rfc9508.original   rfc9508.txt 
ICNRG S. Mastorakis Internet Research Task Force (IRTF) S. Mastorakis
Internet-Draft University of Notre Dame Request for Comments: 9508 University of Notre Dame
Intended status: Experimental D. Oran Category: Experimental D. Oran
Expires: 29 February 2024 Network Systems Research and Design ISSN: 2070-1721 Network Systems Research and Design
J. Gibson J. Gibson
Unaffiliated Unaffiliated
I. Moiseenko I. Moiseenko
Apple Inc Apple Inc.
R. Droms R. Droms
Unaffiliated Unaffiliated
28 August 2023 March 2024
ICN Ping Protocol Specification Information-Centric Networking (ICN) Ping Protocol Specification
draft-irtf-icnrg-icnping-12
Abstract Abstract
This document presents the design of an ICN Ping protocol. It This document presents the design of an Information-Centric
includes the operations of both the client and the forwarder. Networking (ICN) Ping protocol. It includes the operations of both
the client and the forwarder.
This document is a product of the Information-Centric Networking This document is a product of the Information-Centric Networking
Research Group (ICNRG) of the IRTF. Research Group (ICNRG) of the IRTF.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This document is not an Internet Standards Track specification; it is
provisions of BCP 78 and BCP 79. published for examination, experimental implementation, and
evaluation.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months This document defines an Experimental Protocol for the Internet
and may be updated, replaced, or obsoleted by other documents at any community. This document is a product of the Internet Research Task
time. It is inappropriate to use Internet-Drafts as reference Force (IRTF). The IRTF publishes the results of Internet-related
material or to cite them other than as "work in progress." research and development activities. These results might not be
suitable for deployment. This RFC represents the consensus of the
Information-Centric Networking Research Group of the Internet
Research Task Force (IRTF). Documents approved for publication by
the IRSG are not candidates for any level of Internet Standard; see
Section 2 of RFC 7841.
This Internet-Draft will expire on 29 February 2024. Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc9508.
Copyright Notice Copyright Notice
Copyright (c) 2023 IETF Trust and the persons identified as the Copyright (c) 2024 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 (https://trustee.ietf.org/ Provisions Relating to IETF Documents
license-info) in effect on the date of publication of this document. (https://trustee.ietf.org/license-info) in effect on the date of
Please review these documents carefully, as they describe your rights publication of this document. Please review these documents
and restrictions with respect to this document. carefully, as they describe your rights and restrictions with respect
to this document.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3 1.1. Requirements Language
1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 1.2. Terminology
2. Background on IP-Based Ping Operation . . . . . . . . . . . . 4 2. Background on IP-Based Ping Operation
3. Ping Functionality Challenges and Opportunities in ICN . . . 4 3. Ping Functionality Challenges and Opportunities in ICN
4. ICN Ping Echo CCNx Packet Formats . . . . . . . . . . . . . . 7 4. ICN Ping Echo CCNx Packet Formats
4.1. ICN Ping Echo Request CCNx Packet Format . . . . . . . . 7 4.1. ICN Ping Echo Request CCNx Packet Format
4.2. Ping Echo Reply CCNx Packet Format . . . . . . . . . . . 8 4.2. ICN Ping Echo Reply CCNx Packet Format
5. ICN Ping Echo NDN Packet Formats . . . . . . . . . . . . . . 11 5. ICN Ping Echo NDN Packet Formats
5.1. ICN Ping Echo Request NDN Packet Format . . . . . . . . . 11 5.1. ICN Ping Echo Request NDN Packet Format
5.2. Ping Echo Reply NDN Packet Format . . . . . . . . . . . . 12 5.2. ICN Ping Echo Reply NDN Packet Format
6. Forwarder Handling . . . . . . . . . . . . . . . . . . . . . 13 6. Forwarder Handling
7. Protocol Operation For Locally-Scoped Namespaces . . . . . . 15 7. Protocol Operation for Locally Scoped Namespaces
8. Security Considerations . . . . . . . . . . . . . . . . . . . 16 8. Security Considerations
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16 9. IANA Considerations
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 16 10. References
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 16 10.1. Normative References
11.1. Normative References . . . . . . . . . . . . . . . . . . 17 10.2. Informative References
11.2. Informative References . . . . . . . . . . . . . . . . . 17 Appendix A. Ping Client Application (Consumer) Operation
Appendix A. Ping Client Application (Consumer) Operation . . . . 18 Acknowledgements
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 19 Authors' Addresses
1. Introduction 1. Introduction
Ascertaining data plane reachability to a destination and taking 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
facilities for network administration and troubleshooting. In IP, fundamental facilities for network administration and
where routing and forwarding are based on IP addresses, ICMP echo and troubleshooting. In IP, where routing and forwarding are based on IP
ICMP echo response are the protocol mechanisms used for this purpose, addresses, ICMP Echo Request and ICMP Echo Reply packets are the
generally exercised through the familiar ping utility. In ICN, where protocol mechanisms used for this purpose, generally exercised
routing and forwarding are based on name prefixes, the ability to through the familiar ping utility. In Information-Centric Networking
ascertain reachability of names is required. (ICN), where routing and forwarding are based on name prefixes, the
ability to ascertain the reachability of names is required.
This document proposes protocol mechanisms for a ping equivalent in This document proposes protocol mechanisms for a ping equivalent in
ICN (CCNx [RFC8609] and NDN [NDNTLV]) networks. A non-normative ICN networks (Content-Centric Networking (CCNx) [RFC8609] and Named
appendix suggests useful properties for an ICN ping client Data Networking (NDN) [NDNTLV]). A non-normative section
application, analogous to IP ping, that originates echo requests and (Appendix A) suggests useful properties for an ICN Ping client
processes echo replies. application, analogous to IP ping, that originates Echo Requests and
processes Echo Replies.
In order to carry out meaningful experimentation and deployment of In order to carry out meaningful experimentation and deployment of
ICN protocols, tools to manage and debug the operation of ICN ICN protocols, new tools analogous to ping and traceroute used for
architectures and protocols are needed analogous to ping and TCP/IP are needed to manage and debug the operation of ICN
traceroute used for TCP/IP. This document describes the design of a architectures and protocols. This document describes the design of a
management and debugging protocol analogous to the ping protocol of management and debugging protocol analogous to the ping protocol of
TCP/IP, which will aid the experimental deployment of ICN protocols. TCP/IP; this new management and debugging protocol will aid the
As the community continues its experimentation with ICN architectures experimental deployment of ICN protocols. As the community continues
and protocols, the design of ICN Ping might change accordingly. ICN its experimentation with ICN architectures and protocols, the design
Ping is designed as a "first line of defense" tool to troubleshoot of ICN Ping might change accordingly. ICN Ping is designed as a
ICN architectures and protocols. As such, this document is "first line of defense" tool to troubleshoot ICN architectures and
classified as an experimental RFC. Note that a measurement protocols. As such, this document is classified as an Experimental
application is needed to make proper use of ICN Ping in order to RFC. Note that a measurement application is needed to make proper
compute various statistics, such as the variance, average, maximum use of ICN Ping in order to compute various statistics, such as
and minimum RTT values as well as loss rates. average, maximum, and minimum Round-Trip Time (RTT) values, variance
in RTTs, and loss rates.
This document is not an Internet Standards Track specification; it is This RFC represents the consensus of the Information-Centric
published for examination, experimental implementation, and Networking Research Group (ICNRG) of the Internet Research Task Force
evaluation. This document defines an Experimental Protocol for the (IRTF).
Internet community. This document is a product of the Internet
Research 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
consensus of the Information-Centric Networking Research Group of the
Internet Research Task Force (IRTF). Documents approved for
publication by the IRSG are not candidates for any level of Internet
Standard; see Section 2 of RFC 7841.
1.1. Requirements Language 1.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
document are to be interpreted as described in BCP 14 [RFC2119] "OPTIONAL" in this document are to be interpreted as described in
[RFC8174] when, and only when, they appear in all capitals, as shown BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
here. capitals, as shown here.
1.2. Terminology 1.2. Terminology
This specification uses the terminology defined in [RFC8793]. To aid This specification uses the terminology defined in [RFC8793]. To aid
the understanding of readers, we additionally define the following the reader, we additionally define the following terms:
terms:
* Producer's name: The name prefix that a request must carry in Producer's Name: The name prefix that a request must carry in order
order to reach a producer over an ICN network. to reach a producer over an ICN network.
* Named Data: A synonym for a content object. Named Data: A synonym for a Content Object.
* Round Trip Time (RTT): The time between sending a request for a Round-Trip Time (RTT): The time between sending a request for a
specific piece of named data and receiving the corresponding piece specific piece of named data and receiving the corresponding piece
of named data. of named data.
* Sender: An entity that sends a request for named data or a piece Sender: An entity that sends a request for named data or a piece of
of named data. named data.
* Name of a sender: An alias of producer's name. Name of a Sender: An alias of a producer's name.
* Border forwarder: The forwarder that is the border of a network Border Forwarder: The forwarder that is the border of a network
region where a producer's name is directly routable (i.e., the region where a producer's name is directly routable (i.e., the
producer's name is present in the FIB of forwarders within this producer's name is present in the FIB of forwarders within this
network region). network region).
2. Background on IP-Based Ping Operation 2. Background on IP-Based Ping Operation
In IP-based ping, an IP address is specified by the user either In IP-based ping, an IP address is specified by the user either
directly, or via translation of a domain name through DNS. The ping directly or via translation of a domain name through DNS. The ping
client application sends a number of ICMP Echo Request packets with client application sends a number of ICMP Echo Request packets with
the specified IP address as the IP destination address and an IP the specified IP address as the IP destination address and an IP
address from the client's host as the IP source address. address from the client's host as the IP source address.
Each ICMP Echo Request is forwarded across the network based on its Each ICMP Echo Request is forwarded across the network based on its
destination IP address. If it eventually reaches the destination, destination IP address. If it eventually reaches the destination,
the destination responds by sending back an ICMP Echo Reply packet to the destination responds by sending back an ICMP Echo Reply packet to
the IP source address from the ICMP Echo Request. the IP source address from the ICMP Echo Request.
If an ICMP Echo Request does not reach the destination or the Echo If an ICMP Echo Request does not reach the destination or the Echo
reply is lost, the ping client times out. Any ICMP error messages, Reply is lost, the ping client times out. Any ICMP error messages
such as "no route to destination", generated by the ICMP Echo Request generated in response to the ICMP Echo Request message, such as "No
message are returned to the client and reported. route to destination", are returned to the client and reported.
3. Ping Functionality Challenges and Opportunities in ICN 3. Ping Functionality Challenges and Opportunities in ICN
In ICN, the communication paradigm is based exclusively on named In ICN, the communication paradigm is based exclusively on named
objects. An Interest is forwarded across the network based on the objects. An Interest message is forwarded across the network based
name prefix that it carries. Eventually, a content object is on the name prefix that it carries. Eventually, a Content Object is
retrieved either from a producer application or some forwarder's retrieved from either a producer application or some forwarder's
Content Store (CS). Content Store (CS).
IP-based ping was built as an add-on measurement and debugging tool 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 on top of an already-existing network architecture. In ICN, we have
the opportunity to incorporate diagnostic mechanisms directly in the the opportunity to incorporate diagnostic mechanisms directly in the
network layer protocol, and hopefully provide more powerful network-layer protocol and, hopefully, provide more powerful
diagnostic capability than can be realized through the layered ICMP diagnostic capability than can be realized through the layered ICMP
Echo approach. Echo approach.
An ICN network differs from an IP network in at least 4 important An ICN network differs from an IP network in at least four important
ways: ways (four of which are as follows):
* IP identifies interfaces to an IP network with a fixed-length * IP identifies interfaces to an IP network with a fixed-length
address, and delivers IP packets to one or more of these address and delivers IP packets to one or more of these
interfaces. ICN identifies units of data in the network with a interfaces. ICN identifies units of data in the network with a
variable length name consisting of a hierarchical list of name variable-length name consisting of a hierarchical list of name
components. components.
* An IP-based network depends on the IP packets having source IP * An IP-based network depends on the IP packets having source IP
addresses that are used as the destination address for replies. addresses that are used as the destination address for replies.
On the other hand, ICN Interests do not have source addresses and On the other hand, ICN Interests do not have source addresses, and
they are forwarded based on names, which do not refer to a unique they are forwarded based on names, which do not refer to a unique
end-point. Data packets follow the reverse path of the Interests endpoint. Data packets follow the reverse path of the Interests
based on hop-by-hop state created during Interest forwarding. based on hop-by-hop state created during Interest forwarding.
* An IP network supports multi-path, single destination, stateless * An IP network supports multi-path, single-destination, stateless
packet forwarding and delivery via unicast, a limited form of packet 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 multi-destination delivery via multicast. In contrast, ICN
supports multi-path and multi-destination stateful Interest supports multi-path and multi-destination stateful Interest
forwarding and multi-destination delivery of named data. This forwarding and multi-destination delivery of named data. This
single forwarding semantic subsumes the functions of unicast, single forwarding semantic subsumes the functions of unicast,
anycast, and multicast. As a result, consecutive (or anycast, and multicast. As a result, consecutive (or
retransmitted) ICN Interest messages may be forwarded through an retransmitted) ICN Interest messages may be forwarded through an
ICN network along different paths, and may be forwarded to ICN network along different paths and may be forwarded to
different data sources (e.g., end-node applications, in-network different data sources (e.g., end-node applications and in-network
storage) holding a copy of the requested unit of data. This can storage) holding a copy of the requested unit of data. This can
lead to a significant variance in round-trip times, which while lead to a significant variance in RTTs; such variance, while
resulting in a more robust overall forwarding architecture, has resulting in a more robust overall forwarding architecture, has
implications for a network troubleshooting mechanism like ping. implications for a network troubleshooting mechanism like ping.
* In the case of multiple Interests with the same name arriving at a * In the case of multiple Interests with the same name arriving at a
forwarder, a number of Interests may be aggregated in a common forwarder, a number of Interests may be aggregated in a common
Pending Interest Table (PIT) entry and only one of them forwarded Pending Interest Table (PIT) entry and only one of them forwarded
onward. Depending on the lifetime of a PIT entry, the round-trip onward. Depending on the lifetime of a PIT entry, the RTT of an
time an Interest-Data exchange might significantly vary (e.g., it Interest-Data exchange might vary significantly (e.g., it might be
might be shorter than the full round-trip time to reach the shorter than the full RTT to reach the original content producer).
original content producer). To this end, the round-trip time To this end, the RTT experienced by consumers might also vary.
experienced by consumers might also vary.
These differences introduce new challenges, new opportunities and new These differences introduce new challenges, new opportunities, and
requirements in the design of an ICN ping protocol. Following this new requirements regarding the design of an ICN Ping protocol.
communication model, a ping client should be able to express ping Following this communication model, a ping client should be able to
echo requests with some name prefix and receive responses. express Ping Echo Requests with some name prefix and receive
responses.
Our goals are the following: Our goals are as follows:
* Test the reachability and the operational state of an ICN * Test the reachability and the operational state of an ICN
forwarder. forwarder.
* Test the reachability of a producer or a data repository (in the * Test the reachability of a producer or a data repository (in the
sense of whether Interests for a prefix that it serves can be sense of whether Interests for a prefix that it serves can be
forwarded to it) and discover the forwarder with local forwarded to it), and discover the forwarder with local
connectivity to (an instance of) this producer or repository. connectivity to (an instance of) this producer or repository.
* Test whether a specific named object is cached in some on-path CS * Test whether a specific named object is cached in some on-path CS
(e.g., a video segment with a name "/video/_seq=1”), and, if so, (e.g., a video segment with the name "/video/_seq=1"), and, if so,
return the administrative name of the corresponding forwarder return the administrative name of the corresponding forwarder
(e.g., a forwarder with an administrative name "/ISP/forwarder1”). (e.g., a forwarder with the administrative name
"/ISP/forwarder1").
* Perform some simple network performance measurements, such as RTT * Perform some simple network performance measurements, such as RTT
and loss rate. and loss rate.
To this end, a ping name can represent: To this end, a ping name can represent:
* An administrative name that has been assigned to a forwarder. * An administrative name that has been assigned to a forwarder.
* A name that includes an application's namespace as a prefix. * A name that includes an application's namespace as a prefix.
* A named object that might reside in some in-network storage. * A named object that might reside in some in-network storage.
In order to provide stable and reliable diagnostics, it is desirable In order to provide stable and reliable diagnostics, it is desirable
that the packet encoding of a ping echo request enable the forwarders that the packet encoding of a Ping Echo Request enable the forwarders
to distinguish a ping from a normal Interest, while also allowing for to distinguish a ping from a normal Interest, while diverging as
forwarding behavior to be as similar as possible to that of an little as possible from the forwarding behavior for an Interest
Interest packet. In the same way, the encoding of a ping echo reply packet. In the same way, the encoding of a Ping Echo Reply should
should allow for forwarder processing as close as possible to that minimize any processing differences from those employed for a data
used for data packets. packet by the forwarders.
The ping protocol should also enable relatively robust round-trip The ping protocol should also enable relatively robust RTT
time measurements. To this end, it is valuable to have a mechanism measurements. To this end, it is valuable to have a mechanism to
to steer consecutive ping echo requests for the same name towards an steer consecutive Ping Echo Requests for the same name towards an
individual path. Such a capability was initially published in individual path. Such a capability was initially published in
[PATHSTEERING] and has been specified for CCNx and NDN in [PATHSTEERING] and has been specified for CCNx and NDN in [RFC9531].
[I-D.irtf-icnrg-pathsteering].
It is also important, in the case of ping echo requests for the same In the case of Ping Echo Requests for the same name from different
name from different sources to have a mechanism to avoid those sources, it is also important to have a mechanism to avoid those
requests being aggregated in the PIT. To this end, we need some requests being aggregated in the PIT. To this end, we need some
encoding in the ping echo requests to make each request for a common encoding in the Ping Echo Requests to make each request for a common
name unique, hence avoiding PIT aggregation and further enabling the name unique, hence avoiding PIT aggregation and further enabling the
exact match of a response with a particular ping packet. However, exact match of a response with a particular ping packet. However,
avoiding PIT aggregation could lead to PIT DoS attacks. avoiding PIT aggregation could lead to PIT DoS attacks.
4. ICN Ping Echo CCNx Packet Formats 4. ICN Ping Echo CCNx Packet Formats
In this section, we describe the Echo Packet Format according to the In this section, we describe the Echo packet formats according to the
CCNx packet format [RFC8569], where messages exist within outermost CCNx packet format [RFC8569], where messages exist within outermost
containments (packets). Specifically, we specify two types of ping containments (packets). Specifically, we propose two types of ping
packets, an echo request and an echo reply packet type. packets: an Echo Request and an Echo Reply.
4.1. ICN Ping Echo Request CCNx Packet Format 4.1. ICN Ping Echo Request CCNx Packet Format
The format of the ping echo request packet is presented below: The format of the Ping Echo Request packet is presented below:
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 |
| | | |
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
Figure 1: Echo Request CCNx Packet Format Figure 1: Echo Request CCNx Packet Format
The existing packet header fields have the same definition as the The existing packet header fields have the same definition as the
header fields of a CCNx Interest packet. The value of the packet header fields of a CCNx Interest packet. The value of the packet
type field is _PT_ECHO_REQUEST_. See Section 9 for the value type field is _PT_ECHO_REQUEST_. See Section 9 for the value
assignments. assignment.
Compared to the typical format of a CCNx packet header from Compared to the typical format of a CCNx packet header [RFC8609],
[RFC8569], in order to enable path steering of Echo Requests, there there is a new optional fixed header added to the packet header:
is an optional fixed header Path label TLV as specified in section
3.1 of [I-D.irtf-icnrg-pathsteering] added to the packet header:
The message format of an echo request is presented below: * 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 requests expressed by a client towards a
common forwarding path or different forwarding paths. The Path
Label TLV is specified in [RFC9531].
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 The message format of an Echo Request is presented below:
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 |
| | | |
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
Figure 2: Echo Request Message Format Figure 2: Echo Request Message Format
The echo request message is of type T_DISCOVERY. The Name TLV has The Echo Request message is of type T_DISCOVERY. The Name TLV has
the structure described in [RFC8609]. The name consists of the the structure described in [RFC8609]. The name consists of the
prefix that we would like to ping appended with a nonce typed name prefix that we would like to ping appended with a nonce typed name
segment (T_NONCE) as its last segment. The nonce can be encoded as a segment (T_NONCE) as its last segment. The nonce can be encoded as a
base64-encoded string with the URL-safe alphabet as defined in base64-encoded string with the URL-safe alphabet as defined in
Section 5 of [RFC4648], with padding omitted. See Section 9 for the Section 5 of [RFC4648], with padding omitted. See Section 9 for the
value assigned to this name segment type. The value of this TLV is a value assigned to this name segment type. The value of this TLV is a
64-bit nonce. The purpose of the nonce is to avoid Interest 64-bit nonce. The purpose of the nonce is to avoid Interest
aggregation and allow client matching of replies with requests. As aggregation and allow client matching of replies with requests. As
described below, the nonce is ignored for CS checking. described below, the nonce is ignored for CS checking.
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 |
| | | |
| | | |
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
Figure 3: T_NONCE Name Segment TLV for Echo Request messages Figure 3: T_NONCE Name Segment TLV for Echo Request Messages
4.2. Ping Echo Reply CCNx Packet Format 4.2. ICN Ping Echo Reply CCNx Packet Format
The format of a ping echo reply packet is presented below: The format of a Ping Echo Reply packet is presented below:
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 |
| | | |
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
Figure 4: Echo Reply CCNx Packet Format Figure 4: Echo Reply CCNx Packet Format
The header of an echo reply consists of the header fields of a CCNx The header of an Echo Reply consists of the header fields of a CCNx
Content Object and a hop-by-hop Path label TLV. The value of the Content Object and a hop-by-hop Path Label TLV. The value of the
packet type field is PT_ECHO_REPLY. See Section 9 for the value packet type field is PT_ECHO_REPLY. See Section 9 for the value
assignments. The Path label header TLV from section 3.1 of assignment. The Path Label header TLV (Section 3.1 of [RFC9531]) is
[I-D.irtf-icnrg-pathsteering] is as defined for the echo request as defined for the Echo Request packet.
packet.
A ping echo reply message is of type T_OBJECT, contains a Name TLV 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. not be returned from network caches.
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 |
| | | |
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
Figure 5: Echo Reply Message Format Figure 5: Echo Reply Message Format
The PayloadType TLV is presented below. It is of type The PayloadType TLV is presented below. It is of type
T_PAYLOADTYPE_DATA, and the data schema consists of 3 TLVs: 1) the T_PAYLOADTYPE_DATA, and the data schema consists of three TLVs:
name of the sender of this reply (with the same structure as a CCNx
Name TLV), 2) the sender's signature of their own name (with the same
structure as a CCNx ValidationPayload TLV), 3) a TLV with a return
code to indicate what led to the generation of this reply (i.e.,
existence of a local application, a CS hit or a match with a
forwarder's administrative name as specified in Section 6).
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 1) the name of the sender of this reply (with the same structure as
a CCNx Name TLV),
2) the sender's signature of their own name (with the same structure
as a CCNx ValidationPayload TLV), and
3) a TLV with a return code to indicate what led to the generation
of this reply (i.e., the existence of a local application, a CS
hit, or a match with a forwarder's administrative name as
specified in Section 6).
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 /
/ / / /
+---------------+---------------+---------------+---------------+ +---------------+---------------+---------------+---------------+
Figure 6: Echo Reply Message Format
The goal of including the name of the sender in the echo reply is to Figure 6: Echo Reply PayloadType TLV Format
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 enable the user to reach this entity directly to ask for further
management/administrative information using generic Interest-Data management/administrative information using generic Interest-Data
exchanges or by employing a more comprehensive management tool such exchanges or by employing a more comprehensive management tool, such
as CCNinfo [RFC9344] after a successful verification of the sender's as CCNinfo [RFC9344], after a successful verification of the sender's
name. name.
The types of the Echo Reply Code field are the following: The types of the Echo Reply Code field are as follows:
* T_ECHO_RETURN_FORWARDER: Indicates that the target name matched T_ECHO_RETURN_FORWARDER: Indicates that the target name matched the
the administrative name of a forwarder. administrative name of a forwarder.
* T_ECHO_RETURN_APPLICATION: Indicates that the target name matched T_ECHO_RETURN_APPLICATION: Indicates that the target name matched a
a prefix served by an application. prefix served by an application.
* T_ECHO_RETURN_OBJECT: Indicates that the target name matched the T_ECHO_RETURN_OBJECT: Indicates that the target name matched the
name of an object in a forwarder's CS. name of an object in a forwarder's CS.
5. ICN Ping Echo NDN Packet Formats 5. ICN Ping Echo NDN Packet Formats
In this section, we present the ICN Ping Echo Request and Reply In this section, we present the ICN Ping Echo Request and Reply
Format according to the NDN packet specification [NDNTLV]. packet formats according to the NDN packet format specification
[NDNTLV].
5.1. ICN Ping Echo Request NDN Packet Format 5.1. ICN Ping Echo Request NDN Packet Format
An echo request is encoded as an NDN Interest packet. Its format is An Echo Request is encoded as an NDN Interest packet. Its format is
the following: as follows:
EchoRequest = INTEREST-TYPE TLV-LENGTH EchoRequest = INTEREST-TYPE TLV-LENGTH
Name Name
MustBeFresh MustBeFresh
Nonce Nonce
ApplicationParameters? ApplicationParameters?
Figure 7: Echo Request NDN Packet Format Figure 7: Echo Request NDN Packet Format
The name field of an echo request consists of the name prefix to be The name field of an Echo Request consists of the name prefix to be
pinged, a nonce value (it can be the value of the Nonce field) and pinged, a nonce value (it can be the value of the Nonce field), and
the suffix "ping" to denote that this Interest is a ping request the suffix "ping" to denote that this Interest is a ping request
(added as a KeywordNameComponent). When the "ApplicationParameters" (added as a KeywordNameComponent [NDNTLV]). When the
element is present, a parametersSha256DigestComponent is added as the "ApplicationParameters" element is present, a
last name segment. ParametersSha256DigestComponent (Section 6) is added as the last name
segment.
An echo request MAY carry a Path label TLV in the NDN Link Adaptation An Echo Request MAY carry a Path Label TLV in the NDN Link Adaptation
Protocol [NDNLPv2] as specified in [I-D.irtf-icnrg-pathsteering]. Protocol [NDNLPv2] as specified in [RFC9531].
Since the NDN packet format does not provide a mechanism to prevent Since the NDN packet format does not provide a mechanism to prevent
the network from caching specific data packets, we use the the network from caching specific data packets, we use the
MustBeFresh element for echo requests (in combination with a MustBeFresh TLV for Echo Requests (in combination with a
Freshness Period TLV of value 1 for echo replies) to avoid fetching FreshnessPeriod TLV with a value of 1 for Echo Replies) to avoid
cached echo replies with an expired freshness period [REALTIME]. fetching cached Echo Replies with an expired freshness period
[REALTIME].
5.2. Ping Echo Reply NDN Packet Format 5.2. ICN Ping Echo Reply NDN Packet Format
An echo reply is encoded as an NDN Data packet. Its format is the An Echo Reply is encoded as an NDN Data packet. Its format is as
following: follows:
EchoReply = DATA-TLV TLV-LENGTH EchoReply = DATA-TLV TLV-LENGTH
Name Name
MetaInfo MetaInfo
Content Content
Signature Signature
Figure 8: Echo Reply NDN Packet Format Figure 8: Echo Reply NDN Packet Format
An echo reply MAY contain a Path label TLV in the NDN Link Adaptation An Echo Reply MAY carry a Path Label TLV in the NDN Link Adaptation
Protocol [NDNLPv2] as specified in [I-D.irtf-icnrg-pathsteering], Protocol [NDNLPv2] as specified in [RFC9531], since it might be
since it might be modified in a hop-by-hop fashion by the forwarders modified in a hop-by-hop fashion by the forwarders along the reverse
along the reverse path. path.
The name of an echo reply is the name of the corresponding echo The name of an Echo Reply is the name of the corresponding Echo
request, while the format of the MetaInfo field is the following: Request while the format of the MetaInfo field is as follows:
MetaInfo = META-INFO-TYPE TLV-LENGTH MetaInfo = META-INFO-TYPE TLV-LENGTH
ContentType ContentType
FreshnessPeriod FreshnessPeriod
Figure 9: MetaInfo TLV Figure 9: MetaInfo TLV
The value of the ContentType TLV is 0. The value of the The value of the ContentType TLV is 0. The value of the
FreshnessPeriod TLV is 1, so that the replies are treated as stale FreshnessPeriod TLV is 1, so that the replies are treated as stale
data (almost instantly) as they are received by a forwarder. data (almost instantly) as they are received by a forwarder.
The content of an echo reply consists of the following 2 TLVs: The content of an Echo Reply consists of the following two TLVs:
Sender's name (with a structure similar as an NDN Name TLV) and Echo Sender's Name (with a structure similar to an NDN Name TLV) and Echo
Reply Code. There is no need to have a separate TLV for the sender's Reply Code. There is no need to have a separate TLV for the sender's
signature in the content of the reply, since every NDN data packet signature in the content of the reply, since every NDN Data packet
carries the signature of the data producer. carries the signature of the data producer.
The Echo Reply Code TLV format is the following (with the values The Echo Reply Code TLV format is as follows (with the values
specified in Section 4.2): specified in Section 4.2):
EchoReplyCode = ECHOREPLYCODE-TLV-TYPE TLV-LENGTH 2*OCTET EchoReplyCode = ECHOREPLYCODE-TLV-TYPE TLV-LENGTH 2*OCTET
Figure 10: Echo Reply Code TLV Figure 10: Echo Reply Code TLV
6. Forwarder Handling 6. Forwarder Handling
We present the workflow of the forwarder's operation in Figure 11. We present the workflow of the forwarder's operation in Figure 11
When a forwarder receives an echo request, it first extracts the below. When a forwarder receives an Echo Request, it first extracts
message's base name (i.e., the request name with the Nonce name the message's base name (i.e., the request name with the Nonce name
segment excluded as well as the suffix "ping" and the segment excluded as well as the suffix "ping" and the
ParametersSha256DigestComponent in the case of an echo request with ParametersSha256DigestComponent in the case of an Echo Request with
the NDN packet format). the NDN packet format).
In some cases, the forwarder originates an echo reply, sending the In some cases, the forwarder originates an Echo Reply, sending the
reply downstream through the face on which the echo request was reply downstream through the face on which the Echo Request was
received. This echo reply includes the forwarder's own name and received. This Echo Reply includes the forwarder's own name and
signature and the appropriate echo reply code based on the condition signature and the appropriate Echo Reply Code based on the condition
that triggered the reply generation. It also includes a Path label that triggered the generation of the reply. It also includes a Path
TLV, initially containing a null value (since the echo reply Label TLV, initially containing a null value (since the Echo Reply
originator did not forward the request and, thus, does not make a originator does not forward the request and thus does not make a path
path choice). choice).
The forwarder generates and returns an echo reply in the following The forwarder generates and returns an Echo Reply in the following
cases: cases:
* Assuming that a forwarder has been given one or more * Assuming that a forwarder has been given one or more
administrative names, the echo request base name exactly matches administrative names, the Echo Request base name exactly matches
any of the forwarder's administrative name(s). any of the forwarder's administrative names.
* The echo request's base name exactly matches the name of a * The Echo Request's base name exactly matches the name of a Content
content-object residing in the forwarder's CS (unless the ping Object residing in the forwarder's CS (unless the ping client
client application has chosen not to receive replies due to CS application has chosen not to receive replies due to CS hits as
hits as specified in Appendix A). specified in Appendix A).
* The echo request base name matches (in a Longest Prefix Match * The Echo Request base name matches (in a Longest Name Prefix Match
manner) a FIB entry with an outgoing face referring to a local (LNPM) manner) a FIB entry with an outgoing face referring to a
application. local application.
If none of the conditions to reply to the echo request are met, the If none of the conditions for replying to the Echo Request are met,
forwarder will attempt to forward the echo request upstream based on the forwarder will attempt to forward the Echo Request upstream based
the path steering value (if present), the results of the FIB LPM on the Path Steering value (if present), the results of the FIB LNPM
lookup and PIT creation (based on the name including the nonce typed lookup and PIT creation. These lookups are based on including the
name segment and the suffix "ping" in the case of an echo request Nonce and the suffix "ping" as name segments of the Name in the case
with the NDN packet format). If no valid next-hop is found, an of an Echo Request with the NDN packet format. If no valid next hop
InterestReturn is sent downstream indicating "no route" (as with a is found, an InterestReturn is sent downstream indicating "No Route"
failed attempt to forward an ordinary Interest). (as with a failed attempt to forward an ordinary Interest).
A received echo reply will be matched to an existing PIT entry as A received Echo Reply will be matched to an existing PIT entry as
usual. On the reverse path, the path steering TLV of an echo reply usual. On the reverse path, the Path Steering TLV of an Echo Reply
will be updated by each forwarder to encode its next-hop choice. will be updated by each forwarder to encode its next-hop choice.
When included in subsequent echo requests, this Path label TLV allows When included in subsequent Echo Requests, this Path Label TLV allows
the forwarders to steer the echo requests along the same path. the forwarders to steer the Echo Requests along the same path.
------------------------------------------------------------------------ ------------------------------------------------------------------------
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
Figure 11: Forwarder Operation Figure 11: Forwarder Operation
7. Protocol Operation For Locally-Scoped Namespaces 7. Protocol Operation for Locally Scoped Namespaces
In this section, we elaborate on 2 alternative design approaches in In this section, we elaborate on two alternative design approaches in
cases that the pinged prefix corresponds to a locally-scoped cases where the pinged prefix corresponds to a locally scoped
namespace not directly routable from the client's local network. namespace not directly routable from the client's local network.
The first approach leverages the NDN Link Object [SNAMP]. The first approach leverages the NDN Link Object [SNAMP].
Specifically, the ping client attaches to the expressed request a Specifically, the ping client attaches to the expressed request a
LINK Object that contains a number of routable name prefixes, based Link Object that contains a number of routable name prefixes, based
on which the request can be forwarded until it reaches a network on which the request can be forwarded until it reaches a network
region where the request name itself is routable. A LINK Object is region where the request name itself is routable. A Link Object is
created and signed by a data producer allowed to publish data under a created and signed by a data producer allowed to publish data under a
locally-scoped namespace. The way that a client retrieves a LINK locally scoped namespace. The way that a client retrieves a Link
Object depends on various network design factors and is out of the Object depends on various network design factors and is out of scope
scope of the current draft. for this document.
Based on the current usage of the LINK Object by the NDN team, a At the time of this writing, and based on usage of the Link Object by
forwarder at the border of the region where an Interest name becomes the NDN team [NDNLPv2], a forwarder at the border of the region where
routable must remove the LINK Object from incoming Interests. The an Interest name becomes routable must remove the Link Object from
Interest state maintained along the entire forwarding path is based incoming Interests. The Interest state maintained along the entire
on the Interest name regardless of whether it was forwarded based on forwarding path is based on the Interest name regardless of whether
its name or a routable prefix in the LINK Object. it was forwarded based on its name or a routable prefix in the Link
Object.
The second approach is based on prepending a routable prefix to the The second approach is based on prepending a routable prefix to the
locally-scoped name. The resulting prefix will be the name of the locally scoped name. The resulting prefix will be the name of the
echo requests expressed by the client. In this way, a request will Echo Requests expressed by the client. In this way, a request will
be forwarded based on the routable part of its name. When it reaches be forwarded based on the routable part of its name. When it reaches
the network region where the original locally-scoped name is the network region where the original locally scoped name is
routable, the border forwarder rewrites the request name and deletes routable, the border forwarder rewrites the request name and deletes
its routable part. There are two conditions for a forwarder to its routable part. There are two conditions for a forwarder to
perform this rewriting operation on a request: 1) the routable part perform this rewriting operation on a request:
of the request name matches a routable name of the network region
adjacent to the forwarder (assuming that a forwarder is aware of
those names) and 2) the remaining part of the request name is
routable across the network region of this forwarder.
The state maintained along the path, where the locally-scoped name is 1) the routable part of the request name matches a routable name of
not routable, is based on the routable prefix along with the locally- the network region adjacent to the forwarder (assuming that a
scoped prefix. Within the network region that the locally-scoped forwarder is aware of those names), and
prefix is routable, the state is based only on it. To ensure that
the generated replies reach the ping client, the border forwarder has 2) the remaining part of the request name is routable across the
also to rewrite the name of a reply and prepend the routable prefix network region of this forwarder.
of the corresponding echo request.
The state along the path depends on whether the request is traversing
the portion of the network where the locally scoped name is routable.
In this case, the forwarding can be based entirely on the locally
scoped name. However, where a portion of the path lies outside the
region where the locally scoped name is routable, the border router
has to rewrite the name of a reply and prepend the routable prefix of
the corresponding request to ensure that the generated replies will
reach the client.
8. Security Considerations 8. Security Considerations
A reflection attack could be mounted by a compromised forwarder in A reflection attack could be mounted by a compromised forwarder in
the case of an echo reply with the CCNx packet format if that the case of an Echo Reply with the CCNx packet format if that
forwarder includes in the reply the name of a victim forwarder. This forwarder includes in the reply the name of a victim forwarder. This
could convince a client to direct the future administrative traffic could convince a client to direct the future administrative traffic
towards the victim. To foil such reflection attacks, the forwarder towards the victim. To foil such reflection attacks, the forwarder
that generates a reply must sign the name included in the payload. that generates a reply must sign the name included in the payload.
In this way, the client is able to verify that the included name is In this way, the client is able to verify that the included name is
legitimate and refers to the forwarder that generated the reply. legitimate and refers to the forwarder that generated the reply.
Alternatively, the forwarder could include in the reply payload their Alternatively, the forwarder could include in the reply payload their
routable prefix(es) encoded as a signed NDN Link Object [SNAMP]. routable prefix(es) encoded as a signed NDN Link Object [SNAMP].
Interest flooding attack amplification is possible in the case of the Interest flooding attack amplification is possible in the case of the
second approach to deal with locally-scoped namespaces described in second approach for dealing with locally scoped namespaces as
Section 7. To eliminate such amplification, a border forwarder will described in Section 7. To eliminate such amplification, a border
have to maintain extra state in order to prepend the correct routable forwarder will have to maintain extra state in order to prepend the
prefix to the name of an outgoing reply, since the forwarder might be correct routable prefix to the name of an outgoing reply, since the
attached to multiple network regions (reachable under different forwarder might be attached to multiple network regions (reachable
prefixes) or a network region attached to this forwarder might be under different prefixes) or a network region attached to this
reachable under multiple routable prefixes. forwarder might be reachable under multiple routable prefixes.
Another example of an attack could be the ICN equivalent of port Another example of an attack could be the ICN equivalent of port
knocking, where an attacker tries to discover certain forwarder knocking, where an attacker tries to discover certain forwarder
implementations for the purpose of exploiting potential implementations for the purpose of exploiting potential
vulnerabilities. vulnerabilities.
9. IANA Considerations 9. IANA Considerations
IANA will assign 0x05 to "PT_ECHO_REQUEST" and 0x06 to IANA has assigned 0x05 to "PT_ECHO_REQUEST" and 0x06 to
"PT_ECHO_REPLY" in the CCNx Packet Types registry established by "PT_ECHO_REPLY" in the "CCNx Packet Types" registry established by
[RFC8609]. [RFC8609].
IANA will assign 0x0003 to "T_NONCE" in the Name Segment Type IANA IANA has assigned 0x0003 to "T_NONCE" in the "CCNx Name Segment
Registry for CCNx established by [RFC8609]. Types" registry established by [RFC8609].
IANA will create an "Echo Reply Code" registry. IANA will assign
0x01 to "T_ECHO_RETURN_FORWARDER", 0x02 to
"T_ECHO_RETURN_APPLICATION", and 0x03 to "T_ECHO_RETURN_OBJECT" in
the "Echo Reply Code" registry.
10. Acknowledgements IANA has created a new registry called "CCNx Echo Reply Codes". The
registration procedure is Specification Required [RFC8126]. In this
registry, IANA has assigned 0x01 to "T_ECHO_RETURN_FORWARDER", 0x02
to "T_ECHO_RETURN_APPLICATION", and 0x03 to "T_ECHO_RETURN_OBJECT".
The authors would like to thank Mark Stapp for the fruitful 10. References
discussion on the objectives of the ICN ping protocol.
11. References 10.1. Normative References
11.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>. May 2017, <https://www.rfc-editor.org/info/rfc8174>.
skipping to change at page 17, line 32 skipping to change at line 767
DOI 10.17487/RFC8609, July 2019, DOI 10.17487/RFC8609, July 2019,
<https://www.rfc-editor.org/info/rfc8609>. <https://www.rfc-editor.org/info/rfc8609>.
[RFC8793] Wissingh, B., Wood, C., Afanasyev, A., Zhang, L., Oran, [RFC8793] Wissingh, B., Wood, C., Afanasyev, A., Zhang, L., Oran,
D., and C. Tschudin, "Information-Centric Networking D., and C. Tschudin, "Information-Centric Networking
(ICN): Content-Centric Networking (CCNx) and Named Data (ICN): Content-Centric Networking (CCNx) and Named Data
Networking (NDN) Terminology", RFC 8793, Networking (NDN) Terminology", RFC 8793,
DOI 10.17487/RFC8793, June 2020, DOI 10.17487/RFC8793, June 2020,
<https://www.rfc-editor.org/info/rfc8793>. <https://www.rfc-editor.org/info/rfc8793>.
11.2. Informative References 10.2. Informative References
[I-D.irtf-icnrg-pathsteering]
Moiseenko, I. and D. R. Oran, "Path Steering in CCNx and
NDN", Work in Progress, Internet-Draft, draft-irtf-icnrg-
pathsteering-03, 23 July 2023,
<https://datatracker.ietf.org/doc/html/draft-irtf-icnrg-
pathsteering-03>.
[NDNLPv2] "Named Data Networking Link Adaptation Protocol v2", [NDNLPv2] NDN team, "NDNLPv2: Named Data Networking Link Adaptation
various, <https://redmine.named- Protocol v2", February 2023, <https://redmine.named-
data.net/projects/nfd/wiki/NDNLPv2>. data.net/projects/nfd/wiki/NDNLPv2>.
[NDNTLV] "NDN Packet Format Specification.", 2021, [NDNTLV] NDN project team, "NDN Packet Format Specification",
February 2024,
<https://named-data.net/doc/NDN-packet-spec/current/>. <https://named-data.net/doc/NDN-packet-spec/current/>.
[PATHSTEERING] [PATHSTEERING]
Moiseenko, I. and D. Oran, "Path switching in content Moiseenko, I. and D. Oran, "Path switching in content
centric and named data networks", in Proceedings of the centric and named data networks", ICN '17: Proceedings of
4th ACM Conference on Information-Centric Networking, the 4th ACM Conference on Information-Centric Networking,
2017. pp. 66-76, DOI 10.1145/3125719.3125721, September 2017,
<https://dl.acm.org/doi/10.1145/3125719.3125721>.
[REALTIME] Mastorakis, S., Gusev, P., Afanasyev, A., and L. Zhang, [REALTIME] Mastorakis, S., Gusev, P., Afanasyev, A., and L. Zhang,
"Real-Time Data Retrieval in Named Data Networking", in "Real-Time Data Retrieval in Named Data Networking", 2018
Proceedings of the 1st IEEE International Conference on 1st IEEE International Conference on Hot Information-
Hot Topics in Information-Centric Networking, 2017. Centric Networking (HotICN), Shenzhen, China, pp. 61-66,
DOI 10.1109/HOTICN.2018.8605992, August 2018,
<https://ieeexplore.ieee.org/document/8605992>.
[RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data [RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data
Encodings", RFC 4648, DOI 10.17487/RFC4648, October 2006, Encodings", RFC 4648, DOI 10.17487/RFC4648, October 2006,
<https://www.rfc-editor.org/info/rfc4648>. <https://www.rfc-editor.org/info/rfc4648>.
[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>.
[RFC9344] Asaeda, H., Ooka, A., and X. Shao, "CCNinfo: Discovering [RFC9344] Asaeda, H., Ooka, A., and X. Shao, "CCNinfo: Discovering
Content and Network Information in Content-Centric Content and Network Information in Content-Centric
Networks", RFC 9344, DOI 10.17487/RFC9344, February 2023, Networks", RFC 9344, DOI 10.17487/RFC9344, February 2023,
<https://www.rfc-editor.org/info/rfc9344>. <https://www.rfc-editor.org/info/rfc9344>.
[SNAMP] Afanasyev, A. and , "SNAMP: Secure namespace mapping to [RFC9531] Moiseenko, I. and D. Oran, "Path Steering in Content-
scale NDN forwarding", 2015. Centric Networking (CCNx) and Named Data Networking
(NDN)", RFC 9531, DOI 10.17487/RFC9531, March 2024,
<https://www.rfc-editor.org/info/rfc9531>.
[SNAMP] Afanasyev, A., Yi, C., Wang, L., Zhang, B., and L. Zhang,
"SNAMP: Secure namespace mapping to scale NDN forwarding",
2015 IEEE Conference on Computer Communications Workshops
(INFOCOM WKSHPS), Hong Kong, China, pp. 281-286,
DOI 10.1109/INFCOMW.2015.7179398, April 2015,
<https://ieeexplore.ieee.org/abstract/document/7179398>.
Appendix A. Ping Client Application (Consumer) Operation Appendix A. Ping Client Application (Consumer) Operation
This section is an informative appendix regarding the proposed ping This section is an informative appendix regarding the proposed ping
client operation. client operation.
The ping client application is responsible for generating echo The ping client application is responsible for generating Echo
requests for prefixes provided by users. Requests for prefixes provided by users.
When generating a series of echo requests for a specific name, the When generating a series of Echo Requests for a specific name, the
first echo request will typically not include a Path label TLV, since first Echo Request will typically not include a Path Label TLV, since
no TLV value is known. After an echo reply containing a Path label no TLV value is known. After an Echo Reply containing a Path Label
TLV is received, each subsequent echo request can include the TLV is received, each subsequent Echo Request can include the
received path steering value in the Path label header TLV to drive received Path Steering value in the Path Label header TLV to drive
the requests towards a common path as part of checking network the requests towards a common path as part of checking network
performance. To discover more paths, a client can omit the path performance. To discover more paths, a client can omit the Path
steering TLV in future requests. Moreover, for each new ping echo Steering TLV in future requests. Moreover, for each new Ping Echo
request, the client has to generate a new nonce and record the time Request, the client has to generate a new nonce and record the time
that the request was expressed. It will also set the lifetime of an that the request was expressed. It will also set the lifetime of an
echo request, which will have identical semantics to the lifetime of Echo Request, which will have semantics identical to the lifetime of
an Interest. an Interest.
Further, the client application might not wish to receive echo Further, the client application might not wish to receive Echo
replies due to CS hits. A mechanism to achieve that in CCNx would be Replies due to CS hits. A mechanism to achieve that in CCNx would be
to use a Content Object Hash Restriction TLV with a value of 0 in the to use a Content Object Hash Restriction TLV with a value of 0 in the
payload of an echo request message. In NDN, the exclude filter payload of an Echo Request message. In NDN, the exclude filter
selector can be used. selector can be used.
When it receives an echo reply, the client would typically match the When it receives an Echo Reply, the client would typically match the
reply to a sent request and compute the round-trip time of the reply to a sent request and compute the RTT of the request. It
request. It should parse the Path label value and decode the reply's should parse the Path Label value and decode the reply's payload to
payload to parse the the sender's name and signature. The client parse the sender's name and signature. The client should verify that
should verify that both the received message and the forwarder's name both the received message and the forwarder's name have been signed
have been signed by the key of the forwarder, whose name is included by the key of the forwarder, whose name is included in the payload of
in the payload of the reply (by fetching this forwarder's public key the reply (by fetching this forwarder's public key and verifying the
and verifying the contained signature). The client can also decode contained signature). The client can also decode the Echo Reply Code
the Echo Reply Code TLV to understand the condition that triggered TLV to understand the condition that triggered the generation of the
the generation of the reply. reply.
In the case that an echo reply is not received for a request within a In the case that an Echo Reply is not received for a request within a
certain time interval (lifetime of the request), the client should certain time interval (lifetime of the request), the client should
time-out and send a new request with a new nonce value up to some time out and send a new request with a new nonce value up to some
maximum number of requests to be sent specified by the user. maximum number of requests to be sent specified by the user.
Acknowledgements
The authors would like to thank Mark Stapp for the fruitful
discussion on the objectives of the ICN Ping protocol.
Authors' Addresses Authors' Addresses
Spyridon Mastorakis Spyridon Mastorakis
University of Notre Dame University of Notre Dame
South Bend, IN South Bend, IN
United States of America United States of America
Email: smastor2@nd.edu Email: smastor2@nd.edu
Dave Oran Dave Oran
Network Systems Research and Design Network Systems Research and Design
skipping to change at page 20, line 4 skipping to change at line 884
Network Systems Research and Design Network Systems Research and Design
Cambridge, MA Cambridge, MA
United States of America United States of America
Email: daveoran@orandom.net Email: daveoran@orandom.net
Jim Gibson Jim Gibson
Unaffiliated Unaffiliated
Belmont, MA Belmont, MA
United States of America United States of America
Email: jcgibson61@gmail.com Email: jcgibson61@gmail.com
Ilya Moiseenko Ilya Moiseenko
Apple Inc Apple Inc.
Cupertino, CA Cupertino, CA
United States of America United States of America
Email: iliamo@mailbox.org Email: iliamo@mailbox.org
Ralph Droms Ralph Droms
Unaffiliated Unaffiliated
Hopkinton, MA Hopkinton, MA
United States of America United States of America
Email: rdroms.ietf@gmail.com Email: rdroms.ietf@gmail.com
 End of changes. 141 change blocks. 
353 lines changed or deleted 382 lines changed or added

This html diff was produced by rfcdiff 1.48.