IP Performance Measurement Group Y. Wang
Internet-Draft T. Zhou
Intended status: Standards Track Huawei
Expires: August 26, 2021 H. Yang
China Mobile
C. Liu
China Unicom
February 22, 2021
Simple Two-way Active Measurement Protocol Extensions for Hop-by-Hop OAM
Data Collection
draft-wang-ippm-stamp-hbh-extensions-03
Abstract
This document defines optional TLVs which are carried in Simple Two-
way Active Measurement Protocol (STAMP) test packets to enhance the
STAMP base functions. Such extensions to STAMP enable OAM data
measurement and collection at every node and link along a STAMP test
packet's delivery path without maintaining a state for each
configured STAMP-Test session at every devices.
Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
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 August 26, 2021.
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Copyright Notice
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document authors. All rights reserved.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. TLV Extensions to STAMP . . . . . . . . . . . . . . . . . . . 3
3.1. IOAM-Tracing-Data TLV . . . . . . . . . . . . . . . . . . 3
3.2. Forward HbH Delay TLV . . . . . . . . . . . . . . . . . . 5
3.3. Backward HbH Delay TLV . . . . . . . . . . . . . . . . . 7
3.4. HbH Direct Loss TLV . . . . . . . . . . . . . . . . . . . 9
3.5. HbH Bandwidth Utilization TLV . . . . . . . . . . . . . . 11
3.6. HbH Timestamp Information TLV . . . . . . . . . . . . . . 12
3.7. HbH Interface Errors TLV . . . . . . . . . . . . . . . . 14
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
5. Security Considerations . . . . . . . . . . . . . . . . . . . 16
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 16
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 16
7.1. Normative References . . . . . . . . . . . . . . . . . . 16
7.2. Informative References . . . . . . . . . . . . . . . . . 17
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17
1. Introduction
Simple Two-way Active Measurement Protocol (STAMP) [RFC8762] enables
the measurement of both one-way and round-trip performance metrics,
such as delay, delay variation, and packet loss. In the STAMP
session, the bidirectional packet flow is transmitted between STAMP
Session-Sender and STAMP Session-Reflector. The STAMP Session-
Reflector receives test packets transmitted from Session-Sender and
acts according to the configuration. However, the performance of
intermediate nodes and links that STAMP test packets traverse are
invisible. In addition, the STAMP instance must be configured at
every intermediate node to measure the performance per node and link
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that test packets traverse, which increases the complexity of OAM in
large-scale networks.
STAMP Extensions have defined several optional TLVs to enhance the
STAMP base functions. These optional TLVs are defined as updates of
the STAMP Optional Extensions [RFC8972]. This document extents
optional TLVs to STAMP, which enables performance measurement at
every intermediate node and link along a STAMP test packet's delivery
path, such as measurement of delay, delay variation, packet loss, and
record of link errors and route information. The following sections
describe the use of TLVs for STAMP that extend STAMP capability
beyond its base specification.
2. Terminology
Following are abbreviations used in this document:
STAMP: Simple Two-way Active Measurement Protocol.
IOAM: In-situ OAM.
HbH: Hop-by-Hop.
3. TLV Extensions to STAMP
3.1. IOAM-Tracing-Data TLV
STAMP Session-Sender MAY place the IOAM-Tracing-Data TLV in Session-
Sender test packets to record the IOAM tracing data at every IOAM
capable node along the Session-Sender test packet's forward-delivery
path. As STAMP uses symmetrical packets, the Session-Sender MUST set
the Length value as a multiple of 4 octets according to the number of
nodes and the IOAM-Trace-Type (i.e. a 24-bit identifier which
specifies which data types are used in the node data list
[I-D.ietf-ippm-ioam-data]). And the node-data-copied-list fields
MUST be set to zero upon Session-Sender test packets transmission and
ignored upon receipt.
The IOAM-Tracing-Data TLV has the following format:
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-------------------------------+-------------------------------+
| IOAM-Tracing-Data Type | Length |
+---------------------------------------------------------------+
| node-data-copied-list [0] |
+---------------------------------------------------------------+
| node-data-copied-list [1] |
+---------------------------------------------------------------+
~ ... ~
+---------------------------------------------------------------+
| node-data-copied-list [n] |
+---------------------------------------------------------------+
Fig. 1 IOAM-Tracing-Data TLV Format
where fields are defined as the following:
o IOAM-Tracing-Data Type: To be assigned by IANA.
o Length: A 2-octet field that indicates the length of the value
field in octets and equal to a multiple of 4 octets dependent on
the number of nodes and IOAM-Trace-Type bits.
o node-data-copied-list [0..n]: A variable-length field, which
record the copied content of each node data element determined by
the IOAM-Trace-Type. The order of packing the data fields in each
node data element follows the bit order of the IOAM-Trace-Type
field (see section 4.4.1 of [I-D.ietf-ippm-ioam-data]). The last
node data element in this list is the node data of the first IOAM
trace capable node in the path.
In an IOAM domain, the STAMP Session-Sender and the STAMP Session-
Reflector MAY be configured as the IOAM encapsulating node and the
IOAM decapsulating node. The STAMP Session-Sender (i.e. the IOAM
encapsulating node) generates the test packet with the IOAM Tracing
Data TLV. For applying the IOAM Trace-Option functionalities to the
Session-Sender test packet, the Session-Sender must inserts the
"trace option header" and allocate an node-data-list array
[I-D.ietf-ippm-ioam-data] into "option data" fields of Hop-by-Hop
Options header in IPv6 packets [I-D.ietf-ippm-ioam-ipv6-options], and
sets the corresponding bits in the IOAM-Trace-Type. Also, the STAMP
Session-Sender allocates a node-data-copied-list array in the
optional IOAM-Tracing-Data TLV to store OAM data retrieved from every
IOAM transit node along the Session-Sender test packet's delivery
path.
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When the STAMP Session-Reflector (i.e. the IOAM decapsulating node)
received the STAMP Session-Sender test packet with the IOAM-Tracing-
Data TLV, it MUST copy the node-data-list array into the node-data-
copied-list array carried in the Session-Reflector test packet before
transmission and MUST remove the IOAM-Data-Fields. Hence, carrying
IOAM-Tracing-Data TLV in STAMP test packets enables OAM data
collection and measurement at every node and link.
Also the STAMP Session-Reflector MAY be configured as IOAM
encapsulating node to apply the IOAM Trace-Option functionalities to
the Session-Reflector test packet. Hence, OAM data collection and
measurement can be also enabled at every node and link along the
Session-Reflector test packet's backward delivery path. When the
reflected packet arrives at the Session-Sender, it can be either
locally processed or sent to the centralized controller.
3.2. Forward HbH Delay TLV
STAMP Session-Sender MAY place the Forward HbH Delay TLV in Session-
Sender test packets to record the ingress timestamp and the egress
timestamp at every intermediate nodes along the Session-Sender test
packet's forward path. The Session-Sender MUST set the Length value
according to the number of explicitly listed intermediate nodes in
the forward path and the timestamp formats. There are several
methods to synchronize the clock, e.g., Network Time Protocol (NTP)
[RFC5905] and IEEE 1588v2 Precision Time Protocol (PTP)
[IEEE.1588.2008]. For example, if a 64-bit timestamp format defined
in NTP is used, the Length value MUST be set as a multiple of 16
octets. The Timestamp Tuple list [1..n] fields MUST be set to zero
upon Session-Sender test packets transmission.
The Forward HbH Delay TLV has the following format:
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-------------------------------+---------------+---------------+
| Forward HbH Delay Type | Length | Node Left |
+-------------------------------+---------------+---------------+
| |
| Timestamp Tuple list [1] |
| |
| |
+---------------------------------------------------------------+
~ ... ~
+---------------------------------------------------------------+
| |
| Timestamp Tuple list [n] |
| |
| |
+---------------------------------------------------------------+
Fig. 2 Forward HbH Delay TLV Format
where fields are defined as the following:
o Forward HbH Delay Type: To be assigned by IANA.
o Length: A 8-bit field that indicates the length of the value
portion in octets and MUST be a multiple of 16 octets according to
the number of explicitly listed intermediate nodes in the forward
path.
o Node Left: A 8-bit unsigned integer, which indicates the number of
intermediate nodes remaining. That is, number of explicitly
listed intermediate nodes still to be visited before reaching the
destination node in the forward path. The Node Left field is set
to n-1, where n is the number of intermediate nodes.
o Timestamp Tuple list [1..n]: A variable-length field, which record
the timestamp when the Session-Sender test packet is received at
the ingress of the n-th intermediate node and the timestamp when
the Session-Sender test packet is sent at egress of the n-th
intermediate node. For example, if a 64-bit timestamp format
defined in NTP is used, the length of each Timestamp Tuple
(ingress timestamp [n], egress timestamp [n]) must be 16 octets.
The Timestamp Tuple list is encoded starting from the last
intermediate node which is explicitly listed. That is, the first
element of the Timestamp Tuple list [1] records the timestamps
when the Session-Sender test packet received and forwarded at the
last intermediate node of a explicit path, the second element
records the penultimate Timestamp Tuple when the Session-Sender
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test packet received and forwarded at the penultimate intermediate
node of a explicit path, and so on.
In the following reference topology, Node N1, N2, N3, N4 and N5 are
SRv6 capable nodes. Node N1 is the STAMP Session-Sender and Node N5
is the STAMP Session-Reflector. T1 is the Timestamp taken by the
Session-Sender (i.e. N1) at the start of transmitting the test
packet. T2 is the Receive Timestamp when the test packet was
received by the Session-Reflector (i.e. N5). T3 is the Timestamp
taken by the Session-Reflector at the start of transmitting the test
packet. T4 is the Receive Timestamp when the test packet was
received by the Session-Sender. Timestamp tuples (t1,t2), (t3,t4)
and (t5,t6) are the timestamps when the test packet received and
transmitted by sequence of intermediate nodes in the forward path.
Timestamp Tuples (t7,t8), (t9,t10) and (t11,t12) are the timestamps
when the test packet received and transmitted by sequence of
intermediate nodes in the backward path.
====== ====== ====== ====== ======
| | T1--->t1 | | t2--->t3 | | t4--->t5 | | t6--->T2| |
| N1 |==========| N2 |==========| N3 |==========| N4 |=========| N5 |
| | T4<---t12| |t11<---t10| | t9<---t8 | | t7<---T3| |
====== ====== ====== ====== ======
Fig. 3 Reference Topology
The STAMP Session-Sender (i.e. Node N1) generates the STAMP test
packet with the Forward HbH Delay TLV. When an intermediate node
receives the STAMP test packet, the node punts the packet to control
plane and fills the ingress timestamp [n] filed in the Timestamp
Tuple list [n]. Then the time taken by the intermediate node
transmitting the test packet is recorded in to egress timestamp [n]
field. The mechanism of timestamping and punting packet to control
plane is outside the scope of this specification.
When the STAMP Session-Reflector received the test packet with the
Forward HbH Delay TLV, it MUST copy the Forward HbH Delay TLV into
the Session-Reflector test packet before its transmission. Using
Forward HbH Delay TLV in STAMP testing enables delay measurement per
link in the forward path.
3.3. Backward HbH Delay TLV
STAMP Session-Sender MAY place the Backward HbH Delay TLV in Session-
Sender test packets to record the ingress timestamp and egress
timestamp when Session-Reflector test packets are received and sent
at every intermediate nodes in the backward path. The Session-Sender
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MUST set the Length value according to the number of explicitly
listed intermediate nodes in the backward path and the timestamp
formats. There are several methods to synchronize the clock, e.g.,
Network Time Protocol (NTP) [RFC5905] and IEEE 1588v2 Precision Time
Protocol (PTP) [IEEE.1588.2008]. For example, if a 64-bit timestamp
format defined in NTP is used, the Length value MUST be set as a
multiple of 16 octets. The Timestamp Tuple list [1..n] fields MUST
be set to zero upon Session-Sender test packets transmission and
ignored upon receipt.
The Backward HbH Delay TLV has the following format:
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
+-------------------------------+---------------+---------------+
| Backward HbH Delay Type | Length | Node Left |
+-------------------------------+---------------+---------------+
| |
| Timestamp Tuple list [1] |
| |
| |
+---------------------------------------------------------------+
~ ... ~
+---------------------------------------------------------------+
| |
| Timestamp Tuple list [n] |
| |
| |
+---------------------------------------------------------------+
Fig. 4 Backward HbH Delay TLV Format
where fields are defined as the following:
o Backward HbH Delay Type: To be assigned by IANA.
o Length: A 8-bit field that indicates the length of the value
portion in octets and will be a multiple of 16 octets dependent on
the number of explicitly listed intermediate nodes in the backward
path.
o Node Left: A 8-bit unsigned integer, which indicates the number of
intermediate nodes remaining. That is, number of explicitly
listed intermediate nodes still to be visited before reaching the
destination node in the backward path. The Node Left field is set
to n-1, where n is the number of intermediate nodes.
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o Timestamp Tuple list [1..n]: A variable-length field, which record
the timestamp when the reflected test packet is received at the
ingress of the n-th intermediate node and the timestamp when the
reflected test packet is sent at egress of the n-th intermediate
node. For example, if a 64-bit timestamp format defined in NTP is
used, the length of each Timestamp tuple (ingress timestamp [n],
egress timestamp [n]) must be 16 octets. The Timestamp Tuple list
is encoded starting from the last intermediate node which is
explicitly listed. That is, the first element of the Timestamp
Tuple list [1] records the timestamps when the reflected test
packet received and forwarded at the last intermediate node of a
explicit path, the second element records the penultimate
Timestamp Tuple when the reflected test packet received and
forwarded at the penultimate intermediate node of a explicit path,
and so on.
When the STAMP Session-Reflector received the Session-Sender test
packet with the Backward HbH Delay TLV, it MUST copy the Backward HbH
Delay TLV into the Session-Reflector test packet.
When an intermediate node receives the reflected test packet, the
node sends the packet to control plane and fills the ingress
timestamp [n] filed of Backward HbH Delay TLV. Then the time taken
by the intermediate node transmitting the test packet is recorded in
to egress timestamp [n] field of Backward HbH Delay TLV. Using
Backward HbH Delay TLV in STAMP testing enables delay measurement per
link in the backward path.
3.4. HbH Direct Loss TLV
STAMP Session-Sender MAY place the HbH Direct Loss TLV in Session-
Sender test packets to record the number of packets that form a
specific data flow received at and transmitted by every intermediate
nodes along the forward path. The Session-Sender MUST set the Length
value according to the number of explicitly listed intermediate nodes
in the forward path. A Counter Tuple is composed of a 64-bit Receive
Counter field and a 64-bit Transmit Counter field. The Counter Tuple
list [1..n] fields MUST be set to zero upon Session-Sender test
packets transmission.
The HbH Direct Loss TLV has the following format:
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-------------------------------+---------------+---------------+
| HbH Direct Loss Type | Length | Node Left |
+-------------------------------+---------------+---------------+
| |
| Counter Tuple list [1] |
| |
| |
+---------------------------------------------------------------+
~ ... ~
+---------------------------------------------------------------+
| |
| Counter Tuple list [n] |
| |
| |
+---------------------------------------------------------------+
Fig. 5 HbH Direct Loss TLV Format
where fields are defined as the following:
o HbH Direct Loss Type: To be assigned by IANA.
o Length: A 8-bit field that indicates the length of the value
portion in octets and will be a multiple of 16 octets dependent on
the number of explicitly listed intermediate nodes in the forward
path.
o Node Left: A 8-bit unsigned integer, which indicates the number of
intermediate nodes remaining. That is, number of explicitly
listed intermediate nodes still to be visited before reaching the
destination node in the forward path. The Node Left field is set
to n-1, where n is the number of intermediate nodes.
o Counter Tuple list [1..n]: A variable-length field, which record
the Receive Counter and the Transmit Counter when the data packet
is received at and transmitted by the n-th intermediate node. The
Counter Tuple list is encoded starting from the last intermediate
node which is explicitly listed. That is, the first element of
the Counter Tuple list [1] records the Receive Counter and the
Transmit Counter when the data packet is received at and
transmitted by the last intermediate node of a explicit path, the
second element records the penultimate Counter Tuple when the data
packet received and forwarded at the penultimate intermediate node
of a explicit path, and so on.
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The STAMP Session-Sender generates the STAMP test packet with the HbH
Direct Loss TLV. When an intermediate node receives the STAMP test
packet, the node punts the packet to control plane and writes the
Receive Counter [n] and the Transmit Counter [n] at the Counter Tuple
list [n] in the Session-Sender test packet. The mechanism of punting
packet to control plane is outside the scope of this specification.
When the STAMP Session-Reflector received the test packet with the
HbH Direct Loss TLV, it MUST copy the HbH Direct Loss TLV into the
Session-Reflector test packet before its transmission. Using HbH
Direct Loss TLV in STAMP testing enables packet loss measurement per
node/link in the forward path.
3.5. HbH Bandwidth Utilization TLV
STAMP Session-Sender MAY place the HbH Bandwidth Utilization (BW
Utilization) TLV in Session-Sender test packets to record the ingress
and egress BW Utilization at every intermediate nodes along the
forward path. The Session-Sender MUST set the Length value according
to the number of explicitly listed intermediate nodes in the forward
path. A BW Utilization Tuple is composed of a 32-bit ingress BW
Utilization field and a 32-bit egress BW Utilization field. The BW
Utilization Tuple list [1..n] fields MUST be set to zero upon
Session-Sender test packets transmission.
The HbH Bandwidth Utilization TLV has the following format:
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
+-------------------------------+---------------+---------------+
| HbH BW Utilization Type | Length | Node Left |
+-------------------------------+---------------+---------------+
| BW Utilization Tuple list [1] |
| |
+---------------------------------------------------------------+
~ ... ~
+---------------------------------------------------------------+
| BW Utilization Tuple list [n] |
| |
+---------------------------------------------------------------+
Fig. 6 HbH Bandwidth Utilization TLV Format
where fields are defined as the following:
o HbH BW Utilization Type: To be assigned by IANA.
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o Length: A 8-bit field that indicates the length of the value
portion in octets and will be a multiple of 8 octets dependent on
the number of explicitly listed intermediate nodes in the forward
path.
o Node Left: A 8-bit unsigned integer, which indicates the number of
intermediate nodes remaining. That is, number of explicitly
listed intermediate nodes still to be visited before reaching the
destination node in the forward path. The Node Left field is set
to n-1, where n is the number of intermediate nodes.
o BW Utilization Tuple list [1..n]: A variable-length field, which
record the ingress and egress bandwidth utilization when the test
packet is received at and transmitted by the n-th intermediate
node. The BW Utilization Tuple list is encoded starting from the
last intermediate node which is explicitly listed. That is, the
first element of the BW Utilization Tuple list [1] records the
ingress and the egress bandwidth utilization when the test packet
is received at and transmitted by the last intermediate node of a
explicit path, the second element records the penultimate BW
Utilization Tuple when the test packet received at and transmitted
by the penultimate intermediate node of a explicit path, and so
on.
The STAMP Session-Sender generates the STAMP test packet with the HbH
BW Utilization TLV. When an intermediate node receives the STAMP
test packet, the node punts the packet to control plane and writes
the ingress and egress bandwidth utilization at the BW Utilization
Tuple list [n] in the Session-Sender test packet. The mechanism of
punting packet to control plane is outside the scope of this
specification.
When the STAMP Session-Reflector received the test packet with the
HbH BW Utilization TLV, it MUST copy the HbH BW Utilization TLV into
the Session-Reflector test packet before its transmission. The HbH
BW Utilization TLV carried in STAMP test packet is usable to detect
and troubleshoot the link congestion in the forward path.
3.6. HbH Timestamp Information TLV
STAMP Session-Sender MAY place the HbH Timestamp Information TLV in
Session-Sender test packets to record the ingress and egress
Timestamp Information at every intermediate nodes along the forward
path. The Timestamp Information includes the source of clock
synchronization and the method of timestamp obtainment. There are
several types of clock synchronization source, e.g., NTP, PTP. The
method of timestamp obtainment may be from control plane (e.g. NTP)
or from data plane (e.g. PTP).
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A Timestamp Info Tuple is composed of a 8-bit ingress clock source
field, a 8-bit ingress timestamp obtainment field, a 8-bit egress
clock source field, and a 8-bit egress timestamp obtainment field.
The Session-Sender MUST set the Length value according to the number
of explicitly listed intermediate nodes in the forward path. The
Timestamp Info Tuple list [1..n] fields MUST be set to zero upon
Session-Sender test packets transmission.
The HbH Timestamp Information TLV has the following format:
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
+-------------------------------+---------------+---------------+
| HbH Timestamp Info Type | Length | Node Left |
+-------------------------------+---------------+---------------+
| Timestamp Info Tuple list [1] |
+---------------------------------------------------------------+
~ ... ~
+---------------------------------------------------------------+
| Timestamp Info Tuple list [n] |
+---------------------------------------------------------------+
Fig. 6 HbH Timestamp Information TLV Format
where fields are defined as the following:
o HbH Timestamp Info Type: To be assigned by IANA.
o Length: A 8-bit field that indicates the length of the value
portion in octets and will be a multiple of 4 octets dependent on
the number of explicitly listed intermediate nodes in the forward
path.
o Node Left: A 8-bit unsigned integer, which indicates the number of
intermediate nodes remaining. That is, number of explicitly
listed intermediate nodes still to be visited before reaching the
destination node in the forward path. The Node Left field is set
to n-1, where n is the number of intermediate nodes.
o Timestamp Info Tuple list [1..n]: A variable-length field, which
record the source of clock synchronization and the method of
timestamp obtainment at the ingress and egress when the test
packet is received at and transmitted by the n-th intermediate
node. The Timestamp Info Tuple list is encoded starting from the
last intermediate node which is explicitly listed. That is, the
first element of the Timestamp Info Tuple list [1] records the
source of clock synchronization and the method of timestamp
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obtainment at the ingress and egress when the test packet is
received at and transmitted by the last intermediate node of a
explicit path, the second element records the penultimate
Timestamp Info Tuple when the test packet received at and
transmitted by the penultimate intermediate node of a explicit
path, and so on.
The STAMP Session-Sender generates the STAMP test packet with the HbH
Timestamp Information TLV. When an intermediate node receives the
STAMP test packet, the node punts the packet to control plane and
writes the source of clock synchronization and the method of
timestamp obtainment at the Timestamp Info Tuple list [n] in the
Session-Sender test packet. The mechanism of punting packet to
control plane is outside the scope of this specification.
When the STAMP Session-Reflector received the test packet with the
HbH Timestamp Information TLV, it MUST copy the HbH Timestamp
Information TLV into the Session-Reflector test packet before its
transmission. The HbH Timestamp Information TLV carried in STAMP
test packet is usable to query timestamp information from every nodes
in the forward path.
Note that the source of clock synchronization, NTP or PTP, is part of
configuration of the Session-Sender/Reflector or a particular test
session [RFC8762]. This draft recommends every intermediate nodes to
be configured to use the same source of clock synchronization.
3.7. HbH Interface Errors TLV
STAMP Session-Sender MAY place the HbH Interface Errors TLV in
Session-Sender test packets to record the errors detected on the
interface of every intermediate node used to receive the packet along
the forward path. The record of interface errors indicates the
quality of the interfaces along the forward path and is helpful to
analyze the performance degrades associated with the flow.
A Interface Errors is a 32 bits unsigned integer field. This field
records the Bit Error Rate (BER) or number of packet drop due to
Cyclic Redundancy Check (CRC) errors. The Session-Sender MUST set
the Length value according to the number of explicitly listed
intermediate nodes in the forward path. The Interface Errors list
[1..n] fields MUST be set to zero upon Session-Sender test packets
transmission.
The HbH Timestamp Information TLV has the following format:
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-------------------------------+---------------+---------------+
| HbH Interface Errors Type | Length | Node Left |
+-------------------------------+---------------+---------------+
| Interface Errors list [1] |
+---------------------------------------------------------------+
~ ... ~
+---------------------------------------------------------------+
| Interface Errors list [n] |
+---------------------------------------------------------------+
Fig. 6 HbH Timestamp Information TLV Format
where fields are defined as the following:
o HbH Interface Errors Type: To be assigned by IANA.
o Length: A 8-bit field that indicates the length of the value
portion in octets and will be a multiple of 4 octets dependent on
the number of explicitly listed intermediate nodes in the forward
path.
o Node Left: A 8-bit unsigned integer, which indicates the number of
intermediate nodes remaining. That is, number of explicitly
listed intermediate nodes still to be visited before reaching the
destination node in the forward path. The Node Left field is set
to n-1, where n is the number of intermediate nodes.
o Interface Errors list [1..n]: A variable-length field, which
record the errors detected on the interface of the n-th
intermediate node used to receive the packet along the forward
path. The Interface Errors list is encoded starting from the last
intermediate node which is explicitly listed. That is, the first
element of the Interface Errors list [1] records the interface
errors when the test packet is received at the last intermediate
node of a explicit path, the second element records the
penultimate interface errors when the test packet received at the
penultimate intermediate node of a explicit path, and so on.
The STAMP Session-Sender generates the STAMP test packet with the HbH
Interface Errors TLV. When an intermediate node receives the STAMP
test packet, the node punts the packet to control plane and writes
the errors at the Interface Errors list [n] in the Session-Sender
test packet. The mechanism of punting packet to control plane is
outside the scope of this specification.
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When the STAMP Session-Reflector received the test packet with the
HbH Interface Errors TLV, it MUST copy the HbH Interface Errors TLV
into the Session-Reflector test packet before its transmission. The
HbH Interface Errors TLV carried in STAMP test packet is usable to
detect interface errors from every intermediate nodes along the
forward path.
4. IANA Considerations
IANA is requested to allocate values for the following TLV Type from
the "STAMP TLV Type" registry [RFC8972].
+------------+-------------------------------+---------------+
| Code Point | Description | Reference |
+------------+-------------------------------+---------------+
| TBA1 | IOAM Tracing Data TLV | This document |
| TBA2 | Forward HbH Delay TLV | This document |
| TBA3 | Backward HbH Delay TLV | This document |
| TBA4 | HbH Direct Loss TLV | This document |
| TBA5 | HbH BW Utilization TLV | This document |
| TBA6 | HbH Timestamp Information TLV | This document |
| TBA7 | HbH Interface Errors TLV | This document |
+------------+-------------------------------+---------------+
5. Security Considerations
This document extensions new optional TLVs to STAMP. It does not
introduce any new security risks to STAMP.
6. Acknowledgements
The authors would like to thank Giuseppe Fioccola for the reviews and
comments.
7. References
7.1. Normative References
[I-D.ietf-ippm-ioam-data]
"Data Fields for In-situ OAM",
<https://datatracker.ietf.org/doc/draft-ietf-ippm-ioam-
data/>.
[I-D.ietf-ippm-ioam-ipv6-options]
"In-situ OAM IPv6 Options",
<https://datatracker.ietf.org/doc/draft-ietf-ippm-ioam-
ipv6-options/>.
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[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>.
[RFC8762] "Simple Two-Way Active Measurement Protocol",
<https://datatracker.ietf.org/doc/rfc8762/>.
[RFC8972] "Simple Two-way Active Measurement Protocol Optional
Extensions", <https://datatracker.ietf.org/doc/rfc8972/>.
7.2. Informative References
[IEEE.1588.2008]
"IEEE Standard for a Precision Clock Synchronization
Protocol for Networked Measurement and Control Systems",
<https://ieeexplore.ieee.org/document/4579760>.
[RFC5905] "Network Time Protocol Version 4: Protocol and Algorithms
Specification", <https://www.rfc-editor.org/info/rfc5905>.
Authors' Addresses
Yali Wang
Huawei
156 Beijing Rd., Haidian District
Beijing
China
Email: wangyali11@huawei.com
Tianran Zhou
Huawei
156 Beijing Rd., Haidian District
Beijing
China
Email: zhoutianran@huawei.com
Hongwei Yang
China Mobile
Xibianmen Inner St, 53, Xicheng District
Beijing
China
Email: yanghongwei@chinamobile.com
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Chang Liu
China Unicom
Beijing
China
Email: liuc131@chinaunicom.cn
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