draft-ietf-quic-manageability-02.txt   draft-ietf-quic-manageability-03.txt 
Network Working Group M. Kuehlewind Network Working Group M. Kuehlewind
Internet-Draft B. Trammell Internet-Draft B. Trammell
Intended status: Informational ETH Zurich Intended status: Informational ETH Zurich
Expires: January 3, 2019 July 02, 2018 Expires: April 25, 2019 October 22, 2018
Manageability of the QUIC Transport Protocol Manageability of the QUIC Transport Protocol
draft-ietf-quic-manageability-02 draft-ietf-quic-manageability-03
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
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
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
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Drafts is at http://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
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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 January 3, 2019. This Internet-Draft will expire on April 25, 2019.
Copyright Notice Copyright Notice
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Notational Conventions . . . . . . . . . . . . . . . . . 3 1.1. Notational Conventions . . . . . . . . . . . . . . . . . 3
2. Features of the QUIC Wire Image . . . . . . . . . . . . . . . 3 2. Features of the QUIC Wire Image . . . . . . . . . . . . . . . 3
2.1. QUIC Packet Header Structure . . . . . . . . . . . . . . 4 2.1. QUIC Packet Header Structure . . . . . . . . . . . . . . 4
2.2. Coalesced Packets . . . . . . . . . . . . . . . . . . . . 5 2.2. Coalesced Packets . . . . . . . . . . . . . . . . . . . . 5
2.3. Integrity Protection of the Wire Image . . . . . . . . . 5 2.3. Use of Port Numbers . . . . . . . . . . . . . . . . . . . 5
2.4. Connection ID and Rebinding . . . . . . . . . . . . . . . 5 2.4. The QUIC handshake . . . . . . . . . . . . . . . . . . . 5
2.5. Packet Numbers . . . . . . . . . . . . . . . . . . . . . 6 2.5. Integrity Protection of the Wire Image . . . . . . . . . 10
2.6. Version Negotiation and Greasing . . . . . . . . . . . . 6 2.6. Connection ID and Rebinding . . . . . . . . . . . . . . . 10
3. Network-visible information about QUIC flows . . . . . . . . 6 2.7. Packet Numbers . . . . . . . . . . . . . . . . . . . . . 10
3.1. Identifying QUIC traffic . . . . . . . . . . . . . . . . 6 2.8. Version Negotiation and Greasing . . . . . . . . . . . . 10
3.1.1. Identifying Negotiated Version . . . . . . . . . . . 7 3. Network-visible information about QUIC flows . . . . . . . . 11
3.1.2. Rejection of Garbage Traffic . . . . . . . . . . . . 7 3.1. Identifying QUIC traffic . . . . . . . . . . . . . . . . 11
3.2. Connection confirmation . . . . . . . . . . . . . . . . . 7 3.1.1. Identifying Negotiated Version . . . . . . . . . . . 11
3.3. Application Identification . . . . . . . . . . . . . . . 7 3.1.2. Rejection of Garbage Traffic . . . . . . . . . . . . 12
3.4. Flow association . . . . . . . . . . . . . . . . . . . . 8 3.2. Connection confirmation . . . . . . . . . . . . . . . . . 12
3.5. Flow teardown . . . . . . . . . . . . . . . . . . . . . . 8 3.3. Application Identification . . . . . . . . . . . . . . . 12
3.6. Round-trip time measurement . . . . . . . . . . . . . . . 8 3.4. Flow association . . . . . . . . . . . . . . . . . . . . 12
3.7. Flow symmetry measurement . . . . . . . . . . . . . . . . 10 3.5. Flow teardown . . . . . . . . . . . . . . . . . . . . . . 13
4. Specific Network Management Tasks . . . . . . . . . . . . . . 10 3.6. Round-trip time measurement . . . . . . . . . . . . . . . 13
4.1. Stateful treatment of QUIC traffic . . . . . . . . . . . 10 3.7. Flow symmetry measurement . . . . . . . . . . . . . . . . 14
4. Specific Network Management Tasks . . . . . . . . . . . . . . 15
4.1. Stateful treatment of QUIC traffic . . . . . . . . . . . 15
4.2. Passive network performance measurement and 4.2. Passive network performance measurement and
troubleshooting . . . . . . . . . . . . . . . . . . . . . 10 troubleshooting . . . . . . . . . . . . . . . . . . . . . 15
4.3. Server cooperation with load balancers . . . . . . . . . 10 4.3. Server cooperation with load balancers . . . . . . . . . 15
4.4. DDoS Detection and Mitigation . . . . . . . . . . . . . . 11 4.4. DDoS Detection and Mitigation . . . . . . . . . . . . . . 15
4.5. QoS support and ECMP . . . . . . . . . . . . . . . . . . 11 4.5. QoS support and ECMP . . . . . . . . . . . . . . . . . . 16
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
6. Security Considerations . . . . . . . . . . . . . . . . . . . 12 6. Security Considerations . . . . . . . . . . . . . . . . . . . 16
7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 12 7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 17
8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 13 8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 17
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 13 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 17
9.1. Normative References . . . . . . . . . . . . . . . . . . 13 9.1. Normative References . . . . . . . . . . . . . . . . . . 17
9.2. Informative References . . . . . . . . . . . . . . . . . 13 9.2. Informative References . . . . . . . . . . . . . . . . . 17
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 19
1. Introduction 1. Introduction
QUIC [QUIC-TRANSPORT] is a new transport protocol currently under QUIC [QUIC-TRANSPORT] is a new transport protocol currently under
development in the IETF quic working group, focusing on support of development in the IETF quic working group, focusing on support of
semantics as needed for HTTP/2 [QUIC-HTTP]. Based on current semantics as needed for HTTP/2 [QUIC-HTTP]. Based on current
deployment practices, QUIC is encapsulated in UDP and encrypted by deployment practices, QUIC is encapsulated in UDP and encrypted by
default. The current version of QUIC integrates TLS [QUIC-TLS] to default. The current version of QUIC integrates TLS [QUIC-TLS] to
encrypt all payload data and most control information. Given QUIC is encrypt all payload data and most control information. Given QUIC is
an end-to-end transport protocol, all information in the protocol an end-to-end transport protocol, all information in the protocol
skipping to change at page 4, line 33 skipping to change at page 4, line 37
As of draft version 13 of the QUIC transport document, the following As of draft version 13 of the QUIC transport document, the following
information may be exposed in QUIC packet headers: information may be exposed in QUIC packet headers:
o header type: the long header has a 7-bit packet type field o header type: the long header has a 7-bit packet type field
following the Header Form bit. Header types correspond to stages following the Header Form bit. Header types correspond to stages
of the handshake; see Section 4.1 of [QUIC-TRANSPORT]. of the handshake; see Section 4.1 of [QUIC-TRANSPORT].
o version number: The version number is present in the long header, o version number: The version number is present in the long header,
and identifies the version used for that packet. Note that during and identifies the version used for that packet. Note that during
Version Negotiation (see Section 2.6, and Section 4.3 of Version Negotiation (see Section 2.8, and Section 4.3 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. packet.
o source and destination connection ID: The source and destination o source and destination connection ID: The source and destination
connection IDs are variable-length fields that can be used to connection IDs are variable-length fields that can be used to
identify the connection associated with a QUIC packet, for load- identify the connection associated with a QUIC packet, for load-
balancing and NAT rebinding purposes; see Section 4.3 and balancing and NAT rebinding purposes; see Section 4.3 and
Section 2.4. The source connection ID corresponds to the Section 2.6. The source connection ID corresponds to the
destination connection ID the source would like to have on packets destination connection ID the source would like to have on packets
sent to it, and is only present on long packet headers. The sent to it, and is only present on long packet headers. The
destination connection ID, if present, is present on both long and destination connection ID, if present, is present on both long and
short header packets. On long header packets, the length of the short header packets. On long header packets, the length of the
connection IDs is also present; on short header packets, the connection IDs is also present; on short header packets, the
length of the destination connection ID is implicit. length of the destination connection ID is implicit.
o length: the length of the remaining quic packet after the length o length: the length of the remaining quic packet after the length
field, present on long headers. This field is used to implement field, present on long headers. This field is used to implement
coalesced packets during the handshake (see Section 2.2). coalesced packets during the handshake (see Section 2.2).
skipping to change at page 5, line 24 skipping to change at page 5, line 28
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. The
length header field is variable length and its position in the header length header field is variable length and its position in the header
is also variable depending on the length of the source and is also variable depending on the length of the source and
destionation connection ID. See Section 4.6 of [QUIC-TRANSPORT]. destionation connection ID. See Section 4.6 of [QUIC-TRANSPORT].
2.3. Integrity Protection of the Wire Image 2.3. Use of Port Numbers
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-
based services, especially when application layer information is
encrypted, there is no guarantee that a specific application will use
the registered port, or the used port is carrying traffic belonging
to the respective registered service. For example, [QUIC-TRANSPORT]
specifies the use of Alt-Svc for discovery of QUIC/HTTP services on
other ports.
Further, as QUIC has a connection ID, it is also possible to maintain
multiple QUIC connections over one 5-tuple. However, if the
connection ID is not present in the packet header, all packets of the
5-tuple belong to the same QUIC connection.
2.4. The QUIC handshake
New QUIC connections are established using a handshake, which is
distinguishable on the wire and contains some information that can be
passively observed.
To illustrate the information visible in the QUIC wire image during
the handshake, we first show the general communication pattern
visible in the UDP datagams containing the QUIC handshake, then
examine each of the datagrams in detail.
In the nominal case, the QUIC handshake can be recognized on the wire
through at least four datagrams we'll call "QUIC Client Hello", "QUIC
Server Hello", and "Initial Completion", and "Handshake Completion",
for purposes of this illustration, as shown in Figure 1.
Packets in the handshake belong to three separate cryptographic and
transport contexts ("Initial", which contains observable payload, and
"Handshake" and "1-RTT", which do not). QUIC packets in separate
contexts during the handshake are generally coalesced (see
Section 2.2) in order to reduce the number of UDP datagrams sent
during the handshake.
As shown here, the client can send 0-RTT data as soon as it has sent
its Client Hello, and the server can send 1-RTT data as soon as it
has sent its Server Hello.
Client Server
| |
+----QUIC Client Hello-------------------->|
+----(zero or more 0RTT)------------------>|
| |
|<--------------------QUIC Server Hello----+
|<---------(1RTT encrypted data starts)----+
| |
+----Initial Completion------------------->|
+----(1RTT encrypted data starts)--------->|
| |
|<-----------------Handshake Completion----+
| |
Figure 1: General communication pattern visible in the QUIC handshake
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 3 typically containing three
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
1-RTT data, if present.
The content of QUIC Initial packets are encrypted using Initial
Secrets, which are derived from a per-version constant and the
client's destination connection ID; they are therefore observable by
any on-path device that knows the per-version constant; we therefore
consider these as visible in our illustration. The content of QUIC
Handshake packets are encrypted using keys established during the
initial handshake exchange, and are therefore not visible.
Initial, Handshake, and the Short Header packets transmitted after
the handshake belong to cryptographic and transport contexts. The
Initial Completion Figure 4 and the Handshake Completion Figure 5
datagrams finish these first two contexts, by sending the final
acknowledgment and finishing the transmission of CRYPTO frames.
+----------------------------------------------------------+
| UDP header (source and destination UDP ports) |
+----------------------------------------------------------+
| QUIC long header (type = Initial, Version, DCID, SCID) (Length)
+----------------------------------------------------------+ |
| QUIC CRYPTO frame header | |
+----------------------------------------------------------+ |
| TLS Client Hello (incl. TLS SNI) | |
+----------------------------------------------------------+ |
| QUIC PADDING frame | |
+----------------------------------------------------------+<-+
Figure 2: Typical 1-RTT QUIC Client Hello datagram pattern
The Client Hello datagram exposes version number, source and
destination connection IDs, and information in the TLS Client Hello
message, including any TLS Server Name Indication (SNI) present, in
the clear. The QUIC PADDING frame shown here may be present to
ensure the Client Hello datagram has a minumum size of 1200 octets,
to mitigate the possibility of 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) |
+------------------------------------------------------------+
| QUIC long header (type = Initial, Version, DCID, SCID) (Length)
+------------------------------------------------------------+ |
| QUIC CRYPTO frame header | |
+------------------------------------------------------------+ |
| TLS Server Hello | |
+------------------------------------------------------------+ |
| QUIC ACK frame (acknowledging client hello) | |
+------------------------------------------------------------+<-+
| QUIC long header (type = Handshake, Version, DCID, SCID) (Length)
+------------------------------------------------------------+ |
| encrypted payload (presumably CRYPTO frames) | |
+------------------------------------------------------------+<-+
| QUIC short header |
+------------------------------------------------------------+
| 1-RTT encrypted payload |
+------------------------------------------------------------+
Figure 3: Typical QUIC Server Hello datagram pattern
The Server Hello datagram exposes version number, source and
destination connection IDs, and information in the TLS Server Hello
message.
+------------------------------------------------------------+
| UDP header (source and destination UDP ports) |
+------------------------------------------------------------+
| QUIC long header (type = Initial, Version, DCID, SCID) (Length)
+------------------------------------------------------------+ |
| QUIC ACK frame (acknowledging Server Hello Initial) | |
+------------------------------------------------------------+<-+
| QUIC long header (type = Handshake, Version, DCID, SCID) (Length)
+------------------------------------------------------------+ |
| encrypted payload (presumably CRYPTO/ACK frames) | |
+------------------------------------------------------------+<-+
| QUIC short header |
+------------------------------------------------------------+
| 1-RTT encrypted payload |
+------------------------------------------------------------+
Figure 4: Typical QUIC Initial Completion datagram pattern
The Initial Completion datagram does not expose any additional
information; however, recognizing it can be used to determine that a
handshake has completed (see Section 3.2), and for three-way
handshake RTT estimation as in Section 3.6.
+------------------------------------------------------------+
| UDP header (source and destination UDP ports) |
+------------------------------------------------------------+
| QUIC long header (type = Handshake, Version, DCID, SCID) (Length)
+------------------------------------------------------------+ |
| encrypted payload (presumably ACK frame) | |
+------------------------------------------------------------+<-+
| QUIC short header |
+------------------------------------------------------------+
| 1-RTT encrypted payload |
+------------------------------------------------------------+
Figure 5: Typical QUIC Handshake Completion datagram pattern
Similar to Initial Competion, Handshake Completion also exposes no
additional information; observing it serves only to determine that
the handshake has completed.
When the client uses 0-RTT connection resumption, 0-RTT data may also
be seen in the QUIC Client Hello datagram, as shown in Figure 6.
+----------------------------------------------------------+
| UDP header (source and destination UDP ports) |
+----------------------------------------------------------+
| QUIC long header (type = Initial, Version, DCID, SCID) (Length)
+----------------------------------------------------------+ |
| QUIC CRYPTO frame header | |
+----------------------------------------------------------+ |
| TLS Client Hello (incl. TLS SNI) | |
+----------------------------------------------------------+<-+
| QUIC long header (type = 0RTT, Version, DCID, SCID) (Length)
+----------------------------------------------------------+ |
| 0-rtt encrypted payload | |
+----------------------------------------------------------+<-+
Figure 6: Typical 0-RTT QUIC Client Hello datagram pattern
In a 0-RTT QUIC Client Hello datagram, the PADDING frame is only
present if necessary to increase the size of the datagram with 0RTT
data to at least 1200 bytes. Additional datagrams containing only
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 0-RTT data. The amount of 0-RTT protected data is limited by the
initial congestion window, typically around 10 packets [RFC6928].
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 those exposed in the packet header, is in the QUIC header, including information exposed in the packet
integrity protected. Further, information that were sent and exposed header, is integrity protected. Further, information that was sent
in previous packets when the cryptographic context was established and exposed in handshake packets sent before the cryptographic
yet, e.g. for the cryptographic initial handshake itself, will be context was established are validated later during the cryptographic
validated later during the cryptographic handshake. Therefore, handshake. Therefore, devices on path MUST NOT change any
devices on path MUST NOT change any information or bits in QUIC information or bits in QUIC packet headers, since alteration of
packet headers, since alteration of header information will lead to a header information will lead to a failed integrity check at the
failed integrity check at the receiver, and can even lead to receiver, and can even lead to connection termination.
connection termination.
2.4. 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, in the case of the HTTP
binding. Client and server negotiate connection IDs during the binding. Client and server negotiate connection IDs during the
handshake; typically, however, only the server will request a handshake; typically, however, only the server will request a
connection ID for the lifetime of the connection. Connection IDs for connection ID for the lifetime of the connection. Connection IDs for
either endpoint may change during the lifetime of a connection, with either endpoint may change during the lifetime of a connection, with
the new connection ID being negotiated via encrypted frames. See the new connection ID being negotiated via encrypted frames. See
Section 6.1 of [QUIC-TRANSPORT]. Section 6.1 of [QUIC-TRANSPORT].
2.5. 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 useful to on-path observers. part of the wire image that is useful to on-path observers.
2.6. Version Negotiation and Greasing 2.8. Version Negotiation and Greasing
Version negotiation is not protected, given the used protection Version negotiation is not protected, given the used protection
mechanism can change with the version. However, the choices provided mechanism can change with the version. However, the choices provided
in the list of version in the Version Negotiation packet will be in the list of version in the Version Negotiation packet will be
validated as soon as the cryptographic context has been established. validated as soon as the cryptographic context has been established.
Therefore any manipulation of this list will be detected and will Therefore any manipulation of this list will be detected and will
cause the endpoints to terminate the connection. 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
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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, Handshake, and Retry packets
containing a TLS handshake on Stream 0. Connection establishment can containing a TLS handshake. Connection establishment can therefore
therefore be detected using heuristics similar to those used to be detected using heuristics similar to those used to detect TLS over
detect TLS over TCP. A client using 0-RTT connection may also send TCP. A client using 0-RTT connection may also send data packets in
data packets in 0-RTT Protected packets directly after the Initial 0-RTT Protected packets directly after the Initial packet containing
packet containing the TLS Client Hello. Since these packets may be the TLS Client Hello. Since these packets may be reordered in the
reordered in the network, note that 0-RTT Protected data packets may network, note that 0-RTT Protected data packets may be seen before
be seen before the Initial packet. Note that only clients send the Initial packet. Note that only clients send Initial packets, so
Initial packets, so the sides of a connection can be distinguished by the sides of a connection can be distinguished by QUIC packet type in
QUIC packet type in the handshake. the handshake.
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
skipping to change at page 8, line 17 skipping to change at page 12, line 49
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-ENCRYPT-SNI], reducing the information available SNI in TLS 1.3 [TLS-ENCRYPT-SNI], reducing the information available
in the SNI to the name of a fronting service, which can generally be in the SNI to the name of a fronting service, which can generally be
identified by the IP address of the server anyway. If used with identified by the IP address of the server anyway. If used with
QUIC, this would make SNI-based application identification impossible QUIC, this would make SNI-based application identification impossible
through passive measurement. through passive measurement.
3.4. Flow association 3.4. Flow association
The QUIC Connection ID (see Section 2.4) is designed to allow an on- 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.
The connection ID to be used for a long-running flow is chosen by the The connection ID to be used for a long-running flow is chosen by the
server (see [QUIC-TRANSPORT] section 5.6) during the handshake. This server (see [QUIC-TRANSPORT] section 5.6) during the handshake. This
skipping to change at page 8, line 47 skipping to change at page 13, line 30
QUIC flows. QUIC flows.
Changes to this behavior have been discussed in the working group, Changes to this behavior have been discussed in the working group,
but there is no current proposal to implement these changes: see but there is no current proposal to implement these changes: see
https://github.com/quicwg/base-drafts/issues/602. https://github.com/quicwg/base-drafts/issues/602.
3.6. Round-trip time measurement 3.6. Round-trip time 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 the cleartext TLS requires parsing of the QUIC packet header and recognition of the
handshake on stream 0. handshake, as illustrated in Section 2.4.
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 10, line 51 skipping to change at page 15, line 34
traffic; see Section 3.6. No passive measurement of loss is possible traffic; see Section 3.6. 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. the load balancers. Guidance on assigning connection IDs is given in
[QUIC-APPLICABILITY].
Server-generated Connection IDs must not encode any information other
that that needed to route packets to the appropriate backend
server(s): typically the identity of the backend server or pool of
servers, if the data-center's load balancing system keeps "local"
state of all flows itself. Care must be exercised to ensure that the
information encoded in the Connection ID is not sufficient to
identify unique end users. Note that by encoding routing information
in the Connection ID, load balancers open up a new attack vector that
allows bad actors to direct traffic at a specific backend server or
pool. It is therefore recommended that Server-Generated Connection
ID includes a cryptographic MAC that the load balancer pool server
are able to identify and discard packets featuring an invalid MAC.
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 involve passive measurement using of Service (DDoS) attacks generally involve passive measurement using
network flow data [RFC7011], classification of traffic into "good" network flow data [RFC7011], classification of traffic into "good"
(productive) and "bad" (DoS) flows, and filtering of these bad flows (productive) and "bad" (DoS) flows, and filtering of these bad flows
in a "scrubbing" environment. Key to successful DDoS mitigation is in a "scrubbing" environment. Key to successful DDoS mitigation is
efficient classification of this traffic. efficient classification of this traffic.
skipping to change at page 12, line 17 skipping to change at page 16, line 37
desired, multiple QUIC connections to the same server might be used, desired, multiple QUIC connections to the same server might be used,
given that establishing a new connection using 0-RTT support is cheap given that establishing a new connection using 0-RTT support is cheap
and fast. and fast.
QoS mechanisms in the network MAY also use the connection ID for QoS mechanisms in the network MAY also use the connection ID for
service differentiation, as a change of connection ID is bound to a 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 change of address which anyway is likely to lead to a re-route on a
different path with different network characteristics. different path with different network characteristics.
Given that QUIC is more tolerant of packet re-ordering than TCP (see Given that QUIC is more tolerant of packet re-ordering than TCP (see
Section 2.5), Equal-cost multi-path routing (ECMP) does not Section 2.7), Equal-cost multi-path routing (ECMP) does not
necessarily need to be flow based. However, 5-tuple (plus eventually necessarily need to be flow based. However, 5-tuple (plus eventually
connection ID if present) matching is still beneficial for QoS given connection ID if present) matching is still beneficial for QoS given
all packets are handled by the same congestion controller. all packets are handled by the same congestion controller.
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 Supporting manageability of QUIC traffic inherently involves
tradeoffs with the confidentiality of QUIC's control information; tradeoffs with the confidentiality of QUIC's control information;
this entire document is therefore security-relevant. this entire document is therefore security-relevant.
Some of the properties of the QUIC header used in network management
are irrelevant to application-layer protocol operation and/or user
privacy. For example, packet number exposure (and echo, as proposed
in this document), as well as connection establishment exposure for
1-RTT establishment, make no additional information about user
traffic available to devices on path.
At the other extreme, supporting current traffic classification
methods that operate through the deep packet inspection (DPI) of
application-layer headers are directly antithetical to QUIC's goal to
provide confidentiality to its application-layer protocol(s); in
these cases, alternatives must be found.
7. Contributors 7. Contributors
Dan Druta contributed text to Section 4.4. Igor Lubashev contributed Dan Druta contributed text to Section 4.4. Igor Lubashev contributed
text to Section 4.3 on the use of the connection ID for load text to Section 4.3 on the use of the connection ID for load
balancing. Marcus Ilhar contributed text to Section 3.6 on the use balancing. Marcus Ilhar contributed text to Section 3.6 on the use
of the spin bit. of the spin bit.
8. Acknowledgments 8. Acknowledgments
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. References 9. References
9.1. Normative References 9.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/ Requirement Levels", BCP 14, RFC 2119,
RFC2119, March 1997, <https://www.rfc-editor.org/info/ DOI 10.17487/RFC2119, March 1997,
rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
9.2. Informative References 9.2. Informative References
[Ding2015] [Ding2015]
Ding, H. and M. Rabinovich, "TCP Stretch Acknowledgments 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>.
[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)", Internet Measurement (arXiv preprint 1612.02902)",
December 2016, <https://arxiv.org/abs/1612.02902>. December 2016, <https://arxiv.org/abs/1612.02902>.
[QUIC-APPLICABILITY]
Kuehlewind, M. and B. Trammell, "Applicability of the QUIC
Transport Protocol", draft-ietf-quic-applicability-02
(work in progress), July 2018.
[QUIC-HTTP] [QUIC-HTTP]
Bishop, M., "Hypertext Transfer Protocol (HTTP) over Bishop, M., "Hypertext Transfer Protocol (HTTP) over
QUIC", draft-ietf-quic-http-13 (work in progress), June QUIC", draft-ietf-quic-http-15 (work in progress), October
2018. 2018.
[QUIC-INVARIANTS] [QUIC-INVARIANTS]
Thomson, M., "Version-Independent Properties of QUIC", Thomson, M., "Version-Independent Properties of QUIC",
draft-ietf-quic-invariants-01 (work in progress), March draft-ietf-quic-invariants-03 (work in progress), October
2018. 2018.
[QUIC-SPIN] [QUIC-SPIN]
Trammell, B. and M. Kuehlewind, "The QUIC Latency Spin Trammell, B. and M. Kuehlewind, "The QUIC Latency Spin
Bit", draft-ietf-quic-spin-exp-00 (work in progress), Bit", draft-ietf-quic-spin-exp-00 (work in progress),
April 2018. April 2018.
[QUIC-TLS] [QUIC-TLS]
Thomson, M. and S. Turner, "Using Transport Layer Security Thomson, M. and S. Turner, "Using Transport Layer Security
(TLS) to Secure QUIC", draft-ietf-quic-tls-13 (work in (TLS) to Secure QUIC", draft-ietf-quic-tls-15 (work in
progress), June 2018. progress), October 2018.
[QUIC-TRANSPORT] [QUIC-TRANSPORT]
Iyengar, J. and M. Thomson, "QUIC: A UDP-Based Multiplexed Iyengar, J. and M. Thomson, "QUIC: A UDP-Based Multiplexed
and Secure Transport", draft-ietf-quic-transport-13 (work and Secure Transport", draft-ietf-quic-transport-15 (work
in progress), June 2018. in progress), October 2018.
[RFC4737] Morton, A., Ciavattone, L., Ramachandran, G., Shalunov, [RFC4737] Morton, A., Ciavattone, L., Ramachandran, G., Shalunov,
S., and J. Perser, "Packet Reordering Metrics", RFC 4737, S., and J. Perser, "Packet Reordering Metrics", RFC 4737,
DOI 10.17487/RFC4737, November 2006, <https://www.rfc- DOI 10.17487/RFC4737, November 2006,
editor.org/info/rfc4737>. <https://www.rfc-editor.org/info/rfc4737>.
[RFC6066] Eastlake 3rd, D., "Transport Layer Security (TLS) [RFC6066] Eastlake 3rd, D., "Transport Layer Security (TLS)
Extensions: Extension Definitions", RFC 6066, DOI Extensions: Extension Definitions", RFC 6066,
10.17487/RFC6066, January 2011, <https://www.rfc- DOI 10.17487/RFC6066, January 2011,
editor.org/info/rfc6066>. <https://www.rfc-editor.org/info/rfc6066>.
[RFC6928] Chu, J., Dukkipati, N., Cheng, Y., and M. Mathis,
"Increasing TCP's Initial Window", RFC 6928,
DOI 10.17487/RFC6928, April 2013,
<https://www.rfc-editor.org/info/rfc6928>.
[RFC7011] Claise, B., Ed., Trammell, B., Ed., and P. Aitken, [RFC7011] Claise, B., Ed., Trammell, B., Ed., and P. Aitken,
"Specification of the IP Flow Information Export (IPFIX) "Specification of the IP Flow Information Export (IPFIX)
Protocol for the Exchange of Flow Information", STD 77, Protocol for the Exchange of Flow Information", STD 77,
RFC 7011, DOI 10.17487/RFC7011, September 2013, RFC 7011, DOI 10.17487/RFC7011, September 2013,
<https://www.rfc-editor.org/info/rfc7011>. <https://www.rfc-editor.org/info/rfc7011>.
[RFC7301] Friedl, S., Popov, A., Langley, A., and E. Stephan, [RFC7301] Friedl, S., Popov, A., Langley, A., and E. Stephan,
"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,
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