[Docs] [txt|pdf] [Tracker] [WG] [Email] [Diff1] [Diff2] [Nits] [IPR]

Versions: (draft-zheng-p2psip-diagnose) 00 01 02 03 04 05 06 07 08 09 11 12 13 14 15 16 17 18 19 20 21 22 RFC 7851

P2PSIP Working Group                                             H. Song
Internet-Draft                                                  X. Jiang
Intended status: Standards Track                                 R. Even
Expires: August 18, 2014                                          Huawei
                                                                D. Bryan
                                                            Ethernot.org
                                                                  Y. Sun
                                                                 ICT-CAS
                                                       February 14, 2014


                        P2P Overlay Diagnostics
                    draft-ietf-p2psip-diagnostics-14

Abstract

   This document describes mechanisms for P2P overlay diagnostics.  It
   defines extensions to the RELOAD P2PSIP base protocol to collect
   diagnostic information, and details the protocol specifications for
   these extensions.  Useful diagnostic information for connection and
   node status monitoring is also defined.  The document also describes
   the usage scenarios and provides examples of how these methods are
   used to perform diagnostics in P2P overlay networks.

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 August 18, 2014.

Copyright Notice

   Copyright (c) 2014 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



Song, et al.             Expires August 18, 2014                [Page 1]


Internet-Draft           P2P Overlay Diagnostics           February 2014


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

   This document may contain material from IETF Documents or IETF
   Contributions published or made publicly available before November
   10, 2008.  The person(s) controlling the copyright in some of this
   material may not have granted the IETF Trust the right to allow
   modifications of such material outside the IETF Standards Process.
   Without obtaining an adequate license from the person(s) controlling
   the copyright in such materials, this document may not be modified
   outside the IETF Standards Process, and derivative works of it may
   not be created outside the IETF Standards Process, except to format
   it for publication as an RFC or to translate it into languages other
   than English.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   4
   3.  Diagnostic Scenarios  . . . . . . . . . . . . . . . . . . . .   4
   4.  Overview of operations  . . . . . . . . . . . . . . . . . . .   5
     4.1.  "Ping-like" Behavior: Extending Ping  . . . . . . . . . .   7
     4.2.  "Traceroute-like" Behavior: The Path_Track Method . . . .   7
   5.  RELOAD diagnostic extensions  . . . . . . . . . . . . . . . .   8
     5.1.  Diagnostic Data Structures  . . . . . . . . . . . . . . .   8
       5.1.1.  DiagnosticsRequest Data Structure . . . . . . . . . .   9
       5.1.2.  DiagnosticsResponse Data Structure  . . . . . . . . .  10
       5.1.3.  dMFlags and Diagnostic Kind ID Types  . . . . . . . .  11
       5.1.4.  Extending Diagnostic Information  . . . . . . . . . .  14
     5.2.  Request Extension: Ping . . . . . . . . . . . . . . . . .  14
     5.3.  New Request: PathTrack  . . . . . . . . . . . . . . . . .  14
       5.3.1.  PathTrack Request . . . . . . . . . . . . . . . . . .  15
       5.3.2.  PathTrack Response  . . . . . . . . . . . . . . . . .  15
     5.4.  Error Codes . . . . . . . . . . . . . . . . . . . . . . .  16
     5.5.  Message Processing  . . . . . . . . . . . . . . . . . . .  16
       5.5.1.  Message Creation and Transmission . . . . . . . . . .  16
       5.5.2.  Message Processing: Intermediate Peers  . . . . . . .  17
       5.5.3.  Message Response Creation . . . . . . . . . . . . . .  18
       5.5.4.  Interpreting Results  . . . . . . . . . . . . . . . .  19
   6.  Authorization through Overlay Configuration . . . . . . . . .  19
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .  20
   8.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  20
     8.1.  Diagnostic Kind ID Types  . . . . . . . . . . . . . . . .  20



Song, et al.             Expires August 18, 2014                [Page 2]


Internet-Draft           P2P Overlay Diagnostics           February 2014


     8.2.  Message Codes . . . . . . . . . . . . . . . . . . . . . .  21
     8.3.  Error Code  . . . . . . . . . . . . . . . . . . . . . . .  22
     8.4.  Message Extension . . . . . . . . . . . . . . . . . . . .  22
     8.5.  Diagnostics Flag  . . . . . . . . . . . . . . . . . . . .  22
     8.6.  XML Name Space Registration . . . . . . . . . . . . . . .  23
   9.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .  23
   10. References  . . . . . . . . . . . . . . . . . . . . . . . . .  24
     10.1.  Normative References . . . . . . . . . . . . . . . . . .  24
     10.2.  Informative References . . . . . . . . . . . . . . . . .  24
   Appendix A.  Examples . . . . . . . . . . . . . . . . . . . . . .  25
     A.1.  Example 1 . . . . . . . . . . . . . . . . . . . . . . . .  25
     A.2.  Example 2 . . . . . . . . . . . . . . . . . . . . . . . .  25
     A.3.  Example 3 . . . . . . . . . . . . . . . . . . . . . . . .  25
   Appendix B.  Problems with Generating Multiple Responses on Path   26
   Appendix C.  Changes to the Draft . . . . . . . . . . . . . . . .  26
     C.1.  Changes since -00 version . . . . . . . . . . . . . . . .  26
     C.2.  Changes since -01 version . . . . . . . . . . . . . . . .  26
     C.3.  Changes since -02 version . . . . . . . . . . . . . . . .  27
     C.4.  Changes since -03 version . . . . . . . . . . . . . . . .  27
     C.5.  Changes since -04 version . . . . . . . . . . . . . . . .  27
     C.6.  Changes since -05 version . . . . . . . . . . . . . . . .  27
     C.7.  Changes in version -10  . . . . . . . . . . . . . . . . .  27
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  27

1.  Introduction

   In the last few years, overlay networks have rapidly evolved and
   emerged as a promising platform for deployment of new applications
   and services in the Internet.  One of the reasons overlay networks
   are seen as an excellent platform for large scale distributed systems
   is their resilience in the presence of failures.  This resilience has
   three aspects: data replication, routing recovery, and static
   resilience.  Routing recovery algorithms are used to repopulate the
   routing table with live nodes when failures are detected.  Static
   resilience measures the extent to which an overlay can route around
   failures even before the recovery algorithm repairs the routing
   table.  Both routing recovery and static resilience rely on accurate
   and timely detection of failures.

   There are a number of situations in which some nodes in a P2P overlay
   may malfunction or behave badly.  For example, these nodes may be
   disabled, congested, or may be misrouting messages.  The impact of
   these malfunctions on the overlay network may be a degradation of
   quality of service provided collectively by the peers in the overlay
   network or an interruption of the overlay services.  It is desirable
   to identify malfunctioning or badly behaving peers through diagnostic
   tools, and exclude or reject them from the P2P system.  Node failures
   may be also caused by underlying failures, for example the recovery



Song, et al.             Expires August 18, 2014                [Page 3]


Internet-Draft           P2P Overlay Diagnostics           February 2014


   from an incorrect overlay topology may be slow when the IP layer
   routing failover speed after link failures is very slow.  Moreover,
   if a backbone link fails and the failover is slow, the network may be
   partitioned, leading to partitions of overlay topologies and
   inconsistent routing results between different partitioned
   components.

   Some keep-alive algorithms based on periodic probe and acknowledge
   mechanisms enable accurate and timely detection of failures of one
   node's neighbors [Overlay-Failure-Detection], but these algorithms by
   themselves can only detect the disabled neighbors using the periodic
   method.  This may not be enough for service providers operating the
   overlay network.

   A single, general P2PSIP overlay diagnostic framework supporting
   periodic and on-demand methods for detecting node failures and
   network failures is desirable.  This document describes a general
   P2PSIP overlay diagnostic extension to the P2PSIP base protocol
   RELOAD [I-D.ietf-p2psip-base] and is intended as a complement to
   keep-alive algorithms in the P2PSIP overlay itself.

2.  Terminology

   This document uses the concepts defined in RELOAD
   [I-D.ietf-p2psip-base].

   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].

3.  Diagnostic Scenarios

   P2P systems are self-organizing and ideally require no network
   management in the traditional sense to set up and to configure
   individual P2P nodes.  However, users of an overlay, as well as P2P
   service providers may contemplate usage scenarios where some
   monitoring and diagnostics are required.  We present a simple
   connectivity test and some useful diagnostic information that may be
   used in such diagnostics.

   The common usage scenarios for P2P diagnostics can be broadly
   categorized in three classes:

   a.  Automatic diagnostics built into the P2P overlay routing
       protocol.  Nodes perform periodic checks of known neighbors and
       remove those nodes from the routing tables that fail to respond
       to connectivity checks [Handling_Churn_in_a_DHT].  However, the
       unresponsive nodes may only be temporarily disabled, for example



Song, et al.             Expires August 18, 2014                [Page 4]


Internet-Draft           P2P Overlay Diagnostics           February 2014


       due to some local cryptographic processing overload, disk
       processing overload or link overload.  It is therefore useful to
       repeat the connectivity checks to see if such nodes have
       recovered and can be again placed in the routing tables.  This
       process is known as 'failed node recovery' and can be optimized
       as described in the paper "Handling Churn in a DHT"
       [Handling_Churn_in_a_DHT].

   b.  Diagnostics for a particular node to follow up an individual user
       complaint or failure.  For example, in this case a technical
       support person may use a desktop sharing application with the
       permission of the user to determine remotely the health and
       possible problems with the malfunctioning node.  Part of the
       remote diagnostics may consist of simple connectivity tests with
       other nodes in the P2PSIP overlay and retrieval statistics of
       nodes from the overlay.  The simple connectivity tests are not
       dependent on the type of P2PSIP overlay.  Note that other tests
       may be required as well, such as checking the health and
       performance of the user's computer or mobile device and also
       checking the bandwidth of the link connecting the user to the
       Internet.

   c.  P2P system diagnostics to check the overall health of the P2P
       overlay network, the consumption of network bandwidth, for the
       presence of problem links and also to check for abusive or
       malicious nodes.  This is not a trivial problem and has been
       studied in detail for content and streaming P2P overlays
       [Diagnostic_Framework] as well as in earlier P2PSIP documents
       [Diagnostics_and_NAT_traversal_in_P2PP].  While this is a
       difficult problem, a great deal of information can be obtained in
       helping these diagnostics by sending messages to diagnose the
       network.  This document provides a framework for obtaining this
       information.

4.  Overview of operations

   The diagnostic mechanisms described in this document are mainly
   intended to detect and locate failures or monitor performance in
   P2PSIP overlay networks.  It provides mechanisms to detect and locate
   malfunctioning or badly behaving nodes including disabled nodes,
   congested nodes and misrouting peers.  It provides a mechanism to
   detect direct connectivity or connectivity to a specified node, a
   mechanism to detect the availability of specified resource records
   and a mechanism to discover P2PSIP overlay topology and the underlay
   topology failures.

   The P2PSIP diagnostics extensions define two mechanisms to collect
   data.  The first is an extension to the RELOAD Ping mechanism,



Song, et al.             Expires August 18, 2014                [Page 5]


Internet-Draft           P2P Overlay Diagnostics           February 2014


   allowing diagnostic data to be queried from a node, as well as to
   diagnose the path to that node.  The second is a new method and
   response, PathTrack, for collecting diagnostic information
   iteratively.  Payloads for these mechanisms allowing diagnostic data
   to be collected and represented are presented, and additional error
   codes are introduced.  Essentially, this document reuses RELOAD
   [I-D.ietf-p2psip-base]specification and extends them to introduce the
   new diagnostics methods.  The extensions strictly follow RELOAD
   specification on the messages routing, transport, NAT traversal etc.
   The diagnostic methods are however P2PSIP protocol independent.

   This document primarily describes how to detect and locate failures
   including disabled nodes, congested nodes, misrouting behaviors and
   underlying network faults in P2PSIP overlay networks through a simple
   and efficient mechanism.  This mechanism is modeled after the ping/
   traceroute paradigm: ping [RFC0792]is used for connectivity checks,
   and traceroute is used for hop-by-hop fault localization as well as
   path tracing.  This document specifies a "ping-like" mode (by
   extending the RELOAD Ping method to gather diagnostics) and a
   "traceroute-like" mode (by defining the new PathTrack method) for
   diagnosing P2PSIP overlay networks.

   One way these tools can be used is to detect the connectivity to the
   specified node or the availability of the specified resource-record
   through the extended P2PSIP Ping operation.  Once the overlay network
   receives some alarms about overlay service degradation or
   interruption, a Ping is sent.  If the Ping fails, one can then send a
   PathTrack to determine where the fault lies.

   The diagnostic information can only be provided to authorized nodes.
   Some diagnostic information can be provided to all the participants
   in the P2PSIP overlay, and some other diagnostic information can only
   be provided to the nodes authorized by the local or overlay policy.
   The authorization depends on the type of the diagnostic information
   and the administrative considerations, and is application specific.

   This document considers the general administrative scenario based on
   diagnostic kind type, where a whole overlay can authorize a certain
   type of diagnostic information to a small list of particular nodes
   (e.g.  administrative nodes).  That means, if a node gets the
   authorization to access a diagnostic kind type, it can access that
   information from all nodes in the overlay network.  It leaves the
   scenario where a particular node authorizes its diagnostic
   information to a particular list of nodes out of scope.  This could
   be achieved by extension of this document if there is requirement in
   the near future.  The default policy or access rule for a type of
   diagnostic information is "permit" unless specified in the
   diagnostics extension document.  As the RELOAD protocol already



Song, et al.             Expires August 18, 2014                [Page 6]


Internet-Draft           P2P Overlay Diagnostics           February 2014


   requires that each messge carries the message signature of the
   sender, the receiver of the diagnostics requests can use the
   signature to identify the sender.  It can then use the overlay
   configuration file with this signature to determine which types of
   diagnostic information that node is authorized for.

4.1.  "Ping-like" Behavior: Extending Ping

   To provide "ping-like" behavior, the RELOAD Ping method has been
   extended to collect diagnostic data along the path.  The request
   message is forwarded by the intermediate peers along the path and
   then terminated by the responsible peer.  After optional local
   diagnostics, the responsible peer returns a response message.  If an
   error is found when routing, an Error response is sent to the
   initiator node by the intermediate peer.

   The message flow of a Ping message (with diagnostic extensions) is as
   follows:

    Peer A              Peer B               Peer C             Peer D
      |                    |                    |                    |
      |(1). PingReq        |                    |                    |
      |------------------->|(2). PingReq        |                    |
      |                    |------------------->|(3). PingReq        |
      |                    |                    |------------------->|
      |                    |                    |                    |
      |                    |                    |<-------------------|
      |                    |<-------------------|(4). PingAns        |
      |<-------------------|(5). PingAns        |                    |
      |(6). PingAns        |                    |                    |
      |                    |                    |                    |

                  Figure 1: Ping Diagnostic Message Flow

4.2.  "Traceroute-like" Behavior: The Path_Track Method

   We define a simple PathTrack method for retrieving diagnostic
   information iteratively.  For example, in Figure 2, the initiator
   node A asks its neighbor B which is the next hop peer to the
   destination ID, and then retrieves the next hop peer C information,
   along with optional diagnostic information of B, to the initiator
   node.  Then the initiator node A asks the next hop peer C (directly
   or via symmetric routing) to get the further next hop peer D
   information and diagnostic information of C. Unless a failure
   prevents the message from being forwarded, this step can be
   iteratively repeated until the request reaches responsible peer D for
   the destination ID, and retrieves diagnostic information of peer D.




Song, et al.             Expires August 18, 2014                [Page 7]


Internet-Draft           P2P Overlay Diagnostics           February 2014


   The message flow of a PathTrack message (with diagnostic extensions)
   is as follows:

   Peer-A              Peer-B               Peer-C             Peer-D
     |                    |                    |                    |
     |(1).PathTrackReq    |                    |                    |
     |------------------->|                    |                    |
     |(2).PathTrackAns    |                    |                    |
     |<-------------------|                    |                    |
     |                    |(3).PathTrackReq    |                    |
     |--------------------|------------------->|                    |
     |                    |(4).PathTrackAns    |                    |
     |<-------------------|--------------------|                    |
     |                    |                    |(5).PathTrackReq    |
     |--------------------|--------------------|------------------->|
     |                    |                    |(6).PathTrackAns    |
     |<-------------------|--------------------|--------------------|
     |                    |                    |                    |

                Figure 2: PathTrack Diagnostic Message Flow

   There have been proposals that RouteQuery and a series of Fetch
   requests can be used to replace the PathTrack mechanism, but in the
   presence of churn such an operation would not, strictly speaking,
   provide identical results, as the path may change between RouteQuery
   and Fetch operations. (although obviously the path could change
   between steps of PathTrack as well).

5.  RELOAD diagnostic extensions

   This document extends RELOAD to carry diagnostic information.
   Considering the special usage of diagnostics, this document defines
   extensions for a payload to Ping, as well as the new method PathTrack
   and its response.  Additionally, new Error codes, message bodies for
   conveying diagnostics, and some suggested common diagnostic values
   are defined.  Processing of the PathTrack message and the diagnostic
   bodies is discussed.

   The mechanism defined in this document follows the RELOAD
   specification, the new request and response message use the message
   format specified in RELOAD messages.  Please refer to the RELOAD
   [I-D.ietf-p2psip-base] for details of the protocol.

5.1.  Diagnostic Data Structures

   The diagnostics use the following common diagnostics data structures.
   Two common structures are defined, DiagnosticsRequest for requesting
   data, and DiagnosticsResponse for returning information.



Song, et al.             Expires August 18, 2014                [Page 8]


Internet-Draft           P2P Overlay Diagnostics           February 2014


5.1.1.  DiagnosticsRequest Data Structure

   The DiagnosticsRequest data structure is sent to request diagnostic
   information and has the following form:

               enum{ (2^16-1) } DiagnosticKindId;

               struct{
                   DiagnosticKindId kind;
                   opaque  diagnostic_extension_contents<0..2^32-1>;
               }DiagnosticExtension;

               struct{
                   uint64 expiration;
                   uint64 timestamp_initiated;
                   uint64 dMFlags;
                   uint32 length;
                   DiagnosticExtension diagnostic_extensions[length];
                }DiagnosticsRequest;

   The fields in the DiagnosticsRequest are as follows:

      expiration : The time when the request will expire represented as
      the number of milliseconds elapsed since midnight Jan 1, 1970 UTC
      not counting leap seconds.  This will have the same values for
      seconds as standard UNIX time or POSIX time.  More information can
      be found at UnixTime [UnixTime]

      timestamp_initiated : The time when the P2PSIP diagnostics request
      was initiated represented as the number of milliseconds elapsed
      since midnight Jan 1, 1970 UTC not counting leap seconds.  This
      will have the same values for seconds as standard UNIX time or
      POSIX time.

      length : the length of the extended diagnostic request information
      in bytes.  If the value is greater than or equal to 1, then some
      extended diagnostic information is requested.  The value of length
      MUST NOT be negative.

      dMFlags : A mandatory field which is an unsigned 64-bit integer
      indicating which base diagnostic information the request initiator
      node is interested in.  The initiator sets different bits to
      retrieve different kinds of diagnostic information.  If dMFlags is
      set to zero, then no base diagnostic information is conveyed in
      the PathTrack response.  If dMFlag is set to all '1's, then all
      base diagnostic information values are requested.  A request may
      set any number of the flags to request the corresponding
      diagnostic information.



Song, et al.             Expires August 18, 2014                [Page 9]


Internet-Draft           P2P Overlay Diagnostics           February 2014


      Note this memo specifies the initial set of flags, the flags can
      be extended.  The dMflags indicate general diagnostic information
      The mapping between the bits in the dMFlags and the diagnostic
      information kind presented is as described in Section 8.5.

      diagnostic_extensions : consists of one or more
      DiagnosticExtension structures (see below) documenting additional
      diagnostic information being requested.

   Each DiagnosticExtension has the following fields:

      kind : a numerical code indicating the extension kind of
      diagnostic information(see Section 8.1).  Note that kind 0xFFFE is
      reserved for overlay specific diagnostics and may be used without
      IANA registration for local diagnostic information.  And the kind
      from 0x0000 to 0x003F MUST NOT be indicated in the
      diagnostic_extensions in the message request becasue they can be
      represented in the dMFlags in a much simpler way.

      diagnostic_extension_contents : the opaque data containing the
      request for this particular extension.  This data is extension
      dependent.

5.1.2.  DiagnosticsResponse Data Structure

               enum { (2^16-1) } DiagnosticKindId;
               struct{
                   DiagnosticKindId kind;
                   opaque diagnostic_info_contents<0..2^16-1>;
               }DiagnosticInfo;

               struct{
                   uint64 expiration;
                   uint64 timestamp_received;
                   uint8 hop_counter;
                   DiagnosticInfo diagnostic_info_list<0..2^32-1>;
               }DiagnosticsResponse;

   The fields in the DiagnosticsResponse are as follows:

      expiration : The time when the response will expire represented as
      the number of milliseconds elapsed since midnight Jan 1, 1970 UTC
      not counting leap seconds.  This will have the same values for
      seconds as standard UNIX time or POSIX time.

      timestamp_received : The time when P2PSIP Overlay diagnostic
      request was received represented as the number of milliseconds
      elapsed since midnight Jan 1, 1970 UTC not counting leap seconds.



Song, et al.             Expires August 18, 2014               [Page 10]


Internet-Draft           P2P Overlay Diagnostics           February 2014


      This will have the same values for seconds as standard UNIX time
      or POSIX time.

      hop_counter : This field only appears in diagnostic responses.  It
      MUST be exactly copied from the TTL field of the forwarding header
      in the received request.  This information is sent back to the
      request initiator, allowing it to compute the hops that the
      message traversed in the overlay.

      diagnostic_info_list : consists of one or more DiagnosticInfo
      values containing the requested diagnostic information.

   The fields in the DiagnosticInfo structure are as follows:

      kind : A numeric code indicating the type of information being
      returned.  For base data requested using the dMFlags, this code
      corresponds to the dMFlag set, and is described in Section 5.1.1.
      For diagnostic extensions, this code will be identical to the
      value of the DiagnosticKindId set in the "kind" field of the
      DiagnosticExtension of the request.  See Section 8.1.

      diagnostic_information : Data containing the value for the
      diagnostic information being reported.  Various kinds of
      diagnostic information can be retrieved, Please refer to
      Section 5.1.3 for details of the diagnostic kind ID for the base
      diagnostic information that may be reported.

5.1.3.  dMFlags and Diagnostic Kind ID Types

   The dMFlags field described above is a 64 bit field that allows
   initiator nodes to identify up to 62 items of base information to
   request (the first and last flags being reserved) when sending a
   request.  When the requested base information is returned in the
   response, the value of the diagnostic kind ID will correspond to the
   numeric field marked in the dMFlags in the request.  The values for
   the dMFlags are defined in Section 8.5 and the diagnostic kind IDs
   are defined in Section 8.1.  The information contained for each value
   is described in this section.

      STATUS_INFO (8 bits): A single value element containing an
      unsigned byte representing whether or not the node is in
      congestion status.  An example usage of STATUS_INFO is for
      congestion-aware routing.  In this scenario, each peer has to
      update its congestion status periodically, an intermediate peer in
      the distributed hash table (DHT) network will choose its next hop
      according to both the DHT routing algorithm and the status
      information, and then forward requests to the chosen next hop, so
      as to avoid increasing load on congested peers.  The rightmost 4



Song, et al.             Expires August 18, 2014               [Page 11]


Internet-Draft           P2P Overlay Diagnostics           February 2014


      bits are used and other bits MUST be cleared to "0"s for future
      use.  There are 16 levels of congestion status, with "0x00"
      represent zero load and "0x0F" represent congested.  This document
      is not going to provide a measurement method for congestion,
      although a node can contemplate its CPU/memory/bandwidth usage
      percentage in the past seconds and normalize the highest value to
      the range [0x00, 0x0F].  This document reserves these bits and
      leave it for this purpose.  A future draft may define it.

      ROUTING_TABLE_SIZE (32 bits): A single value element containing an
      unsigned 32-bit integer representing the number of peers in the
      peer's routing table.  The administrator of the overlay may be
      interested in statistics of this value for reasons such as routing
      efficiency.  Access to this kind of diagnostic information MUST
      NOT be allowed unless compliant to the rules defined in Section 6.

      PROCESS_POWER (32 bits): A single value element containing an
      unsigned 32-bit integer specifying the processing power of the
      node in unit of MIPS.

      BANDWIDTH (32 bits): A single value element containing an unsigned
      32-bit integer specifying the bandwidth of the node in unit of
      Kbps.

      SOFTWARE_VERSION: A single value element containing a US-ASCII
      string that identifies the manufacture, model, operating system
      information and the version of the software.  The format is as
      follows: ApplicationProductToken (Platform; OS-or-CPU) *
      VendorProductToken (VendorComment).  One example is: MyReloadApp/
      1.0 (Unix; Linux x86_64) libreload-java/0.7.0 (Stonyfish Inc.).
      Access to this kind of diagnostic information MUST NOT be allowed
      unless compliant to the rules defined in Section 6.

      MACHINE_UPTIME (64 bits): A single value element containing an
      unsigned 64-bit integer specifying the time the node has been up
      in seconds.

      APP_UPTIME (64 bits): A single value element containing an
      unsigned 64-bit integer specifying the time the P2P application
      has been up in seconds.

      MEMORY_FOOTPRINT (32 bits): A single value element containing an
      unsigned 32-bit integer representing the memory footprint of the
      peer program in kibibytes (1024 bytes).  Access to this kind of
      diagnostic information MUST NOT be allowed unless compliant to the
      rules defined in Section 6.





Song, et al.             Expires August 18, 2014               [Page 12]


Internet-Draft           P2P Overlay Diagnostics           February 2014


      DATASIZE_STORED (64 bits): An unsigned 64-bit integer representing
      the number of bytes of data being stored by this node.  Access to
      this kind of diagnostic information MUST NOT be allowed unless
      compliant to the rules defined in Section 6.

      INSTANCES_STORED: An array element containing the number of
      instances of each kind stored.  The array is indexed by Kind-ID.
      Each entry is an unsigned 64-bit integer.  Access to this kind of
      diagnostic information MUST NOT be allowed unless compliant to the
      rules defined in Section 6.

      MESSAGES_SENT_RCVD: An array element containing the number of
      messages sent and received.  The array is indexed by method code.
      Each entry in the array is a pair of unsigned 64-bit integers
      (packed end to end) representing sent and received.  Access to
      this kind of diagnostic information MUST NOT be allowed unless
      compliant to the rules defined in Section 6.

      EWMA_BYTES_SENT (32 bits): A single value element containing an
      unsigned 32-bit integer representing an exponential weighted
      average of bytes sent per second by this peer. sent = alpha x
      sent_present + (1 - alpha) x sent where sent_present represents
      the bytes sent per second since the last calculation and sent
      represents the last calculation of bytes sent per second.  A
      suitable value for alpha is 0.8.  This value is calculated every
      five seconds.  Access to this kind of diagnostic information MUST
      NOT be allowed unless compliant to the rules defined in Section 6.

      EWMA_BYTES_RCVD (32 bits): A single value element containing an
      unsigned 32-bit integer representing an exponential weighted
      average of bytes received per second by this peer. rcvd = alpha x
      rcvd_present + (1 - alpha) x rcvd where rcvd_present represents
      the bytes received per second since the last calculation and rcvd
      represents the last calculation of bytes received per second.  A
      suitable value for alpha is 0.8.  This value is calculated every
      five seconds.  Access to this kind of diagnostic information MUST
      NOT be allowed unless compliant to the rules defined in Section 6.

      UNDERLAY_HOP (8 bits): Indicates the IP layer hops from the
      intermediate peer which receives the diagnostics message to the
      next hop peer for this message.  (Note: RELOAD does not require
      the intermediate peers to look into the message body.  So here we
      use PathTrack to gather underlay hops for diagnostics purpose).

      BATTERY_STATUS (8 bits): The left-most bit is used to indicate
      whether this peer is using battery or not.  If this bit is clear
      as '0', then the peer is using a battery power.  The other 7 bits
      are to be determined by specific applications.



Song, et al.             Expires August 18, 2014               [Page 13]


Internet-Draft           P2P Overlay Diagnostics           February 2014


5.1.4.  Extending Diagnostic Information

   The DiagnosticsExtension structure may be used to extend the
   diagnostic information collected.

5.2.  Request Extension: Ping

   To extend the ping request for use in diagnostics, a new extension of
   RELOAD is defined.  The structure for a MessageExtension in RELOAD is
   defined as:

            struct {
              MessageExtensionType  type;
              Boolean               critical;
              opaque                extension_contents<0..2^32-1>;
            } MessageExtension;

   For the Ping request extension, we define a new MessageExtensionType,
   extension 0x0002 named Diagnostic_Ping, as specified in Table 4 and
   specified in the RELOAD.  The extension contents consists of a
   DiagnosticsRequest structure as defined in Section 5.1.1.  This
   extension MAY be used for new requests of the the Ping method and
   MUST NOT be included in requests using any other method.

   This extension is not critical.  If a peer does not support the
   extension, they will simply ignore the diagnostic portion of the
   message, and will treat the message if it was a normal ping.  Senders
   MUST accept a response that lacks diagnostic information and SHOULD
   NOT resend the message expecting a reply.  Receivers who receive a
   method other than Ping including this extension MUST ignore the
   extension.

5.3.  New Request: PathTrack

   This document defines a simple PathTrack method to retrieve the
   diagnostic information from the intermediate peers along the routing
   path.  At each step of the PathTrack request, the responsible peer
   responds to the initiator node with requested status information such
   as congestion state, its processing power, its available bandwidth,
   the number of entries in its neighbor table, its uptime, its identity
   and network address information, and the next hop peer information.

   A PathTrack request specifies which diagnostic information is
   requested using a DiagnosticsRequest Data structure.  Base
   information is requested by setting the appropriate flags in the
   dMFlags field of the DiagnosticsRequest.  If the flag is clear (no
   bits are set), then the PathTrack request is only used for requesting
   the next hop information.  In this case the iterative mode of



Song, et al.             Expires August 18, 2014               [Page 14]


Internet-Draft           P2P Overlay Diagnostics           February 2014


   PathTrack is degraded to a RouteQuery method which is only used for
   checking the liveness of the peers along the routing path.  The
   PathTrack request can be routed directly or through the overlay based
   on the routing mode chosen by the initiator node.

   A response to a successful PathTrackReq is a PathTrackAns message.
   There is a general diagnostic information portion of the payload, the
   contents of which are based on the flags in the request.  Please
   refer to Section 5.1.3 for the definitions of the base diagnostic
   information, and Section 8.2 for the numeric message code for the new
   request.

5.3.1.  PathTrack Request

   The structure of the PathTrack request is as follows:

                           struct{
                               Destination destination;
                               DiagnosticsRequest request;
                           }PathTrackReq;

   The fields of the PathTrackReq are as follows:

      destination : The destination which the initiator node is
      interested in.  This may be any valid destination object,
      including a NodeID, opaque ids, or ResourceID.

      request : A DiagnosticsRequest, as discussed in Section 5.1.

5.3.2.  PathTrack Response

   The structure of the PathTrack Response is as follows:

                             struct{
                                  Destination next_hop;
                                  DiagnosticsResponse response;
                              }PathTrackAns;

   The fields of the PathTrackAns are as follows:

      next_hop : The information of the next hop node from the
      responding intermediate peer to the destination node.  If the
      responding peer is the responsible peer for the destination ID,
      then the next_hop node ID equals the responding node ID, and after
      that the initiator MUST stop the iterative process.

      response : A DiagnosticsResponse, as discussed in Section 5.1.




Song, et al.             Expires August 18, 2014               [Page 15]


Internet-Draft           P2P Overlay Diagnostics           February 2014


5.4.  Error Codes

   This document extends the Error response method defined in the RELOAD
   specification to describe the result of diagnostics.  When an error
   is encountered in RELOAD, the Message Code 0xFFFF is returned.  The
   ErrorResponse structure includes an error code, and we define new
   error codes to report on possible error conditions detected while
   performing diagnostics:

      Code Value         Error Code Name
      101                Underlay Destination Unreachable
      102                Underlay Time exceeded
      103                Message Expired
      104                Upstream Misrouting
      105                Loop detected
      106                TTL hops exceeded

   The final error codes will be assigned by IANA as specified in RELOAD
   protocol [I-D.ietf-p2psip-base].

   This document introduces several types of error information in the
   error_info field in the case of Code 101.  These are represented as
   an opaque UTF-8 text string.  Here are some examples for the error
   info.

      error_info:

      net unreachable
      host unreachable
      protocol unreachable
      port unreachable
      fragmentation needed
      source route failed

   The error_info field of the Code 102 to 106 are to be specified by
   the specific overlay.

5.5.  Message Processing

5.5.1.  Message Creation and Transmission

   When constructing either a Ping message with diagnostic extensions or
   a PathTrack message, the sender MUST create a DiagnosticsRequest data
   structure.  The sender MUST set the expiration field of this
   structure in Unix time timestamp format.  The value MUST be at least
   10 seconds in the future, and MUST NOT be more than 600 seconds in
   the future.  The timestamp_initiated field MUST be set to the current
   time in Unix time timestamp format.  The sender includes the dMFlags



Song, et al.             Expires August 18, 2014               [Page 16]


Internet-Draft           P2P Overlay Diagnostics           February 2014


   field in the structure, and MAY send any number (or all) of the flags
   to request the desired diagnostic information.  The sender MAY leave
   all the bits unset, requesting no diagnostic information.  The sender
   MAY also include diagnostic extensions for additional information.
   If the sender includes any extensions, it MUST calculate the length
   of these extensions and set the length field to the correct length.
   If no extensions are included, the sender MUST set length to zero.

   When constructing a diagnostic Ping message, the sender MUST create
   an MessageExtension structure as defined in RELOAD.  The value of
   type MUST be 0x0002.  The value of critical MUST be FALSE.  The value
   of extension_contents MUST be the DiagnosticsRequest structure
   defined above.  The sender MUST place the MessageExtension structure
   in the extensions field of the MessageContents structure.  The
   message MAY be directed to a particular NodeId or ResourceID, but
   SHOULD NOT be sent to the broadcast NodeID.

   When constructing a PathTrack message, the sender MUST set the
   message_code for the RELOAD MessageContents structure for PathTrack.
   The request field of the PathTrackReq MUST be set to the
   DiagnosticsRequest data structure defined above.  The destination
   field MUST be set to the desired destination, which MAY be either a
   NodeId or ResourceID but SHOULD NOT be the broadcast NodeID.

5.5.2.  Message Processing: Intermediate Peers

   When a request arrives at a peer, if the peer's responsible ID space
   does not cover the destination ID of the request, then the peer MUST
   continue processing this request according to the overlay specified
   routing mode from RELOAD protocol.

   In P2PSIP overlay, the error response can be generated by the
   intermediate peer or responsible peer, either to a diagnostic message
   or other messages.  When a request is received at a peer, the peer
   may find some connectivity failures or malfunction peers through the
   pre-defined rules of the overlay network, e.g. by analyzing via list
   or underlay error messages.  The peer SHOULD report the error
   responses to the initiator node.  The malfunction node information
   SHOULD also be reported to the initiator node in the error message
   payload.  All error responses contain the Error code followed by
   descriptions if they exist.

   Each intermediate peer receiving a Ping message with extensions (and
   which understands the extension) or receiving a PathTrack request/
   response SHOULD check the expiration value (Unix time format) to
   determine if the message is expired.  If the message expired, the
   intermediate peer SHOULD generate a message with Error Code 103




Song, et al.             Expires August 18, 2014               [Page 17]


Internet-Draft           P2P Overlay Diagnostics           February 2014


   "Message Expired" and return it to the initiator node, and discard
   the message.

   The peer SHOULD return an Error response with the Error Code 101
   "Underlay Destination Unreachable" when it receives an ICMP message
   with "Destination Unreachable" information after forwarding the
   received request to the destination peer.

   The peer SHOULD return an Error response with the Error Code 102
   "Underlay Time Exceeded" when it receives an ICMP message with "Time
   Exceeded" information after forwarding the received request.

   The peer SHOULD return an Error response with Error Code 104
   "Upstream Misrouting" when it finds its upstream peer disobeys the
   routing rules defined in the overlay.  The immediate upstream peer
   information SHOULD also be conveyed to the initiator node.

   The peer SHOULD return an Error response with Error Code 105 "Loop
   detected" when it finds a loop through the analysis of via list.

   The peer SHOULD return an Error response with Error Code 106 "TTL
   hops exceeded" when it finds that the TTL field value is no more than
   0 when forwarding.

5.5.3.  Message Response Creation

   When a diagnostic request message arrives at a peer, it understands
   the extension (in the case of Ping) or the new request type
   PathTrack, and it is responsible for the destination ID specified in
   the forwarding header, it MUST follow the specifications defined in
   5.1.3 of RELOAD protocol to form the response header, and perform the
   following operations:

   The receiver MUST check the expiration value (Unix time format) in
   the DiagnosticsRequest to determine if the message is expired.  If
   the message is expired, the peer MUST generate a message with the
   Error Code 103 "Message Expired" and return it to the initiator node,
   and discard the message.

   If the message is not expired, the receiver MUST construct a
   DiagnosticsResponse structure.  The destination peer MUST copy the
   TTL value from the forwarding header to the hop_counter field of the
   DiagnosticsResponse structure.  Note that the default value for TTL
   at the beginning represents 100-hops unless overlay configuration has
   overridden the value.  The receiver MUST generate an Unix time format
   timestamp for the current time of day and place it in the
   timestamp_received field.  The receiver MUST construct a new
   expiration time and place it in the expiration field of the



Song, et al.             Expires August 18, 2014               [Page 18]


Internet-Draft           P2P Overlay Diagnostics           February 2014


   DiagnosticsResponse.  This expiration MUST be at least 10 seconds in
   the future and MUST NOT be more than 600 seconds in the future.

   The destination peer MUST check if the initiator node has the
   authority to request that type of diagnostic information, and if
   appropriate, appends the diagnostic information requested in the
   dMFlags and diagnostic_extensions (if any) in the
   diagnostic_info_list field of the DiagnosticsResponse structure.  If
   there is any information returned, the receiver MUST calculate the
   length of the response and set length appropriately.  If there is no
   diagnostic information returned, length MUST be set to zero.

   In the event of an error, an error response containing the error code
   followed by the description (if they exist) MUST be created and sent
   to the sender.  If the initiator node asks for diagnostic information
   that they are not authorized to query, the receiving peer MUST return
   an Error response with the Error Code 2 "Error_Forbidden".

5.5.4.  Interpreting Results

   The initiator node, as well as the responding peer, MAY compute the
   overlay One-Way-Delay time through the value in timestamp_received
   and the timestamp_initiated field.  However, for a single hop
   measurement, the traditional measurement methods MUST be used instead
   of the overlay layer diagnostics methods.

   The P2P overlay network that uses the diagnostics methods specified
   in this document MUST enforce time synchronization with a central
   time server.  Network Time Protocol [RFC5905] can usually maintain
   time to within tens of milliseconds over the public Internet, and can
   achieve better than one millisecond accuracy in local area networks
   under ideal conditions.  However, this document does not specify the
   choice for time synchronization.  It depends on the implementation.

   The initiator node receiving the Ping response MAY check the
   hop_counter field and compute the overlay hops to the destination
   peer for the statistics of connectivity quality from the perspective
   of overlay hops.

6.  Authorization through Overlay Configuration

   The overlay configuration file MUST contain the following XML
   elements for authorizating a node to access the relative diagnostic
   kinds.

   diagnostic-kind: This has the attribute "kind" with the hexadecimal
   number indicating the diagnostic Kind Type, this attribute has the




Song, et al.             Expires August 18, 2014               [Page 19]


Internet-Draft           P2P Overlay Diagnostics           February 2014


   same value with Section 8.1, and at least one sub element "access-
   node".

   access-node: This element contains one hexadecimal number indicating
   a NodeID, and the node with this NodeID is allowed to access the
   diagnostic "kind" under the same diagnostic-kind element.

7.  Security Considerations

   The authorization for diagnostic information must be designed with
   care to prevent it becoming a method to retrieve information for bot
   attacks.  It should also be noted that attackers can use diagnostics
   to analyze overlay information to attack certain key peers.  As this
   document is a RELOAD extension, it follows RELOAD message header and
   routing specifications, the common security considerations described
   in the base document [I-D.ietf-p2psip-base] are also applicable to
   this document.  Overlays may define their own requirements on who can
   collect/share diagnostic information.

8.  IANA Considerations

8.1.  Diagnostic Kind ID Types

   IANA SHALL create a "RELOAD Diagnostic Kind ID Types" Registry.
   Entries in this registry are 16-bit integers denoting diagnostics
   extension data kind types carried in the diagnostic request and
   response message, as described in Section 5.1.2.  Code points from
   0x0000 to 0x003F SHALL be assigned together with flags within "RELOAD
   Diagnostics Flag" registry via RFC 5226 [RFC5226] standards action.
   Code points in the range 0x0040 to 0xFFFD SHALL be registered via RFC
   5226 standards action.




















Song, et al.             Expires August 18, 2014               [Page 20]


Internet-Draft           P2P Overlay Diagnostics           February 2014


             +----------------------+--------+---------------+
             | Diagnostic Kind Type |  Code  | Specification |
             +----------------------+--------+---------------+
             |       reserved       | 0x0000 |    RFC-XXXX   |
             |     STATUS_INFO      | 0x0001 |    RFC-XXXX   |
             |  ROUTING_TABLE_SIZE  | 0x0002 |    RFC-XXXX   |
             |    PROCESS_POWER     | 0x0003 |    RFC-XXXX   |
             |      BANDWIDTH       | 0x0004 |    RFC-XXXX   |
             |   SOFTWARE_VERSION   | 0x0005 |    RFC-XXXX   |
             |    MACHINE_UPTIME    | 0x0006 |    RFC-XXXX   |
             |      APP_UPTIME      | 0x0007 |    RFC-XXXX   |
             |   MEMORY_FOOTPRINT   | 0x0008 |    RFC-XXXX   |
             |   DATASIZE_STORED    | 0x0009 |    RFC-XXXX   |
             |   INSTANCES_STORED   | 0x000A |    RFC-XXXX   |
             |  MESSAGES_SENT_RCVD  | 0x000B |    RFC-XXXX   |
             |   EWMA_BYTES_SENT    | 0x000C |    RFC-XXXX   |
             |   EWMA_BYTES_RCVD    | 0x000D |    RFC-XXXX   |
             |     UNDERLAY_HOP     | 0x000E |    RFC-XXXX   |
             |    BATTERY_STATUS    | 0x000F |    RFC-XXXX   |
             |       reserved       | 0x003F |    RFC-XXXX   |
             | local use (reserved) | 0xFFFE |    RFC-XXXX   |
             |       reserved       | 0xFFFF |    RFC-XXXX   |
             +----------------------+--------+---------------+

                      Table 1: Diagnostic Kind Types

8.2.  Message Codes

   This document introduces two new types of messages and their
   responses, requiring the following additions to the "RELOAD Message
   Code" Registry defined in RELOAD [I-D.ietf-p2psip-base].  These
   additions are:

               +-------------------+------------+----------+
               | Message Code Name | Code Value |   RFC    |
               +-------------------+------------+----------+
               |   path_track_req  |    101     | RFC-AAAA |
               |   path_track_ans  |    102     | RFC-AAAA |
               +-------------------+------------+----------+

                Table 2: Extensions to RELOAD Message Codes

   [To RFC editor: Values starting at 101 were used to prevent
   collisions with RELOAD base values.  Once RELOAD moves to RFC, these
   values may start at the next higher value after the RELOAD base
   values.  The final message code will be assigned by IANA.  And all
   RFC-AAAA should be replaced with the RFC number of RELOAD when
   publication.]



Song, et al.             Expires August 18, 2014               [Page 21]


Internet-Draft           P2P Overlay Diagnostics           February 2014


8.3.  Error Code

   This document introduces the following new error codes, extending the
   "RELOAD Message Code" registry as described below:

    +----------------------------------------+------------+----------+
    |           Message Code Name            | Code Value |   RFC    |
    +----------------------------------------+------------+----------+
    | Error_Underlay_Destination_Unreachable |    101     | RFC-AAAA |
    |      Error_Underlay_Time_Exceeded      |    102     | RFC-AAAA |
    |         Error_Message_Expired          |    103     | RFC-AAAA |
    |       Error_Upstream_Misrouting        |    104     | RFC-AAAA |
    |          Error_Loop_Detected           |    105     | RFC-AAAA |
    |        Error_TTL_Hops_Exceeded         |    106     | RFC-AAAA |
    +----------------------------------------+------------+----------+

                 Table 3: Extensions to RELOAD Error Codes

8.4.  Message Extension

   This document introduces the following new RELOAD extension code:

                +-----------------+------------+----------+
                |  Extension Name | Code Value |   RFC    |
                +-----------------+------------+----------+
                | Diagnostic_Ping |   0x0002   | RFC-AAAA |
                +-----------------+------------+----------+

                    Table 4: New RELOAD Extension Code

8.5.  Diagnostics Flag

   IANA SHALL create a "RELOAD Diagnostics Flag" Registry.  Entries in
   this registry are 1-bit flags contained in a 64-bits long integer
   dMFlags denoting diagnostic information to be retrieved as described
   in Section 5.3.  New entries SHALL be defined via [RFC5226] Standards
   Action.  The initial contents of this registry are:














Song, et al.             Expires August 18, 2014               [Page 22]


Internet-Draft           P2P Overlay Diagnostics           February 2014


    +-------------------------+------------------------------+--------+
    |  diagnostic information |diagnostic flag in dMFlags    | RFC    |
    |-------------------------+------------------------------+--------|
    |Reserved                 | 0x 0000 0000 0000 0000       |RFC-XXXX|
    |STATUS_INFO              | 0x 0000 0000 0000 0001       |RFC-XXXX|
    |ROUTING_TABLE_SIZE       | 0x 0000 0000 0000 0002       |RFC-XXXX|
    |PROCESS_POWER            | 0x 0000 0000 0000 0004       |RFC-XXXX|
    |BANDWIDTH                | 0x 0000 0000 0000 0008       |RFC-XXXX|
    |SOFTWARE_VERSION         | 0x 0000 0000 0000 0010       |RFC-XXXX|
    |MACHINE_UPTIME           | 0x 0000 0000 0000 0020       |RFC-XXXX|
    |APP_UPTIME               | 0x 0000 0000 0000 0040       |RFC-XXXX|
    |MEMORY_FOOTPRINT         | 0x 0000 0000 0000 0080       |RFC-XXXX|
    |DATASIZE_STORED          | 0x 0000 0000 0000 0100       |RFC-XXXX|
    |INSTANCES_STORED         | 0x 0000 0000 0000 0200       |RFC-XXXX|
    |MESSAGES_SENT_RCVD       | 0x 0000 0000 0000 0400       |RFC-XXXX|
    |EWMA_BYTES_SENT          | 0x 0000 0000 0000 0800       |RFC-XXXX|
    |EWMA_BYTES_RCVD          | 0x 0000 0000 0000 1000       |RFC-XXXX|
    |UNDERLAY_HOP             | 0x 0000 0000 0000 2000       |RFC-XXXX|
    |BATTERY_STATUS           | 0x 0000 0000 0000 4000       |RFC-XXXX|
    |Reserved                 | 0x FFFF FFFF FFFF FFFF       |RFC-XXXX|
    +-------------------------+------------------------------+--------+

   [To RFC editor: Please replace all RFC-XXXX in this document with the
   RFC number of this document.]

8.6.  XML Name Space Registration

   This document registers a URI for the config-diagnostics XML
   namespaces in the IETF XML registry defined in [RFC3688].  All the
   elements defined in this document belong to this namespace.

   URI: urn:ietf:params:xml:ns:p2p:config-diagnostics
   Registrant Contact: The IESG.
   XML: N/A, the requested URIs are XML namespaces

   And the overlay configuration file MUST contain the following xml
   language declaring P2PSIP diagnostics as a mandatory extension to
   RELOAD.

   <mandatory-extension>
                 urn:ietf:params:xml:ns:p2p:config-diagnostics
   </mandatory-extension>

9.  Acknowledgments

   We would like to thank Zheng Hewen for the contribution of the
   initial version of this document.  We would also like to thank Bruce
   Lowekamp, Salman Baset, Henning Schulzrinne, Jiang Haifeng and Marc



Song, et al.             Expires August 18, 2014               [Page 23]


Internet-Draft           P2P Overlay Diagnostics           February 2014


   Petit-Huguenin for the email discussion and their valued comments,
   and special thanks to Henry Sinnreich for contributing to the usage
   scenarios text.  We would like to thank the authors of the RELOAD
   protocol for transferring text about diagnostics to this document.

10.  References

10.1.  Normative References

   [RFC0792]  Postel, J., "Internet Control Message Protocol", STD 5,
              RFC 792, September 1981.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
              January 2004.

   [RFC5905]  Mills, D., Martin, J., Burbank, J., and W. Kasch, "Network
              Time Protocol Version 4: Protocol and Algorithms
              Specification", RFC 5905, June 2010.

   [I-D.ietf-p2psip-base]
              Jennings, C., Lowekamp, B., Rescorla, E., Baset, S., and
              H. Schulzrinne, "REsource LOcation And Discovery (RELOAD)
              Base Protocol", draft-ietf-p2psip-base-26 (work in
              progress), February 2013.

10.2.  Informative References

   [UnixTime]
              "UnixTime", <Wikipedia, "Unix Time",
              <http:/wikipedia.org/wiki/Unix_time>.>.

   [I-D.ietf-p2psip-self-tuning]
              Maenpaa, J. and G. Camarillo, "Self-tuning Distributed
              Hash Table (DHT) for REsource LOcation And Discovery
              (RELOAD)", draft-ietf-p2psip-self-tuning-10 (work in
              progress), February 2014.

   [I-D.ietf-p2psip-concepts]
              Bryan, D., Matthews, P., Shim, E., Willis, D., and S.
              Dawkins, "Concepts and Terminology for Peer to Peer SIP",
              draft-ietf-p2psip-concepts-05 (work in progress), July
              2013.






Song, et al.             Expires August 18, 2014               [Page 24]


Internet-Draft           P2P Overlay Diagnostics           February 2014


   [Overlay-Failure-Detection]
              Zhuang, S., "On failure detection algorithms in overlay
              networks", Proc. IEEE Infocomm, Mar 2005.

   [Handling_Churn_in_a_DHT]
              Rhea, S., "Handling Churn in a DHT", USENIX Annual
              Conference, June 2004.

   [Diagnostic_Framework]
              Jin, X., "A Diagnostic Framework for Peer-to-Peer
              Streaming", 2005.

   [Diagnostics_and_NAT_traversal_in_P2PP]
              Gupta, G., "Diagnostics and NAT Traversal in P2PP - Design
              and Implementation", Columbia University Report , June
              2008.

   [RFC5226]  Narten, T. and H. Alvestrand, "Guidelines for Writing an
              IANA Considerations Section in RFCs", BCP 26, RFC 5226,
              May 2008.

Appendix A.  Examples

   Below, we sketch how these metrics can be used.

A.1.  Example 1

   A peer may set EWMA_BYTES_SENT and EWMA_BYTES_RCVD flags in the
   PathTrackReq to its direct neighbors.  A peer can use EWMA_BYTES_SENT
   and EWMA_BYTES_RCVD of another peer to infer whether it is acting as
   a media relay.  It may then choose not to forward any requests for
   media relay to this peer.  Similarly, among the various candidates
   for filling up routing table, a peer may prefer a peer with a large
   UPTIME value, small RTT, and small LAST_CONTACT value.

A.2.  Example 2

   A peer may set the STATUS_INFO Flag in the PathTrackReq to a remote
   destination peer.  The overlay has its own threshold definition for
   congestion.  The peer can obtain knowledge of all the status
   information of the intermediate peers along the path.  Then it can
   choose other paths to that node for the subsequent requests.

A.3.  Example 3

   A peer may use Ping to evaluate the average overlay hops to other
   peers by sending PingReq to a set of random resource or node IDs in




Song, et al.             Expires August 18, 2014               [Page 25]


Internet-Draft           P2P Overlay Diagnostics           February 2014


   the overlay.  A peer may adjust its timeout value according to the
   change of average overlay hops.

Appendix B.  Problems with Generating Multiple Responses on Path

   An earlier version of this document considered an approach where a
   response was generated by each intermediate peer as the message
   traversed the overlay.  This approach was discarded.  One reason this
   approach was discarded was that it could provide a DoS mechanism,
   whereby an attacker could send an arbitrary message claiming to be
   from a spoofed "sender" the real sender wished to attack.  As a
   result of sending this one message, many messages would be generated
   and sent back to the spoofed "sender" - one from each intermediate
   peer on the message path.  While authentication mechanisms could
   reduce some risk of this attack, it still resulted in a fundamental
   break from the request-response nature of the RELOAD protocol, as
   multiple responses are generated to a single request.  Although one
   request with responses from all the peers in the route will be more
   efficient, it was determined to be too great a security risk and
   deviation from the RELOAD architecture.

Appendix C.  Changes to the Draft

   To RFC editor: This section is to track the changes.  Please remove
   this section before publication.

C.1.  Changes since -00 version

   1.  Changed title from "Diagnose P2PSIP Overlay Network" to "P2PSIP
       Overlay Diagnostics".

   2.  Changed the table of contents.  Add a section about message
       processing and a section of examples.

   3.  Merge diagnostics text from the p2psip base draft -01.

   4.  Removed ECHO method for security reasons.

C.2.  Changes since -01 version

      Added BATTERY_STATUS as diagnostic information.

      Removed UnderlayTTL test from the Ping method, instead adding an
      UNDERLAY_HOP diagnostic information for PathTrack method.

      Give some examples for diagnostic information, and give some
      editor's notes for further work.




Song, et al.             Expires August 18, 2014               [Page 26]


Internet-Draft           P2P Overlay Diagnostics           February 2014


C.3.  Changes since -02 version

   Provided further explanation as to why the base draft Ping in the
   current form cannot be used to replace Ping, and why some combination
   of methods cannot replace PathTrack.

C.4.  Changes since -03 version

   Modified structure used to share information collected.  Both
   mechanisms now use a common data structure to convey information.

C.5.  Changes since -04 version

   Updated the authors' addresses and modified the last sentence in .
   (Section 5.3.2)

C.6.  Changes since -05 version

   Resolve Marc's comments from the mailing list.  And define the
   details of STATUS_INO.

C.7.  Changes in version -10

   Resolve the authorization issue and other comments (e.g. define
   diagnostics as a mandatory extension) from WGLC.  And check for the
   languages.

Authors' Addresses

   Haibin Song
   Huawei

   Email: haibin.song@huawei.com


   Jiang Xingfeng
   Huawei

   Email: jiang.x.f@huawei.com


   Roni Even
   Huawei
   14 David Hamelech
   Tel Aviv 64953
   Israel

   Email: roni.even@mail01.huawei.com



Song, et al.             Expires August 18, 2014               [Page 27]


Internet-Draft           P2P Overlay Diagnostics           February 2014


   David A. Bryan
   Ethernot.org
   Williamsburg, Virginia
   United States of America

   Email: dbryan@ethernot.org


   Yi Sun
   ICT-CAS

   Email: sunyi@ict.ac.cn







































Song, et al.             Expires August 18, 2014               [Page 28]


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