Network Working Group H. Song
Internet-Draft H. Zheng
Intended status: Standards Track X. Jiang
Expires: January 8, 2009 Huawei
July 7, 2008
Diagnose P2PSIP Overlay Network Failures
draft-zheng-p2psip-diagnose-02
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Abstract
This document describes a simple and efficient mechanism that can be
used to detect and localize failures in P2PSIP overlay network. This
document mainly consists of two parts: information carried in a
P2PSIP "Echo request" message and "Echo response" message for the
purpose of fault detection and localization, and mechanisms for
processing those messages.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Usage Scenarios . . . . . . . . . . . . . . . . . . . . . 3
2. Overview of Functions . . . . . . . . . . . . . . . . . . . . 4
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
4. Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . 4
5. Packets Formats . . . . . . . . . . . . . . . . . . . . . . . 6
5.1. Message Header . . . . . . . . . . . . . . . . . . . . . . 6
5.2. Message Attributes . . . . . . . . . . . . . . . . . . . . 6
5.2.1. Response Attribute . . . . . . . . . . . . . . . . . . 7
5.2.2. Echo Attribute . . . . . . . . . . . . . . . . . . . . 8
5.2.3. Respond Peer Info Attribute . . . . . . . . . . . . . 10
6. Message . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
6.1. Echo request . . . . . . . . . . . . . . . . . . . . . . . 12
6.2. Echo response . . . . . . . . . . . . . . . . . . . . . . 12
6.2.1. Echo response from the terminator peer . . . . . . . . 13
6.2.2. Echo response from the intermediate peer . . . . . . . 14
7. Security Considerations . . . . . . . . . . . . . . . . . . . 15
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15
9. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
9.1. P2PSIP Ping . . . . . . . . . . . . . . . . . . . . . . . 16
9.2. P2PSIP Traceroute . . . . . . . . . . . . . . . . . . . . 17
10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 18
11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 18
11.1. Normative References . . . . . . . . . . . . . . . . . . . 18
11.2. Informative References . . . . . . . . . . . . . . . . . . 19
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 20
Intellectual Property and Copyright Statements . . . . . . . . . . 22
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1. Introduction
P2P systems are self-organizing and ideally require no network
management in the traditional sense to set up and to configure
individual P2P nodes. P2P service providers may however contemplate
usage scenarios where some diagnostics are required. We present a
simple connectivity test that may be used in such diagnostics.
1.1. Usage Scenarios
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]. The unresponsive
nodes may however be only temporarily disabled 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
it can be optimized as described in the reference [Handling Churn in
a DHT].
b. P2P system diagnostics to check the overall health of the P2P
overlay network, the consumption of network bandwidth, problem links
and also checks for abusive or malicious nodes. This is not a
trivial problem and has been studied in detail for content and
streaming P2P overlays, such as for example in [Diagnostic
Framework].
Similar work has been reported more recently for P2PSIP overlays as
applied to the P2PP protocol [Diagnostics and NAT traversal in P2PP].
c. Diagnostics for a particular node to follow up an individual user
complaint. 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. The
simple connectivity tests are not dependent on the type of P2PSIP
overlay and they are the topic of this memo. Note however 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 link bandwidth connecting the user to the Internet.
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2. Overview of Functions
As one diagnostics protocol, P2PSIP diagnostics protocol is mainly
used to detect and localize failures in P2PSIP overlay network. It
provides mechanisms to detect and localize malfunctioning or badly
behaving peers including disabled peers, congested peers and
misrouting peers. It provides a mechanism to detect connectivity to
the specified peer, a mechanism to detect availabilities of specified
resource records and a mechanism to discover P2PSIP overlay topology
and the underlay topology.
The P2PSIP diagnostics protocol described here reuses P2PSIP peer
protocol [I-D.jiang-p2psip-sep]; essentially it reuses P2PSIP peer
protocol specification and then introduces one new type of message
(i.e., Echo message). P2PSIP diagnostics protocol strictly follows
the P2PSIP peer protocol specification on the messages routing,
transporting and NAT traversal etc. The diagnostic method is however
P2PSIP protocol independent.
3. Terminology
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].
The other concepts used in this document are compatible with
"Concepts and Terminology for Peer to Peer SIP" [I-D.ietf-p2psip-
concepts] and the P2PSIP peer protocol SEP[I-D.jiang-p2psip-sep].
4. Motivation
In the last few years, overlay networks have rapidly evolved and
emerged as a promising platform to deploy 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 relies on
accurate and timely detection of failures.
As descriptions in the "P2PSIP Security Analysis and Evaluation"[I-
D.song-p2psip-security-eval], "Security requirements in P2PSIP"
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[I-D.matuszewski-p2psip-security- requirement] and "Security
Mechanisms for Peer to Peer SIP"[I-D.jennins-p2psip-security-
mechanisms], there are some malfunctioning or badly behaving peers in
the P2PSIP overlay, those peers may be disabled peers, congested
peers or peers behaving with misrouting, and the impact of those
peers in the overlay network is degradation of quality of service
provided collectively by the peers in the overlay network or
interruption of those services. It is desirable to identify
malfunctioning or badly behaving peers through some diagnostics
tools, and exclude or reject them from the P2PSIP system. Besides
those faults, node failures may be caused by underlying failures, for
example, when the IP layer routing failover speed after link failures
is very slow, then the recovery from the incorrect overlay topology
may also be slow. Moreover, if a backbone link fails and the
failover is slow, the network may be partitioned, which may lead to
partitions of overlay topologies and inconsistent routing results
between different partitioned components.
Some keep-alive algorithms based on periodically probe and
acknowledge enable accurate and timely detection of failures of one
peer's neighbors [Overlay-Failure-Detection], but those algorithms
only can detect the disabled neighbors using the periodical method,
it may not be enough for operating the overlay network by service
providers.
One general P2PSIP overlay diagnostics protocol supporting periodical
method and on-demand method for node failures and network failures is
desirable. This document describes one general P2PSIP overlay
diagnostics protocol useful for P2PSIP peer protocols and it is a
good complementation for some keep-alive algorithms in the P2P or
P2PSIP overlay itself.
In this document, we mainly describe how to detect and localize those
failures including disabled peers, congested peers, misrouting
behaviors and underlying network faults in P2PSIP overlay network
through a simple and efficient mechanism. This mechanism is modeled
after the ping/traceroute paradigm: ping (ICMP echo request [RFC792])
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" mode and a "traceroute" mode for diagnose P2PSIP
overlay network.
The basic idea is to transmit a P2PSIP peer protocol request message
(Echo request message) along the same path which all other P2PSIP
peer protocol request messages would traverse. In "Ping" mode, an
Echo request message are forwarded by the intermediate peers along
the path and then terminated by the responsible peer, and after local
diagnostics, the responsible peer returns an Echo response message.
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In "Traceroute" mode, an Echo request message is received and
disposed by each peer along the routing path, each peer along the
path returns an Echo response message with local diagnostics
information including the result and causes if existing.
One approach these tools can be used is to detect the connectivity to
the specified peer or the availability of the specified resource-
record through P2PSIP Ping operation once the overlay network
receives some alarms about overlay service degradation or
interruption, if the ping fails, one can then send a P2PSIP
Traceroute to determine where the fault lies.
5. Packets Formats
This document reuses the P2PSIP peer protocol to carry diagnostics
information. Considering special usage due to diagnostics, this
document extends the P2PSIP peer protocol by introducing one new type
of message and some attributes.
5.1. Message Header
The mechanism defined in this document follows P2PSIP peer protocol
specification, the introduced message whatever requests or responses
adopts the same message format with existing P2PSIP peer protocol
messages. Different types of messages convey different TLV objects
following by the common message header according to the protocol
design. Those objects are called "Attributes". Please refer to
P2PSIP peer protocol [I-D.jiang-p2psip-sep] for the detailed format
of Message Header.
This document introduces one new type of message as below:
Message Type Name
11 Echo
5.2. Message Attributes
As P2PSIP peer protocol, A P2PSIP diagnostics protocol message
contains zero, one or multiple Attributes which describe the
specified contents. All attributes follow P2PSIP peer protocol
specification and adopt TLV style. Please refer to P2PSIP peer
protocol [I-D.jiang-p2psip-sep] for the detailed format of Message
Attributes.
This document introduces two new types of attributes as below:
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Attribute Type Name
15 Echo
16 Respond Peer Info
In addition to the newly introduced Echo attribute, this document
extends the Response attribute defined in P2PSIP peer protocol
specification.
5.2.1. Response Attribute
This document extends the Response attribute defined in the P2PSIP
peer protocol specification to describe the result of diagnostics as
Figure 1.
0 1 2 3
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|M| Reserved |Attribute Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Response code | Response sub-code |
+-+-+-+-+-+-+-+-++-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-++-+-+-+-+-+-+-+
Figure 1 Response Attribute Format
M-flag: the value is set;
Reserved (7 bits): those bits are reserved and ignored;
Attribute Type (8 bits): the value is 7 (0x07) for Response
Attribute;
Length (16 bits): the length in bytes of this attribute;
Response Code (16 bits): response code is determined by the
responder, this field is necessary for any response attribute;
Response Sub-Code (16 bits): response sub-code is determined by the
responder, this field is optional.
This document introduces new response codes as below:
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Response Code Meaning
414 Underlay Destination Unreachable
415 Underlay Time exceeded
416 Upstream Misrouting
417 Loop detected
419 TTL hops exceeded
This document introduces response sub-codes for response code 414 as
below:
Response Sub-Code Meaning
0 net unreachable
1 host unreachable
2 protocol unreachable
3 port unreachable
4 fragmentation needed
5 source route failed
5.2.2. Echo Attribute
This document introduces Echo attribute to describe diagnostics
control information, including but not limited to: the routing mode
of the Echo message, the number of hops that the Echo message
traverses, the reply rule to generate the Echo response message, the
timestamp of initiating the Echo request message, the timestamp of
receiving the Echo request message, and the expiration time of the
Echo request message.
The Echo attribute format is shown as Figure 2:
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0 1 2 3
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|M|U|P|Reserved |Attribute Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Routing Mode | Hop Counter | Reply rule | Underlay TTL |
+-+-+-+-+-+-+-+-++-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-++-+-+-+-+-+-+-+
| TimeStamp Initiated (seconds) |
+-+-+-+-+-+-+-+-++-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-++-+-+-+-+-+-+-+
| TimeStamp Initiated (microseconds) |
+-+-+-+-+-+-+-+-++-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-++-+-+-+-+-+-+-+
| TimeStamp Received (seconds) |
+-+-+-+-+-+-+-+-++-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-++-+-+-+-+-+-+-+
| TimeStamp Received (microseconds) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Expiration time (seconds) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Expiration time (microseconds) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2 Echo Attribute Format
M-flag: the flag is set;
U-flag: indicate whether the receiver of Echo request message needs
to carry immediate upstream peer information in the following Echo
response message. If set (U=1), the Echo response message must carry
its immediate upstream peer information such as Peer-ID;
P-flag: indicate whether the intermediate peer continues to forward
the Echo request message when it detects misrouting behavior of its
immediate upstream peer for this Echo request message. If set (P=1),
the intermediate peer continues to forward the Echo request message
upon detecting misrouting behavior of its immediate upstream peer;
otherwise the intermediate peer stops forwarding. Certainly the
intermediate peer should stop forwarding any received Echo request
message once detecting looping even when P-flag is set;
Reserved (5 bits): those bits are reserved and ignored;
Attribute Type (8 bits): the value is 15 (0x0F);
Length (16 bits): the length in bytes of this attribute;
Routing Mode (8 bits): indicate the routing mode of the Echo message
in the overlay.
Hop Counter (8 bits): This field is ignored by Echo requests. In
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Echo responses, this field must be exactly copied from the TTL field
of the message header in the received Echo request. Then this
information is sent back to the request initiator to compute the hops
that the message traverses in the overlay.
Reply rule (8 bits): indicate the process policy to the Echo request
specified by the initiator;
Underlay TTL (8 bits): indicate the underlay TTL which the
intermediate peer must adopt when forwarding the Echo requests, it is
specified by the initiator;
Timestamp Initiated (64 bits): the time-of-day (in seconds and
microseconds, according to the sender's clock) in NTP format
[RFC2030] when the P2PSIP Overlay Echo request is sent。It can
be carried in the Echo response message from the receiver; certainly
it first appears in the Echo request message;
Timestamp Received (64 bits): it is in an Echo response message and
the time-of-day (according to the receiver's clock) in NTP format
[RFC2030] that the corresponding the P2PSIP Overlay Echo request was
received;
Expiration time (64 bits): the expiration time of Echo request
message, it is the time-of-day in NTP format [RFC2030].
This document defines those routing modes as below:
Forward mode Meaning
0 Recursive
1 Iterative
2 Semi-recursive
3 Overlay native
This document defines those reply rules as below:
Reply rule Meaning
1 Do not reply except destination peer
2 Immediately reply
5.2.3. Respond Peer Info Attribute
This document introduces Respond Peer attribute to describe Peer
information such as Peer-ID.
Respond Peer Info attribute is also a composite attribute. Like the
Source Peer Info attribute and Destination Peer Info attribute, it
may be also comprised of Peer-ID attribute, Peer Service Capability
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attribute and several Peer Address Info attributes, the Peer-ID
attribute and at least one Peer Address Info attribute are necessary
among them.
The Respond Peer Info attribute format is shown as Figure 3.
0 1 2 3
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|M|U|D|Reserved |Attribute Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Peer-ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Peer service capability |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Peer Address Info - 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ............ |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Peer Address Info - N |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3 Respond Peer Info attribute format
M-flag: the value is 1;
U-flag: indicate whether this attribute describe the immediate
upstream peer of the initiator generating this attribute. If set
(U=1), the attribute is used to describe the immediate upstream peer
on the path;
D-flag: indicate whether this attribute describe the immediate
downstream peer of the initiator generating this attribute (e.g.
next-hop peer in the overlay forwarding path). If set (D=1), the
attribute is used to describe the immediate downstream peer on the
path. If U=0 and D=0, the attribute is used to describe the peer
itself (i.e. the attribute generator);
Reserved (5 bits): those bits are reserved and ignored;
Attribute Type (8 bits): the value is 16 (0x10);
Length (16 bits): the length in bytes of this attribute.
6. Message
All P2PSIP peer protocol requests and responses use the common
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message header after which zero, one or more TLV-style attributes
follow.
This document introduces the new Echo message to detect and localize
failures in P2PSIP overlay network.
6.1. Echo request
An Echo request message is used to detect possible failures in the
specified path of P2PSIP overlay network, including disabled peers,
congested peers, misrouting behavior and underlying network faults.
An Echo request message is also used to discover the topology of the
specified path and check the reachability to the specified peer or
the availability of the specified resource-record.
An Echo request is normal P2PSIP peer protocol message; it can be
initiated by any peer supporting P2PSIP peer protocol specification
in the P2PSIP overlay network.
An Echo request must contain a message header and an Echo attribute.
Echo request =
Message Header
Echo Attribute
Source Peer Info
6.2. Echo response
An Echo response message is used to convey local diagnostics
information including result, causes and possible other assistant
information.
An Echo response message must contain a message header, a Response
attribute, an Echo attribute and one or more Respond Peer Info
attributes. It may contain a Resource Info attribute and a Status
attribute. If the peer is one intermediate peer, the Echo response
message must contain three Respond Peer Info attributes to describe
the response peer itself, immediate upstream peer and next-hop peer
individually. If the peer is the last peer terminating the Echo
request message, the Echo message must contain two Respond Peer Info
attributes to describe self and immediate upstream peer. The TTL in
the received Echo request must be copied to the Hop Counter field in
the Echo response. In the following section, the last peer
terminating the Echo request message is called as the "terminator
peer", in comparison with "intermediate peer" and "initiator peer" or
"initiator".
One implementation to estimate whether one peer is disabled is that
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the initiator uses local timer to determine whether the expected Echo
response message is expired, i.e., the peer thinks that the specified
peer is disabled if it does not receive the Echo response message
before the local timer expires which starts when issuing an Echo
request message to the specified peer in the P2PSIP overlay network.
This local timer can be updated in the specified interval by the Echo
response message from the intermediate peers in the "Traceroute"
mode.
Echo response =
Message Header
Response Attribute
Echo Attribute
Respond Peer Info Attribute
[Resource Info Attribute]
[Status Attribute]
6.2.1. Echo response from the terminator peer
When an Echo request message arrived at a peer, if the peer's
responsible ID space covers the destination ID of the Echo request
message or the peer finds that the destination ID is unreachable in
the P2PSIP overlay (e.g., detecting loop), then the peer constructs
and returns an Echo response message using the specified Routing Mode
indicated by the Echo request message when the Reply rule field of
the received Echo attribute is not Zero, and the peer does not give
any response when the Reply rule field is Zero.
The Echo response must carry a Response attribute, a Respond Peer
Info attribute describing the receiver of the Echo request message,
an Echo attribute containing TimeStamp Received field and TimeStamp
Initiated field copied from the received Echo request message.
The returning Echo response message further must carry a Resource
attribute when the responsible resource-record exists in the peer.
If the Echo response message does not carry any Resource attribute,
it means that the resource-record whose Resource-ID is equal to the
destination ID of the Echo request message does not exist in the
peer.
If the peer finds that it is bush or congested, the returning Echo
response message must carry a Status attribute.
If the peer finds that its immediate upstream peer behaves with
misrouting, the returning Echo response message must carry a Response
attribute with the response code 416 "Upstream Misrouting" and a
Respond Peer Info attribute describing information of its immediate
upstream peer.
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6.2.2. Echo response from the intermediate peer
When an Echo request arrived at a peer, if the peer's responsible ID
space does not cover the destination ID of the Echo request, then the
peer continues to forward this Echo request according to the
specified Routing Mode field in the received Echo request.
The peer should return an Echo response carrying a Response attribute
with the response code 414 "Underlay Destination Unreachable" when it
receives an ICMP message with "Destination Unreachable" information
after forwarding the received Echo request.
The peer should return an Echo response carrying a Response attribute
with the response code 415 "Underlay Time Exceeded" when it receives
an ICMP message with "Time Exceeded" information after forwarding the
received Echo request.
When an Echo request arrived at a peer, if the peer's responsible ID
space does not cover the destination ID of the Echo request message
and the value of received Reply rule field is 2, then the peer must
construct and return an Echo response and continue to forward the
Echo request.
The Echo response must carry a Response attribute, a Respond Peer
Info attribute describing the receiver of the Echo request message, a
Respond Peer Info attribute describing the immediate downstream peer
(i.e. next hop to forward the Echo request message in the P2PSIP
overlay network), an Echo attribute containing TimeStamp Received
field and TimeStamp Initiated field copied from the received Echo
request.
The returning Echo response must carry a Resource attribute when the
responsible resource-record exists in the peer. If the Echo response
does not carry any Resource attribute, it means that the resource-
record whose Resource-ID is equal with the destination ID of the Echo
request message does not exist in the peer.
If the peer finds that it is bush or congested, the returning Echo
response message must carry a Status attribute.
If the peer finds that its immediate upstream peer behaves with
misrouting, the returning Echo response must carry a Response
attribute with the response code 416 "Upstream Misrouting" and
Respond Peer Info attribute describing information of its immediate
upstream peer.
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7. Security Considerations
One feasible P2PSIP Traceroute implementation based on the value of
"Reply Rule" field 2 "Immediately reply" (Section 9.2) may cause DoS
attack to the initiator, though this implementation is more efficient
than traditional Traceroute operation of Internet using pacing ICMP
message.
An advice is to use the efficient Traceroute operation in
administrated P2PSIP overlay and use the pacing-style Traceroute
operation in the untrustworthy P2PSIP overlay network, certainly, the
probability of this type of DoS attack is very low because the
overlay is distributed and the it is very hard for the attacker to
know the accurate Peer-IDs and attack most of all peers
simultaneously.
8. IANA Considerations
Message Type: this document introduces a new type of message as
below:
Message Type Name
11 Echo
Attribute Type: this document introduces two new types of attributes
as below:
Attribute Type Name
15 Echo
16 Respond Peer Info
Response Code: this document introduces some new response definitions
as below:
Result Code Name
414 Underlay Destination Unreachable
415 Underlay Time exceeded
416 Upstream Misrouting
417 Loop detected
419 TTL hops exceeded
Response Sub-Code: this document defines response sub-codes for the
response code 414 "Underlay Destination Unreachable" as below:
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Response Sub-Code Meaning
0 net unreachable
1 host unreachable
2 protocol unreachable
3 port unreachable
4 fragmentation needed
5 source route failed
9. Examples
9.1. P2PSIP Ping
Any peer supporting P2PSIP diagnostics protocol can use P2PSIP Ping
operation to check the reachability to the specified peer in the
overlay or the availability of the specified resource-record.
In the normal P2PSIP Ping operation, a peer constructs and issues an
Echo request message to the specified destination ID. The
destination ID of the Echo request message is the specified Peer-ID
or Resource-ID, the source ID of the Echo request message is the
Peer-ID of the initiator. The "Reply Rule" value must be 1 "Do not
reply except last peer", and the initiator determines the "Routing
Mode", and "Underlay TTL" of the Echo request message by itself. Any
intermediate peer does only simply forward this message to its next
hop in the overlay and not disposes this Echo request message until
the message arrives at the terminator peer who may be the responsible
peer or one peer who finds that the destination ID is unreachable,
eventually the terminator peer returns an Echo response message.
Here is an example of a P2PSIP Ping operation; it is shown as Figure
4:
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Peer-1 Peer-2 Peer-3 Peer-4
| | | |
| (1).Echo Request | | |
|------------------->| | |
| | (2).Echo Request | |
| |------------------->| |
| | | (3).Echo Request |
| | |------------------->|
| | | |
| | | (4).Echo Response |
|<-------------------|--------------------|--------------------|
| | | |
Figure 4 P2PSIP Ping example
The overlay network operator may use P2PSIP Ping operation to measure
the message transmission delay and jitter between two specified
peers.
9.2. P2PSIP Traceroute
Any peer supporting P2PSIP diagnostics protocol can use P2PSIP
traceroute operation to detect and localize malfunctioning or badly
behaving peers including disabled peers, congested peers and
misrouting peers, or detect and localize network failure, or to
discover the topology of the specified path in the overlay network.
In one possible P2PSIP Traceroute operation, a peer constructs and
issues an Echo request message to the specified destination ID. The
destination ID in the Echo request message is the specified Peer-ID
or Resource-ID, the source ID in the Echo request message is the
Peer-ID of the initiator. The value of "Reply Rule" field must be 2
"Immediately reply", and the initiator determines the "Routing mode"
and "Underlay TTL" of the Echo request message by itself. Any
intermediate peer does dispose this Echo request message, i.e.,
forwards this message to its next hop in the overlay and then returns
an Echo response message. The terminator peer for the Echo request
message is the destination peer or one peer who finds that the
destination ID is unreachable; eventually the terminator peer returns
an Echo response message.
Here is an example of a P2PSIP Traceroute operation; it is shown as
Figure 5:
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Peer-1 Peer-2 Peer-3 Peer-4
| | | |
| (1).Echo Request | | |
|------------------->| | |
| | (2).Echo Request | |
| |------------------->| |
| (3).Echo Response | | |
|<-------------------| | |
| | | (4).Echo Request |
| | |------------------->|
| | (5).Echo Response | |
|<-------------------|--------------------| |
| | | (6).Echo Response |
|<-------------------|--------------------|--------------------|
| | | |
Figure 5 P2PSIP Traceroute example
10. Acknowledgments
Thanks to Jiang Haifeng for his valued comments. We would also like
to thank Henry Sinnreich for contributing to the usage scenarios in
the Introduction.
11. References
11.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston,
A., Peterson, J., Sparks, R., Handley, M., and E. Schooler, "SIP:
Session Initiation Protocol", RFC 3261, June 2002.
[RFC792] Postel, J., "Internet Control Message Protocol", STD5, RFC
792, September 1981.
[RFC2030] Mills, D., "Simple Network Time Protocol (SNTP) Version 4
for IPv4, IPv6 and OSI", RFC 2030, October 1996.
[RFC4981] J. Risson, "Survey of Research towards Robust Peer-to-Peer
Networks: Search Methods", RFC 4981, September 2007.
[I-D.ietf-p2psip-concepts] Bryan, D., "Concepts and Terminology for
Peer to Peer SIP", draft-ietf-p2psip-concepts-00 (work in progress),
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June 2007.
[I-D.song-p2psip-security-eval] Song, Yongchao., "P2PSIP Security
Analysis and Evaluation", draft-song-p2psip-security-eval-00 (work in
progress), February 2008
[I-D.matuszewski-p2psip-security-requirement] M. Matuszewski,
"Security requirements in P2PSIP",
draft-matuszewski-p2psip-security-requirements-01 (work in progress),
July 2007
[I-D.jennins-p2psip-security-mechanisms] C. Jennings, "Security
Mechanisms for Peer to Peer SIP", draft-jennings-p2psip-security-00
(work in progress), February 2007
[I-D.jiang-p2psip-sep] X. Jiang, "Service Extensible P2P Peer
Protocol", draft-jiang-p2psip-sep-00 (work in progress), November
2007.
[I-D.bryan-p2psip-requirement] D. Bryan, "P2PSIP Protocol Framework
and Requirements", draft-bryan-p2psip-requirements-00 (work in
progress), July 2007
[Overlay-Failure-Detection] S. Zhuang, "On failure detection
algorithms in overlay networks", Proc. IEEE Infocomm, Mar 13-17
2005.
[P2PSIP-Concepts-Terminology] Dean Willis, "P2PSIP Concepts and
Terminology", http://www3.ietf.org/proceedings/07jul/slides/p2psip-
13.pdf, July 2007
[Handling Churn in a DHT] S. Rhea et al: "Handling Churn in a DHT".
USENIX Annual Conference, June 2004
[Diagnostic Framework] X. Jin et al: "A Diagnostic Framework for
Peer-to-Peer Streaming", Hong Kong University and Microsoft, 2005
[Diagnostics and NAT traversal in P2PP] G. Gupta et al: "Diagnostics
and NAT Traversal in P2PP - Design and Implementation." Columbia
University Report. June 2008
11.2. Informative References
[I-D.ietf-behave-rfc3489bis] Rosenberg, J., Huitema, C., Mahy, R.,
and D. Wing, "Simple Traversal Underneath Network Address Translators
(NAT) (STUN)", draft-ietf-behave- rfc3489bis-08 (work in progress),
July 2007.
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[I-D.ietf-behave-turn] Rosenberg, J., Mahy, R., and C. Huitema,
"Obtaining Relay Addresses from Simple Traversal Underneath NAT
(STUN)", draft-ietf-behave-turn-04 (work in progress), July 2007.
[I-D.ietf-mmusic-ice] Rosenberg, J., "Interactive Connectivity
Establishment (ICE): A Methodology for Network Address Translator
(NAT) Traversal for Offer/Answer Protocols", draft-ietf-mmusic-ice-17
(work in progress), July 2007
[I-D.bryan-p2psip-dsip] Bryan, D., "dSIP: A P2P Approach to SIP
Registration and Resource Location", draft-bryan-p2psip-dsip-00 (work
in progress), February 2007.
[I-D.bryan-p2psip-reload] Bryan, D., "REsource LOcation And Discovery
(RELOAD)", draft-bryan-p2psip-reload-00 (work in progress), June
2007.
[I-D.baset-p2psip-p2pp] S. Baset, "Peer-to-Peer Protocol (P2PP)",
draft-baset-p2psip-p2pp-00 (work in progress), July 2007.
[I-D.Jennings-p2psip-asp] C. Jennings, "Address Settlement by Peer to
Peer", draft-jennings-p2psip-asp-00 (work in progress), July 2007.
[I-D.marocco-p2psip-xpp-pcan] Marocco, E. and E. Ivov, "XPP
Extensions for Implementing a Passive P2PSIP Overlay Network based on
the CAN Distributed Hash Table", draft-marocco-p2psip-xpp-pcan-00
(work in progress), June 2007.
[I-D.matthews-p2psip-hip-hop] Cooper, E., "A Distributed Transport
Function in P2PSIP using HIP for Multi-Hop Overlay Routing",
draft-matthews-p2psip-hip-hop-00 (work in progress), June 2007.
Authors' Addresses
Song Haibin
Huawei
Baixia Road No.91
Nanjing, Jiangsu Province 210001
PRC
Phone: +86-25-84565081
Fax: +86-25-84565070
Email: melodysong@huawei.com
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Zheng Hewen
Huawei
Baixia Road No. 91
Nanjing, Jiangsu Province 210001
PRC
Email: hwzheng@huawei.com
Jiang Xingfeng
Huawei
Baixia Road No.91
Nanjing, Jiangsu Province 210001
PRC
Phone: +86-25-84565079
Fax: +86-25-84565070
Email: jiang.x.f@huawei.com
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