Internet DRAFT - draft-gandhi-mpls-stamp-pw
draft-gandhi-mpls-stamp-pw
MPLS Working Group R. Gandhi, Ed.
Internet-Draft P. Brissette
Intended status: Standards Track Cisco Systems, Inc.
Expires: 8 August 2024 E. Leyton
Verizon Wireless
X. Min
ZTE Corp.
5 February 2024
Encapsulation of Simple TWAMP (STAMP) for Pseudowires and LSPs in MPLS
Networks
draft-gandhi-mpls-stamp-pw-05
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.
Status of This Memo
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provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on 8 August 2024.
Copyright Notice
Copyright (c) 2024 IETF Trust and the persons identified as the
document authors. All rights reserved.
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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
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions Used in This Document . . . . . . . . . . . . . . 5
2.1. Requirements Language . . . . . . . . . . . . . . . . . . 5
2.2. Abbreviations . . . . . . . . . . . . . . . . . . . . . . 5
2.3. STAMP Reference Topology . . . . . . . . . . . . . . . . 6
3. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.1. Using STAMP for MPLS LSPs and MPLS-TP LSPs . . . . . . . 8
3.2. Example Use Cases of STAMP Header Formats for MPLS Data
Traffic Type . . . . . . . . . . . . . . . . . . . . . . 8
3.3. Applicability of Control Channel Types to STAMP Test
Packets for MPLS . . . . . . . . . . . . . . . . . . . . 8
4. Session-Sender Test Packet . . . . . . . . . . . . . . . . . 9
4.1. Session-Sender Test Packet with IP/UDP Header . . . . . . 9
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 . . . . . . . . . . . . . . . . . . . . . 15
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.
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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].
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 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 the STAMP test packets with or without an IP/UDP
header. This document defines two new G-ACh types when using STAMP
without IP/UDP header, those are PW demultiplexer agnostic and hence
applicable to both MPLS 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 IP/UDP header.
1.1. Requirements
The STAMP test packets need to be transmitted with the same MPLS
label stack that is used by the PW and LSP data traffic to ensure
proper validation of underlay path taken by the actual PW and LSP
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 Control Word [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 Control Word but do not carry 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 Control
Word, but they do not carry any IP header. As such, the STAMP test
packets need to be transmitted using the same MPLS label stack
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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]. For example, G-ACh types for BFD packets with or without
IP/UDP headers allow to demultiplex VCCV Control Channel as described
in [RFC5885]. Similarly, STAMP G-ACh types with or withour IP/UDP
headers allow to demultiplex VCCV Control Channel. Signaling
extensions for PW VCCV 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 allow to demultiplex
OAM Control Channel for MPLS-TP. Similarly, the VCCV Control Channel
is also applicable to MPLS-TP PWs [RFC7189]. The G-ACh types for
STAMP allow to demultiplex VCCV Control Channel for MPLS-TP PWs.
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 IP/UDP header.
o The G-ACh MUST support STAMP test packets without IP/UDP header.
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 Control Word.
o The Session-Sender test packets MUST follow the same ECMP underlay
path taken by the data traffic that is using Control Word 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 Control Word 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.
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This document concerns with the STAMP operation for the Single-
Segment PWs (SS-PWs).
The procedure for STAMP operation for point-to-multipoint (P2MP) PWs
is outside the scope of this document.
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.
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2.3. STAMP Reference Topology
In the STAMP Reference Topology shown in Figure 1, there exists a
packet PW or LSP to transport data between Provider Edge (PE)
Endpoints S1 and R1. The STAMP Session-Sender on PE S1 initiates a
Session-Sender test packet and the STAMP Session-Reflector on PE R1
transmits a reply test packet. The Session-Reflector reply test
packet may be transmitted to the STAMP Session-Sender on the same
path (same set of links and nodes) in the reverse direction of the
path taken towards the Session-Reflector. The T1 is a transmit
timestamp and T4 is a receive timestamp added by S1. The T2 is a
receive timestamp and T3 is a transmit timestamp added by 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 dynamically selected by the Session-Sender.
The STAMP test packets are encapsulated with MPLS header using the
same label stack as the PW data traffic (including PW Label) and
G-ACh header (instead of Control Word header 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.
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There are two ways in which STAMP test packets may be encapsulated
over a G-ACh, either using an IP/UDP header or without using an IP/
UDP header.
For encapsulating the STAMP test packets over a G-ACh with an IP/UDP
header, 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 signaling for dynamically
established PWs or IP version MUST be configured for statically
provisioned PWs.
For encapsulating the STAMP test packets over a G-ACh without adding
an IP/UDP header, 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.
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 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
MPLS PWs. Specifically, 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 also
applicable to the STAMP test packets to force test packets to be
processed on Session-Sender and Session-Reflector control-planes. As
such, the PW Labels MUST be added with TTL value 1 in the STAMP
Session-Sender and Session-Reflector test packets.
The VCCC Type 2 is also referred to as 'MPLS Router Alert Label"
[RFC5085]. This approach could result in a different Equal Cost
Multi-Path (ECMP) hashing behavior than pseudowire PDUs, and thus
result in the VCCV control channel traffic 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 monitoring MPLS
PW and MPLS LSP traffic.
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3.1. Using STAMP for MPLS LSPs and MPLS-TP LSPs
The procedure defined in this document to encapsulate STAMP test
packets is also aplicable to MPLS LSPs and MPLS-TP LSPs. For
monitoring data traffic over MPLS LSPs (no Control Word case) using
IP header, STAMP test packet format 1 (with IP/UDP headers) is used.
For monoitoring data traffic over MPLS-TP LSPs (with Control Word),
not using IP header, STAMP test packets with format 2 (without IP/UDP
headers) are transmitted with TTL value 1 with the ultimate 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 format 2 (without IP/UDP header), for example, in case of
MPLS-TP LSPs (STAMP headers similar to [RFC6374]).
3.2. Example Use Cases of STAMP Header Formats for MPLS Data Traffic
Type
For STAMP test packet format1 with IP/UDP headers:
1. MPLS PW Data Traffic (Using CW and IP Header)
2. MPLS-TP PW Data Traffic (Using CW and IP header)
3. MPLS LSP Data Traffic (Using IP Header)
For STAMP test packet format2 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 (no IP Header case)
5. MPLS-TP LSP Data Traffic
3.3. Applicability of Control Channel Types to STAMP Test Packets for
MPLS
Editor's Note: Convert this into a table.
Control Channel Types defined in [RFC5085] are applicable to STAMP
Test Packets for MPLS as follows:
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Control Channel Type 1 : In-band: Control Word with 0001b as first
nibble : No IP/UDP Headers Format 2 : G-ACH Type STAMP G-ACH (TBD1/
TBD2)
Control Channel Type 2 : Out-of-band: MPLS Router Alert Label : Not
supported : Not supported
Control Channel Type 3 : TTL Expiry: MPLS PW Label with TTL as 1 :
IP/UDP Headets Format 1 : IPv4 G-ACH (0x21) and IPv6 G-ACH (0x57)
Control Channel Type 3 : TTL Expiry: MPLS PW Label with TTL as 1 : No
IP/UDP Headets Format 2 : G-ACH Type STAMP G-ACH (TBD1/TBD2)
4. Session-Sender Test Packet
4.1. Session-Sender Test Packet with IP/UDP Header
The content of an example STAMP Session-Sender test packet for a PW
encapsulated using a G-ACh and an IP/UDP header is shown in Figure 2.
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Label(1) | TC |S| TTL |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PW 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 TLVs defined in RFC 8972 |
. .
+---------------------------------------------------------------+
Figure 2: Example Session-Sender Test Packet with IP/UDP Header
for PW
The G-ACh header [RFC5586] with channel type for IPv4 or IPv6 MUST
immediately follow the bottom of the MPLS 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
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(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
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 | 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 TLVs defined in RFC 8972 |
. .
+---------------------------------------------------------------+
Figure 3: Example Session-Sender Test Packet without IP/UDP
Header for PW
The G-ACh header [RFC5586] with new STAMP Session-Sender channel type
(value TBD1) MUST immediately follow the bottom of the MPLS label
stack. The payload contains the STAMP Session-Sender test packet
defined in [RFC8972].
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.
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Channel Type: G-ACh type for STAMP Session-Sender packet (TBD1).
5. Session-Reflector Test Packet
The STAMP Session-Reflector reply test packet is sent on the same
path in the reverse direction of a bidirectional PW. The STAMP test
packet can be sent using an MPLS header with or without 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.
5.1. Session-Reflector Test Packet with IP/UDP Header
The content of an example STAMP Session-Reflector test packet for a
PW encapsulated using a G-ACh and an IP/UDP header is shown in
Figure 4.
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Label(1) | TC |S| TTL |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PW 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 .
. = Destination Port from Session-Sender Test Packet .
. 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 for PW
The G-ACh header [RFC5586] with channel type IPv4 or IPv6 MUST
immediately follow the bottom of the MPLS 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.
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The STAMP Session-Reflector 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].
5.2. Session-Reflector Test Packet without IP/UDP Header
The content of an example STAMP Session-Reflector test packet for a
PW 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 | 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 for PW
The G-ACh header [RFC5586] with new STAMP Session-Reflector channel
type (value TBD2) MUST immediately follow the bottom of the MPLS
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.
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The STAMP Session-Reflector reflects the test packet back to the
Session-Sender using the same channel in the reverse direction of the
PW 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 context.
The STAMP Session-Reflector 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-Reflector packet (TBD2).
6. Security Considerations
The procedures defined in this document is intended for deployment in
a single operator network 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.
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.
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+=======+====================================+===============+
| Value | Description | Reference |
+=======+====================================+===============+
| TBD1 | STAMP Session-Sender G-ACh Type | This document |
+-------+------------------------------------+---------------+
| TBD2 | STAMP Session-Reflector G-ACh Type | This document |
+-------+------------------------------------+---------------+
Table 1: 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>.
[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>.
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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>.
[RFC5885] Nadeau, T., Ed. and C. Pignataro, Ed., "Bidirectional
Forwarding Detection (BFD) for the Pseudowire Virtual
Circuit Connectivity Verification (VCCV)", RFC 5885,
DOI 10.17487/RFC5885, June 2010,
<https://www.rfc-editor.org/info/rfc5885>.
[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>.
[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>.
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[RFC7189] Mirsky, G., "Virtual Circuit Connectivity Verification
(VCCV) Capability Advertisement for MPLS Transport Profile
(MPLS-TP)", RFC 7189, DOI 10.17487/RFC7189, March 2014,
<https://www.rfc-editor.org/info/rfc7189>.
[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>.
[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-01, 21 October 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-pals-
ple-01>.
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 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
Patrice Brissette
Cisco Systems, Inc.
Canada
Email: pbrisset@cisco.com
Edward Leyton
Verizon Wireless
Email: edward.leyton@verizonwireless.com
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Xiao Min
ZTE Corp.
Nanjing
China
Email: xiao.min2@zte.com.cn
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