wdiff draft-ietf-ippm-stamp-option-tlv-06.txt draft-ietf-ippm-stamp-option-tlv-07.txt

Network Working Group G. Mirsky
Internet-Draft X. Min
Updates: 8762 (if approved) ZTE Corp.
Intended status: Standards Track H. Nydell
Expires: December 24, 2020 January 9, 2021 Accedian Networks
R. Foote
Nokia
A. Masputra
Apple Inc.
E. Ruffini
OutSys
June 22,
July 8, 2020

Simple Two-way Active Measurement Protocol Optional Extensions
draft-ietf-ippm-stamp-option-tlv-06
draft-ietf-ippm-stamp-option-tlv-07

Abstract

This document describes optional extensions to Simple Two-way Active
Measurement Protocol (STAMP) which that enable measurement of performance
metrics
metrics, in addition to ones supported by the STAMP base
specification. The document also defines a STAMP Test Session
Identifier and thus updates RFC 8762.

Status of This Memo

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

Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.

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

This Internet-Draft will expire on December 24, 2020. January 9, 2021.

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Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of
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described in the Simplified BSD License.

Table of Contents

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions Used in This Document . . . . . . . . . . . . . . 3
2.1. Acronyms . . . . . . . . . . . . . . . . . . . . . . . . 3
2.2. Requirements Language . . . . . . . . . . . . . . . . . . 3
3. STAMP Test Session Identifier . . . . . . . . . . . . . . . . 4
4. TLV Extensions to STAMP . . . . . . . . . . . . . . . . . . . 8
4.1. Extra Padding TLV . . . . . . . . . . . . . . . . . . . . 9 11
4.2. Location TLV . . . . . . . . . . . . . . . . . . . . . . 10 11
4.3. Timestamp Information TLV . . . . . . . . . . . . . . . . 11 13
4.4. Class of Service TLV . . . . . . . . . . . . . . . . . . 12 14
4.5. Direct Measurement TLV . . . . . . . . . . . . . . . . . 14 15
4.6. Access Report TLV . . . . . . . . . . . . . . . . . . . . 15 17
4.7. Follow-up Telemetry TLV . . . . . . . . . . . . . . . . . 16 18
4.8. HMAC TLV . . . . . . . . . . . . . . . . . . . . . . . . 18 20
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19 21
5.1. STAMP TLV Registry . . . . . . . . . . . . . . . . . . . 19 21
5.2. STAMP TLV Flags Sub-registry . . . . . . . . . . . . . . 22
5.3. Synchronization Source Sub-registry . . . . . . . . . . . 20
5.3. 22
5.4. Timestamping Method Sub-registry . . . . . . . . . . . . 20
5.4. 23
5.5. Return Code Sub-registry . . . . . . . . . . . . . . . . 21 24
6. Security Considerations . . . . . . . . . . . . . . . . . . . 22 25
7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 22 25
8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 22 25
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 22 25
9.1. Normative References . . . . . . . . . . . . . . . . . . 22 26
9.2. Informative References . . . . . . . . . . . . . . . . . 23 26
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 24 27

1. Introduction

Simple Two-way Active Measurement Protocol (STAMP) [RFC8762] supports
the use of optional extensions that use Type-Length-Value (TLV)
encoding. Such extensions enhance the STAMP base functions, such as
measurement of one-way and round-trip delay, latency, packet loss,
and the ability to detect
packet duplication duplication, and out-of- order out-of-order delivery of the test packets. This
specification defines optional STAMP extensions, their formats, and
the theory of operation. Also, a STAMP Test Session Identifier is
defined as an update of the base STAMP specification [RFC8762].

2. Conventions Used in This Document

2.1. Acronyms

STAMP Simple Two-way Active Measurement Protocol

BDS BeiDou Navigation Satellite System

BITS Building Integrated Timing Supply

CoS Class of Service

DSCP Differentiated Services Code Point

ECN Explicit Congestion Notification

NTP Network Time Protocol

PTP Precision Time Protocol

HMAC Hashed Message Authentication Code

TLV Type-Length-Value

BITS Building Integrated Timing Supply

SSU Synchronization Supply Unit

GPS Global Positioning System

GLONASS Global Orbiting Navigation Satellite System

GPS Global Positioning System [GPS]

HMAC Hashed Message Authentication Code

LORAN-C Long Range Navigation System Version C

MBZ Must Be Zero

CoS Class of Service

NTP Network Time Protocol [RFC5905]

PMF Performance Measurement Function

PTP Precision Time Protocol [IEEE.1588.2008]

TLV Type-Length-Value

SSID STAMP Session Identifier

SSU Synchronization Supply Unit

STAMP Simple Two-way Active Measurement Protocol

2.2. Requirements Language

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.

3. STAMP Test Session Identifier

The STAMP Session-Sender transmits test packets to the STAMP Session-
Reflector. The STAMP Session-Reflector receives the Session-Sender's
packet and acts according to the configuration and optional control
information communicated in the Session-Sender's test packet. STAMP
defines two different test packet formats, one for packets
transmitted by the STAMP-Session-Sender STAMP Session-Sender and one for packets
transmitted by the STAMP-Session-Reflector. STAMP Session-Reflector. STAMP supports two
modes: unauthenticated and authenticated. Unauthenticated STAMP test
packets are compatible on the wire with unauthenticated TWAMP-Test
[RFC5357] packet formats. packets.

By default, STAMP uses symmetrical packets, i.e., the size of the
packet transmitted by the Session-Reflector equals the size of the
packet received by the Session-Reflector.

A STAMP Session is identified using by the 4-tuple (source and destination
IP addresses, source and destination UDP port numbers). A STAMP
Session-Sender MAY generate a locally unique STAMP Session Identifier
(SSID). SSID is two octets long a two-octet-long non-zero unsigned integer. A
Session-Sender MAY use SSID to identify a STAMP test session. If
SSID is used, it MUST be present in each test packet of the given
test session. In the unauthenticated mode, SSID is located, located as
displayed in Figure 1.

Figure 1: An example of an extended STAMP Session-Sender test packet
format in unauthenticated mode

An implementation of the STAMP Session-Reflector that supports this
specification SHOULD identify a STAMP Session using the SSID in
combination with elements of the usual 4-tuple for the session.
Before a test session commences, a Session-Reflector MUST be
provisioned with all the elements that identify the STAMP Session. A
STAMP Session-Reflector MUST discard the non-matching STAMP test
packet(s). The means of provisioning the STAMP Session
identification is outside the scope of this specification. A
conforming implementation of STAMP Session-Reflector MUST copy the
SSID value from the received test packet and put it into the
reflected packet, as displayed in Figure 2.

0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Timestamp |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Error Estimate | SSID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Receive Timestamp |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Session-Sender Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Session-Sender Timestamp |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Session-Sender Error Estimate | MBZ |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Ses-Sender TTL | MBZ |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Value TLVs ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Figure 2: An example of an extended STAMP Session-Reflector test
packet format in unauthenticated mode

A STAMP Session-Reflector that does not support this specification, specification
will return the zeroed SSID field in the reflected STAMP test packet.
The Session-Sender MAY stop the session if it receives a zeroed SSID
field. An implementation of a Session-Sender MUST support control of
its behavior in such a scenario. If the test session is not stopped,
the Session-Sender, can, for example, send a base STAMP packet
[RFC8762].

In the authenticated mode, location

Location of the SSID field in the authenticated mode is shown in
Figure 3 and Figure 4.

Figure 3: Base STAMP Session-Sender test packet format in
authenticated mode

0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MBZ (12 octets) |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Timestamp |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Error Estimate | SSID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MBZ (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Receive Timestamp |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MBZ (8 octets) |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Session-Sender Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MBZ (12 octets) |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Session-Sender Timestamp |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Session-Sender Error Estimate | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
| MBZ (6 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Ses-Sender TTL | |
+-+-+-+-+-+-+-+-+ +
| |
| MBZ (15 octets) |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| HMAC (16 octets) |
| |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Figure 4: Base STAMP Session-Reflector test packet format in
authenticated mode

4. TLV Extensions to STAMP

The Type-Length-Value (TLV) encoding scheme provides a flexible
extension mechanism for optional informational elements. TLV is an
optional field in the STAMP test packet. Multiple TLVs MAY be placed
in the a STAMP test packet. A TLV MAY be enclosed in a TLV. TLVs have the
two octets long a
one-octet-long STAMP TLV Flags field, one-octet-long Type field, two octets long and
two-octet-long Length field that is equal to the length of the Value
field in octets. If a Type value for TLV or sub-TLV is in the range
for Vendor Private Use, the Length MUST be at least 4, and the first
four octets MUST be that vendor's the Structure of Management
Information (SMI) Private Enterprise
Codes, Code, as recorded in IANA's SMI
Private Enterprise Codes sub-
registry, sub-registry, in network octet order. The
rest of the Value field is private to the vendor. The following
sections describe the use of TLVs for STAMP that extend STAMP
capability beyond its base specification.

0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|STAMP TLV Flags| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Value ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Figure 5: TLV Format in a STAMP node, whether Extended Packet

where fields are defined as the following:

o STAMP TLV Flags - eight-bit-long field. Detailed format and
interpretation of flags defined in this specification is below.

o Type - one-octet-long field that characterizes the interpretation
of the Value field. It is allocated by IANA, as specified in
Section 5.1.

o Length - two-octet-long field equal to the length of the Value
field in octets.

o Value - a variable-length field. Its interpretation and encoding
is determined by the value of the Type field.

The format of the STAMP TLV Flags displayed in Figure 6 and the
location of flags is according to Section 5.2.

0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+
|U|L|A|R|R|R|R|R|
+-+-+-+-+-+-+-+-+

Figure 6: STAMP TLV Flags Format

where fields are defined as the following:

o U - a one-bit flag. A Session-Sender MUST set the U flag to 0
before transmitting an extended STAMP test packet. A Session-
Reflector MUST set the U flag to 1 if the Session-Reflector has
not understood the TLV.

o L - a one-bit flag. A Session-Sender MUST set the L flag to 0
before transmitting an extended STAMP test packet. A Session-
Reflector MUST set the L flag to 1 if the Session-Reflector
determined the TLV is malformed, i.e., the Length field value of
the fixed-size TLV is not equal to the value defined for the
particular type, or the remaining length of the extended STAMP
packet is less than the size of the TLV.

o A - a one-bit flag. A Session-Sender MUST set the A flag to 0
before transmitting an extended STAMP test packet. A Session-
Reflector MUST set the A flag to 1 if the STAMP extensions have
failed HMAC verification (Section 4.8).

o R - reserved flags for future use. These flags MUST be zeroed on
transmit and ignored on receipt.

A STAMP node, whether Session-Sender or Session-Reflector, receiving
a test packet MUST determine whether the packet is a base STAMP
packet or includes one or more TLVs. The node MUST compare the value
in the Length field of the UDP header and the length of the base
STAMP test packet in the mode, unauthenticated or authenticated based
on the configuration of the particular STAMP test session. If the
difference between the two values is larger than the length of the
UDP header, then the test packet includes one or more STAMP TLVs that
immediately follow the base STAMP test packet. A Session-Reflector
that does not support STAMP extensions is not expected to compare the
value in the Length field of the UDP header and the length of the
STAMP base packet. Hence the Session-Reflector will transmit the
base STAMP packet. It is the local policy on the Session-Sender
(similar to the handling of SSID == 0 scenario described in
Section 3) that will control the sender's behavior.

A system that has received a STAMP test packet with extension TLVs
MUST validate each TLV:

If the U flag is set, the STAMP system MUST skip the processing of
the TLV. The implementation MUST try to process the next TLV if
present in the extended STAMP packet.

If the L flag is set, the STAMP system MUST stop processing the
remainder of the extended STAMP packet.

If the A flag is set, the STAMP system MUST discard all TLVs and
MUST stop processing the remainder of the extended STAMP packet.

If an implementation of a Session-Reflector does not recognize the value in the
Type field value, it MUST include a copy of the Extra Padding TLV into the
reflected STAMP packet. The Length field Session-Reflector MUST be set equal to the value of
the Length field of that TLV. The size of the Value field MUST
equal the value of the Length field. Then proceed U flag
to 1. The Session-Reflector MUST try to process the next TLV if any present;

fixed-size TLVs are verified that the Length field value equals
the value defined for in
the particular type. extended STAMP packet.

If the values are not
equal, a TLV is malformed, the processing of extension TLVs MUST be
stopped. Also, if The Session-Reflector MUST copy the system is remainder of the Session-Reflector, it MUST send
received extended STAMP packet into the ICMP
Parameter Problem message with Code reflected STAMP packet.
The Session-Reflector MUST set to 0 and the Pointer
referring L flag to the Length field of the TLV. 1.

Detected error events MUST be logged. Note that transmission rate of ICMP
Error messages and logging SHOULD MUST
be throttled. controlled.

4.1. Extra Padding TLV

0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extra Padding
|STAMP TLV Flags|Extra Pad Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Extra Padding ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Figure 5: 7: Extra Padding TLV

where fields are defined as the following:

o STAMP TLV Flags - is an eight-bit-long field. Its format is
presented in Figure 6.

o Extra Padding Type - is a one-octet-long field, value TBA1
allocated by IANA Section 5.1 5.1.

o Length - two octets long two-octet-long field equals equal to the length on of the Extra
Padding field in octets.

o Extra Padding - a pseudo-random sequence of numbers. bits. The field MAY
be filled with all zeros.

The Extra Padding TLV is similar to the Packet Padding field in a
TWAMP-Test packet [RFC5357]. The use of the Extra Padding TLV is
RECOMMENDED to perform a STAMP test using test packets of larger size
than the base STAMP packet [RFC8762]. The length of the base STAMP
packet is 44 octets in the unauthenticated mode or 112 octets in the
authenticated mode. The Extra Padding TLV MAY be present more than
one time in an extended STAMP test packet.

4.2. Location TLV

STAMP Session-Sender Session-Senders MAY include the Location TLV to request
information from the Session-Reflector. The Session-Sender SHOULD
NOT fill any information fields except for Type STAMP TLV Flags, Type, and
Length. The Session-Reflector MUST validate the Length value against
the address family of the transport encapsulating the STAMP test
packet. If the Length field's value is invalid, the Session-Reflector Session-
Reflector MUST zero all fields and MUST NOT return any information to
the Session-Sender. The Session-Reflector MUST ignore all other
fields of the received Location TLV.

0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|STAMP TLV Flags| Location Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Source MAC |
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Destination IP Address ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Source IP Address ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Destination Port | Source Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Figure 6: 8: Session-Reflector Location TLV

where fields are defined as the following:

o STAMP TLV Flags - is an eight-bit-long field. Its format is
presented in Figure 6.

o Location Type - is a one-octet-long field, value TBA2 allocated by
IANA Section 5.1 5.1.

o Length - two octets long two-octet-long field equals equal to the length of the Value
field in octets. The Length field value MUST equal 20 octets for
the IPv4 address family. For the IPv6 address family, the value
of the Length field MUST equal 44 octets. All other values are
invalid.

o Source MAC - 6 octets 48 bits long 6-octet-long field. The Session-Reflector MUST copy
the Source MAC of the received STAMP packet into this field.

o Reserved - two octets long two-octet-long field. MUST be zeroed on transmission
and ignored on reception.

o Destination IP Address - IPv4 or IPv6 destination address of the
packet received by the STAMP Session-Reflector.

o Source IP Address - IPv4 or IPv6 source address of the packet
received by the STAMP Session-Reflector.

o Destination Port - two octets long two-octet-long UDP destination port number of
the received STAMP packet.

o Source Port - two octets long two-octet-long UDP source port number of the
received STAMP packet.

The Location TLV MAY be used to determine the last-hop IP addresses,
ports, and last-hop MAC address for STAMP packets. The MAC address
can indicate a path switch on the last hop hop. The IP addresses and UDP
port
ports will indicate if there is a NAT router on the path, and path. It allows
the Session-Sender to identify the IP address of the Session-
Reflector behind the NAT, and detect changes in the NAT mapping that
could cause sending the STAMP packets to the wrong Session-Reflector.

4.3. Timestamp Information TLV

The STAMP Session-Sender MAY include the Timestamp Information TLV to
request information from the Session-Reflector. The Session-Sender
SHOULD NOT fill any information fields except for Type STAMP TLV Flags,
Type, and Length. The Session-Reflector MUST validate the Length
value of the STAMP
test packet. TLV. If the value of the Length field is invalid, the
Session-Reflector MUST zero all fields and MUST NOT return any
information to the Session-Sender.

Figure 7: 9: Timestamp Information TLV

where fields are defined as the following:

o STAMP TLV Flags - is an eight-bit-long field. Its format is
presented in Figure 6.

o Timestamp Information Type - is a one-octet-long field, value TBA3
allocated by IANA Section 5.1 5.1.

o Length - two octets long two-octet-long field, set equal to the value 4.

o Sync Src In - one octet long one-octet-long field that characterizes the source
of clock synchronization at the ingress of a Session-Reflector.
There are several methods to synchronize the clock, e.g., Network
Time Protocol (NTP) [RFC5905]. The value is one of those listed
in Table 4. 5.

o Timestamp In - one octet long one-octet-long field that characterizes the method
by which the ingress of the Session-Reflector obtained the
timestamp T2. A timestamp may be obtained with hardware
assistance, via software API from a local wall clock, or from a
remote clock (the latter is referred to as "control plane"). The
value is one of those listed in Table 6. 7.

o Sync Src Out - one octet long one-octet-long field that characterizes the source
of clock synchronization at the egress of the Session-Reflector.
The value is one of those listed in Table 4. 5.

o Timestamp Out - one octet long one-octet-long field that characterizes the method
by which the egress of the Session-Reflector obtained the
timestamp T3. The value is one of those listed in Table 6. 7.

4.4. Class of Service TLV

The STAMP Session-Sender MAY include a Class of Service (CoS) TLV in
the STAMP test packet. The format of the CoS TLV is presented in
Figure 8. 10.

Figure 8: 10: Class of Service TLV

where fields are defined as the following:

o Class STAMP TLV Flags - is an eight-bit-long field. Its format is
presented in Figure 6.

o CoS (Class of Service Service) Type - is a one-octet-long field, value
TBA4 allocated by IANA Section 5.1 5.1.

o Length - two octets long two-octet-long field, set equal to the value 4.

o DSCP1 - The Differentiated Services Code Point (DSCP) intended by
the Session-Sender to be used as the DSCP value of the reflected
by the Session-Reflector reflected
test packet.

o DSCP2 - The received value in the DSCP field at the Session-
Reflector in the forward direction.

o ECN - The received value in the ECN field at the Session-Reflector
in the forward direction.

o Reserved - 18 bits long 18-bit-long field, must MUST be zeroed in on transmission and
ignored on receipt.

A STAMP Session-Reflector that received the receives a test packet with the CoS
TLV MUST include the CoS TLV in the reflected test packet. Also, the
Session-Reflector MUST copy the value of the DSCP and ECN fields of
the IP header of the received STAMP test packet into the DSCP2 field
in the reflected test packet. Finally, the Session-Reflector MUST
set the DSCP field's value in the IP header of the reflected test
packet equal to the value of the DSCP1 field of the received test
packet. Upon receiving the reflected packet, the Session-Sender will
save the DSCP and ECN values for analysis of the CoS in the reverse
direction.

Re-mapping of CoS can be used to provide multiple services (e,g., 2G,
3G, LTE in mobile backhaul networks) over the same network. But if
it is misconfigured, then it is often difficult to diagnose the root
cause of excessive packet drops of higher-level service while packet
drops for lower service packets are at a normal level. Using a CoS
TLV in STAMP testing helps to troubleshoot the existing problem and
also verify whether DiffServ policies are processing CoS as required
by the configuration.

4.5. Direct Measurement TLV

The Direct Measurement TLV enables collection of "in profile" the number of in-
profile packets that had been transmitted and received by the
Session-Sender and
Session-Reflector respectfully. Session-Reflector, respectively. The definition
of "in-profile packet" is outside the scope of this document and is
left to the test operators to determine.

0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|STAMP TLV Flags| Direct Measurement Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Session-Sender Tx counter (S_TxC) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Session-Reflector Rx counter (R_RxC) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Session-Reflector Tx counter (R_TxC) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Figure 9: 11: Direct Measurement TLV

where fields are defined as the following:

o STAMP TLV Flags - is an eight-bit-long field. Its format is
presented in Figure 6.

o Direct Measurement (Measurement) Type - is a one-octet-long field, value TBA5
allocated by IANA Section 5.1 5.1.

o Length - two octets long two-octet-long field equals length on of the Value field in
octets. The Length field value MUST equal 12 octets.

o Session-Sender Tx counter (S_TxC) is four octets long a four-octet-long field. The
Session-Sender MUST set its value equal to the number of the
transmitted in-profile packets.

o Session-Reflector Rx counter (R_RxC) is four octets long a four-octet-long field.
MUST be zeroed by the Session-Sender on transmit and filled ignored by
the Session-
Reflector. Session-Reflector on receipt. The Session-Reflector MUST fill
it with the value of in-profile packets received.

o Session-Reflector Tx counter (R_TxC) is four octets long a four-octet-long field.
MUST be zeroed by the Session-Sender and filled ignored by the Session-
Reflector.
Reflector on receipt. The Session-Reflector MUST fill it with the
value of the transmitted in-profile packets.

A Session-Sender MAY include the Direct Measurement TLV in a STAMP
test packet. The Session-Sender MUST zero the R_RxC and R_TxC fields
before the transmission of the STAMP test packet. If the received
STAMP test packet includes the Direct Measurement TLV, the Session-
Reflector MUST include it in the reflected test packet. The Session-
Reflector MUST copy the value from the S_TxC field of the received
test packet into the same field of the reflected packet before its
transmission.

4.6. Access Report TLV

A STAMP Session-Sender MAY include an Access Report TLV (Figure 10) 12)
to indicate changes to the access network status to the Session-
Reflector. The definition of an access network is outside the scope
of this document.

Figure 10: 12: Access Report TLV

where fields are defined as follows:

o STAMP TLV Flags - is an eight-bit-long field. Its format
presented in Figure 6.

o Access Report Type - is a one-octet-long field, value TBA6
allocated by IANA Section 5.1.

o Length - two octets long two-octet-long field, set equal to the value 4.

o ID (Access ID) - four bits long four-bit-long field that identifies the access
network, e.g., 3GPP (Radio Access Technologies specified by 3GPP)
or Non-3GPP (accesses that are not specified by 3GPP) [TS23501].
The value is one of those listed below:

* 1 - 3GPP Network

* 2 - Non-3GPP Network

All other values are invalid and the TLV that contains it MUST be
discarded.

o Resv - four bits long four-bit-long field, must MUST be zeroed on transmission and
ignored on receipt.

o Return Code - one octet long one-octet-long field that identifies the report
signal, e.g., available, available or unavailable. The value is passed, supplied to
the STAMP end-point through some mechanism that is outside the
scope of this document. The value is one of those listed in
Section 5.4. 5.5.

o Reserved - two octets long two-octet-long field, must MUST be zeroed on transmission
and ignored on receipt.

The STAMP Session-Sender that includes the Access Report TLV sets the
value of the Access ID field according to the type of access network
it reports on. Also, the Session-Sender sets the value of the Return
Code field to reflect the operational state of the access network.
The mechanism to determine the state of the access network is outside
the scope of this specification. A STAMP Session-Reflector that
received the test packet with the Access Report TLV MUST include the
Access Report TLV in the reflected test packet. The Session-
Reflector MUST set the value of the Access ID and Return Code fields
equal to the values of the corresponding fields from the test packet
it has received.

The Session-Sender MUST also arm a retransmission timer after sending
a test packet that includes the Access Report TLV. This timer MUST
be disarmed upon the reception of the reflected STAMP test packet that
includes the Access Report TLV. In the event the timer expires
before such a packet is received, the Session-Sender MUST retransmit
the STAMP test packet that contains the Access Report TLV. This
retransmission SHOULD be repeated up to four times before the
procedure is aborted. Setting the value for the retransmission timer
is based on local policies, policies and network environment. The default
value of the retransmission timer for the Access Report TLV SHOULD be
three seconds. An implementation MUST provide control of the
retransmission timer value and the number of retransmissions.

The Access Report TLV is used by the Performance Measurement Function
(PMF) components of the Access Steering, Switching and Splitting
feature for 5G networks [TS23501]. The PMF component in the User
Equipment acts as the STAMP Session-Sender, and the PMF component in
the User Plane Function acts as the STAMP Session-Reflector.

4.7. Follow-up Telemetry TLV

A Session-Reflector might be able to put in the Timestamp field only
an "SW Local" (see Table 6) 7) timestamp. But the hosting system might
provide the a timestamp closer to the start of the actual packet
transmission even though when it is not possible to deliver the
information to the Session-Sender in time for the packet itself.
This timestamp might nevertheless be important for the Session-Sender, Session-
Sender, as it improves the accuracy of measuring network delay by
minimizing the impact of egress queuing delays on the measurement.

A STAMP Session-Sender MAY include the Follow-up Telemetry TLV to
request information from the Session-Reflector. The Session-Sender
MUST set the Follow-up Telemetry Type and Length fields to their
appropriate values. The Sequence Number and Timestamp fields MUST be
zeroed on transmission by the Session-Sender and ignored by the
Session-Reflector upon receipt of the STAMP test packet that includes
the Follow-up Telemetry TLV. The Session-Reflector MUST validate the
Length value of the STAMP test packet. If the value of the Length
field is invalid, the Session-Reflector MUST zero the Sequence Number
and Timestamp fields. fields and set the L flag in the STAMP TLV Flags field
in the reflected packet. If the Session-Reflector is in stateless
mode (defined in Section 4.2 [RFC8762]), it MUST zero the Sequence
Number and Timestamp fields.

Figure 11: 13: Follow-up Telemetry TLV

where fields are defined as follows:

o STAMP TLV Flags - is an eight-bit-long field. Its format
presented in Figure 6.

o Follow-up Telemetry (Telemetry) Type - is a one-octet-long field, value TBA7
allocated by IANA Section 5.1.

o Length - two octets long two-octet-long field, set equal to the value 16 octets.

o Sequence Number - four octets long four-octet-long field indicating the sequence
number of the last packet reflected in the same STAMP-test
session. Since the Session-Reflector runs in the stateful mode
(defined in Section 4.2 [RFC8762]), it is the Session-Reflector's
Sequence Number of the previous reflected packet.

o Follow-up Timestamp - eight octets long eight-octet-long field, with the format
indicated by the Z flag of the Error Estimate field of the packet
transmitted by a Session-Reflector, as described in Section 4.1
[RFC8762]. It carries the timestamp when the reflected packet
with the specified sequence number was sent.

o Timestamp M(ode) - one octet long one-octet-long field that characterizes the
method by which the entity that transmits a reflected STAMP packet
obtained the Follow-up Timestamp. The value is one of those
listed in Table 6. 7.

o Reserved - the three octets-long three-octet-long field. Its value MUST be zeroed on
transmission and ignored on receipt.

4.8. HMAC TLV

The STAMP authenticated mode protects the integrity of data collected
in the STAMP base packet. STAMP extensions are designed to provide
valuable information about the condition of a network, and protecting
the integrity of that data is also essential. The keyed Hashed
Message Authentication Code (HMAC) TLV MUST be included in a STAMP
test packet in the authenticated mode, excluding when the only TLV
present is Extra Padding TLV. The HMAC TLV MUST follow all TLVs
included in a STAMP test packet, except for the Extra Padding TLV.
The HMAC TLV MAY be used to protect the integrity of STAMP extensions
in STAMP unauthenticated mode.

0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|STAMP TLV Flags| HMAC Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| HMAC |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Figure 12: 14: HMAC TLV

where fields are defined as follows:

o STAMP TLV Flags - is an eight-bit-long field. Its format is
presented in Figure 6.

o HMAC Type - is two octets long a one-octet-long field, value TBA8 allocated by
IANA Section 5.1.

o Length - two octets long two-octet-long field, set equal to the value 16 octets.

o HMAC - is 16 octets long a 16-octet-long field that carries HMAC digest of the
text of all preceding TLVs.

As defined in [RFC8762], STAMP uses HMAC-SHA-256 truncated to 128
bits ([RFC4868]). All considerations regarding using the key and key
distribution and management listed in Section 4.4 of [RFC8762] are
fully applicable to the use of the HMAC TLV. HMAC is calculated as
defined in [RFC2104] over text as the concatenation of all preceding
TLVs. The digest then MUST be truncated to 128 bits and written into
the HMAC field. In the authenticated mode, HMAC MUST be verified
before using any data in the included STAMP TLVs. If HMAC
verification by the Session-Reflector fails, then an ICMP Parameter
Problem message the Session-
Reflector MUST stop processing the received extended STAMP test
packet. The Session-Reflector MUST be generated (with consideration of limiting copy the
rate remainder of error messages). the
extended STAMP test packet into the reflected packet. The Code value Session-
Reflector MUST be set to 0 and the
Pointer identifying A flag in the copy of the HMAC Type. TLV in the
reflected packet to 1 before transmitting the reflected test packet.
Also, both the Session-Sender and Session-Reflector SHOULD log the
notification that HMAC verification of STAMP TLVs failed. The packet that failed HMAC verification MUST
be dropped.

5. IANA Considerations

5.1. STAMP TLV Registry

IANA is requested to create the STAMP TLV Type registry. All code
points in the range 1 through 32759 175 in this registry shall be allocated
according to the "IETF Review" procedure as specified in [RFC8126].
Code points in the range 32760 176 through 65279 239 in this registry shall be
allocated according to the "First Come First Served" procedure as
specified in [RFC8126]. Remaining The remaining code points are allocated
according to Table 1:

+---------------+---------------------------------+---------------+

Table 1: STAMP TLV Type Registry

This document defines the following new values in the STAMP Extension
TLV range of the STAMP TLV Type registry:

Table 2: STAMP Types

5.2. STAMP TLV Flags Sub-registry

IANA is requested to create the STAMP TLV Flags sub-registry as part
of the STAMP TLV Type registry. The registration procedure is "IETF
Review" [RFC8126]. Flags are 8 bits. This document defines the
following bit positions in the STAMP TLV Flags sub-registry:

+--------------+--------+-----------------------+---------------+
| Bit position | Symbol | Description | Reference |
+--------------+--------+-----------------------+---------------+
| 0 | U | Unrecognized TLV | This document |
| 1 | L | Malformed TLV | This document |
| 2 | A | Authentication failed | This document |
+--------------+--------+-----------------------+---------------+

Table 3: STAMP TLV Flags

5.3. Synchronization Source Sub-registry

IANA is requested to create the Synchronization Source sub-registry
as part of the STAMP TLV Type registry. All code points in the range
1 through 127 in this registry shall be allocated according to the
"IETF Review" procedure as specified in [RFC8126]. Code points in
the range 128 through 239 in this registry shall be allocated
according to the "First Come First Served" procedure as specified in
[RFC8126]. Remaining code points are allocated according to Table 1: 4:

Table 3: 4: Synchronization Source Sub-registry

This document defines the following new values in the Synchronization
Source sub-registry:

+-------+---------------------+---------------+

+-------+-------------------------+---------------+
| Value | Description | Reference |
+-------+---------------------+---------------+
+-------+-------------------------+---------------+
| 1 | NTP | This document |
| 2 | PTP | This document |
| 3 | SSU/BITS | This document |
| 4 | GPS/GLONASS/LORAN-C GPS/GLONASS/LORAN-C/BDS | This document |
| 5 | Local free-running | This document |
+-------+---------------------+---------------+
+-------+-------------------------+---------------+

Table 4: 5: Synchronization Sources

5.3.

5.4. Timestamping Method Sub-registry

IANA is requested to create the Timestamping Method sub-registry as
part of the STAMP TLV Type registry. All code points in the range 1
through 127 in this registry shall be allocated according to the
"IETF Review" procedure as specified in [RFC8126]. Code points in
the range 128 through 239 in this registry shall be allocated
according to the "First Come First Served" procedure as specified in
[RFC8126]. Remaining code points are allocated according to Table 1: 6:

Table 5: 6: Timestamping Method Sub-registry

This document defines the following new values in the Timestamping
Methods sub-registry:

Table 6: 7: Timestamping Methods

5.4.

5.5. Return Code Sub-registry

IANA is requested to create the Return Code sub-registry as part of
the STAMP TLV Type registry. All code points in the range 1 through
127 in this registry shall be allocated according to the "IETF
Review" procedure as specified in [RFC8126]. Code points in the
range 128 through 239 in this registry shall be allocated according
to the "First Come First Served" procedure as specified in [RFC8126].
Remaining code points are allocated according to Table 7: 8:

Table 7: 8: Return Code Sub-registry

This document defines the following new values in the Return Code
sub-registry:

+-------+---------------------+---------------+
| Value | Description | Reference |
+-------+---------------------+---------------+
| 1 | Network available | This document |
| 2 | Network unavailable | This document |
+-------+---------------------+---------------+

Table 8: 9: Return Codes

6. Security Considerations

This document defines extensions to STAMP [RFC8762] and inherits all
the security considerations applicable to the base protocol.
Additionally, the HMAC TLV is defined in this document to protect the
integrity of optional STAMP extensions. The use of HMAC TLV is
discussed in detail in Section 4.8.

7. Acknowledgments

Authors much appreciate the thorough review and thoughtful comments
received from Tianran Zhou, Rakesh Gandhi, Yuezhong Song and Yali
Wang. Authors The authors express their gratitude to Al Morton for his
comments and the most valuable suggestions. Authors The authors greatly
appreciate comments and thoughtful suggestions received from Martin
Duke.

8. Contributors

The following people contributed text to this document:

Guo Jun
ZTE Corporation
68# Zijinghua Road
Nanjing, Jiangsu 210012
P.R.China

Phone: +86 18105183663
Email: guo.jun2@zte.com.cn

9. References
9.1. Normative References

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

[RFC5357] Hedayat, K., Krzanowski, R., Morton, A., Yum, K., and J.
Babiarz, "A Two-Way Active Measurement Protocol (TWAMP)",
RFC 5357, DOI 10.17487/RFC5357, October 2008,
<https://www.rfc-editor.org/info/rfc5357>.

[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>.

[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.

[RFC8762] Mirsky, G., Jun, G., Nydell, H., and R. Foote, "Simple
Two-Way Active Measurement Protocol", RFC 8762,
DOI 10.17487/RFC8762, March 2020,
<https://www.rfc-editor.org/info/rfc8762>.

[TS23501] 3GPP (3rd Generation Partnership Project), "Technical
Specification Group Services and System Aspects; System
Architecture for the 5G System; Stage 2 (Release 16)",
3GPP TS23501, 2019.

9.2. Informative References

[GPS] "Global Positioning System (GPS) Standard Positioning
Service (SPS) Performance Standard", GPS SPS 5th Edition,
April 2020.

[IEEE.1588.2008]
"Standard for a Precision Clock Synchronization Protocol
for Networked Measurement and Control Systems",
IEEE Standard 1588, March 2008.

[RFC2104] Krawczyk, H., Bellare, M., and R. Canetti, "HMAC: Keyed-
Hashing for Message Authentication", RFC 2104,
DOI 10.17487/RFC2104, February 1997,
<https://www.rfc-editor.org/info/rfc2104>.

[RFC4868] Kelly, S. and S. Frankel, "Using HMAC-SHA-256, HMAC-SHA-
384, and HMAC-SHA-512 with IPsec", RFC 4868,
DOI 10.17487/RFC4868, May 2007,
<https://www.rfc-editor.org/info/rfc4868>.

[RFC5905] Mills, D., Martin, J., Ed., Burbank, J., and W. Kasch,
"Network Time Protocol Version 4: Protocol and Algorithms
Specification", RFC 5905, DOI 10.17487/RFC5905, June 2010,
<https://www.rfc-editor.org/info/rfc5905>.

[TS23501] 3GPP (3rd Generation Partnership Project), "Technical
Specification Group Services and System Aspects; System
Architecture for the 5G System; Stage 2 (Release 16)",
3GPP TS23501, 2019.

Authors' Addresses

Greg Mirsky
ZTE Corp.

Email: gregimirsky@gmail.com

Xiao Min
ZTE Corp.

Email: xiao.min2@zte.com.cn

Henrik Nydell
Accedian Networks

Email: hnydell@accedian.com

Richard Foote
Nokia

Email: footer.foote@nokia.com

Adi Masputra
Apple Inc.
One Apple Park Way
Cupertino, CA 95014
USA

Email: adi@apple.com
Ernesto Ruffini
OutSys
via Caracciolo, 65
Milano 20155
Italy

Email: eruffini@outsys.org