Encapsulation of Simple Two-Way Active Measurement Protocol for Pseudowires and LSPs in MPLS Networks
draft-ietf-mpls-stamp-pw-01
The information below is for an old version of the document.
| Document | Type |
This is an older version of an Internet-Draft whose latest revision state is "Active".
|
|
|---|---|---|---|
| Authors | Rakesh Gandhi , Patrice Brissette , Eddie Leyton , Xiao Min | ||
| Last updated | 2025-06-05 (Latest revision 2024-12-04) | ||
| Replaces | draft-gandhi-mpls-stamp-pw | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Formats | |||
| Additional resources | Mailing list discussion | ||
| Stream | WG state | WG Document | |
| Associated WG milestone |
|
||
| Document shepherd | (None) | ||
| IESG | IESG state | I-D Exists | |
| Consensus boilerplate | Unknown | ||
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | (None) |
draft-ietf-mpls-stamp-pw-01
MPLS Working Group R. Gandhi, Ed.
Internet-Draft P. Brissette
Intended status: Standards Track Cisco Systems, Inc.
Expires: 7 December 2025 E. Leyton
Verizon Wireless
X. Min
ZTE Corp.
5 June 2025
Encapsulation of Simple Two-Way Active Measurement Protocol for
Pseudowires and LSPs in MPLS Networks
draft-ietf-mpls-stamp-pw-01
Abstract
Pseudowires (PWs) and Label Switched Paths (LSPs) are used in MPLS
networks for various services including carrying layer 2 and layer 3
data packets. This document describes the procedure for
encapsulation of the Simple Two-Way Active Measurement Protocol
(STAMP) defined in RFC 8762 and its optional extensions defined in
RFC 8972 for PWs and LSPs in MPLS networks. The procedure uses
Generic Associated Channel (G-ACh) to encapsulate the STAMP test
packets with or without adding an IP/UDP header for PWs and LSPs.
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 7 December 2025.
Copyright Notice
Copyright (c) 2025 IETF Trust and the persons identified as the
document authors. All rights reserved.
Gandhi, et al. Expires 7 December 2025 [Page 1]
Internet-Draft STAMP for MPLS PWs and LSPs June 2025
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document. Code Components
extracted from this document must include Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements . . . . . . . . . . . . . . . . . . . . . . 4
1.2. Examples of MPLS Data Traffic Use Cases . . . . . . . . . 5
2. Conventions Used in This Document . . . . . . . . . . . . . . 6
2.1. Requirements Language . . . . . . . . . . . . . . . . . . 6
2.2. Abbreviations . . . . . . . . . . . . . . . . . . . . . . 6
2.3. STAMP Reference Topology . . . . . . . . . . . . . . . . 6
3. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.1. G-ACh Types for STAMP . . . . . . . . . . . . . . . . . . 7
3.2. Using STAMP for PWs and LSPs . . . . . . . . . . . . . . 8
3.3. Applicability of Control Channel Types to STAMP for PWs and
LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4. Session-Sender Test Packet . . . . . . . . . . . . . . . . . 10
4.1. Session-Sender Test Packet with IP/UDP Header . . . . . . 10
4.2. Session-Sender Test Packet without IP/UDP Header . . . . 11
5. Session-Reflector Test Packet . . . . . . . . . . . . . . . . 12
5.1. Session-Reflector Test Packet with IP/UDP Header . . . . 12
5.2. Session-Reflector Test Packet without IP/UDP Header . . . 14
6. Security Considerations . . . . . . . . . . . . . . . . . . . 15
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 16
8.1. Normative References . . . . . . . . . . . . . . . . . . 16
8.2. Informative References . . . . . . . . . . . . . . . . . 17
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 18
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 18
1. Introduction
The Simple Two-way Active Measurement Protocol (STAMP) provides
capabilities for the measurement of various metrics in IP networks
[RFC8762] without the use of a control channel to pre-signal session
parameters. [RFC8972] defines optional extensions for STAMP.
Gandhi, et al. Expires 7 December 2025 [Page 2]
Internet-Draft STAMP for MPLS PWs and LSPs June 2025
Pseudowires (PWs) are used in MPLS networks for various services
including carrying layer 2 and layer 3 data packets [RFC6658]. The
PWs are bidirectional in nature. The PWs can be point-to-point or
point-to-multipoint. The PWs may use optional Control Word (CW) as
defined in the Section 3, "Generic PW MPLS Control Word" of
[RFC4385].
Label Switched Paths (LSPs) are used in MPLS networks for various
services including carrying layer 2 and layer 3 data packets The MPLS
LSPs may use optional CW as defined in the Section 3, "Generic PW
MPLS Control Word" of [RFC4385].
MPLS Transport Profile (MPLS-TP) [RFC5960] was designed to use the
MPLS data plane without any changes, therefore when we specify STAMP
over an MPLS data plane, it is equally applicable to the MPLS-TP
networks. As specified in Section 2 of [RFC5921], "OAM and
protection mechanisms, and forwarding of data packets, must be able
to operate without IP forwarding support".
When using STAMP for MPLS and MPLS-TP for both PWs and LSPs, there
are unique aspects that need to be considered concerning the CW, and
these aspects are addressed in this document.
A Generic Associated Channel (G-ACh) [RFC5586] provides a mechanism
to transport Operations, Administration, and Maintenance (OAM) and
other control messages over MPLS data plane. The G-ACh types
identify the various OAM messages being transported over the channel.
Virtual Circuit Connectivity Verification (VCCV) is used as Control
Channel for PWs as described in [RFC5085]. A G-ACh can be used as a
VCCV control channel as described in [RFC7708].
This document describes the procedure for encapsulation of the STAMP
defined in [RFC8762] and its optional extensions defined in [RFC8972]
for point-to-point PWs and LSPs in MPLS networks. The procedure uses
G-ACh to encapsulate STAMP test packets with or without an IP/UDP
header for PWs and LSPs. This document defines two new G-ACh types
when using STAMP without an IP/UDP header, those are PW demultiplexer
agnostic and hence applicable to both PWs and Layer 2 Tunneling
Protocol version 3 (L2TPv3) PW demultiplexers. This document uses
existing G-ACh types for IPv4 and IPv6 when using STAMP with an IP/
UDP header for PWs and LSPs.
Gandhi, et al. Expires 7 December 2025 [Page 3]
Internet-Draft STAMP for MPLS PWs and LSPs June 2025
1.1. Requirements
The STAMP test packets need to be transmitted with the same label
stack that is used by the PW and LSP to ensure proper validation of
underlay path taken by the actual data traffic. Also, the test
packets need to follow the same ECMP underlay path taken by the PW
and LSP data traffic in the network. The PW data traffic may be
encapsulated using CW [RFC4385] with an IP header. As such, the
STAMP test packets need to be transmitted over the PW using G-ACh and
an IP/UDP header.
The data traffic over L2-Specific Sublayer (L2SS) as used in L2TP PW
carry CW but do not carry an IP/UDP header. As such, the STAMP
packets need to be transmitted over L2-Specific Sublayer (L2SS) as
used in L2TP PW using G-ACh without any IP/UDP header (as raw STAMP
payload).
The Private Line Emulation (PLE) [I-D.ietf-pals-ple] traffic is sent
over a Packet Switched Network (PSN) as Virtual Private Wire Services
(VPWS) using PWs. The data packets are encapsulated with PLE CW, but
they do not carry any IP header. As such, the STAMP test packets
need to be transmitted using the same label stack including VPWS PW
Label [I-D.ietf-pals-ple] as the PLE traffic and encapsulated using
G-ACh but without any IP/UDP header. This allows the STAMP test
packets to experience the same forwarding behaviour, follow the same
underlay path as the PLE traffic and avoid different ECMP behavior on
intermediate nodes.
The G-ACh type allows to demultiplex VCCV Control Channel for PWs
[RFC7708]. The G-ACh types for STAMP packets with or without IP/UDP
headers are also used to demultiplex VCCV Control Channel for PWs.
Signaling extensions for VCCV Control Channel for PW for STAMP are
outside the scope of this document.
The G-ACh provides support for OAM Control Channel associated with
the MPLS Transport Profile (MPLS-TP) [RFC5960] LSPs and PWs. The OAM
Control Channel for MPLS-TP needs to be extended to encapsulate STAMP
test packets (just like the delay and loss measurement packets
defined in [RFC6374]). The G-ACh types for STAMP also allow to
demultiplex OAM Control Channel for MPLS-TP.
The requirements for the encapsulation of the STAMP test packets for
the PWs and LSPs in MPLS networks can be summarized as follows:
o The G-ACh MUST support STAMP test packets with an IP/UDP header.
o The G-ACh MUST support STAMP test packets without an IP/UDP header.
Gandhi, et al. Expires 7 December 2025 [Page 4]
Internet-Draft STAMP for MPLS PWs and LSPs June 2025
o The G-ACh MUST support STAMP to demultiplex Control Channel.
o The Session-Sender test packets MUST follow the underlay path taken
by the data traffic that is using CW.
o The Session-Sender test packets MUST follow the same ECMP underlay
path taken by the data traffic that is using CW and Entropy Label
defined in [RFC6790].
o The Session-Sender test packets MUST follow the same ECMP underlay
path taken by the data traffic that is using CW but not using Entropy
Label defined in [RFC6790].
o The Session-Reflector test packets MAY follow the reverse underlay
path taken by Session-Sender test packets.
o The Session-Reflector test packets MAY follow the same reverse ECMP
underlay path taken by Session-Sender test packets.
This document concerns with the STAMP operation for the P2P Single-
Segment PWs (SS-PWs). The procedure for STAMP operation for point-
to-multipoint (P2MP) PWs is outside the scope of this document.
1.2. Examples of MPLS Data Traffic Use Cases
Examples of MPLS data traffic use cases for STAMP test packets with
IP/UDP headers:
1. MPLS PW Data Traffic (with CW and IP header)
2. MPLS-TP PW Data Traffic (with CW and IP header)
3. MPLS LSP Data Traffic (with IP header)
Examples of MPLS data traffic use cases for STAMP test packets
without IP/UDP headers:
1. MPLS Ethernet PW Data Traffic [RFC4448]
2. L2-Specific Sublayer (L2SS) used in L2TPv3 PW Data Traffic
[RFC3931]
3. Private Line Emulation [I-D.ietf-pals-ple] PW Data Traffic
4. TDM over IP [RFC5087] PW Data Traffic (with no IP header)
5. MPLS-TP LSP Data Traffic
Gandhi, et al. Expires 7 December 2025 [Page 5]
Internet-Draft STAMP for MPLS PWs and LSPs June 2025
2. Conventions Used in This Document
2.1. 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.
2.2. Abbreviations
ECMP: Equal Cost Multi-Path.
G-ACh: Generic Associated Channel.
GAL: G-ACh Label.
HMAC: Hashed Message Authentication Code.
MPLS: Multiprotocol Label Switching.
OAM: Operations, Administration, and Maintenance.
PLE: Private Line Emulation.
PW: Pseudowire.
SHA: Secure Hash Algorithm.
STAMP: Simple Two-way Active Measurement Protocol.
TC: Traffic Class.
TTL: Time-To-Live.
2.3. STAMP Reference Topology
In the STAMP reference topology shown in Figure 1, there exists a PW
or an LSP to transport data between Provider Edge (PE) Endpoints S1
and R1. The STAMP Session-Sender on PE node S1 initiates a Session-
Sender test packet and the STAMP Session-Reflector on PE node R1
transmits a reply test packet. The Session-Reflector reply test
packet may be transmitted to the STAMP Session-Sender node S1 on the
same path (same set of links and nodes) in the reverse direction of
the path taken towards the Session-Reflector node R1.
Gandhi, et al. Expires 7 December 2025 [Page 6]
Internet-Draft STAMP for MPLS PWs and LSPs June 2025
T1 is a transmit timestamp, and T4 is a receive timestamp added by
node S1. T2 is a receive timestamp, and T3 is a transmit timestamp
added by node R1.
|<-------- Pseudowire ------->|
|<-------- LSP -------------->|
| |
| T1 T2 |
| / \ |
+-------+ Test Packet +-------+
| | - - - - - - - - - ->| |
| S1 |=====================| R1 |
| |<- - - - - - - - - - | |
+-------+ Reply Test Packet +-------+
\ /
T4 T3
STAMP Session-Sender STAMP Session-Reflector
Provider Edge Endpoint Provider Edge Endpoint
Figure 1: STAMP Reference Topology using PW and LSP
3. Overview
The STAMP Session-Sender and Session-Reflector test packets defined
in [RFC8972] are encapsulated and transmitted over the PWs in MPLS
networks. The base STAMP test packets can be encapsulated using an
IP/UDP header and may use destination UDP port 862 [RFC8762]. The
source UDP port is chosen by the Session-Sender.
3.1. G-ACh Types for STAMP
There are two ways in which STAMP test packets may be encapsulated
over a G-ACh, either using an IP/UDP header, referred to as Format1
or without using an IP/UDP header, referred to as Format2.
For encapsulating the STAMP test packets over a G-ACh with IP/UDP
headers (in Format1), IPv4 and IPv6 channel types [RFC4385] are used
for both Session-Sender and Session-Reflector test packets. The
destination UDP port number in the Session-Sender and Session-
Reflector test packets discriminate the test packets. The IP version
(IPv4 or IPv6) MUST match the IP version used for for the PWs and
LSPs being measured.
Gandhi, et al. Expires 7 December 2025 [Page 7]
Internet-Draft STAMP for MPLS PWs and LSPs June 2025
For encapsulating the STAMP test packets over a G-ACh without adding
IP/UDP headers (in Format2), two new channel types are defined in
this document, one for the Session-Sender test packets and one for
the Session-Reflector test packets. The different channel types are
required for the Session-Sender and Session-Reflector test packets as
the STAMP test packets do not have a way to discriminate them.
3.2. Using STAMP for PWs and LSPs
The STAMP test packets are encapsulated with MPLS header using the
same label stack as the PW data traffic (including the PW label) and
G-ACh header (instead of CW used by the data traffic). The
encapsulation allows the STAMP test packets to follow the same path
as the PW data traffic, and provide the same ECMP behaviour on the
intermediate nodes.
The IPv4 Time to Live (TTL), IPv6 Hop Limit and Generalized TTL
Security Mechanism (GTSM) procedures from [RFC5082] also apply to the
encapsulation of STAMP test packets, and hence the IPv4 and MPLS TTL
and IPv6 Hop Limit MUST be set to 255.
The OAM Control Channel traffic between two Provider Edge (PE)
endpoints is not forwarded past the PE endpoints towards the Customer
Edge (CE) devices; instead, the OAM messages are intercepted at the
PE endpoints for exception processing in control-plane. [RFC5085]
defines mechanisms for VCCV Control Channel to carry OAM messages for
PWs.
The "In-band VCCV for Control Word with 0001b as first nibble (Type
1)" defined in Section 5.1.1 of [RFC5085] MUST be added when when
measuring PW with CW to avoid the different ECMP hashing behaviour.
The method for "TTL Expiry VCCV (Type 3)" defined in Section 5.1.3 of
[RFC5085] allows to terminate the OAM messages on the remote PE
endpoint nodes. This method is applied to the STAMP test packets to
force test packets to be processed on Session-Sender and Session-
Reflector control-planes by adding the PW label with TTL value 1.
The VCCC Type 2 is also referred to as 'MPLS Router Alert Label"
[RFC5085]. This method could result in a different Equal Cost Multi-
Path (ECMP) hashing behavior, and thus result in the STAMP packets
taking a path which differs from that of the actual data traffic
under test [RFC5085]. Hence, the VCCV Type 2 is not supported for
STAMP for measuring the PW traffic.
The procedure to encapsulate STAMP packets for PWs, is also
applicable to MPLS LSPs and MPLS-TP LSPs when using CW. For
measuring the data traffic over MPLS LSPs using an IP header, STAMP
Gandhi, et al. Expires 7 December 2025 [Page 8]
Internet-Draft STAMP for MPLS PWs and LSPs June 2025
test packet in Format1 is transmitted. For measuring the data
traffic over MPLS-TP LSPs, not using an IP header, STAMP test packet
in Format2 is transmitted with TTL value 1 with the ultimate LSP
label in the MPLS header.
The G-ACh label (GAL) [RFC5586] along with Generic Associated Channel
(G-ACh) types defined in this document can be used with STAMP test
packets without an IP/UDP header (in Format2), similar to the case of
MPLS-TP LSP performance measurement defined in [RFC6374].
3.3. Applicability of Control Channel Types to STAMP for PWs and LSPs
Control Channel Types defined in [RFC5085] are applicable to STAMP
Test Packets for PWs and LSPs as follows:
+==============+==================+==============+=================+
| Control | Control Channel | STAMP Header | G-ACh Type |
| Channel Type | Name | Format | |
+==============+==================+==============+=================+
| Type 1 | In-band: Control | Format1 (IP/ | IPv4 G-ACH |
| | Word with 0001b | UDP Headers) | (0x21) and IPv6 |
| | as first nibble | | G-ACH (0x57) |
+--------------+------------------+--------------+-----------------+
| Type 1 | In-band: Control | Format2 (No | G-ACH Type |
| | Word with 0001b | IP/UDP | STAMP G-ACH |
| | as first nibble | Headers) | (TBD1/TBD2) |
+--------------+------------------+--------------+-----------------+
| Type 2 | Out-of-band: | Not | Not supported |
| | MPLS Router | supported | |
| | Alert Label | | |
+--------------+------------------+--------------+-----------------+
| Type 3 | TTL Expiry: | Format 1 | IPv4 G-ACH |
| | Label with TTL | (IP/UDP | (0x21) and IPv6 |
| | as 1 | Headers) | G-ACH (0x57) |
+--------------+------------------+--------------+-----------------+
| Type 3 | TTL Expiry: | Format2 (No | G-ACH Type |
| | Label with TTL | IP/UDP | STAMP G-ACH |
| | as 1 | Headers) | (TBD1/TBD2) |
+--------------+------------------+--------------+-----------------+
Table 1: Control Channel Types for PWs and LSPs
Gandhi, et al. Expires 7 December 2025 [Page 9]
Internet-Draft STAMP for MPLS PWs and LSPs June 2025
4. Session-Sender Test Packet
The STAMP Session-Sender test packets are transmitted for a PW or an
LSP using an MPLS header with or without an IP/UDP header. The
Session-Sender STAMP test packets are transmitted using the label
stack of the PW, including the PW label of the PW and G-ACh. The
Session-Sender STAMP test packets are transmitted using the label
stack of the LSP as well as G-ACh.
4.1. Session-Sender Test Packet with IP/UDP Header
The content of an example STAMP Session-Sender test packet for a PW
or an LSP encapsulated using a G-ACh and an IP/UDP header is shown 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Label(1) | TC |S| TTL |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PW Label or Ultimate LSP Label | TC |1| 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0 0 0 1|Version| Reserved | IPv4 (0x0021) or IPv6 (0x0057)|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IP Header |
. Source IP Address = Session-Sender IPv4 or IPv6 Address .
. Destination IP Address=Session-Reflector IPv4 or IPv6 Address.
. IPv4 Protocol or IPv6 Next header = UDP (17) .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| UDP Header |
. Source Port = As chosen by Session-Sender .
. Destination Port = User-configured Destination Port | 862 .
. .
+---------------------------------------------------------------+
| Payload = Test Packet as specified in Section 3 of RFC 8972 |
. in Figure 1 and Figure 3 .
. .
+---------------------------------------------------------------+
| Optional STAMP Extension TLVs |
. .
+---------------------------------------------------------------+
Figure 2: Example Session-Sender Test Packet with IP/UDP Header
Gandhi, et al. Expires 7 December 2025 [Page 10]
Internet-Draft STAMP for MPLS PWs and LSPs June 2025
The G-ACh header [RFC5586] with channel type for IPv4 or IPv6 MUST
immediately follow the bottom of the label stack. The payload
contains the STAMP Session-Sender test packet defined in [RFC8972].
The STAMP Session-Sender test packet G-ACh header contains following
fields:
Version: The Version field is set to 0, as defined in [RFC4385].
Reserved: Reserved Bits MUST be set to zero upon transmission and
ignored upon receipt.
Channel Type: G-ACh type for IPv4 header (0x0021) or IPv6 header
(0x0057) [RFC4385].
4.2. Session-Sender Test Packet without IP/UDP Header
The content of an example STAMP Session-Sender test packet for a PW
or an LSP encapsulated using a G-ACh without an IP/UDP header is
shown in Figure 3.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Label(1) | TC |S| TTL |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PW Label or Ultimate LSP Label | TC |1| 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0 0 0 1|Version| Reserved | STAMP Sender G-ACh (TBD1) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Payload = Test Packet as specified in Section 3 of RFC 8972 |
. in Figure 1 and Figure 3 .
. .
+---------------------------------------------------------------+
| Optional STAMP Extension TLVs |
. .
+---------------------------------------------------------------+
Figure 3: Example Session-Sender Test Packet without IP/UDP Header
The G-ACh header [RFC5586] with new STAMP Session-Sender channel type
(value TBD1) MUST immediately follow the bottom of the label stack.
The payload contains the STAMP Session-Sender test packet defined in
[RFC8972].
Gandhi, et al. Expires 7 December 2025 [Page 11]
Internet-Draft STAMP for MPLS PWs and LSPs June 2025
The STAMP channel type allows the identification of the encased STAMP
payload when demultiplexing G-ACh.
The STAMP Session-Sender test packet G-ACh header contains following
fields:
Version: The Version field is set to 0, as defined in [RFC4385].
Reserved: Reserved Bits MUST be set to zero upon transmission and
ignored upon receipt.
Channel Type: G-ACh type for STAMP Session-Sender packet (TBD1).
5. Session-Reflector Test Packet
The STAMP Session-Reflector reflects the test packet back to the
Session-Sender using the same channel in the reverse direction of the
PW or the LSP on which it was received. The Session-Reflector has
enough information to reflect the test packet received by it to the
Session- Sender using the PW or the LSP context.
The STAMP Session-Reflector reply test packet is transmitted on the
same path in the reverse direction of the PW or the LSP. The STAMP
test packet can be transmitted using an MPLS header with or without
an IP/UDP header. The Session-Reflector test packet is sent with an
IP/UDP header if the Session-Sender test packet is received with an
IP/UDP header, otherwise, it is sent without an IP/UDP header.
The Session-Reflector can use the PW label or the ultimate LSP label
in the received packet to find the PW or the LSP in the reverse
direction. The Session-Reflector uses the label stack of that PW or
LSP as well as G-ACh, to transmit the Session-Reflector test packet.
The Session-Reflector test packet uses the same G-ACh as the received
in the Session-Sender test packet.
5.1. Session-Reflector Test Packet with IP/UDP Header
The content of an example STAMP Session-Reflector test packet for a
PW or an LSP encapsulated using a G-ACh and an IP/UDP header is shown
in Figure 4.
Gandhi, et al. Expires 7 December 2025 [Page 12]
Internet-Draft STAMP for MPLS PWs and LSPs June 2025
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Label(1) | TC |S| TTL |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PW Label or Ultimate LSP Label | TC |1| 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0 0 0 1|Version| Reserved | IPv4 (0x0021) or IPv6 (0x0057)|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IP Header |
. Source IP Address .
. = Destination IP Address from Session-Sender Test Packet .
. Destination IP Address .
. = Source IP Address from Session-Sender Test Packet .
. IPv4 Protocol or IPv6 Next header = UDP (17) .
. .
+---------------------------------------------------------------+
| UDP Header |
. Source Port = As chosen by Session-Reflector .
. Destination Port .
. = Source Port from Session-Sender Test Packet .
. .
+---------------------------------------------------------------+
| Payload = Test Packet as specified in Section 3 of RFC 8972 |
. in Figure 2 and Figure 4 .
. .
+---------------------------------------------------------------+
| STAMP TLVs from Session-Sender Test Packet |
. .
+---------------------------------------------------------------+
Figure 4: Example Session-Reflector Test Packet with IP/UDP Header
The G-ACh header [RFC5586] with channel type IPv4 or IPv6 MUST
immediately follow the bottom of the label stack. The payload
contains the STAMP Session-Reflector test packet defined in
[RFC8972].
The STAMP Session-Reflector reply test packet MUST use the IP/UDP
information from the received test packet when an IP/UDP header is
present in the received test packet.
The STAMP Session-Reflector test packet G-ACh header contains
following fields:
Gandhi, et al. Expires 7 December 2025 [Page 13]
Internet-Draft STAMP for MPLS PWs and LSPs June 2025
Version: The Version field is set to 0, as defined in [RFC4385].
Reserved: Reserved Bits MUST be set to zero upon transmission and
ignored upon receipt.
Channel Type: G-ACh type for IPv4 header (0x0021) or IPv6 header
(0x0057) [RFC4385].
5.2. Session-Reflector Test Packet without IP/UDP Header
The content of an example STAMP Session-Reflector test packet for a
PW or an LSP encapsulated using a G-ACh without an IP/UDP header is
shown in Figure 5.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Label(1) | TC |S| TTL |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PW Label or Ultimate LSP Label | TC |1| 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0 0 0 1|Version| Reserved | STAMP Reflector G-ACh (TBD2) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Payload = Test Packet as specified in Section 3 of RFC 8972 |
. in Figure 2 and Figure 4 .
. .
+---------------------------------------------------------------+
| STAMP TLVs from Session-Sender Test Packet |
. .
+---------------------------------------------------------------+
Figure 5: Example Session-Reflector Test Packet without IP/UDP Header
The G-ACh header [RFC5586] with new STAMP Session-Reflector channel
type (value TBD2) MUST immediately follow the bottom of the label
stack. The payload contains the STAMP Session-Reflector test packet
defined in [RFC8972].
The STAMP channel type allows the identification of the encased STAMP
payload when demultiplexing G-ACh.
The STAMP Session-Reflector test packet G-ACh header contains
following fields:
Gandhi, et al. Expires 7 December 2025 [Page 14]
Internet-Draft STAMP for MPLS PWs and LSPs June 2025
Version: The Version field is set to 0, as defined in [RFC4385].
Reserved: Reserved Bits MUST be set to zero upon transmission and
ignored upon receipt.
Channel Type: G-ACh type for STAMP Session-Reflector packet (TBD2).
6. Security Considerations
The procedures defined in this document is intended for deployment in
a single network administrative domain. As such, the Session-Sender
address, Session-Reflector address, and IP and MPLS forward and
return paths are provisioned by the operator for the STAMP session.
It is assumed that the operator has verified the integrity of the IP
and MPLS forward and return paths used to transmit STAMP test
packets.
The security considerations specified in [RFC8762] and [RFC8972] also
apply to the procedure described in this document. Specifically, the
message integrity protection using HMAC, as defined in Section 4.4 of
[RFC8762], also apply to the procedure described in this document.
Routers that support G-ACh are subject to the same security
considerations as defined in [RFC4385] and [RFC5586].
The message throttling mechanisms described in Security Section of
[RFC5085] also apply to the procedure described in this document.
STAMP uses the well-known UDP port number that could become a target
of denial of service (DoS) or could be used to aid on-path attacks.
Thus, the security considerations and measures to mitigate the risk
of the attack documented in Section 6 of [RFC8545] equally apply to
the STAMP extensions in this document.
If desired, attacks can be mitigated by performing basic validation
checks of the timestamp fields (such as T2 is later than T1 in the
STAMP Reference Topology shown in Figure 1 in received reply test
packets at the Session-Sender. The minimal state associated with
these protocols also limit the extent of measurement disruption that
can be caused by a corrupt or invalid test packet to a single test
cycle.
Gandhi, et al. Expires 7 December 2025 [Page 15]
Internet-Draft STAMP for MPLS PWs and LSPs June 2025
7. IANA Considerations
IANA maintains G-ACh Type Registry (see
https://www.iana.org/assignments/g-ach-parameters/g-ach-
parameters.xhtml). IANA is requested to allocate values for the
G-ACh Types for STAMP from "MPLS Generalized Associated Channel
(G-ACh) Types (including Pseudowire Associated Channel Types)"
registry.
+=======+====================================+===============+
| Value | Description | Reference |
+=======+====================================+===============+
| TBD1 | STAMP Session-Sender G-ACh Type | This document |
+-------+------------------------------------+---------------+
| TBD2 | STAMP Session-Reflector G-ACh Type | This document |
+-------+------------------------------------+---------------+
Table 2: STAMP G-ACh Type
8. References
8.1. 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>.
[RFC4385] Bryant, S., Swallow, G., Martini, L., and D. McPherson,
"Pseudowire Emulation Edge-to-Edge (PWE3) Control Word for
Use over an MPLS PSN", RFC 4385, DOI 10.17487/RFC4385,
February 2006, <https://www.rfc-editor.org/info/rfc4385>.
[RFC5085] Nadeau, T., Ed. and C. Pignataro, Ed., "Pseudowire Virtual
Circuit Connectivity Verification (VCCV): A Control
Channel for Pseudowires", RFC 5085, DOI 10.17487/RFC5085,
December 2007, <https://www.rfc-editor.org/info/rfc5085>.
[RFC5586] Bocci, M., Ed., Vigoureux, M., Ed., and S. Bryant, Ed.,
"MPLS Generic Associated Channel", RFC 5586,
DOI 10.17487/RFC5586, June 2009,
<https://www.rfc-editor.org/info/rfc5586>.
[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>.
Gandhi, et al. Expires 7 December 2025 [Page 16]
Internet-Draft STAMP for MPLS PWs and LSPs June 2025
[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>.
[RFC8972] Mirsky, G., Min, X., Nydell, H., Foote, R., Masputra, A.,
and E. Ruffini, "Simple Two-Way Active Measurement
Protocol Optional Extensions", RFC 8972,
DOI 10.17487/RFC8972, January 2021,
<https://www.rfc-editor.org/info/rfc8972>.
8.2. Informative References
[RFC3931] Lau, J., Ed., Townsley, M., Ed., and I. Goyret, Ed.,
"Layer Two Tunneling Protocol - Version 3 (L2TPv3)",
RFC 3931, DOI 10.17487/RFC3931, March 2005,
<https://www.rfc-editor.org/info/rfc3931>.
[RFC4448] Martini, L., Ed., Rosen, E., El-Aawar, N., and G. Heron,
"Encapsulation Methods for Transport of Ethernet over MPLS
Networks", RFC 4448, DOI 10.17487/RFC4448, April 2006,
<https://www.rfc-editor.org/info/rfc4448>.
[RFC5082] Gill, V., Heasley, J., Meyer, D., Savola, P., Ed., and C.
Pignataro, "The Generalized TTL Security Mechanism
(GTSM)", RFC 5082, DOI 10.17487/RFC5082, October 2007,
<https://www.rfc-editor.org/info/rfc5082>.
[RFC5087] Stein, Y., Shashoua, R., Insler, R., and M. Anavi, "Time
Division Multiplexing over IP (TDMoIP)", RFC 5087,
DOI 10.17487/RFC5087, December 2007,
<https://www.rfc-editor.org/info/rfc5087>.
[RFC5921] Bocci, M., Ed., Bryant, S., Ed., Frost, D., Ed., Levrau,
L., and L. Berger, "A Framework for MPLS in Transport
Networks", RFC 5921, DOI 10.17487/RFC5921, July 2010,
<https://www.rfc-editor.org/info/rfc5921>.
[RFC5960] Frost, D., Ed., Bryant, S., Ed., and M. Bocci, Ed., "MPLS
Transport Profile Data Plane Architecture", RFC 5960,
DOI 10.17487/RFC5960, August 2010,
<https://www.rfc-editor.org/info/rfc5960>.
[RFC6374] Frost, D. and S. Bryant, "Packet Loss and Delay
Measurement for MPLS Networks", RFC 6374,
DOI 10.17487/RFC6374, September 2011,
<https://www.rfc-editor.org/info/rfc6374>.
Gandhi, et al. Expires 7 December 2025 [Page 17]
Internet-Draft STAMP for MPLS PWs and LSPs June 2025
[RFC6658] Bryant, S., Ed., Martini, L., Swallow, G., and A. Malis,
"Packet Pseudowire Encapsulation over an MPLS PSN",
RFC 6658, DOI 10.17487/RFC6658, July 2012,
<https://www.rfc-editor.org/info/rfc6658>.
[RFC6790] Kompella, K., Drake, J., Amante, S., Henderickx, W., and
L. Yong, "The Use of Entropy Labels in MPLS Forwarding",
RFC 6790, DOI 10.17487/RFC6790, November 2012,
<https://www.rfc-editor.org/info/rfc6790>.
[RFC7708] Nadeau, T., Martini, L., and S. Bryant, "Using a Generic
Associated Channel Label as a Virtual Circuit Connectivity
Verification Channel Indicator", RFC 7708,
DOI 10.17487/RFC7708, November 2015,
<https://www.rfc-editor.org/info/rfc7708>.
[RFC8545] Morton, A., Ed. and G. Mirsky, Ed., "Well-Known Port
Assignments for the One-Way Active Measurement Protocol
(OWAMP) and the Two-Way Active Measurement Protocol
(TWAMP)", RFC 8545, DOI 10.17487/RFC8545, March 2019,
<https://www.rfc-editor.org/info/rfc8545>.
[I-D.ietf-pals-ple]
Gringeri, S., Whittaker, J., Leymann, N., Schmutzer, C.,
and C. Brown, "Private Line Emulation over Packet Switched
Networks", Work in Progress, Internet-Draft, draft-ietf-
pals-ple-15, 12 February 2025,
<https://datatracker.ietf.org/doc/html/draft-ietf-pals-
ple-15>.
Acknowledgments
The authors would like to thank Bharath Vasudevan, Ali Sianati, and
Parag Jain for the discussions on method to punt STAMP test packets
to control-plane for processing. The authors would also like to
thank Greg Mirsky, Loa Andersson, and Stewart Bryant for reviewing
this document and providing useful comments and suggestions.
Authors' Addresses
Rakesh Gandhi (editor)
Cisco Systems, Inc.
Canada
Email: rgandhi@cisco.com
Gandhi, et al. Expires 7 December 2025 [Page 18]
Internet-Draft STAMP for MPLS PWs and LSPs June 2025
Patrice Brissette
Cisco Systems, Inc.
Canada
Email: pbrisset@cisco.com
Edward Leyton
Verizon Wireless
Email: edward.leyton@verizonwireless.com
Xiao Min
ZTE Corp.
Nanjing
China
Email: xiao.min2@zte.com.cn
Gandhi, et al. Expires 7 December 2025 [Page 19]