draft-ietf-quic-manageability-08.txt   draft-ietf-quic-manageability-09.txt 
Network Working Group M. Kuehlewind Network Working Group M. Kuehlewind
Internet-Draft Ericsson Internet-Draft Ericsson
Intended status: Informational B. Trammell Intended status: Informational B. Trammell
Expires: 6 May 2021 Google Expires: 26 July 2021 Google
2 November 2020 22 January 2021
Manageability of the QUIC Transport Protocol Manageability of the QUIC Transport Protocol
draft-ietf-quic-manageability-08 draft-ietf-quic-manageability-09
Abstract Abstract
This document discusses manageability of the QUIC transport protocol, This document discusses manageability of the QUIC transport protocol,
focusing on caveats impacting network operations involving QUIC focusing on caveats impacting network operations involving QUIC
traffic. Its intended audience is network operators, as well as traffic. Its intended audience is network operators, as well as
content providers that rely on the use of QUIC-aware middleboxes, content providers that rely on the use of QUIC-aware middleboxes,
e.g. for load balancing. e.g. for load balancing.
Status of This Memo Status of This Memo
skipping to change at page 1, line 35 skipping to change at page 1, line 35
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/. Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on 6 May 2021. This Internet-Draft will expire on 26 July 2021.
Copyright Notice Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the Copyright (c) 2021 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Notational Conventions . . . . . . . . . . . . . . . . . 4
2. Features of the QUIC Wire Image . . . . . . . . . . . . . . . 4 2. Features of the QUIC Wire Image . . . . . . . . . . . . . . . 4
2.1. QUIC Packet Header Structure . . . . . . . . . . . . . . 4 2.1. QUIC Packet Header Structure . . . . . . . . . . . . . . 4
2.2. Coalesced Packets . . . . . . . . . . . . . . . . . . . . 6 2.2. Coalesced Packets . . . . . . . . . . . . . . . . . . . . 6
2.3. Use of Port Numbers . . . . . . . . . . . . . . . . . . . 6 2.3. Use of Port Numbers . . . . . . . . . . . . . . . . . . . 6
2.4. The QUIC handshake . . . . . . . . . . . . . . . . . . . 7 2.4. The QUIC Handshake . . . . . . . . . . . . . . . . . . . 7
2.5. Integrity Protection of the Wire Image . . . . . . . . . 11 2.5. Integrity Protection of the Wire Image . . . . . . . . . 11
2.6. Connection ID and Rebinding . . . . . . . . . . . . . . . 11 2.6. Connection ID and Rebinding . . . . . . . . . . . . . . . 11
2.7. Packet Numbers . . . . . . . . . . . . . . . . . . . . . 12 2.7. Packet Numbers . . . . . . . . . . . . . . . . . . . . . 12
2.8. Version Negotiation and Greasing . . . . . . . . . . . . 12 2.8. Version Negotiation and Greasing . . . . . . . . . . . . 12
3. Network-visible information about QUIC flows . . . . . . . . 12 3. Network-visible Information about QUIC Flows . . . . . . . . 12
3.1. Identifying QUIC traffic . . . . . . . . . . . . . . . . 13 3.1. Identifying QUIC Traffic . . . . . . . . . . . . . . . . 13
3.1.1. Identifying Negotiated Version . . . . . . . . . . . 13 3.1.1. Identifying Negotiated Version . . . . . . . . . . . 13
3.1.2. Rejection of Garbage Traffic . . . . . . . . . . . . 14 3.1.2. Rejection of Garbage Traffic . . . . . . . . . . . . 14
3.2. Connection confirmation . . . . . . . . . . . . . . . . . 14 3.2. Connection Confirmation . . . . . . . . . . . . . . . . . 14
3.3. Application Identification . . . . . . . . . . . . . . . 14 3.3. Application Identification . . . . . . . . . . . . . . . 14
3.3.1. Extracting Server Name Indication (SNI) 3.3.1. Extracting Server Name Indication (SNI)
Information . . . . . . . . . . . . . . . . . . . . . 15 Information . . . . . . . . . . . . . . . . . . . . . 15
3.4. Flow association . . . . . . . . . . . . . . . . . . . . 16 3.4. Flow Association . . . . . . . . . . . . . . . . . . . . 16
3.5. Flow teardown . . . . . . . . . . . . . . . . . . . . . . 16 3.5. Flow teardown . . . . . . . . . . . . . . . . . . . . . . 16
3.6. Flow symmetry measurement . . . . . . . . . . . . . . . . 16 3.6. Flow Symmetry Measurement . . . . . . . . . . . . . . . . 16
3.7. Round-Trip Time (RTT) Measurement . . . . . . . . . . . . 17 3.7. Round-Trip Time (RTT) Measurement . . . . . . . . . . . . 17
3.7.1. Measuring initial RTT . . . . . . . . . . . . . . . . 17 3.7.1. Measuring Initial RTT . . . . . . . . . . . . . . . . 17
3.7.2. Using the Spin Bit for Passive RTT Measurement . . . 17 3.7.2. Using the Spin Bit for Passive RTT Measurement . . . 17
4. Specific Network Management Tasks . . . . . . . . . . . . . . 19 4. Specific Network Management Tasks . . . . . . . . . . . . . . 19
4.1. Stateful treatment of QUIC traffic . . . . . . . . . . . 19 4.1. Stateful Treatment of QUIC Traffic . . . . . . . . . . . 19
4.2. Passive network performance measurement and 4.2. Passive Network Performance Measurement and
troubleshooting . . . . . . . . . . . . . . . . . . . . . 19 Troubleshooting . . . . . . . . . . . . . . . . . . . . . 19
4.3. Server cooperation with load balancers . . . . . . . . . 20 4.3. Server Cooperation with Load Balancers . . . . . . . . . 20
4.4. DDoS Detection and Mitigation . . . . . . . . . . . . . . 20 4.4. DDoS Detection and Mitigation . . . . . . . . . . . . . . 20
4.5. UDP Policing . . . . . . . . . . . . . . . . . . . . . . 21 4.5. UDP Policing . . . . . . . . . . . . . . . . . . . . . . 21
4.6. Distinguishing acknowledgment traffic . . . . . . . . . . 21 4.6. Distinguishing Acknowledgment traffic . . . . . . . . . . 21
4.7. QoS support and ECMP . . . . . . . . . . . . . . . . . . 21 4.7. Quality of Service handling and ECMP . . . . . . . . . . 22
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22 4.8. QUIC and Network Address Translation (NAT) . . . . . . . 22
6. Security Considerations . . . . . . . . . . . . . . . . . . . 22 4.8.1. Resource Conservation . . . . . . . . . . . . . . . . 23
7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 22 4.8.2. "Helping" with routing infrastructure issues . . . . 23
8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 22 4.9. Filtering behavior . . . . . . . . . . . . . . . . . . . 24
9. Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . 22 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 25
9.1. Distinguishing IETF QUIC and Google QUIC Versions . . . . 23 6. Security Considerations . . . . . . . . . . . . . . . . . . . 25
9.2. Extracting the CRYPTO frame . . . . . . . . . . . . . . . 24 7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 25
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 25 8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 25
10.1. Normative References . . . . . . . . . . . . . . . . . . 25 9. Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . 26
10.2. Informative References . . . . . . . . . . . . . . . . . 25 9.1. Distinguishing IETF QUIC and Google QUIC Versions . . . . 26
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 28 9.2. Extracting the CRYPTO frame . . . . . . . . . . . . . . . 27
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 28
10.1. Normative References . . . . . . . . . . . . . . . . . . 28
10.2. Informative References . . . . . . . . . . . . . . . . . 28
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 31
1. Introduction 1. Introduction
QUIC [QUIC-TRANSPORT] is a new transport protocol currently under QUIC [QUIC-TRANSPORT] is a new transport protocol encapsulated in UDP
development in the IETF QUIC working group, focusing on support of and encrypted by default. QUIC integrates TLS [QUIC-TLS] to encrypt
semantics as needed for HTTP/2 [QUIC-HTTP]. Based on current all payload data and most control information. The design focused on
deployment practices, QUIC is encapsulated in UDP and encrypted by support of semantics for HTTP, which required changes to HTTP known
default. The current version of QUIC integrates TLS [QUIC-TLS] to as HTTP/3 [QUIC-HTTP].
encrypt all payload data and most control information.
Given that QUIC is an end-to-end transport protocol, all information Given that QUIC is an end-to-end transport protocol, all information
in the protocol header, even that which can be inspected, is not in the protocol header, even that which can be inspected, is not
meant to be mutable by the network, and is therefore integrity- meant to be mutable by the network, and is therefore integrity-
protected. While less information is visible to the network than for protected. While less information is visible to the network than for
TCP, integrity protection can also simplify troubleshooting because TCP, integrity protection can also simplify troubleshooting, because
none of the nodes on the network path can modify the transport layer none of the nodes on the network path can modify the transport layer
information. information.
This document provides guidance for network operation on the This document provides guidance for network operations that manage
management of QUIC traffic. This includes guidance on how to QUIC traffic. This includes guidance on how to interpret and utilize
interpret and utilize information that is exposed by QUIC to the information that is exposed by QUIC to the network, requirements and
network as well as explaining requirement and assumptions that the assumptions that the QUIC design with respect to network treatment,
QUIC protocol design takes toward the expected network treatment. It and a description of how common network management practices will be
also discusses how common network management practices will be
impacted by QUIC. impacted by QUIC.
Since QUIC's wire image [WIRE-IMAGE] is integrity protected and not Since QUIC's wire image [WIRE-IMAGE] is integrity protected and not
modifiable on path, in-network operations are not possible without modifiable on path, in-network operations are not possible without
terminating the QUIC connection, for instance using a back-to-back terminating the QUIC connection, for instance using a back-to-back
proxy. Proxy operations are not in scope for this document. QUIC proxy. Proxy operations are not in scope for this document. A proxy
proxies must be fully-fledged QUIC endpoints, implementing the can either explicit identify itself as providing a proxy service, or
transport as defined in [QUIC-TRANSPORT] and [QUIC-TLS] as well as may share the TLS credentials to authenticate as the server and (in
proxy-relevant semantics for the application(s) running over QUIC some cases) client acting as a front-facing instance for the endpoint
(e.g. HTTP/3 as defined in [QUIC-HTTP]). itself.
Network management is not a one-size-fits-all endeavour: practices Network management is not a one-size-fits-all endeavour: practices
considered necessary or even mandatory within enterprise networks considered necessary or even mandatory within enterprise networks
with certain compliance requirements, for example, would be with certain compliance requirements, for example, would be
impermissible on other networks without those requirements. This impermissible on other networks without those requirements. This
document therefore does not make any specific recommendations as to document therefore does not make any specific recommendations as to
which practices should or should not be applied; for each practice, which practices should or should not be applied; for each practice,
it describes what is and is not possible with the QUIC transport it describes what is and is not possible with the QUIC transport
protocol as defined. protocol as defined.
QUIC is at the moment very much a moving target. This document
refers the state of the QUIC working group drafts as well as to
changes under discussion, via issues and pull requests in GitHub
current as of the time of writing.
1.1. Notational Conventions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
2. Features of the QUIC Wire Image 2. Features of the QUIC Wire Image
In this section, we discusses those aspects of the QUIC transport In this section, we discuss those aspects of the QUIC transport
protocol that have an impact on the design and operation of devices protocol that have an impact on the design and operation of devices
that forward QUIC packets. Here, we are concerned primarily with the that forward QUIC packets. Here, we are concerned primarily with the
unencrypted part of QUIC's wire image [WIRE-IMAGE], which we define unencrypted part of QUIC's wire image [WIRE-IMAGE], which we define
as the information available in the packet header in each QUIC as the information available in the packet header in each QUIC
packet, and the dynamics of that information. Since QUIC is a packet, and the dynamics of that information. Since QUIC is a
versioned protocol, the wire image of the header format can also versioned protocol, the wire image of the header format can also
change from version to version. However, at least the mechanism by change from version to version. However, the field that identifies
which a receiver can determine which version is used and the meaning the QUIC version in some packets, and the format of the Version
and location of fields used in the version negotiation process is Negotiation Packet, are both inspectable and invariant
invariant [QUIC-INVARIANTS]. [QUIC-INVARIANTS].
This document describes only version 1 the QUIC protocol, whose wire This document describes version 1 of the QUIC protocol, whose wire
image is fully defined in [QUIC-TRANSPORT] and [QUIC-TLS]. Note that image is fully defined in [QUIC-TRANSPORT] and [QUIC-TLS]. Features
features of the wire image described herein and in those documents of the wire image described herein may change in future versions of
may change in future versions of the protocol, and cannot be used to the protocol, except when specified as an invariant
identify QUIC as a protocol or to infer the behavior of future [QUIC-INVARIANTS], and cannot be used to identify QUIC as a protocol
versions of QUIC. Section 9.1 provides non-normative guidance on the or to infer the behavior of future versions of QUIC.
identification of QUIC version 1 packets compared to other deployed
versions at the date if publication. Section 9.1 provides non-normative guidance on the identification of
QUIC version 1 packets compared to some pre-standard versions.
2.1. QUIC Packet Header Structure 2.1. QUIC Packet Header Structure
QUIC packets may have either a long header, or a short header. The QUIC packets may have either a long header, or a short header. The
first bit of the QUIC header us the Header Form bit, and indicates first bit of the QUIC header is the Header Form bit, and indicates
which type of header is present. which type of header is present. The purpose of this bit is
invariant across QUIC versions.
The long header exposes more information. It is used during The long header exposes more information. It is used during
connection establishment, including version negotiation, retry, and connection establishment, including version negotiation, retry, and
0-RTT data. It contains a version number, as well as source and 0-RTT data. It contains a version number, as well as source and
destination connection IDs for grouping packets belonging to the same destination connection IDs for grouping packets belonging to the same
flow. The definition and location of these fields in the QUIC long flow. The definition and location of these fields in the QUIC long
header are invariant for future versions of QUIC, although future header are invariant for future versions of QUIC, although future
versions of QUIC may provide additional fields in the long header versions of QUIC may provide additional fields in the long header
[QUIC-INVARIANTS]. [QUIC-INVARIANTS].
Short headers are used after connection establishment, and contain Short headers are used after connection establishment, and contain
only an optional destination connection ID and the spin bit for RTT only an optional destination connection ID and the spin bit for RTT
measurement. measurement.
The following information is exposed in QUIC packet headers: The following information is exposed in QUIC packet headers:
* "fixed bit": the second most significant bit of the first octet * "fixed bit": the second most significant bit of the first octet
most QUIC packets of the current version is currently set to 1, most QUIC packets of the current version is currently set to 1,
for demultiplexing with other UDP-encapsulated protocols. for endpoints to demultiplex with other UDP-encapsulated
protocols. Even thought this bit is fixed in the QUICv1
specification, endpoints may use a version or extension that
varies the bit. Therefore, observers cannot reliably use it as an
identifier for QUIC.
* latency spin bit: the third most significant bit of first octet in * latency spin bit: the third most significant bit of first octet in
the short packet header. The spin bit is set by endpoints such the short packet header. The spin bit is set by endpoints such
that tracking edge transitions can be used to passively observe that tracking edge transitions can be used to passively observe
end-to-end RTT. See Section 3.7.2 for further details. end-to-end RTT. See Section 3.7.2 for further details.
* header type: the long header has a 2 bit packet type field * header type: the long header has a 2 bit packet type field
following the Header Form and fixed bits. Header types correspond following the Header Form and fixed bits. Header types correspond
to stages of the handshake; see Section 17.2 of [QUIC-TRANSPORT] to stages of the handshake; see Section 17.2 of [QUIC-TRANSPORT]
for details. for details.
* version number: the version number present in the long header, and * version number: the version number is present in the long header,
identifies the version used for that packet. Note that during and identifies the version used for that packet. During Version
Version Negotiation (see Section 2.8, and Section 17.2.1 of Negotiation (see Section 2.8 and Section 17.2.1 of
[QUIC-TRANSPORT], the version number field has a special value [QUIC-TRANSPORT]), the version number field has a special value
(0x00000000) that identifies the packet as a Version Negotiation (0x00000000) that identifies the packet as a Version Negotiation
packet. QUIC versions that start with 0xff are IETF drafts. QUIC packet. Many QUIC versions that start with 0xff implement IETF
versions that start with 0x0000 are reserved for IETF consensus drafts. QUIC versions that start with 0x0000 are reserved for
documents, for example the QUIC version 1 is expected to use IETF consensus documents. For example, QUIC version 1 uses
version 0x00000001. version 0x00000001. Operators should expect to observe packets
with other version numbers as a result of various internet
experiments and future standards.
* source and destination connection ID: short and long packet * source and destination connection ID: short and long packet
headers carry a destination connection ID, a variable-length field headers carry a destination connection ID, a variable-length field
that can be used to identify the connection associated with a QUIC that can be used to identify the connection associated with a QUIC
packet, for load-balancing and NAT rebinding purposes; see packet, for load-balancing and NAT rebinding purposes; see
Section 4.3 and Section 2.6. Long packet headers additionally Section 4.3 and Section 2.6. Long packet headers additionally
carry a source connection ID. The source connection ID carry a source connection ID. The source connection ID
corresponds to the destination connection ID the source would like corresponds to the destination connection ID the source would like
to have on packets sent to it, and is only present on long packet to have on packets sent to it, and is only present on long packet
headers. On long header packets, the length of the connection IDs headers. On long header packets, the length of the connection IDs
skipping to change at page 6, line 20 skipping to change at page 6, line 20
explicit in both cases. explicit in both cases.
Retry (Section 17.2.5 of [QUIC-TRANSPORT]) and Version Negotiation Retry (Section 17.2.5 of [QUIC-TRANSPORT]) and Version Negotiation
(Section 17.2.1 of [QUIC-TRANSPORT]) packets are not encrypted or (Section 17.2.1 of [QUIC-TRANSPORT]) packets are not encrypted or
obfuscated in any way. For other kinds of packets, other information obfuscated in any way. For other kinds of packets, other information
in the packet headers is cryptographically obfuscated: in the packet headers is cryptographically obfuscated:
* packet number: All packets except Version Negotiation and Retry * packet number: All packets except Version Negotiation and Retry
packets have an associated packet number; however, this packet packets have an associated packet number; however, this packet
number is encrypted, and therefore not of use to on-path number is encrypted, and therefore not of use to on-path
observers. The offset of the packet number is encoded in the observers. The offset of the packet number is encoded in long
header for packets with long headers, while it is implicit headers, while it is implicit (depending on destination connection
(depending on Destination Connection ID length) in short header ID length) in short headers. The length of the packet number is
packets. The length of the packet number is cryptographically cryptographically obfuscated.
obfuscated.
* key phase: The Key Phase bit, present in short headers, specifies * key phase: The Key Phase bit, present in short headers, specifies
the keys used to encrypt the packet, supporting key rotation. The the keys used to encrypt the packet to support key rotation. The
Key Phase bit is cryptographically obfuscated. Key Phase bit is cryptographically obfuscated.
2.2. Coalesced Packets 2.2. Coalesced Packets
Multiple QUIC packets may be coalesced into a UDP datagram, with a Multiple QUIC packets may be coalesced into a UDP datagram, with a
datagram carrying one or more long header packets followed by zero or datagram carrying one or more long header packets followed by zero or
one short header packets. When packets are coalesced, the Length one short header packets. When packets are coalesced, the Length
fields in the long headers are used to separate QUIC packets. The fields in the long headers are used to separate QUIC packets; see
length header field is variable length and its position in the header Section 12.2 of [QUIC-TRANSPORT]. The length header field is
is also variable depending on the length of the source and variable length, and its position in the header is also variable
destination connection ID. See Section 4.6 of [QUIC-TRANSPORT]. depending on the length of the source and destination connection ID;
see Section 17.2 of [QUIC-TRANSPORT].
2.3. Use of Port Numbers 2.3. Use of Port Numbers
Applications that have a mapping for TCP as well as QUIC are expected Applications that have a mapping for TCP as well as QUIC are expected
to use the same port number for both services. However, as with TCP- to use the same port number for both services. However, as with TCP-
based services, especially when application layer information is based services, especially when application layer information is
encrypted, there is no guarantee that a specific application will use encrypted, there is no guarantee that a specific application will use
the registered port, or the used port is carrying traffic belonging the registered port, or the used port is carrying traffic belonging
to the respective registered service. For example, [QUIC-TRANSPORT] to the respective registered service. For example, [QUIC-HTTP]
specifies the use of Alt-Svc for discovery of QUIC/HTTP services on specifies the use of Alt-Svc for discovery of HTTP/3 services on
other ports. other ports.
Further, as QUIC has a connection ID, it is also possible to maintain Further, as QUIC has a connection ID, it is also possible to maintain
multiple QUIC connections over one 5-tuple. However, if the multiple QUIC connections over one 5-tuple. However, if the
connection ID is not present in the packet header, all packets of the connection ID is not present in the packet header, all packets of the
5-tuple belong to the same QUIC connection. 5-tuple belong to the same QUIC connection.
2.4. The QUIC handshake 2.4. The QUIC Handshake
New QUIC connections are established using a handshake, which is New QUIC connections are established using a handshake, which is
distinguishable on the wire and contains some information that can be distinguishable on the wire and contains some information that can be
passively observed. passively observed.
To illustrate the information visible in the QUIC wire image during To illustrate the information visible in the QUIC wire image during
the handshake, we first show the general communication pattern the handshake, we first show the general communication pattern
visible in the UDP datagrams containing the QUIC handshake, then visible in the UDP datagrams containing the QUIC handshake, then
examine each of the datagrams in detail. examine each of the datagrams in detail.
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| | | |
Figure 1: General communication pattern visible in the QUIC handshake Figure 1: General communication pattern visible in the QUIC handshake
A typical handshake starts with the client sending of a QUIC Client A typical handshake starts with the client sending of a QUIC Client
Hello datagram as shown in Figure 2, which elicits a QUIC Server Hello datagram as shown in Figure 2, which elicits a QUIC Server
Hello datagram as shown in Figure 3 typically containing three Hello datagram as shown in Figure 3 typically containing three
packets: an Initial packet with the Server Hello, a Handshake packet packets: an Initial packet with the Server Hello, a Handshake packet
with the rest of the server's side of the TLS handshake, and initial with the rest of the server's side of the TLS handshake, and initial
1-RTT data, if present. 1-RTT data, if present.
The Initial Completion datagram contains at least one Handshake
packet and some also include an Initial packet.
Datagrams that contain a QUIC Initial Packet (Client Hello, Server
Hello, and some Initial Completion) must be at least 1200 octets
long. This protects against amplification attacks and verifies that
the network path meets minimum Maximum Transmission Unit (MTU)
requirements. This is usually accomplished with either the addition
of PADDING frames to the Initial packet, or coalescing of the Initial
Packet with packets from other encryption contexts.
The content of QUIC Initial packets are encrypted using Initial The content of QUIC Initial packets are encrypted using Initial
Secrets, which are derived from a per-version constant and the Secrets, which are derived from a per-version constant and the
client's destination connection ID; they are therefore observable by client's destination connection ID; they are therefore observable by
any on-path device that knows the per-version constant; we therefore any on-path device that knows the per-version constant. We therefore
consider these as visible in our illustration. The content of QUIC consider these as visible in our illustration. The content of QUIC
Handshake packets are encrypted using keys established during the Handshake packets are encrypted using keys established during the
initial handshake exchange, and are therefore not visible. initial handshake exchange, and are therefore not visible.
Initial, Handshake, and the Short Header packets transmitted after Initial, Handshake, and the Short Header packets transmitted after
the handshake belong to cryptographic and transport contexts. The the handshake belong to cryptographic and transport contexts. The
Initial Completion Figure 4 and the Handshake Completion Figure 5 Initial Completion Figure 4 and the Handshake Completion Figure 5
datagrams finish these first two contexts, by sending the final datagrams finish these first two contexts, by sending the final
acknowledgment and finishing the transmission of CRYPTO frames. acknowledgment and finishing the transmission of CRYPTO frames.
+----------------------------------------------------------+ +----------------------------------------------------------+
| UDP header (source and destination UDP ports) | | UDP header (source and destination UDP ports) |
+----------------------------------------------------------+ +----------------------------------------------------------+
| QUIC long header (type = Initial, Version, DCID, SCID) (Length) | QUIC long header (type = Initial, Version, DCID, SCID) (Length)
+----------------------------------------------------------+ | +----------------------------------------------------------+ |
| QUIC CRYPTO frame header | | | QUIC CRYPTO frame header | |
+----------------------------------------------------------+ | +----------------------------------------------------------+ |
| TLS Client Hello (incl. TLS SNI) | | | TLS Client Hello (incl. TLS SNI) | |
+----------------------------------------------------------+ | +----------------------------------------------------------+ |
| QUIC PADDING frame | | | QUIC PADDING frames | |
+----------------------------------------------------------+<-+ +----------------------------------------------------------+<-+
Figure 2: Typical 1-RTT QUIC Client Hello datagram pattern Figure 2: Typical QUIC Client Hello datagram pattern with no 0-RTT
The Client Hello datagram exposes version number, source and The Client Hello datagram exposes version number, source and
destination connection IDs in the clear. Information in the TLS destination connection IDs in the clear. Information in the TLS
Client Hello frame, including any TLS Server Name Indication (SNI) Client Hello frame, including any TLS Server Name Indication (SNI)
present, is obfuscated using the Initial secret. The QUIC PADDING present, is obfuscated using the Initial secret. Note that the
frame shown here may be present to ensure the Client Hello datagram location of PADDING is implementation-dependent, and PADDING frames
has a minimum size of 1200 octets, to mitigate the possibility of may not appear in a coalesced Initial packet.
handshake amplification. Note that the location of PADDING is
implementation-dependent, and PADDING frames may not appear in the
Initial packet in a coalesced packet.
+------------------------------------------------------------+ +------------------------------------------------------------+
| UDP header (source and destination UDP ports) | | UDP header (source and destination UDP ports) |
+------------------------------------------------------------+ +------------------------------------------------------------+
| QUIC long header (type = Initial, Version, DCID, SCID) (Length) | QUIC long header (type = Initial, Version, DCID, SCID) (Length)
+------------------------------------------------------------+ | +------------------------------------------------------------+ |
| QUIC CRYPTO frame header | | | QUIC CRYPTO frame header | |
+------------------------------------------------------------+ | +------------------------------------------------------------+ |
| TLS Server Hello | | | TLS Server Hello | |
+------------------------------------------------------------+ | +------------------------------------------------------------+ |
skipping to change at page 11, line 8 skipping to change at page 11, line 11
present if necessary to increase the size of the datagram with 0RTT present if necessary to increase the size of the datagram with 0RTT
data to at least 1200 bytes. Additional datagrams containing only data to at least 1200 bytes. Additional datagrams containing only
0-RTT protected long header packets may be sent from the client to 0-RTT protected long header packets may be sent from the client to
the server after the Client Hello datagram, containing the rest of the server after the Client Hello datagram, containing the rest of
the 0-RTT data. The amount of 0-RTT protected data is limited by the the 0-RTT data. The amount of 0-RTT protected data is limited by the
initial congestion window, typically around 10 packets [RFC6928]. initial congestion window, typically around 10 packets [RFC6928].
2.5. Integrity Protection of the Wire Image 2.5. Integrity Protection of the Wire Image
As soon as the cryptographic context is established, all information As soon as the cryptographic context is established, all information
in the QUIC header, including information exposed in the packet in the QUIC header, including exposed information, is integrity
header, is integrity protected. Further, information that was sent protected. Further, information that was sent and exposed in
and exposed in handshake packets sent before the cryptographic handshake packets sent before the cryptographic context was
context was established are validated later during the cryptographic established are validated later during the cryptographic handshake.
handshake. Therefore, devices on path MUST NOT change any Therefore, devices on path cannot alter any information or bits in
information or bits in QUIC packet headers, since alteration of QUIC packet headers, except specific parts of Initial packets, since
header information will lead to a failed integrity check at the alteration of header information will lead to a failed integrity
receiver, and can even lead to connection termination. check at the receiver, and can even lead to connection termination.
2.6. Connection ID and Rebinding 2.6. Connection ID and Rebinding
The connection ID in the QUIC packet headers allows routing of QUIC The connection ID in the QUIC packet headers allows routing of QUIC
packets at load balancers on other than five-tuple information, packets at load balancers on other than five-tuple information,
ensuring that related flows are appropriately balanced together; and ensuring that related flows are appropriately balanced together; and
to allow rebinding of a connection after one of the endpoint's to allow rebinding of a connection after one of the endpoint's
addresses changes - usually the client's, in the case of the HTTP addresses changes - usually the client's. Client and server
binding. Client and server negotiate connection IDs during the negotiate connection IDs during the handshake; typically, however,
handshake; typically, however, only the server will request a only the server will request a connection ID for the lifetime of the
connection ID for the lifetime of the connection. Connection IDs for connection. Connection IDs for either endpoint may change during the
either endpoint may change during the lifetime of a connection, with lifetime of a connection, with the new connection ID being negotiated
the new connection ID being negotiated via encrypted frames. See via encrypted frames. See Section 5.1 of [QUIC-TRANSPORT].
Section 5.1 of [QUIC-TRANSPORT]. Therefore, observing a new connection ID does not necessary indicate
a new connection.
Server-generated connection IDs should seek to obscure any encoding, Server-generated connection IDs should seek to obscure any encoding,
of routing identities or any other information. Exposing the server of routing identities or any other information. Exposing the server
mapping would allow linkage of multiple IP addresses to the same host mapping would allow linkage of multiple IP addresses to the same host
if the server also supports migration. Furthermore, this opens an if the server also supports migration. Furthermore, this opens an
attack vector on specific servers or pools. attack vector on specific servers or pools.
The best way to obscure an encoding is to appear random to observers, The best way to obscure an encoding is to appear random to observers,
which is most rigorously achieved with encryption. Even when which is most rigorously achieved with encryption. Even when
encrypted, a scheme could embed the unencrypted length of the encrypted, a scheme could embed the unencrypted length of the
Connection ID in the Connection ID itself, instead of remembering it, connection ID in the connection ID itself, instead of remembering it.
e.g. by using the first few bits to indicate a certain size of a
well-known set of possible sizes with multiple values that indicate
the same size but are selected randomly.
[QUIC_LB] further specified possible algorithms to generate [QUIC_LB] further specified possible algorithms to generate
Connection IDs at load balancers. connection IDs at load balancers.
2.7. Packet Numbers 2.7. Packet Numbers
The packet number field is always present in the QUIC packet header; The packet number field is always present in the QUIC packet header;
however, it is always encrypted. The encryption key for packet however, it is always encrypted. The encryption key for packet
number protection on handshake packets sent before cryptographic number protection on handshake packets sent before cryptographic
context establishment is specific to the QUIC version, while packet context establishment is specific to the QUIC version, while packet
number protection on subsequent packets uses secrets derived from the number protection on subsequent packets uses secrets derived from the
end-to-end cryptographic context. Packet numbers are therefore not end-to-end cryptographic context. Packet numbers are therefore not
part of the wire image that is visible to on-path observers. part of the wire image that is visible to on-path observers.
2.8. Version Negotiation and Greasing 2.8. Version Negotiation and Greasing
Version negotiation is not protected, given the used protection Version Negotiation packets are not intrinsically protected, but QUIC
mechanism can change with the version. However, the choices provided versions can use later encrypted messages to verify that they were
in the list of version in the Version Negotiation packet will be authentic. Therefore any manipulation of this list will be detected
validated as soon as the cryptographic context has been established. and may cause the endpoints to terminate the connection attempt.
Therefore any manipulation of this list will be detected and will
cause the endpoints to terminate the connection.
Also note that the list of versions in the Version Negotiation packet Also note that the list of versions in the Version Negotiation packet
may contain reserved versions. This mechanism is used to avoid may contain reserved versions. This mechanism is used to avoid
ossification in the implementation on the selection mechanism. ossification in the implementation on the selection mechanism.
Further, a client may send a Initial Client packet with a reserved Further, a client may send a Initial Client packet with a reserved
version number to trigger version negotiation. In the Version version number to trigger version negotiation. In the Version
Negotiation packet the connection ID and packet number of the Client Negotiation packet the connection ID and packet number of the Client
Initial packet are reflected to provide a proof of return- Initial packet are reflected to provide a proof of return-
routability. Therefore changing these information will also cause routability. Therefore changing this information will also cause the
the connection to fail. connection to fail.
QUIC is expected to evolve rapidly, so new versions, both QUIC is expected to evolve rapidly, so new versions, both
experimental and IETF standard versions, will be deployed in the experimental and IETF standard versions, will be deployed in the
Internet more often than with traditional Internet- and transport- Internet more often than with traditional Internet- and transport-
layer protocols. Using a particular version number to recognize layer protocols. Using a particular version number to recognize
valid QUIC traffic is likely to persistently miss a fraction of QUIC valid QUIC traffic is likely to persistently miss a fraction of QUIC
flows and completely fail in the multi-year timeframe so therefore flows and completely fail in the near future, and is therefore not
not recommended. recommended. In addition, due to the speed of evolution of the
protocol, devices that attempt to distinguish QUIC traffic from non-
QUIC traffic for purposes of network admission control should admit
all QUIC traffic regardless of version.
3. Network-visible information about QUIC flows 3. Network-visible Information about QUIC Flows
This section addresses the different kinds of observations and This section addresses the different kinds of observations and
inferences that can be made about QUIC flows by a passive observer in inferences that can be made about QUIC flows by a passive observer in
the network based on the wire image in Section 2. Here we assume a the network based on the wire image in Section 2. Here we assume a
bidirectional observer (one that can see packets in both directions bidirectional observer (one that can see packets in both directions
in the sequence in which they are carried on the wire) unless noted. in the sequence in which they are carried on the wire) unless noted.
3.1. Identifying QUIC traffic 3.1. Identifying QUIC Traffic
The QUIC wire image is not specifically designed to be The QUIC wire image is not specifically designed to be
distinguishable from other UDP traffic. distinguishable from other UDP traffic.
The only application binding defined by the IETF QUIC WG is HTTP/3 The only application binding defined by the IETF QUIC WG is HTTP/3
[QUIC-HTTP] at the time of this writing; however, many other [QUIC-HTTP] at the time of this writing; however, many other
applications are currently being defined and deployed over QUIC, so applications are currently being defined and deployed over QUIC, so
an assumption that all QUIC traffic is HTTP/3 is not valid. HTTP an assumption that all QUIC traffic is HTTP/3 is not valid. HTTP
over QUIC uses UDP port 443 by default, although URLs referring to over QUIC uses UDP port 443 by default, although URLs referring to
resources available over HTTP over QUIC may specify alternate port resources available over HTTP/3 may specify alternate port numbers.
numbers. Simple assumptions about whether a given flow is using QUIC Simple assumptions about whether a given flow is using QUIC based
based upon a UDP port number may therefore not hold; see also upon a UDP port number may therefore not hold; see also [RFC7605]
[RFC7605] section 5. section 5.
While the second most significant bit (0x40) of the first octet is While the second most significant bit (0x40) of the first octet is
set to 1 in most QUIC packets of the current version (see set to 1 in most QUIC packets of the current version (see
Section 2.1), this method of recognizing QUIC traffic is NOT Section 2.1), this method of recognizing QUIC traffic is NOT
RECOMMENDED. First, it only provides one bit of information and is RECOMMENDED. First, it only provides one bit of information and is
quite prone to collide with UDP-based protocols other than those that quite prone to collide with UDP-based protocols other than those that
this static bit is meant to allow multiplexing with. Second, this this static bit is meant to allow multiplexing with. Second, this
feature of the wire image is not invariant [QUIC-INVARIANTS] and may feature of the wire image is not invariant [QUIC-INVARIANTS] and may
change in future versions of the protocol, or even be negotiated change in future versions of the protocol, or even be negotiated
after handshake via future transport parameters. during the handshake via the use of transport parameters.
Even though transport parameters transmitted in the client initial
are obserable by the network, they cannot be modified by the network
without risking connection failure. Further, the negotiated reply
from the server cannot be observed, so observers on the network
cannot know which parameters are actually in use.
3.1.1. Identifying Negotiated Version 3.1.1. Identifying Negotiated Version
An in-network observer assuming that a set of packets belongs to a An in-network observer assuming that a set of packets belongs to a
QUIC flow can infer the version number in use by observing the QUIC flow can infer the version number in use by observing the
handshake: an Initial packet with a given version from a client to handshake: an Initial packet with a given version from a client to
which a server responds with an Initial packet with the same version which a server responds with an Initial packet with the same version
implies acceptance of that version. implies acceptance of that version.
Negotiated version cannot be identified for flows for which a Negotiated version cannot be identified for flows for which a
handshake is not observed, such as in the case of connection handshake is not observed, such as in the case of connection
migration; however, these flows can be associated with flows for migration; however, these flows can be associated with flows for
which a version has been identified; see Section 3.4. which a version has been identified; see Section 3.4.
This document focuses on QUIC Version 1, and this section applies This document focuses on QUIC Version 1, and this section applies
only to packets belonging to Version 1 QUIC flows; for purposes of only to packets belonging to Version 1 QUIC flows; for purposes of
on-path observation, it assumes that these packets have been on-path observation, it assumes that these packets have been
identified as such through the observation of a version negotiation. identified as such through the observation of a version number
exchange as described above.
3.1.2. Rejection of Garbage Traffic 3.1.2. Rejection of Garbage Traffic
A related question is whether a first packet of a given flow on known A related question is whether a first packet of a given flow on a
QUIC-associated port is a valid QUIC packet, in order to support in- known QUIC-associated port is a valid QUIC packet, to support in-
network filtering of garbage UDP packets (reflection attacks, random network filtering of garbage UDP packets (reflection attacks, random
backscatter). While heuristics based on the first byte of the packet backscatter). While heuristics based on the first byte of the packet
(packet type) could be used to separate valid from invalid first (packet type) could be used to separate valid from invalid first
packet types, the deployment of such heuristics is not recommended, packet types, the deployment of such heuristics is not recommended,
as packet types may have different meanings in future versions of the as packet types may have different meanings in future versions of the
protocol. protocol.
3.2. Connection confirmation 3.2. Connection Confirmation
Connection establishment uses Initial, Handshake, and Retry packets Connection establishment uses Initial and Handshake packets
containing a TLS handshake. Connection establishment can therefore containing a TLS handshake, and Retry packets that do not contain
be detected using heuristics similar to those used to detect TLS over parts of the handshake. Connection establishment can therefore be
TCP. A client using 0-RTT connection may also send data packets in detected using heuristics similar to those used to detect TLS over
0-RTT Protected packets directly after the Initial packet containing TCP. A client initiating a 0-RTT connection may also send data
the TLS Client Hello. Since these packets may be reordered in the packets in 0-RTT Protected packets directly after the Initial packet
network, note that 0-RTT Protected data packets may be seen before containing the TLS Client Hello. Since these packets may be
the Initial packet. reordered in the network, 0-RTT Protected data packets could be seen
before the Initial packet.
Note that clients send Initial packets before servers do, servers Note that clients send Initial packets before servers do, servers
send Handshake packets before clients do, and only clients send send Handshake packets before clients do, and only clients send
Initial packets with tokens, so the sides of a connection can be Initial packets with tokens. Therefore, the role as a client or
generally be confirmed by an on-path observer. An attempted server can generally be confirmed by an on- path observer. An
connection after Retry can be detected by correlating the token on attempted connection after Retry can be detected by correlating the
the Retry with the token on the subsequent Initial packet. token on the Retry with the token on the subsequent Initial packet
and the destination connection ID of the new Initial packet.
3.3. Application Identification 3.3. Application Identification
The cleartext TLS handshake may contain Server Name Indication (SNI) The cleartext TLS handshake may contain Server Name Indication (SNI)
[RFC6066], by which the client reveals the name of the server it [RFC6066], by which the client reveals the name of the server it
intends to connect to, in order to allow the server to present a intends to connect to, in order to allow the server to present a
certificate based on that name. It may also contain information from certificate based on that name. It may also contain information from
Application-Layer Protocol Negotiation (ALPN) [RFC7301], by which the Application-Layer Protocol Negotiation (ALPN) [RFC7301], by which the
client exposes the names of application-layer protocols it supports; client exposes the names of application-layer protocols it supports;
an observer can deduce that one of those protocols will be used if an observer can deduce that one of those protocols will be used if
the connection continues. the connection continues.
Work is currently underway in the TLS working group to encrypt the Work is currently underway in the TLS working group to encrypt the
SNI in TLS 1.3 [TLS-ESNI]. If used with QUIC, this would make SNI- SNI in TLS 1.3 [TLS-ESNI]. This would make SNI-based application
based application identification impossible through passive identification impossible through passive measurement for QUIC and
measurement. other protocols that use TLS.
3.3.1. Extracting Server Name Indication (SNI) Information 3.3.1. Extracting Server Name Indication (SNI) Information
If the SNI is not encrypted it can be derived from the QUIC Initial If the SNI is not encrypted it can be derived from the QUIC Initial
packet by calculating the Initial Secret to decrypt the packet packet by calculating the Initial Secret to decrypt the packet
payload and parse the QUIC CRYPTO Frame containing the TLS payload and parse the QUIC CRYPTO Frame containing the TLS
ClientHello. ClientHello.
As both the initial salt for the Initial Secret as well as CRYPTO As both the initial salt for the Initial Secret as well as CRYPTO
frame itself are version-specific, the first step is always to parse frame itself are version-specific, the first step is always to parse
the version number (second to sixth byte of the long header). Note the version number (second to sixth byte of the long header). Note
that only long header packets carry the version number, so it is that only long header packets carry the version number, so it is
necessary to also check the if first bit of the QUIC packet is set to necessary to also check the if first bit of the QUIC packet is set to
1, indicating a long header. 1, indicating a long header.
Note, that proprietary QUIC versions, that have been deployed before Note that proprietary QUIC versions, that have been deployed before
standardization, might not set the first bit in a QUIC long header standardization, might not set the first bit in a QUIC long header
packets to 1. To parse these versions example code is provided in packets to 1. To parse these versions, example code is provided in
the appendix (see Section 9.1), however, it is expected that these the appendix (see Section 9.1), however, it is expected that these
versions will gradually disappear over time. versions will gradually disappear over time.
When the version has been identified as QUIC version 1, the packet When the version has been identified as QUIC version 1, the packet
type needs to be verified as an Initial packet by checking that the type needs to be verified as an Initial packet by checking that the
third and fourth bit of the header are both set to 0. Then the third and fourth bit of the header are both set to 0. Then the
Client Destination Connection ID needs to be extracted to calculate client destination connection ID needs to be extracted to calculate
the Initial Secret together with the version specific initial salt, the Initial Secret together with the version specific initial salt,
as described in [QUIC-TLS]. The length of the connection ID is as described in [QUIC-TLS]. The length of the connection ID is
indicated in the 6th byte of the header followed by the connection ID indicated in the 6th byte of the header followed by the connection ID
itself. itself.
To determine the end of the header and find the start of the payload To determine the end of the header and find the start of the payload,
further the packet number length, the source connection ID length, as the packet number length, the source connection ID length, and the
well as the token length need to be extracted. The packet number token length need to be extracted. The packet number length is
length is defined by the seventh and eight bits of the header as defined by the seventh and eight bits of the header as described in
described in section 17.2. of [QUIC-TRANSPORT]. The source section 17.2. of [QUIC-TRANSPORT], but is obfuscated as described in
connection ID length is specified in the byte after the destination [QUIC-TLS]. The source connection ID length is specified in the byte
connection ID. And the token length, which follows the source after the destination connection ID. And the token length, which
connection ID, is a variable length integer as specified in section follows the source connection ID, is a variable length integer as
16 of [QUIC-TRANSPORT]. specified in Section 16 of [QUIC-TRANSPORT].
Finally after decryption, the Initial Client packet can be parsed to After decryption, the Initial Client packet can be parsed to detect
detect the CRYPTO frame that contains the TLS Client Hello, which the CRYPTO frame that contains the TLS Client Hello, which then can
then can be respectively parsed similar as for all other TLS be parsed similarly to TLS over TCP connections. The Initial client
connections. The Initial client packet may contain other frames, so packet may contain other frames, so the first bytes of each frame
the first byte of each frame need to be checked to identify the frame need to be checked to identify the frame type, and if needed skip
type and the skip over the frame. Note that the length of the frames over it. Note that the length of the frames is dependent on the
is dependent on the frame type. Usually for QUIC version 1, the frame type. In QUIC version 1, the packet is expected to only carry
packet is expected to only carry the CRYPTO frame and optionally the CRYPTO frame and optionally padding frames. However, PADDING
padding frames. However, padding which is one byte of zeros, may frames, which are each one byte of zeros, may also occur before or
also occur before or after the CRYPTO frame. after the CRYPTO frame.
3.4. Flow association Note that client Initial packets after the first do not always use
the destination connection ID that was used to generate the Initial
keys. Therefore, attempts to decrypt these packets using the
procedure above might fail.
The QUIC Connection ID (see Section 2.6) is designed to allow an on- 3.4. Flow Association
The QUIC connection ID (see Section 2.6) is designed to allow an on-
path device such as a load-balancer to associate two flows as path device such as a load-balancer to associate two flows as
identified by five-tuple when the address and port of one of the identified by five-tuple when the address and port of one of the
endpoints changes; e.g. due to NAT rebinding or server IP address endpoints changes; e.g. due to NAT rebinding or server IP address
migration. An observer keeping flow state can associate a connection migration. An observer keeping flow state can associate a connection
ID with a given flow, and can associate a known flow with a new flow ID with a given flow, and can associate a known flow with a new flow
when when observing a packet sharing a connection ID and one endpoint when when observing a packet sharing a connection ID and one endpoint
address (IP address and port) with the known flow. address (IP address and port) with the known flow.
However, since the connection ID may change multiple times during the However, since the connection ID may change multiple times during the
lifetime of a flow, and the negotiation of connection ID changes is lifetime of a flow, and the negotiation of connection ID changes is
skipping to change at page 16, line 43 skipping to change at page 16, line 43
for caveats regarding connection ID selection at servers. for caveats regarding connection ID selection at servers.
3.5. Flow teardown 3.5. Flow teardown
QUIC does not expose the end of a connection; the only indication to QUIC does not expose the end of a connection; the only indication to
on-path devices that a flow has ended is that packets are no longer on-path devices that a flow has ended is that packets are no longer
observed. Stateful devices on path such as NATs and firewalls must observed. Stateful devices on path such as NATs and firewalls must
therefore use idle timeouts to determine when to drop state for QUIC therefore use idle timeouts to determine when to drop state for QUIC
flows, see further section Section 4.1. flows, see further section Section 4.1.
3.6. Flow symmetry measurement 3.6. Flow Symmetry Measurement
QUIC explicitly exposes which side of a connection is a client and QUIC explicitly exposes which side of a connection is a client and
which side is a server during the handshake. In addition, the which side is a server during the handshake. In addition, the
symmetry of a flow (whether primarily client-to-server, primarily symmetry of a flow (whether primarily client-to-server, primarily
server-to-client, or roughly bidirectional, as input to basic traffic server-to-client, or roughly bidirectional, as input to basic traffic
classification techniques) can be inferred through the measurement of classification techniques) can be inferred through the measurement of
data rate in each direction. While QUIC traffic is protected and data rate in each direction. While QUIC traffic is protected and
ACKs may be padded, padding is not required. ACKs may be padded, padding is not required.
3.7. Round-Trip Time (RTT) Measurement 3.7. Round-Trip Time (RTT) Measurement
Round-trip time of QUIC flows can be inferred by observation once per Round-trip time of QUIC flows can be inferred by observation once per
flow, during the handshake, as in passive TCP measurement; this flow, during the handshake, as in passive TCP measurement; this
requires parsing of the QUIC packet header and recognition of the requires parsing of the QUIC packet header and recognition of the
handshake, as illustrated in Section 2.4. It can also be inferred handshake, as illustrated in Section 2.4. It can also be inferred
during the flow's lifetime, if the endpoints use the spin bit during the flow's lifetime, if the endpoints use the spin bit
facility described below and in [QUIC-TRANSPORT], section 17.3.1. facility described below and in [QUIC-TRANSPORT], section 17.3.1.
3.7.1. Measuring initial RTT 3.7.1. Measuring Initial RTT
In the common case, the delay between the Initial packet containing In the common case, the delay between the Initial packet containing
the TLS Client Hello and the Handshake packet containing the TLS the TLS Client Hello and the Handshake packet containing the TLS
Server Hello represents the RTT component on the path between the Server Hello represents the RTT component on the path between the
observer and the server. The delay between the TLS Server Hello and observer and the server. The delay between the TLS Server Hello and
the Handshake packet containing the TLS Finished message sent by the the Handshake packet containing the TLS Finished message sent by the
client represents the RTT component on the path between the observer client represents the RTT component on the path between the observer
and the client. While the client may send 0-RTT Protected packets and the client. While the client may send 0-RTT Protected packets
after the Initial packet during 0-RTT connection re-establishment, after the Initial packet during 0-RTT connection re-establishment,
these can be ignored for RTT measurement purposes. these can be ignored for RTT measurement purposes.
skipping to change at page 17, line 44 skipping to change at page 17, line 44
The spin bit provides an additional method to measure per-flow RTT The spin bit provides an additional method to measure per-flow RTT
from observation points on the network path throughout the duration from observation points on the network path throughout the duration
of a connection. Endpoint participation in spin bit signaling is of a connection. Endpoint participation in spin bit signaling is
optional in QUIC. That is, while its location is fixed in this optional in QUIC. That is, while its location is fixed in this
version of QUIC, an endpoint can unilaterally choose to not support version of QUIC, an endpoint can unilaterally choose to not support
"spinning" the bit. Use of the spin bit for RTT measurement by "spinning" the bit. Use of the spin bit for RTT measurement by
devices on path is only possible when both endpoints enable it. Some devices on path is only possible when both endpoints enable it. Some
endpoints may disable use of the spin bit by default, others only in endpoints may disable use of the spin bit by default, others only in
specific deployment scenarios, e.g. for servers and clients where the specific deployment scenarios, e.g. for servers and clients where the
RTT would reveal the presence of a VPN or proxy. To avoid making RTT would reveal the presence of a VPN or proxy. To avoid making
these connections identifiable based on the usage of the spin bit, it these connections identifiable based on the usage of the spin bit,
is recommended that all endpoints randomly disable "spinning" for at all endpoints randomly disable "spinning" for at least one eighth of
least one eighth of connections, even if otherwise enabled by connections, even if otherwise enabled by default. An endpoint not
default. An endpoint not participating in spin bit signaling for a participating in spin bit signaling for a given connection can use a
given connection can use a fixed spin value for the duration of the fixed spin value for the duration of the connection, or can set the
connection, or can set the bit randomly on each packet sent. bit randomly on each packet sent.
When in use and a QUIC flow sends data continuously, the latency spin When in use and a QUIC flow sends data continuously, the latency spin
bit in each direction changes value once per round-trip time (RTT). bit in each direction changes value once per round-trip time (RTT).
An on-path observer can observe the time difference between edges An on-path observer can observe the time difference between edges
(changes from 1 to 0 or 0 to 1) in the spin bit signal in a single (changes from 1 to 0 or 0 to 1) in the spin bit signal in a single
direction to measure one sample of end-to-end RTT. direction to measure one sample of end-to-end RTT.
Note that this measurement, as with passive RTT measurement for TCP, Note that this measurement, as with passive RTT measurement for TCP,
includes any transport protocol delay (e.g., delayed sending of includes any transport protocol delay (e.g., delayed sending of
acknowledgements) and/or application layer delay (e.g., waiting for a acknowledgements) and/or application layer delay (e.g., waiting for a
skipping to change at page 19, line 10 skipping to change at page 19, line 10
observer and the server and the observer and the client, observer and the server and the observer and the client,
respectively. It does this by measuring the delay between a spin respectively. It does this by measuring the delay between a spin
edge observed in the upstream direction and that observed in the edge observed in the upstream direction and that observed in the
downstream direction, and vice versa. downstream direction, and vice versa.
4. Specific Network Management Tasks 4. Specific Network Management Tasks
In this section, we review specific network management and In this section, we review specific network management and
measurement techniques and how QUIC's design impacts them. measurement techniques and how QUIC's design impacts them.
4.1. Stateful treatment of QUIC traffic 4.1. Stateful Treatment of QUIC Traffic
Stateful treatment of QUIC traffic (e.g., at a firewall or NAT Stateful treatment of QUIC traffic (e.g., at a firewall or NAT
middlebox) is possible through QUIC traffic and version middlebox) is possible through QUIC traffic and version
identification (Section 3.1) and observation of the handshake for identification (Section 3.1) and observation of the handshake for
connection confirmation (Section 3.2). The lack of any visible end- connection confirmation (Section 3.2). The lack of any visible end-
of-flow signal (Section 3.5) means that this state must be purged of-flow signal (Section 3.5) means that this state must be purged
either through timers or through least-recently-used eviction, either through timers or through least-recently-used eviction,
depending on application requirements. depending on application requirements.
[RFC4787] recommends a 2 minute timeout interval for UDP, however, [RFC4787] recommends a 2 minute timeout interval for UDP. However,
often timer are lower in the range of 15 to 30 second. In constrast timers can be lower, in the range of 15 to 30 seconds. In contrast,
[RFC5382] recommends a timeout of more than 2 hours for TCP, given [RFC5382] recommends a timeout of more than 2 hours for TCP, given
TCP is a connection-oriented protocol with well defined closure that TCP is a connection-oriented protocol with well-defined closure
semantics. For network devices that are QUIC-aware, it is semantics. For network devices that are QUIC-aware, it is
recommended to also use longer timeouts for QUIC traffic, as QUIC is recommended to also use longer timeouts for QUIC traffic, as QUIC is
connection-oriented and as such a handshake packet from the server connection-oriented. As such, a handshake packet from the server
indicates the willingness of the server to communicate with the indicates the willingness of the server to communicate with the
client. client.
The QUIC header optionally contains a Connection ID which can be used The QUIC header optionally contains a connection ID which can be used
as additional entropy beyond the 5-tuple, if needed. The QUIC as additional entropy beyond the 5-tuple, if needed. The QUIC
handshake needs to be observed in order to understand whether the handshake needs to be observed in order to understand whether the
Connection ID is present and what length it has. However, Connection connection ID is present and what length it has. However, connection
IDs may be renegotiated during a connection, and this renegotiation IDs may be renegotiated during a connection, and this renegotiation
is not visible to the path. Keying state off the Connection ID may is not visible to the path. Keying state off the connection ID may
therefore cause undetectable and unrecoverable loss of state in the therefore cause undetectable and unrecoverable loss of state in the
middle of a connection. Use of Connection ID specifically middle of a connection. Use of connection ID specifically
discouraged for NAT applications. discouraged for NAT applications.
4.2. Passive network performance measurement and troubleshooting 4.2. Passive Network Performance Measurement and Troubleshooting
Limited RTT measurement is possible by passive observation of QUIC Limited RTT measurement is possible by passive observation of QUIC
traffic; see Section 3.7. No passive measurement of loss is possible traffic; see Section 3.7. No passive measurement of loss is possible
with the present wire image. Extremely limited observation of with the present wire image. Extremely limited observation of
upstream congestion may be possible via the observation of CE upstream congestion may be possible via the observation of CE
markings on ECN-enabled QUIC traffic. markings on ECN-enabled QUIC traffic.
4.3. Server cooperation with load balancers 4.3. Server Cooperation with Load Balancers
In the case of content distribution networking architectures In the case of content distribution networking architectures
including load balancers, the connection ID provides a way for the including load balancers, the connection ID provides a way for the
server to signal information about the desired treatment of a flow to server to signal information about the desired treatment of a flow to
the load balancers. Guidance on assigning connection IDs is given in the load balancers. Guidance on assigning connection IDs is given in
[QUIC-APPLICABILITY]. [QUIC-APPLICABILITY].
4.4. DDoS Detection and Mitigation 4.4. DDoS Detection and Mitigation
Current practices in detection and mitigation of Distributed Denial Current practices in detection and mitigation of Distributed Denial
of Service (DDoS) attacks generally involves classification of of Service (DDoS) attacks generally involve classification of
incoming traffic (as packets, flows, or some other aggregate) into incoming traffic (as packets, flows, or some other aggregate) into
"good" (productive) and "bad" (DDoS) traffic, then differential "good" (productive) and "bad" (DDoS) traffic, and then differential
treatment of this traffic to forward only good traffic, to the extent treatment of this traffic to forward only good traffic. This
possible. This operation is often done in a separate specialized operation is often done in a separate specialized mitigation
mitigation environment through which all traffic is filtered; a environment through which all traffic is filtered; a generalized
generalized architecture for separation of concerns in mitigation is architecture for separation of concerns in mitigation is given in
given in [DOTS-ARCH]. [DOTS-ARCH].
Key to successful DDoS mitigation is efficient classification of this Key to successful DDoS mitigation is efficient classification of this
traffic in the mitigation environment. Limited first-packet garbage traffic in the mitigation environment. Limited first-packet garbage
detection as in Section 3.1.2 and stateful tracking of QUIC traffic detection as in Section 3.1.2 and stateful tracking of QUIC traffic
as in Section 4.1 above may be useful during classification. as in Section 4.1 above may be useful during classification.
Note that the use of a connection ID to support connection migration Note that the use of a connection ID to support connection migration
renders 5-tuple based filtering insufficient and requires more state renders 5-tuple based filtering insufficient and requires more state
to be maintained by DDoS defense systems. For the common case of NAT to be maintained by DDoS defense systems. For the common case of NAT
rebinding, DDoS defense systems can detect a change in client's rebinding, DDoS defense systems can detect a change in the client's
endpoint address by linking flows based on the first 8 bytes of the endpoint address by linking flows based on the server's connection
server's connection IDs, provided the server is using at least 8- IDs. QUIC's linkability resistance ensures that a deliberate
bytes-long connection IDs. QUIC's linkability resistance ensures connection migration is accompanied by a change in the connection ID.
that a deliberate connection migration is accompanied by a change in
the connection ID and necessitate that connection ID aware DDoS
defense system must have the same information about connection IDs as
the load balancer [I-D.ietf-quic-load-balancers]. This may be
complicated where mitigation and load balancing environments are
logically separate.
It is questionable whether connection migrations must be supported It is questionable whether connection migrations must be supported
during a DDoS attack. If the connection migration is not visible to during a DDoS attack. If the connection migration is not visible to
the network that performs the DDoS detection, an active, migrated the network that performs the DDoS detection, an active, migrated
QUIC connection may be blocked by such a system under attack. As QUIC connection may be blocked by such a system under attack. As
soon as the connection blocking is detected by the client, the client soon as the connection blocking is detected by the client, the client
may rely on the fast resumption mechanism provided by QUIC. When may rely on the fast resumption mechanism provided by QUIC. When
clients migrate to a new path, they should be prepared for the clients migrate to a new path, they should be prepared for the
migration to fail and attempt to reconnect quickly. migration to fail and attempt to reconnect quickly.
TCP syncookies [RFC4937] are a well-established method of mitigating
some kinds of TCP DDoS attacks. QUIC Retry packets are the
functional analogue to syncookies, forcing clients to prove
possession of their IP address before committing server state.
However, there are safeguards in QUIC against unsolicited injection
of these packets by intermediaries who do not have consent of the end
server. See [QUIC_LB] for standard ways for intermediaries to send
Retry packets on behalf of consenting servers.
4.5. UDP Policing 4.5. UDP Policing
Today, UDP is the most prevalent DDoS vector, since it is easy for Today, UDP is the most prevalent DDoS vector, since it is easy for
compromised non-admin applications to send a flood of large UDP compromised non-admin applications to send a flood of large UDP
packets (while with TCP the attacker gets throttled by the congestion packets (while with TCP the attacker gets throttled by the congestion
controller) or to craft reflection and amplification attacks. controller) or to craft reflection and amplification attacks.
Networks should therefore be prepared for UDP flood attacks on ports Networks should therefore be prepared for UDP flood attacks on ports
used for QUIC traffic. One possible response to this threat is to used for QUIC traffic. One possible response to this threat is to
police UDP traffic on the network, allocating a fixed portion of the police UDP traffic on the network, allocating a fixed portion of the
network capacity to UDP and blocking UDP datagram over that cap. network capacity to UDP and blocking UDP datagram over that cap.
skipping to change at page 21, line 26 skipping to change at page 21, line 35
The recommended way to police QUIC packets is to either drop them all The recommended way to police QUIC packets is to either drop them all
or to throttle them based on the hash of the UDP datagram's source or to throttle them based on the hash of the UDP datagram's source
and destination addresses, blocking a portion of the hash space that and destination addresses, blocking a portion of the hash space that
corresponds to the fraction of UDP traffic one wishes to drop. When corresponds to the fraction of UDP traffic one wishes to drop. When
the handshake is blocked, QUIC-capable applications may failover to the handshake is blocked, QUIC-capable applications may failover to
TCP (at least applications using well-known UDP ports). However, TCP (at least applications using well-known UDP ports). However,
blindly blocking a significant fraction of QUIC packets will allow blindly blocking a significant fraction of QUIC packets will allow
many QUIC handshakes to complete, preventing a TCP failover, but the many QUIC handshakes to complete, preventing a TCP failover, but the
connections will suffer from severe packet loss. connections will suffer from severe packet loss.
4.6. Distinguishing acknowledgment traffic 4.6. Distinguishing Acknowledgment traffic
Some deployed in-network functions distinguish pure-acknowledgment Some deployed in-network functions distinguish pure-acknowledgment
(ACK) packets from packets carrying upper-layer data in order to (ACK) packets from packets carrying upper-layer data in order to
attempt to enhance performance, for example by queueing ACKs attempt to enhance performance, for example by queueing ACKs
differently or manipulating ACK signaling. Distinguishing ACK differently or manipulating ACK signaling. Distinguishing ACK
packets is trivial in TCP, but not supported by QUIC, since packets is trivial in TCP, but not supported by QUIC, since
acknowledgment signaling is carried inside QUIC's encrypted payload, acknowledgment signaling is carried inside QUIC's encrypted payload,
and ACK manipulation is impossible. Specifically, heuristics and ACK manipulation is impossible. Specifically, heuristics
attempting to distinguish ACK-only packets from payload-carrying attempting to distinguish ACK-only packets from payload-carrying
packets based on packet size are likely to fail, and are emphatically packets based on packet size are likely to fail, and are emphatically
NOT RECOMMENDED. NOT RECOMMENDED.
4.7. QoS support and ECMP 4.7. Quality of Service handling and ECMP
[EDITOR'S NOTE: this is a bit speculative; keep?] It is expected that any QoS handling in the network, e.g. based on
use of DiffServ Code Points (DSCPs) [RFC2475] as well as Equal-Cost
Multi-Path (ECMP) routing, is applied on a per flow-basis (and not
per-packet) and as such that all packets belonging to the same QUIC
connection get uniform treatment. Using ECMP to distribute packets
from a single flow across multiple network paths or any other non-
uniform treatment of packets belong to the same connection could
result in variations in order, delivery rate, and drop rate. As
feedback about loss or delay of each packet is used as input to the
congestion controller, these variations could adversely affect
performance.
QUIC does not provide any additional information on requirements on Depending of the loss recovery mechanism implemented, QUIC may be
Quality of Service (QoS) provided from the network. QUIC assumes more tolerant of packet re-ordering than traditional TCP traffic (see
that all packets with the same 5-tuple {dest addr, source addr, Section 2.7). However, it cannot be known by the network which exact
protocol, dest port, source port} will receive similar network recovery mechanism is used and therefore reordering tolerance should
treatment. That means all stream that are multiplexed over the same be considered as unknown.
QUIC connection require the same network treatment and are handled by
the same congestion controller. If differential network treatment is
desired, multiple QUIC connections to the same server might be used,
given that establishing a new connection using 0-RTT support is cheap
and fast.
QoS mechanisms in the network MAY also use the connection ID for 4.8. QUIC and Network Address Translation (NAT)
service differentiation, as a change of connection ID is bound to a
change of address which anyway is likely to lead to a re-route on a
different path with different network characteristics.
Given that QUIC is more tolerant of packet re-ordering than TCP (see QUIC Connection IDs are opaque byte fields that are expressed
Section 2.7), Equal-cost multi-path routing (ECMP) does not consistently across all QUIC versions [QUIC-INVARIANTS], see
necessarily need to be flow based. However, 5-tuple (plus eventually Section 2.6. This feature may appear to present opportunities to
connection ID if present) matching is still beneficial for QoS given optimize NAT port usage and simplify the work of the QUIC server. In
all packets are handled by the same congestion controller. fact, NAT behavior that relies on CID may instead cause connection
failure when endpoints change Connection ID, and disable important
protocol security features. NATs should retain their existing 4-
tuple-based operation and refrain from parsing or otherwise using
QUIC connection IDs.
This section uses the colloquial term NAT to mean NAPT (section 2.2
of [RFC3022]), which overloads several IP addresses to one IP address
or to an IP address pool, as commonly deployed in carrier-grade NATs
or residential NATs.
The remainder of this section explains how QUIC supports NATs better
than other connection-oriented protocols, why NAT use of Connection
ID might appear attractive, and how NAT use of CID can create serious
problems for the endpoints.
[RFC4787] contains some guidance on building NATs to interact
constructively with a wide range of applications. This section
extends the discussion to QUIC.
By using the CID, QUIC connections can survive NAT rebindings as long
as no routing function in the path is dependent on client IP address
and port to deliver packets between server and NAT. Reducing the
timeout on UDP NATs might be tempting in light of this property, but
not all QUIC server deployments will be robust to rebinding.
4.8.1. Resource Conservation
NATs sometimes hit an operational limit where they exhaust available
public IP addresses and ports, and must evict flows from their
address/port mapping. CIDs might appear to offer a way to multiplex
many connections over a single address and port.
However, QUIC endpoints may negotiate new connection IDs inside
cryptographically protected packets, and begin using them at will.
Imagine two clients behind a NAT that are sharing the same public IP
address and port. The NAT is differentiating them using the incoming
Connection ID. If one client secretly changes its connection ID,
there will be no mapping for the NAT, and the connection will
suddenly break.
QUIC is deliberately designed to fail rather than persist when the
network cannot support its operation. For HTTP/3, this extends to
recommending a fallback to TCP-based versions of HTTP rather than
persisting with a QUIC connection that might be unstable. And
[I-D.ietf-quic-applicability] recommends TCP fallback for other
protocols on the basis that this is preferable to sudden connection
errors and time outs. Furthermore, wide deployment of NATs with this
behavior hinders the use of QUIC's migration function, which relies
on the ability to change the connection ID any time during the
lifetime of a QUIC connection.
It is possible, in principle, to encode the client's identity in a
connection ID using the techniques described in [QUIC_LB] and
explicit coordination with the NAT. However, this implies that the
client shares configuration with the NAT, which might be logistically
difficult. This adds administrative overhead while not resolving the
case where a client migrates to a point behind the NAT.
Note that multiplexing connection IDs over a single port anyway
violates the best common practice to avoid "port overloading" as
described in [RFC4787].
4.8.2. "Helping" with routing infrastructure issues
Concealing client address changes in order to simplify operational
routing issues will mask important signals that drive security
mechanisms, and therefore opens QUIC up to various attacks.
One challenge in QUIC deployments that want to benefit from QUIC's
migration capability is server infrastructures with routers and
switches that direct traffic based on address-port 4-tuple rather
than connection ID. The use of source IP address means that a NAT
rebinding or address migration will deliver packets to the wrong
server. As all QUIC payloads are encrypted, routers and switches
will not have access to negotiated but not-yet-in-use CIDs. This is
a particular problem for low-state load balancers. [QUIC_LB]
addresses this problem proposing a QUIC extension to allow some
server-load balancer coordination for routable CIDs.
It seems that a NAT anywhere in the front of such an infrastructure
setup could save the effort of converting all these devices by
decoding routable connection IDs and rewriting the packet IP
addresses to allow consistent routing by legacy devices.
Unfortunately, the change of IP address or port is an important
signal to QUIC endpoints. It requires a review of path-dependent
variables like congestion control parameters. It can also signify
various attacks that mislead one endpoint about the best peer address
for the connection (see section 9 of [QUIC-TRANSPORT]). The QUIC
PATH_CHALLENGE and PATH_RESPONSE frames are intended to detect and
mitigate these attacks and verify connectivity to the new address.
This mechanism cannot work if the NAT is bleaching peer address
changes.
For example, an attacker might copy a legitimate QUIC packet and
change the source address to match its own. In the absence of a
bleaching NAT, the receiving endpoint would interpret this as a
potential NAT rebinding and use a PATH_CHALLENGE frame to prove that
the peer endpoint is not truly at the new address, thus thwarting the
attack. A bleaching NAT has no means of sending an encrypted
PATH_CHALLENGE frame, so it might start redirecting all QUIC traffic
to the attacker address and thus allow an observer to break the
connection.
4.9. Filtering behavior
[RFC4787] describes possible packet filtering behaviors that relate
to NATs. Though the guidance there holds, a particularly unwise
behavior is to admit a handful of UDP packets and then make a
decision as to whether or not to filter it. QUIC applications are
encouraged to fail over to TCP if early packets do not arrive at
their destination. Admitting a few packets allows the QUIC endpoint
to determine that the path accepts QUIC. Sudden drops afterwards
will result in slow and costly timeouts before abandoning the
connection.
5. IANA Considerations 5. IANA Considerations
This document has no actions for IANA. This document has no actions for IANA.
6. Security Considerations 6. Security Considerations
Supporting manageability of QUIC traffic inherently involves QUIC is an encrypted and authenticated transport. That means, once
tradeoffs with the confidentiality of QUIC's control information; the cryptographic handshake is complete, QUIC endpoints discard most
this entire document is therefore security-relevant. packets that are not authenticated, greatly limiting the ability of
an attacker to interfere with existing connections.
However, some information is still observerable, as supporting
manageability of QUIC traffic inherently involves tradeoffs with the
confidentiality of QUIC's control information; this entire document
is therefore security-relevant.
More security considerations for QUIC are discussed in
[QUIC-TRANSPORT] and [QUIC-TLS], generally considering active or
passive attackers in the network as well as attacks on specific QUIC
mechanism.
Version Negotiation packets do not contain any mechanism to prevent
version downgrade attacks. However, future versions of QUIC that use
Version Negotiation packets are require to define a mechanism that is
robust against version downgrade attacks. Therefore a network node
should not attempt to impact version selection, as version downgrade
may result in connection failure.
7. Contributors 7. Contributors
Dan Druta contributed text to Section 4.4. Igor Lubashev contributed The following people have contributed text to sections of this
text to Section 4.3 on the use of the connection ID for load document:
balancing. Marcus Ilhar contributed text to Section 3.7 on the use
of the spin bit. The pseudo provided in the appendix is based on * Dan Druta
input provided by David Schinazi.
* Martin Duke
* Marcus Ilhar
* Igor Lubashev
* David Schinazi
8. Acknowledgments 8. Acknowledgments
Thanks to Martin Thomson and Martin Duke for contributing by Special thanks to Martin Thomson and Martin Duke for the detailed
reviewing and providing text proposals. reviews and feedback.
This work is partially supported by the European Commission under This work is partially supported by the European Commission under
Horizon 2020 grant agreement no. 688421 Measurement and Architecture Horizon 2020 grant agreement no. 688421 Measurement and Architecture
for a Middleboxed Internet (MAMI), and by the Swiss State Secretariat for a Middleboxed Internet (MAMI), and by the Swiss State Secretariat
for Education, Research, and Innovation under contract no. 15.0268. for Education, Research, and Innovation under contract no. 15.0268.
This support does not imply endorsement. This support does not imply endorsement.
9. Appendix 9. Appendix
This appendix uses the following conventions: array[i] - one byte at This appendix uses the following conventions: array[i] - one byte at
skipping to change at page 25, line 32 skipping to change at page 28, line 32
crypto_data_length = payload[counter:counter+2] crypto_data_length = payload[counter:counter+2]
counter += 2 counter += 2
} }
crypto_data = payload[counter:counter+crypto_data_length] crypto_data = payload[counter:counter+crypto_data_length]
ParseTLS(crypto_data) ParseTLS(crypto_data)
10. References 10. References
10.1. Normative References 10.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [QUIC-TLS] Thomson, M. and S. Turner, "Using TLS to Secure QUIC",
Requirement Levels", BCP 14, RFC 2119, Work in Progress, Internet-Draft, draft-ietf-quic-tls-34,
DOI 10.17487/RFC2119, March 1997, 14 January 2021, <http://www.ietf.org/internet-drafts/
<https://www.rfc-editor.org/info/rfc2119>. draft-ietf-quic-tls-34.txt>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC [QUIC-TRANSPORT]
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, Iyengar, J. and M. Thomson, "QUIC: A UDP-Based Multiplexed
May 2017, <https://www.rfc-editor.org/info/rfc8174>. and Secure Transport", Work in Progress, Internet-Draft,
draft-ietf-quic-transport-34, 14 January 2021,
<http://www.ietf.org/internet-drafts/draft-ietf-quic-
transport-34.txt>.
10.2. Informative References 10.2. Informative References
[Ding2015] Ding, H. and M. Rabinovich, "TCP Stretch Acknowledgments [Ding2015] Ding, H. and M. Rabinovich, "TCP Stretch Acknowledgments
and Timestamps - Findings and Impliciations for Passive and Timestamps - Findings and Impliciations for Passive
RTT Measurement (ACM Computer Communication Review)", July RTT Measurement (ACM Computer Communication Review)", July
2015, <http://www.sigcomm.org/sites/default/files/ccr/ 2015, <http://www.sigcomm.org/sites/default/files/ccr/
papers/2015/July/0000000-0000002.pdf>. papers/2015/July/0000000-0000002.pdf>.
[DOTS-ARCH] [DOTS-ARCH]
Mortensen, A., Reddy.K, T., Andreasen, F., Teague, N., and Mortensen, A., Reddy.K, T., Andreasen, F., Teague, N., and
R. Compton, "Distributed-Denial-of-Service Open Threat R. Compton, "Distributed-Denial-of-Service Open Threat
Signaling (DOTS) Architecture", Work in Progress, Signaling (DOTS) Architecture", Work in Progress,
Internet-Draft, draft-ietf-dots-architecture-18, 6 March Internet-Draft, draft-ietf-dots-architecture-18, 6 March
2020, <http://www.ietf.org/internet-drafts/draft-ietf- 2020, <http://www.ietf.org/internet-drafts/draft-ietf-
dots-architecture-18.txt>. dots-architecture-18.txt>.
[I-D.ietf-quic-load-balancers] [I-D.ietf-quic-applicability]
Duke, M. and N. Banks, "QUIC-LB: Generating Routable QUIC Kuehlewind, M. and B. Trammell, "Applicability of the QUIC
Connection IDs", Work in Progress, Internet-Draft, draft- Transport Protocol", Work in Progress, Internet-Draft,
ietf-quic-load-balancers-05, 30 October 2020, draft-ietf-quic-applicability-08, 2 November 2020,
<http://www.ietf.org/internet-drafts/draft-ietf-quic-load- <http://www.ietf.org/internet-drafts/draft-ietf-quic-
balancers-05.txt>. applicability-08.txt>.
[IPIM] Allman, M., Beverly, R., and B. Trammell, "In-Protocol [IPIM] Allman, M., Beverly, R., and B. Trammell, "In-Protocol
Internet Measurement (arXiv preprint 1612.02902)", 9 Internet Measurement (arXiv preprint 1612.02902)", 9
December 2016, <https://arxiv.org/abs/1612.02902>. December 2016, <https://arxiv.org/abs/1612.02902>.
[QUIC-APPLICABILITY] [QUIC-APPLICABILITY]
Kuehlewind, M. and B. Trammell, "Applicability of the QUIC Kuehlewind, M. and B. Trammell, "Applicability of the QUIC
Transport Protocol", Work in Progress, Internet-Draft, Transport Protocol", Work in Progress, Internet-Draft,
draft-ietf-quic-applicability-07, 8 July 2020, draft-ietf-quic-applicability-08, 2 November 2020,
<http://www.ietf.org/internet-drafts/draft-ietf-quic- <http://www.ietf.org/internet-drafts/draft-ietf-quic-
applicability-07.txt>. applicability-08.txt>.
[QUIC-HTTP] [QUIC-HTTP]
Bishop, M., "Hypertext Transfer Protocol Version 3 Bishop, M., "Hypertext Transfer Protocol Version 3
(HTTP/3)", Work in Progress, Internet-Draft, draft-ietf- (HTTP/3)", Work in Progress, Internet-Draft, draft-ietf-
quic-http-32, 20 October 2020, <http://www.ietf.org/ quic-http-33, 15 December 2020, <http://www.ietf.org/
internet-drafts/draft-ietf-quic-http-32.txt>. internet-drafts/draft-ietf-quic-http-33.txt>.
[QUIC-INVARIANTS] [QUIC-INVARIANTS]
Thomson, M., "Version-Independent Properties of QUIC", Thomson, M., "Version-Independent Properties of QUIC",
Work in Progress, Internet-Draft, draft-ietf-quic- Work in Progress, Internet-Draft, draft-ietf-quic-
invariants-11, 24 September 2020, <http://www.ietf.org/ invariants-13, 14 January 2021, <http://www.ietf.org/
internet-drafts/draft-ietf-quic-invariants-11.txt>. internet-drafts/draft-ietf-quic-invariants-13.txt>.
[QUIC-TLS] Thomson, M. and S. Turner, "Using TLS to Secure QUIC",
Work in Progress, Internet-Draft, draft-ietf-quic-tls-32,
20 October 2020, <http://www.ietf.org/internet-drafts/
draft-ietf-quic-tls-32.txt>.
[QUIC-TRANSPORT]
Iyengar, J. and M. Thomson, "QUIC: A UDP-Based Multiplexed
and Secure Transport", Work in Progress, Internet-Draft,
draft-ietf-quic-transport-32, 20 October 2020,
<http://www.ietf.org/internet-drafts/draft-ietf-quic-
transport-32.txt>.
[QUIC_LB] Duke, M. and N. Banks, "QUIC-LB: Generating Routable QUIC [QUIC_LB] Duke, M. and N. Banks, "QUIC-LB: Generating Routable QUIC
Connection IDs", Work in Progress, Internet-Draft, draft- Connection IDs", Work in Progress, Internet-Draft, draft-
ietf-quic-load-balancers-05, 30 October 2020, ietf-quic-load-balancers-05, 30 October 2020,
<http://www.ietf.org/internet-drafts/draft-ietf-quic-load- <http://www.ietf.org/internet-drafts/draft-ietf-quic-load-
balancers-05.txt>. balancers-05.txt>.
[RFC2475] Blake, S., Black, D., Carlson, M., Davies, E., Wang, Z.,
and W. Weiss, "An Architecture for Differentiated
Services", RFC 2475, DOI 10.17487/RFC2475, December 1998,
<https://www.rfc-editor.org/info/rfc2475>.
[RFC3022] Srisuresh, P. and K. Egevang, "Traditional IP Network
Address Translator (Traditional NAT)", RFC 3022,
DOI 10.17487/RFC3022, January 2001,
<https://www.rfc-editor.org/info/rfc3022>.
[RFC4787] Audet, F., Ed. and C. Jennings, "Network Address [RFC4787] Audet, F., Ed. and C. Jennings, "Network Address
Translation (NAT) Behavioral Requirements for Unicast Translation (NAT) Behavioral Requirements for Unicast
UDP", BCP 127, RFC 4787, DOI 10.17487/RFC4787, January UDP", BCP 127, RFC 4787, DOI 10.17487/RFC4787, January
2007, <https://www.rfc-editor.org/info/rfc4787>. 2007, <https://www.rfc-editor.org/info/rfc4787>.
[RFC4937] Arberg, P. and V. Mammoliti, "IANA Considerations for PPP
over Ethernet (PPPoE)", RFC 4937, DOI 10.17487/RFC4937,
June 2007, <https://www.rfc-editor.org/info/rfc4937>.
[RFC5382] Guha, S., Ed., Biswas, K., Ford, B., Sivakumar, S., and P. [RFC5382] Guha, S., Ed., Biswas, K., Ford, B., Sivakumar, S., and P.
Srisuresh, "NAT Behavioral Requirements for TCP", BCP 142, Srisuresh, "NAT Behavioral Requirements for TCP", BCP 142,
RFC 5382, DOI 10.17487/RFC5382, October 2008, RFC 5382, DOI 10.17487/RFC5382, October 2008,
<https://www.rfc-editor.org/info/rfc5382>. <https://www.rfc-editor.org/info/rfc5382>.
[RFC6066] Eastlake 3rd, D., "Transport Layer Security (TLS) [RFC6066] Eastlake 3rd, D., "Transport Layer Security (TLS)
Extensions: Extension Definitions", RFC 6066, Extensions: Extension Definitions", RFC 6066,
DOI 10.17487/RFC6066, January 2011, DOI 10.17487/RFC6066, January 2011,
<https://www.rfc-editor.org/info/rfc6066>. <https://www.rfc-editor.org/info/rfc6066>.
skipping to change at page 27, line 42 skipping to change at page 30, line 45
"Transport Layer Security (TLS) Application-Layer Protocol "Transport Layer Security (TLS) Application-Layer Protocol
Negotiation Extension", RFC 7301, DOI 10.17487/RFC7301, Negotiation Extension", RFC 7301, DOI 10.17487/RFC7301,
July 2014, <https://www.rfc-editor.org/info/rfc7301>. July 2014, <https://www.rfc-editor.org/info/rfc7301>.
[RFC7605] Touch, J., "Recommendations on Using Assigned Transport [RFC7605] Touch, J., "Recommendations on Using Assigned Transport
Port Numbers", BCP 165, RFC 7605, DOI 10.17487/RFC7605, Port Numbers", BCP 165, RFC 7605, DOI 10.17487/RFC7605,
August 2015, <https://www.rfc-editor.org/info/rfc7605>. August 2015, <https://www.rfc-editor.org/info/rfc7605>.
[TLS-ESNI] Rescorla, E., Oku, K., Sullivan, N., and C. Wood, "TLS [TLS-ESNI] Rescorla, E., Oku, K., Sullivan, N., and C. Wood, "TLS
Encrypted Client Hello", Work in Progress, Internet-Draft, Encrypted Client Hello", Work in Progress, Internet-Draft,
draft-ietf-tls-esni-08, 16 October 2020, draft-ietf-tls-esni-09, 16 December 2020,
<http://www.ietf.org/internet-drafts/draft-ietf-tls-esni- <http://www.ietf.org/internet-drafts/draft-ietf-tls-esni-
08.txt>. 09.txt>.
[TMA-QOF] Trammell, B., Gugelmann, D., and N. Brownlee, "Inline Data [TMA-QOF] Trammell, B., Gugelmann, D., and N. Brownlee, "Inline Data
Integrity Signals for Passive Measurement (in Proc. TMA Integrity Signals for Passive Measurement (in Proc. TMA
2014)", April 2014. 2014)", April 2014.
[WIRE-IMAGE] [WIRE-IMAGE]
Trammell, B. and M. Kuehlewind, "The Wire Image of a Trammell, B. and M. Kuehlewind, "The Wire Image of a
Network Protocol", RFC 8546, DOI 10.17487/RFC8546, April Network Protocol", RFC 8546, DOI 10.17487/RFC8546, April
2019, <https://www.rfc-editor.org/info/rfc8546>. 2019, <https://www.rfc-editor.org/info/rfc8546>.
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