[Docs] [txt|pdf|xml] [Tracker] [Email] [Nits]

Versions: 00 01 02 03 04

ICNRG                                                      S. Mastorakis
Internet-Draft                                                      UCLA
Intended status: Experimental                                  J. Gibson
Expires: February 27, 2017                                  I. Moiseenko
                                                                R. Droms
                                                                 D. Oran
                                                           Cisco Systems
                                                         August 26, 2016


                           ICN Ping Protocol
                   draft-mastorakis-icnrg-icnping-00

Abstract

   This document presents the design of an ICN Ping protocol.  This
   includes the operations both on the client and the forwarder side.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   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 http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on February 27, 2017.

Copyright Notice

   Copyright (c) 2016 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of




Mastorakis, et al.      Expires February 27, 2017               [Page 1]


Internet-Draft                  ICN Ping                     August 2016


   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Requirements Language . . . . . . . . . . . . . . . . . .   2
   2.  Background on IP-Based Ping Operation . . . . . . . . . . . .   2
   3.  Ping Functionality Challenges and Opportunities in ICN  . . .   3
   4.  ICN Ping Echo Packet Formats  . . . . . . . . . . . . . . . .   5
     4.1.  ICN Ping Echo Request Packet Format . . . . . . . . . . .   5
     4.2.  Ping Echo Reply Packet Format . . . . . . . . . . . . . .   8
   5.  Forwarder Handling  . . . . . . . . . . . . . . . . . . . . .  11
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  12
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  12
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  12
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .  12
     8.2.  Informative References  . . . . . . . . . . . . . . . . .  12
   Appendix A.  Ping Client Application (Consumer) Operation . . . .  13
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  14

1.  Introduction

   Determining data plane reachability to a destination and taking
   coarse performance measurements of round trip time are fundamental
   facilities for network administration and troubleshooting.  In IP,
   where routing and forwarding are based on IP addresses, ICMP echo and
   ICMP echo response are the protocol mechanisms used for this purpose,
   generally exercised through the familiar ping utility.  In ICN, where
   routing and forwarding are based on name prefixes, the ability to
   determine reachability of names is required.

   This document proposes protocol mechanisms for a ping equivalent in
   ICN networks.  A non-normative appendix suggests useful properties
   for an ICN ping client application, analogous to IP ping, that
   originates echo requests and process echo replies.

1.1.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [RFC2119].

2.  Background on IP-Based Ping Operation

   In IP-based ping, an IP address is specified, either directly, or via
   translation of a domain name through DNS.  The ping client
   application sends a number of ICMP Echo Request packets with the



Mastorakis, et al.      Expires February 27, 2017               [Page 2]


Internet-Draft                  ICN Ping                     August 2016


   specified IP address as the IP destination address and an IP address
   from the client's host as the IP source address.

   An ICMP Echo Request is forwarded across the network based on its
   destination IP address.  If it eventually reaches the destination,
   the destination responds by sending back an ICMP Echo Reply packet to
   the IP source address from the ICMP Echo Request.

   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,
   such as "no route to destination", generated by the ICMP Echo Request
   message are returned to the client and reported.

3.  Ping Functionality Challenges and Opportunities in ICN

   In ICN protocols (e.g., NDN and CCNx), the communication paradigm is
   based exclusively on named objects.  An Interest is forwarded across
   the network based on its name.  Eventually, it retrieves a content
   object either from a producer application or some forwarder's Content
   Store (CS).

   IP-based ping was built as an add-on on top of an already existing
   network architecture.  In ICN, we have the opportunity to incorporate
   diagnostic mechanisms directly in the network layer protocol, and
   hopefully provide more powerful diagnostic capability than can be
   realized through the layered ICMP Echo approach.

   An ICN network differs from an IP network in at least 4 important
   ways:

   o  IP identifies interfaces to an IP network with a fixed-length
      number, and delivers IP packets to one or more interfaces.  ICN
      identifies units of data in the network with a variable length
      name consisting of a list of components.

   o  An IP-based network depends on the IP packets having source IP
      addresses that are used as the destination address for replies.
      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
      end-point.  Data packets follow the reverse path of the Interests
      based on hop-by-hop state created during Interest forwarding.

   o  An IP network supports multi-path, single destination, stateless
      packet forwarding and delivery via unicast, a limited form of
      multi-destination selected delivery with anycast, and group-based
      multi-destination delivery via multicast.  In contrast, ICN
      supports multi-path and multi-destination stateful Interest
      forwarding and multi-destination data delivery to units of named



Mastorakis, et al.      Expires February 27, 2017               [Page 3]


Internet-Draft                  ICN Ping                     August 2016


      data.  This single forwarding semantic subsumes the functions of
      unicast, anycast, and multicast.  As a result, consecutive (or
      retransmitted) ICN Interest messages may be forwarded through an
      ICN network along different paths, and may be forwarded to
      different data sources (e.g., end-node applications, in-network
      storage) holding a copy of the requested unit of data.  This can
      lead to a significant variance in round-trip times, which might
      not be desirable in the case of a network troubleshooting
      mechanism like ping.

   o  In the case of multiple Interests with the same name arriving at a
      forwarder, a number of Interests may be aggregated in a common
      Pending Interest Table (PIT) entry.  Depending on the lifetime of
      a PIT entry, the round-trip time an Interest-Data exchange might
      significantly vary (e.g., it might be shorter than the full round-
      trip time to reach the original content producer).  To this end,
      the round-trip time experienced by consumers might also vary.

   These differences introduce new challenges, new opportunities and new
   requirements in the design of an ICN ping protocol.  Following this
   communication model, a ping client should be able to express ping
   echo requests with some name prefix and receive responses.

   Our goals are the following:

   o  Test the reachability and the operation of an ICN forwarder.

   o  Test the reachability of an application (in the sense of whether
      Interests for a prefix that it serves can be forwarded to it) and
      discover the forwarder with local connectivity to (an instance of)
      the application.

   o  Test whether a specific named object is cached in some on-path CS,
      and, if so, return the corresponding forwarder.

   o  Perform some simple network performance measurements.

   To this end, a ping name can represent:

   o  An administrative name that has been assigned to a forwarder.

   o  A name that includes an application's namespace as a prefix.

   o  A named object that might reside in some in-network storage.

   In order to provide stable and reliable diagnostics, it is desirable
   that the packet encoding of a ping echo request enables the
   forwarders to distinguish a ping from a normal Interest, while also



Mastorakis, et al.      Expires February 27, 2017               [Page 4]


Internet-Draft                  ICN Ping                     August 2016


   allowing for forwarding behavior to be as similar as possible to that
   of an Interest packet.  In the same way, the encoding of a ping echo
   reply should allow for forwarder processing similar to that used for
   data packets.

   The ping protocol should also enable relatively stable round-trip
   time measurements.  To this end, it is important to have a mechanism
   to steer consecutive ping echo requests for the same name towards a
   common path.

   It is also important, in the case of ping echo requests for the same
   name from different sources, to have a mechanism to avoid aggregating
   those requests in the PIT.  To this end, we need some encoding in the
   ping echo requests to make each request for a common name unique, and
   hence avoid PIT aggregation and further enabling the exact matching
   of a response with a particular ping packet.

4.  ICN Ping Echo Packet Formats

   Based on the goals mentioned in the previous section, we propose two
   types of ping packets, an echo request and an echo reply packet type.
   Both these packets follow the CCNx packet format [CCNMessages], where
   messages exist within outermost containments (packets).

4.1.  ICN Ping Echo Request Packet Format

   The format of the ping echo request packet is presented below:
























Mastorakis, et al.      Expires February 27, 2017               [Page 5]


Internet-Draft                  ICN Ping                     August 2016


    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    |  EchoRequest  |         PacketLength          |
    |               |               |                               |
    +---------------+---------------+---------------+---------------+
    |               |               |               |               |
    |    HopLimit   |    Reserved   |     Flags     |  HeaderLength |
    |               |               |               |               |
    +---------------+---------------+---------------+---------------+
    /                                                               /
    /                       PathSteering TLV                        /
    /                                                               /
    +---------------+---------------+---------------+---------------+
    |                                                               |
    |                   Echo Request Message TLVs                   |
    |                                                               |
    +---------------+---------------+---------------+---------------+


                        Echo Request Packet Format

   The existing packet header fields have similar functionality to the
   header fields of a CCNx Interest packet.  The value of the packet
   type field is Echo Request.  The exact numeric value of this field
   type is to be determined.

   Compared to the typical format of a CCNx packet header [CCNMessages],
   there is a new optional fixed header TLV added to the packet header:

   o  A PathSteering hop-by-hop header TLV, which is constructed hop-by-
      hop in the echo reply and included in the echo request to steer
      consecutive echo requests expressed by a ping client towards a
      common forwarding path.  An example of such a scheme is presented
      in [LIPSIN].















Mastorakis, et al.      Expires February 27, 2017               [Page 6]


Internet-Draft                  ICN Ping                     August 2016


    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

    +---------------+---------------+---------------+---------------+
    |                               |                               |
    |      PathSteering_Type        |      PathSteering_Length      |
    |                               |                               |
    +---------------+---------------+---------------+---------------+
    |                                                               |
    |                      PathSteering_Value                       |
    |                                                               |
    +---------------+---------------+---------------+---------------+


                             PathSteering TLV

   The message 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 = 1        |          MessageLength        |
    |                               |                               |
    +---------------+---------------+---------------+---------------+
    |                                                               |
    |                          Name TLV                             |
    |                                                               |
    +---------------+---------------+---------------+---------------+



                        Echo Request Message Format

   The echo request message is of type Interest in order to leverage the
   Interest forwarding behavior provided by the network.  The Name TLV
   has the structure described in [CCNMessages].  The name consists of
   the prefix that we would like to ping appended with a nonce typed
   name component as its last component.  The value of this TLV will be
   a 64-bit nonce.  The purpose of the nonce is to avoid Interest
   aggregation and allow client matching of replies with requests.  As
   described below, the nonce is ignored for CS checking.










Mastorakis, et al.      Expires February 27, 2017               [Page 7]


Internet-Draft                  ICN Ping                     August 2016


    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

    +---------------+---------------+---------------+---------------+
    |                               |                               |
    |           Nonce_Type          |       Nonce_Length = 8        |
    |                               |                               |
    +---------------+---------------+---------------+---------------+
    |                                                               |
    |                                                               |
    |                                                               |
    |                          Nonce_Value                          |
    |                                                               |
    |                                                               |
    +---------------+---------------+---------------+---------------+




                      Nonce Typed Name Component TLV

4.2.  Ping Echo Reply Packet Format

   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

    +---------------+---------------+---------------+---------------+
    |               |               |                               |
    |    Version    |   EchoReply   |          PacketLength         |
    |               |               |                               |
    +---------------+---------------+---------------+---------------+
    |                               |               |               |
    |            Reserved           |     Flags     | HeaderLength  |
    |                               |               |               |
    +---------------+---------------+---------------+---------------+
    |                                                               |
    |                        PathSteering TLV                       |
    |                                                               |
    +---------------+---------------+---------------+---------------+
    |                                                               |
    |                    Echo Reply Message TLVs                    |
    |                                                               |
    +---------------+---------------+---------------+---------------+



                         Echo Reply Packet Format




Mastorakis, et al.      Expires February 27, 2017               [Page 8]


Internet-Draft                  ICN Ping                     August 2016


   The header of an echo reply consists of the header fields of a CCNx
   Content Object and a hop-by-hop PathSteering TLV.  The value of the
   packet type field is Echo Reply.  The exact numeric value of this
   field type is to be determined.  The PathSteering header TLV is as
   defined for the echo request packet.

   A ping echo reply message is of type Content Object, contains a Name
   TLV (name of the corresponding echo request), a PayloadType TLV and
   an ExpiryTime TLV with a value of 0 to indicate that echo replies
   must not be cached by the network.

    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 = 2        |          MessageLength        |
    |                               |                               |
    +---------------+---------------+---------------+---------------+
    |                                                               |
    |                            Name TLV                           |
    |                                                               |
    +---------------+---------------+---------------+---------------+
    |                                                               |
    |                         PayloadType TLV                       |
    |                                                               |
    +---------------+---------------+---------------+---------------+
    |                                                               |
    |                         ExpiryTime TLV                        |
    |                                                               |
    +---------------+---------------+---------------+---------------+



                         Echo Reply Message Format

   The PayloadType TLV is presented below.  It is of type
   T_PAYLOADTYPE_DATA, and the data schema consists of 2 TLVs: 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), 3) a TLV with return
   codes 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 5).








Mastorakis, et al.      Expires February 27, 2017               [Page 9]


Internet-Draft                  ICN Ping                     August 2016


    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            |
    |                               |                               |
    +---------------+---------------+---------------+---------------+
    /                                                               /
    /                      Sender's Name TLV                        /
    /                                                               /
    +---------------+---------------+---------------+---------------+
    /                                                               /
    /                    Sender's Signature TLV                     /
    /                                                               /
    +---------------+---------------+---------------+---------------+
    /                                                               /
    /                     Echo Reply Code TLV                       /
    /                                                               /
    +---------------+---------------+---------------+---------------+



                         Echo Reply Message 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
   management/administrative information using generic Interest-Data
   exchanges after a successful verification of the sender's name.

   The structure of the Echo Reply Code TLV is presented below (16-bit
   value).  The potential values are the following:

   o  1: Indicates that the target name matched the administrative name
      of a forwarder.

   o  2: Indicates that the target name matched a prefix served by an
      application.

   o  3: Indicates that the target name matched the name of an object in
      a forwarder's CS.











Mastorakis, et al.      Expires February 27, 2017              [Page 10]


Internet-Draft                  ICN Ping                     August 2016


    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

    +---------------+---------------+---------------+---------------+
    |                               |                               |
    |     Echo_Reply_Code_Type      |  Echo_Reply_Code_Length = 2   |
    |                               |                               |
    +---------------+---------------+---------------+---------------+
    |                                                               |
    |                      Echo_Reply_Code_Value                    |
    +---------------+---------------+---------------+---------------+




                            Echo Reply Code TLV

5.  Forwarder Handling

   When a forwarder receives an echo request, it will first extract the
   message's base name (i.e., the request name with the Nonce name
   component excluded).

   In some cases, the forwarder will originate an echo reply, sending
   the reply downstream through the face on which the echo request was
   received.  An echo reply will include the forwarder's own name and
   signature, and, the appropriate echo reply code based on the
   condition that triggered the reply generation.  It will also include
   a path steering TLV, initially a null value (since the echo reply
   originator does not forward the request and, thus, does not make a
   path choice).

   The forwarder generates an echo reply in the following cases:

   o  Assuming that a forwarder has been given one or more
      administrative names, the echo request base name exactly matches
      any of the forwarder's administrative name(s).

   o  The echo request's base name exactly matches the name of a
      content-object residing in the forwarder's CS (unless the ping
      client application has chosen not to receive replies due to CS
      hits as specified in Appendix A).

   o  The echo request base name matches (in a Longest Prefix Match
      manner) a FIB entry with an outgoing face referring to a local
      application.

   If none of the conditions to reply to the echo request are met, the
   forwarder will attempt to forward the echo request upstream based on



Mastorakis, et al.      Expires February 27, 2017              [Page 11]


Internet-Draft                  ICN Ping                     August 2016


   the path steering value (if present) the results of the FIB LPM
   lookup and PIT creation (based on the name including the nonce typed
   name component).  If no valid next-hop is found, an InterestReturn is
   sent downstream (as with a failed attempt to forward an ordinary
   Interest).

   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
   will be updated by each forwarder to encode its next-hop choice.
   When included in subsequent echo requests, this path steering TLV
   will allow the forwarders to steer the requests along the same path.

6.  Security Considerations

   To avoid reflection attacks, where a compromised forwarder includes
   in the reply the name of a victim forwarder to redirect the future
   administrative traffic towards the victim, the forwarder that
   generates a reply has to sign the name included in the payload.  In
   this way, the client is able to verify that the included name is
   legitimate and refers to the forwarder that generated the reply.
   Alternatively, the forwarder can include in the reply payload their
   routable prefix(es) encoded as a signed NDN Link Object [SNAMP].

7.  Acknowledgements

   The authors would like to thank Mark Stapp for the fruitful
   discussion on the objectives of ICN ping protocol.

8.  References

8.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <http://www.rfc-editor.org/info/rfc2119>.

8.2.  Informative References

   [CCNMessages]
              Mosko, M., Solis, I., and C. Wood, "CCNx Messages in TLV
              Format.", 2016, <https://tools.ietf.org/html/draft-irtf-
              icnrg-ccnxmessages-03>.

   [LIPSIN]   Jokela, P. and et al, "LIPSIN: line speed publish/
              subscribe inter-networking, ACM SIGCOMM Computer
              Communication Review 39.4: 195-206", 2009.




Mastorakis, et al.      Expires February 27, 2017              [Page 12]


Internet-Draft                  ICN Ping                     August 2016


   [SNAMP]    Afanasyev, A. and et al, "SNAMP: Secure namespace mapping
              to scale NDN forwarding, IEEE Conference on Computer
              Communications Workshops (INFOCOM WKSHPS)", 2015.

Appendix A.  Ping Client Application (Consumer) Operation

   This section is an informative appendix regarding the proposed ping
   client operation.

   The ping client application is responsible for generating echo
   requests for prefixes provided by users.

   When generating a series of echo requests for a specific name, the
   first echo request will typically not include a PathSteering TLV,
   since no TLV value is known.  After an echo reply containing a
   PathSteering TLV is received, each subsequent echo request can
   include the received path steering value in the PathSteering header
   TLV to drive the requests towards a common path as part of checking
   the network performance.  To discover more paths, a client can omit
   the path steering TLV in future requests.  Moreover, for each new
   ping echo 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 echo request, which will have semantics similar to the
   lifetime of an Interest.

   Moreover, the client application might like not to receive echo
   replies due to CS hits.  A mechanism to achieve that would be to use
   a Content Object Hash Restriction TLV with a value of 0 in the
   payload of an echo request message.

   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
   request.  It should parse the PathSteering value and decode the
   reply's payload to parse the 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 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 can also decode the Echo Reply Code TLV to understand the
   condition that triggered the generation of the reply.

   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
   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.






Mastorakis, et al.      Expires February 27, 2017              [Page 13]


Internet-Draft                  ICN Ping                     August 2016


Authors' Addresses

   Spyridon Mastorakis
   UCLA
   Los Angeles, CA
   US

   Email: mastorakis@cs.ucla.edu


   Jim Gibson
   Cisco Systems
   Cambridge, MA
   US

   Email: gibson@cisco.com


   Ilya Moiseenko
   Cisco Systems
   Cambridge, MA
   US

   Email: iliamo@mailbox.org


   Ralph Droms
   Cisco Systems
   Cambridge, MA
   US

   Email: rdroms.ietf@gmail.com


   Dave Oran
   Cisco Systems
   Cambridge, MA
   US

   Email: daveoran@orandom.net











Mastorakis, et al.      Expires February 27, 2017              [Page 14]


Html markup produced by rfcmarkup 1.129b, available from https://tools.ietf.org/tools/rfcmarkup/