV TLV-LENGTH
Name Name
MetaInfo MetaInfo
Content Content
Signature Signature
]]></artwork> ]]></artwork>
</figure> </figure>
<t>An echo reply MAY contain a Path label TLV in the <xref target="NDNLP v2">NDN Link Adaptation Protocol</xref> as specified in <xref target="I-D .irtf-icnrg-pathsteering"/>, since it might be modified in a hop-by-hop fashion by the forwarders along the reverse path.</t> <t>An Echo Reply <bcp14>MAY</bcp14> carry a Path Label TLV in the <xref target="NDNLPv2">NDN Link Adaptation Protocol</xref> as specified in <xref targe t="RFC9531"/>, since it might be modified in a hop-by-hop fashion by the forward ers along the reverse path.</t>
<t>The name of an echo reply is the name of the corresponding echo reque st, while the format of the MetaInfo field is the following:</t> <t>The name of an Echo Reply is the name of the corresponding Echo Reque st while the format of the MetaInfo field is as follows:</t>
<figure align="center"> <figure align="center">
<name>MetaInfo TLV</name> <name>MetaInfo TLV</name>
<artwork align="left" name="" type="" alt=""><![CDATA[ <artwork align="left" name="" type="" alt=""><![CDATA[
MetaInfo = META-INFO-TYPE TLV-LENGTH MetaInfo = META-INFO-TYPE TLV-LENGTH
ContentType ContentType
FreshnessPeriod FreshnessPeriod
]]></artwork> ]]></artwork>
</figure> </figure>
<t>The value of the ContentType TLV is 0. The value of the <t>The value of the ContentType TLV is 0. The value of the
FreshnessPeriod TLV is 1, so that the replies are treated as stale data (a lmost instantly) as they are received by a forwarder.</t> FreshnessPeriod TLV is 1, so that the replies are treated as stale data (a lmost instantly) as they are received by a forwarder.</t>
<t>The content of an echo reply consists of the following 2 TLVs: Sender <t>The content of an Echo Reply consists of the following two TLVs: Send
's name er's Name
(with a structure similar as an NDN Name TLV) and Echo Reply Code. There i (with a structure similar to an NDN Name TLV) and Echo Reply Code. There i
s no need to have a separate TLV for the sender's signature in the content of th s no need to have a separate TLV for the sender's signature in the content of th
e reply, since every NDN data packet carries the signature of the data producer. e reply, since every NDN Data packet carries the signature of the data producer.
</t> </t>
<t>The Echo Reply Code TLV format is the following (with the values specif ied in <t>The Echo Reply Code TLV format is as follows (with the values specified in
<xref target="CCNxReply" format="default"/>):</t> <xref target="CCNxReply" format="default"/>):</t>
<figure align="center"> <figure align="center">
<name>Echo Reply Code TLV</name> <name>Echo Reply Code TLV</name>
<artwork align="left" name="" type="" alt=""><![CDATA[ <artwork align="left" name="" type="" alt=""><![CDATA[
EchoReplyCode = ECHOREPLYCODE-TLV-TYPE TLV-LENGTH 2*OCTET EchoReplyCode = ECHOREPLYCODE-TLV-TYPE TLV-LENGTH 2*OCTET
]]></artwork> ]]></artwork>
</figure> </figure>
</section> </section>
</section> </section>
<section anchor="forwarder" numbered="true" toc="default"> <section anchor="forwarder" numbered="true" toc="default">
<name>Forwarder Handling</name> <name>Forwarder Handling</name>
<t>We present the workflow of the forwarder's operation in <xref target="f orwarder-operation"/>. When a forwarder receives an echo request, it first extra cts the message's base name (i.e., the request name with the Nonce name segment excluded as well as the suffix "ping" and the ParametersSha256DigestComponent in the case of an echo request with the NDN packet format).</t> <t>We present the workflow of the forwarder's operation in <xref target="f orwarder-operation"/> below. When a forwarder receives an Echo Request, it first extracts the message's base name (i.e., the request name with the Nonce name se gment excluded as well as the suffix "ping" and the ParametersSha256DigestCompon ent in the case of an Echo Request with the NDN packet format).</t>
<t>In some cases, the forwarder originates an echo reply, <t>In some cases, the forwarder originates an Echo Reply,
sending the reply downstream through the face on which the sending the reply downstream through the face on which the
echo request was received. This echo reply includes the forwarder's Echo Request was received. This Echo Reply includes the forwarder's
own name and signature and the appropriate echo reply code based on the c own name and signature and the appropriate Echo Reply Code based on the
ondition that condition that
triggered the reply generation. It also includes a Path label TLV, initia triggered the generation of the reply. It also includes a Path Label TLV
lly containing a , initially containing a
null value (since the echo reply originator did not null value (since the Echo Reply originator does not
forward the request and, thus, does not make a path choice).</t> forward the request and thus does not make a path choice).</t>
<t>The forwarder generates and returns an echo reply in the <t>The forwarder generates and returns an Echo Reply in the
following cases:</t> following cases:</t>
<ul spacing="normal"> <ul spacing="normal">
<li>Assuming that a forwarder has been given one or more administrative names, <li>Assuming that a forwarder has been given one or more administrative names,
the echo request base name exactly matches any of the forwarder's the Echo Request base name exactly matches any of the forwarder's
administrative name(s).</li> administrative names.</li>
<li>The echo request's base name exactly matches the name of a content-o <li>The Echo Request's base name exactly matches the name of a Content O
bject bject
residing in the forwarder's CS (unless the ping client application residing in the forwarder's CS (unless the ping client application
has chosen not to receive replies due to CS hits as specified in has chosen not to receive replies due to CS hits as specified in
<xref target="app-additional" format="default"/>).</li> <xref target="app-additional" format="default"/>).</li>
<li>The echo request base name matches (in a Longest Prefix Match manner <li>The Echo Request base name matches (in a Longest Name Prefix Match (
) a FIB LNPM) manner) a FIB
entry with an outgoing face referring to a local application.</li> entry with an outgoing face referring to a local application.</li>
</ul> </ul>
<t>If none of the conditions to reply to the echo request are met, the <t>If none of the conditions for replying to the Echo Request are met, the
forwarder will attempt to forward the echo request upstream based on the forwarder will attempt to forward the Echo Request upstream based on the
path Path
steering value (if present), the results of the Steering value (if present), the results of the
FIB LPM lookup and PIT creation (based on the name including the nonce ty FIB LNPM lookup and PIT creation. These lookups are based on including t
ped name segment and the suffix "ping" in the case of an echo request with the N he Nonce and the suffix "ping" as name segments of the Name in the case of an Ec
DN packet format). If no valid next-hop is found, an ho Request with the NDN packet format. If no valid next hop is found, an
InterestReturn is sent downstream indicating "no route" (as with a failed InterestReturn is sent downstream indicating "No Route" (as with a faile
attempt to d attempt to
forward an ordinary Interest).</t> forward an ordinary Interest).</t>
<t>A received echo reply will be matched to an existing PIT entry as usual <t>A received Echo Reply will be matched to an existing PIT entry as usual
. On . On
the reverse path, the path steering TLV of an echo reply will be updated the reverse path, the Path Steering TLV of an Echo Reply will be updated
by each forwarder to encode its next-hop choice. When included in subsequ by each forwarder to encode its next-hop choice. When included in subseq
ent uent
echo requests, this Path label TLV allows the forwarders to steer Echo Requests, this Path Label TLV allows the forwarders to steer
the echo requests along the same path.</t> the Echo Requests along the same path.</t>
<figure align="center" anchor="forwarder-operation"> <figure align="center" anchor="forwarder-operation">
<name>Forwarder Operation</name> <name>Forwarder Operation</name>
<artwork><![CDATA[ <artwork><![CDATA[
------------------------------------------------------------------------ ------------------------------------------------------------------------
FORWARD PATH FORWARD PATH
------------------------------------------------------------------------ ------------------------------------------------------------------------
Request +------+ +-----+ +-----+(path label) +--------+(match)Request Request +------+ +-----+ +-----+(path label) +--------+(match)Request
------> |Admin |->| CS |->| PIT | ------------>| Label |-------------> ------> |Admin |->| CS |->| PIT | ------------>| Label |------------->
| Name | +-----+ +-----+ | Lookup | | Name | +-----+ +-----+ | Lookup |
|Lookup| | | \ (no path label)+--------+ |Lookup| | | \ (no path label)+--------+
+------+ | | \ |\(path label mismatch) +------+ | | \ |\(path label mismatch)
Reply | | | \ | \ Reply | | | \ | \
<---------+ | v \ | \ <---------+ | v \ | \
(base matches | aggregate \ | \ (base matches | aggregate \ | \
admin name) | \ | \ admin name) | \ | \
| (base \ | +------+ Request | (base \ | +------+ Request
Reply | matches +----------|---->| FIB | -------> Reply | matches +----------|---->| FIB | ------->
<---------+ cached object) | +------+ <---------+ cached object) | +------+
| (no | | (base | (no | | (base
Interest-Return (NACK) v route)| | matches InterestReturn (NACK) v route)| | matches
<----------------------------------------------+<-------+ | local app <----------------------------------------------+<-------+ | local app
<----------------------------------------------------------+ face) <----------------------------------------------------------+ face)
Reply Reply
------------------------------------------------------------------------ ------------------------------------------------------------------------
REVERSE PATH REVERSE PATH
------------------------------------------------------------------------ ------------------------------------------------------------------------
Interest-return(NACK) +-----+ (update path label) Interest-Return(NACK) InterestReturn (NACK) +-----+ (update path label) InterestReturn (NACK)
<---------------------| |<----------------------------------------- <---------------------| |<-----------------------------------------
| | | |
Reply +------+ | PIT | (update path label) Reply Reply +------+ | PIT | (update path label) Reply
<------| CS |<------| |<----------------------------------------- <------| CS |<------| |<-----------------------------------------
+------+ | | +------+ | |
+-----+ +-----+
| |
| (no match) | (no match)
v v
]]></artwork> ]]></artwork>
skipping to change at line 619 skipping to change at line 614
| | | |
Reply +------+ | PIT | (update path label) Reply Reply +------+ | PIT | (update path label) Reply
<------| CS |<------| |<----------------------------------------- <------| CS |<------| |<-----------------------------------------
+------+ | | +------+ | |
+-----+ +-----+
| |
| (no match) | (no match)
v v
]]></artwork> ]]></artwork>
</figure> </figure>
</section> </section>
<section anchor="local" numbered="true" toc="default"> <section anchor="local" numbered="true" toc="default">
<name>Protocol Operation For Locally-Scoped Namespaces</name> <name>Protocol Operation for Locally Scoped Namespaces</name>
<t>In this section, we elaborate on 2 alternative design approaches in cas <t>In this section, we elaborate on two alternative design approaches in c
es that ases where
the pinged prefix corresponds to a locally-scoped namespace not directly the pinged prefix corresponds to a locally scoped namespace not directly
routable from the routable from the
client's local network.</t> client's local network.</t>
<t>The first approach leverages the NDN Link Object <xref target="SNAMP" f ormat="default"/>. <t>The first approach leverages the NDN Link Object <xref target="SNAMP" f ormat="default"/>.
Specifically, the ping client attaches to the expressed request a LINK Ob Specifically, the ping client attaches to the expressed request a Link O
ject that bject that
contains a number of routable name prefixes, based on which the request c contains a number of routable name prefixes, based on which the request
an be forwarded can be forwarded
until it reaches a network region where the request name itself is until it reaches a network region where the request name itself is
routable. A LINK Object is created and signed by a data producer allowed routable. A Link Object is created and signed by a data producer allowed
to to
publish data under a locally-scoped namespace. The way that a client retr publish data under a locally scoped namespace. The way that a client ret
ieves a LINK Object rieves a Link Object
depends on various network design factors and is out of the scope of the depends on various network design factors and is out of scope for this d
current draft.</t> ocument.</t>
<t>Based on the current usage of the LINK Object by the NDN team, a forwar <t> At the time of this writing, and based on usage of the Link Object
der at the border by the NDN team <xref target="NDNLPv2"/>, a forwarder at the border of the regi
of the region where an Interest name becomes routable must remove the LIN on
K Object from where an Interest name becomes routable must remove the Link Object
incoming Interests. The Interest state maintained along the entire forwar from incoming Interests. The Interest state maintained along the entire forward
ding path is based on the ing path is based on the
Interest name regardless of whether it was forwarded based on its name or Interest name regardless of whether it was forwarded based on its name o
a routable prefix in the r a routable prefix in the
LINK Object.</t> Link Object.</t>
<t>The second approach is based on prepending a routable prefix to the loc <t>The second approach is based on prepending a routable prefix to the loc
ally-scoped ally scoped
name. The resulting prefix will be the name of the echo requests expresse name. The resulting prefix will be the name of the Echo Requests express
d by the client. ed by the client.
In this way, a request will be forwarded based on the routable In this way, a request will be forwarded based on the routable
part of its name. When it reaches the network region where the original l part of its name. When it reaches the network region where the original
ocally-scoped locally scoped
name is routable, the border forwarder rewrites the request name and dele name is routable, the border forwarder rewrites the request name and del
tes etes
its routable part. There are two conditions for a forwarder to perform th its routable part. There are two conditions for a forwarder to perform t
is rewriting operation his rewriting operation
on a request: 1) the routable part of the request name on a request:</t>
matches a routable name of the network region adjacent to the forwarder ( <ol type="%d)">
assuming that a forwarder is aware of <li>the routable part of the request name
those names) and 2) the remaining part of the request name is routable ac matches a routable name of the network region adjacent to the forwarder
ross the (assuming that a forwarder is aware of
network region of this forwarder.</t> those names), and</li>
<t>The state maintained along the path, where the locally-scoped name is n <li>the remaining part of the request name is routable across the
ot routable, is based network region of this forwarder.</li>
on the routable prefix along with the locally-scoped prefix. Within the n </ol>
etwork region that <t>The state along the path depends on whether the request is traversing the
the locally-scoped prefix is routable, the state is based only on it. To portion of the network where the locally scoped name is routable. In this case,
ensure that the generated replies the forwarding can be based entirely on the locally scoped name. However, where
reach the ping client, the border forwarder has also to rewrite the name a portion of the path lies outside the region where the locally scoped name is
of a reply routable, the border router has to rewrite the name of a reply and prepend the r
and prepend the routable prefix of the corresponding echo request.</t> outable prefix of the corresponding request to ensure that the generated replies
will reach the client.</t>
</section> </section>
<section numbered="true" toc="default"> <section numbered="true" toc="default">
<name>Security Considerations</name> <name>Security Considerations</name>
<t>A reflection attack could be mounted by a compromised forwarder in the case of an echo reply with the CCNx packet format <t>A reflection attack could be mounted by a compromised forwarder in the case of an Echo Reply with the CCNx packet format
if that forwarder includes in the reply the name of a victim forwarder. if that forwarder includes in the reply the name of a victim forwarder.
This could convince a client to direct the future administrative traffic This could convince a client to direct the future administrative traffic
towards the victim. To foil such reflection attacks, the forwarder that ge nerates a reply towards the victim. To foil such reflection attacks, the forwarder that ge nerates a reply
must sign the name included in the payload. In this way, the client is abl e to verify that the must sign the name included in the payload. In this way, the client is abl e to verify that the
included name is legitimate and refers to the forwarder that generated the reply. included name is legitimate and refers to the forwarder that generated the reply.
Alternatively, the forwarder could include in the reply payload their rout able Alternatively, the forwarder could include in the reply payload their rout able
prefix(es) encoded as a signed NDN Link Object <xref target="SNAMP" format ="default"/>.</t> prefix(es) encoded as a signed NDN Link Object <xref target="SNAMP" format ="default"/>.</t>
<t>Interest flooding attack amplification is possible in the case of the s <t>Interest flooding attack amplification is possible in the case of the s
econd approach to deal econd approach for dealing
with locally-scoped namespaces described in <xref target="local" format="d with locally scoped namespaces as described in <xref target="local" format
efault"/>. To eliminate such amplification, ="default"/>. To eliminate such amplification,
a border forwarder will have to maintain extra state in order to prepend t he correct routable prefix a border forwarder will have to maintain extra state in order to prepend t he correct routable prefix
to the name of an outgoing reply, since the forwarder might be attached to to the name of an outgoing reply, since the forwarder might be attached to
multiple network regions (reachable under different prefixes) or a network region attached to this multiple network regions (reachable under different prefixes) or a network region attached to this
forwarder might be reachable under multiple routable prefixes.</t> forwarder might be reachable under multiple routable prefixes.</t>
<t>Another example of an attack could be the ICN equivale <t>Another example of an attack could be the ICN equival
nt of port knocking, where an attacker ent of port knocking, where an attacker
tries to discover certain forwarder implementatio tries to discover certain forwarder implementati
ns for the purpose of exploiting potential vulnerabilities.</t> ons for the purpose of exploiting potential vulnerabilities.</t>
</section> </section>
<section anchor="IANA" numbered="true" toc="default"><name>IANA Considera <section anchor="IANA" numbered="true" toc="default"><name>IANA Consider
tions</name> ations</name>
<t>IANA will assign 0x05 to "PT_ECHO_REQUEST" and 0x06 to "PT_ECH <t>IANA has assigned 0x05 to "PT_ECHO_REQUEST" and 0x06 to "PT_E
O_REPLY" in the CCNx Packet Types registry established by <xref target="RFC8609" CHO_REPLY" in the "CCNx Packet Types" registry established by <xref target="RFC8
/>.</t> 609"/>.</t>
<t>IANA will assign 0x0003 to "T_NONCE" in the Name Segment Type
IANA Registry for CCNx established by <xref target="RFC8609"/>.</t>
<t> IANA will create an "Echo Reply Code" registry. IANA will ass <t>IANA has assigned 0x0003 to "T_NONCE" in the "CCNx Name Segme
ign 0x01 to "T_ECHO_RETURN_FORWARDER", 0x02 to "T_ECHO_RETURN_APPLICATION", and nt Types" registry established by <xref target="RFC8609"/>.</t>
0x03 to "T_ECHO_RETURN_OBJECT" in the "Echo Reply Code" registry. </t>
</section>
<section anchor="Acknowledgements" numbered="true" toc="default"> <t> IANA has created a new registry called "CCNx Echo Reply Code
<name>Acknowledgements</name> s". The registration procedure is
<t>The authors would like to thank Mark Stapp for the fruitful discussion Specification Required <xref target="RFC8126"/>. In this registry, IANA has as
on the objectives signed 0x01 to "T_ECHO_RETURN_FORWARDER", 0x02 to "T_ECHO_RETURN_APPLICATION", a
of the ICN ping protocol.</t> nd 0x03 to "T_ECHO_RETURN_OBJECT".</t>
</section> </section>
</middle> </middle>
<back> <back>
<references><name>References</name> <references><name>References</name>
<references><name>Normative References</name> <references><name>Normative References</name>
<xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/referenc <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.2
e.RFC.2119.xml"/> <xi:include href="https://xml2rfc.ietf.org/public/rfc 119.xml"/>
/bibxml/reference.RFC.8174.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8
174.xml"/>
<xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RF <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8
C.8569.xml"/> 569.xml"/>
<xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RF <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8
C.8609.xml"/> 609.xml"/>
<xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RF <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8
C.8793.xml"/> 793.xml"/>
</references> </references>
<references><name>Informative References</name> <references><name>Informative References</name>
<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8
126.xml"/>
<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.9
344.xml"/>
<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.4
648.xml"/>
<xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/referenc <!-- draft-irtf-icnrg-pathsteering (RFC-to-be 9531)
e.RFC.9344.xml"/> "Long way" to fix author initials -->
<xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/referenc <reference anchor="RFC9531" target="https://www.rfc-editor.org/info/rfc9531">
e.RFC.4648.xml"/> <front>
<xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml3/ref <title>Path Steering in Content-Centric Networking (CCNx) and Named Data
erence.I-D.irtf-icnrg-pathsteering.xml"/> Networking (NDN)</title>
<author fullname="Ilya Moiseenko" initials="I." surname="Moiseenko">
<organization>Apple, Inc.</organization>
</author>
<author fullname="David R. Oran" initials="D." surname="Oran">
<organization>Network Systems Research and Design</organization>
</author>
<date month="March" year="2024"/>
</front>
<seriesInfo name="RFC" value="9531"/>
<seriesInfo name="DOI" value="10.17487/RFC9531"/>
</reference>
<reference anchor="NDNTLV" target="https://named-data.net/doc/NDN-packet -spec/current/"> <reference anchor="NDNTLV" target="https://named-data.net/doc/NDN-packet -spec/current/">
<front> <front>
<title>NDN Packet Format Specification.</title> <title>NDN Packet Format Specification</title>
<author surname="NDN Project Team"> <author>
<organization/> <organization>NDN project team</organization>
</author> </author>
<date year="2021"/> <date month="February" year="2024"/>
</front> </front>
</reference> </reference>
<reference anchor="SNAMP"> <reference anchor="SNAMP" target="https://ieeexplore.ieee.org/abstract/d ocument/7179398">
<front> <front>
<title>SNAMP: Secure namespace mapping to scale NDN forwarding</titl e> <title>SNAMP: Secure namespace mapping to scale NDN forwarding</titl e>
<author initials="A" surname="Afanasyev"> <author initials="A" fullname="Alexander Afanasyev" surname="Afanasy ev">
<organization/> <organization/>
</author> </author>
<author surname="et al"> <author initials="C" fullname="Cheng Yi" surname="Yi">
<organization/> <organization/>
</author> </author>
<date year="2015"/> <author initials="L" fullname="Lan Wang" surname="Wang">
<organization/>
</author>
<author initials="B" fullname="Beichuan Zhang" surname="Zhang">
<organization/>
</author>
<author initials="L" fullname="Lixia Zhang" surname="Zhang">
<organization/>
</author>
<date month="April" year="2015"/>
</front> </front>
<refcontent>2015 IEEE Conference on Computer Communications Workshops
(INFOCOM WKSHPS), Hong Kong, China, pp. 281-286</refcontent>
<seriesInfo name="DOI" value="10.1109/INFCOMW.2015.7179398"/>
</reference> </reference>
<reference anchor="PATHSTEERING"> <reference anchor="PATHSTEERING" target="https://dl.acm.org/doi/10.1145/ 3125719.3125721">
<front> <front>
<title>Path switching in content centric and named data networks</ti tle> <title>Path switching in content centric and named data networks</ti tle>
<author initials="I" surname="Moiseenko"> <author initials="I" surname="Moiseenko">
<organization/> <organization/>
</author> </author>
<author initials="D" surname="Oran"> <author initials="D" surname="Oran">
<organization/> <organization/>
</author> </author>
<date year="2017"/> <date month="September" year="2017"/>
</front> </front>
<refcontent>in Proceedings of the 4th ACM Conference on Information-Ce <refcontent>ICN '17: Proceedings of the 4th ACM Conference on Informat
ntric Networking</refcontent> ion-Centric Networking, pp. 66-76</refcontent>
<seriesInfo name="DOI" value="10.1145/3125719.3125721"/>
</reference> </reference>
<reference anchor="REALTIME"> <reference anchor="REALTIME" target="https://ieeexplore.ieee.org/documen t/8605992">
<front> <front>
<title>Real-Time Data Retrieval in Named Data Networking</title> <title>Real-Time Data Retrieval in Named Data Networking</title>
<author initials="S" surname="Mastorakis"> <author initials="S" surname="Mastorakis">
<organization/> <organization/>
</author> </author>
<author initials="P" surname="Gusev"> <author initials="P" surname="Gusev">
<organization/> <organization/>
</author> </author>
<author initials="A" surname="Afanasyev"> <author initials="A" surname="Afanasyev">
<organization/> <organization/>
</author> </author>
<author initials="L" surname="Zhang"> <author initials="L" surname="Zhang">
<organization/> <organization/>
</author> </author>
<date year="2017"/> <date month="August" year="2018"/>
</front> </front>
<refcontent>in Proceedings of the 1st IEEE International Conference on <refcontent>2018 1st IEEE International Conference on Hot Information-
Hot Topics in Information-Centric Networking</refcontent> Centric Networking (HotICN), Shenzhen, China, pp. 61-66</refcontent>
<seriesInfo name="DOI" value="10.1109/HOTICN.2018.8605992"/>
</reference> </reference>
<reference anchor="NDNLPv2" target="https://redmi ne.named-data.net/projects/nfd/wiki/NDNLPv2"> <reference anchor="NDNLPv2" target="https://redmine.named-data.net/proje cts/nfd/wiki/NDNLPv2">
<front> <front>
<title>Named Data Networking Link Adaptation Protocol v2</title> <title>NDNLPv2: Named Data Networking Link Adaptation Protocol v2</
<author surname="NDN team"/> title>
<date>various</date> <author>
<organization>NDN team</organization>
</author>
<date year="2023" month="February"></date>
</front> </front>
</reference> </reference>
</references> </references>
</references> </references>
<section anchor="app-additional" numbered="true" toc="default"> <section anchor="app-additional" numbered="true" toc="default">
<name>Ping Client Application (Consumer) Operation</name> <name>Ping Client Application (Consumer) Operation</name>
<t>This section is an informative appendix regarding the proposed ping cli ent <t>This section is an informative appendix regarding the proposed ping cli ent
operation.</t> operation.</t>
<t>The ping client application is responsible for generating echo requests for <t>The ping client application is responsible for generating Echo Requests for
prefixes provided by users.</t> prefixes provided by users.</t>
<t>When generating a series of echo requests for a specific name, the firs <t>When generating a series of Echo Requests for a specific name, the firs
t t
echo request will typically not include a Path label TLV, since no TLV va Echo Request will typically not include a Path Label TLV, since no TLV va
lue lue
is known. After an echo reply containing a Path label TLV is received, ea is known. After an Echo Reply containing a Path Label TLV is received, ea
ch ch
subsequent echo request can include the received path steering value subsequent Echo Request can include the received Path Steering value
in the Path label header TLV to drive the requests towards a common path in the Path Label header TLV to drive the requests towards a common path
as part of checking network performance. To discover more paths, a client can as part of checking network performance. To discover more paths, a client can
omit the path steering TLV in future requests. Moreover, for each new pin omit the Path Steering TLV in future requests. Moreover, for each new Pin
g echo g Echo
request, the client has to generate a new nonce and record the time that Request, the client has to generate a new nonce and record the time that
the the
request was expressed. It will also set the lifetime of an echo request, request was expressed. It will also set the lifetime of an Echo Request,
which will have identical semantics to the lifetime of an Interest.</t> which will have semantics identical to the lifetime of an Interest.</t>
<t>Further, the client application might not wish to receive echo replies <t>Further, the client application might not wish to receive Echo Replies
due to due to
CS hits. A mechanism to achieve that in CCNx would be to use a Content Obj ect Hash CS hits. A mechanism to achieve that in CCNx would be to use a Content Obj ect Hash
Restriction TLV with a value of 0 in the payload of an echo request messag e. In NDN, Restriction TLV with a value of 0 in the payload of an Echo Request messag e. In NDN,
the exclude filter selector can be used.</t> the exclude filter selector can be used.</t>
<t>When it receives an echo reply, the client would typically match the re <t>When it receives an Echo Reply, the client would typically match the re
ply to a sent ply to a sent
request and compute the round-trip time of the request. It should parse th request and compute the RTT of the request. It should parse the
e Path Label value and decode the reply's payload to parse
Path label value and decode the reply's payload to parse the
the sender's name and signature. The client should verify that both the sender's name and signature. The client should verify that both
the received message and the forwarder's name have been signed by the the received message and the forwarder's name have been signed by the
key of the forwarder, whose name is included in the payload of the reply ( by key of the forwarder, whose name is included in the payload of the reply ( by
fetching this forwarder's public key and verifying the contained signature ). The client fetching this forwarder's public key and verifying the contained signature ). The client
can also decode the Echo Reply Code TLV to understand the condition that t riggered can also decode the Echo Reply Code TLV to understand the condition that t riggered
the generation of the reply.</t> the generation of the reply.</t>
<t>In the case that an echo reply is not received for a request within a c <t>In the case that an Echo Reply is not received for a request within a c
ertain ertain
time interval (lifetime of the request), the client should time-out and se time interval (lifetime of the request), the client should time out and se
nd a new nd a new
request with a new nonce value up to some maximum number of requests request with a new nonce value up to some maximum number of requests
to be sent specified by the user.</t> to be sent specified by the user.</t>
</section> </section>
<section anchor="Acknowledgements" numbered="false" toc="default">
<!-- Change Log <name>Acknowledgements</name>
v03 2021-10-25 DRO Update references <t>The authors would like to thank <contact fullname="Mark Stapp"/> for th
v08 2023-04-20 DRO Keepalive + update Spiros' author info e fruitful discussion on the objectives
--> of the ICN Ping protocol.</t>
</section>
</back> </back>
</rfc> </rfc>
 End of changes. 124 change blocks. 
440 lines changed or deleted 463 lines changed or added

This html diff was produced by rfcdiff 1.48.