Internet Engineering Task Force Luca Martini
Internet Draft Monoski LLC
Intended status: Standards Track George Swallow
Expires: August 2017 Cisco
Elisa Bellagamba
Ericsson
February 2017
MPLS LSP PW status refresh reduction for Static Pseudowires
draft-ietf-pals-status-reduction-02.txt
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Abstract
This document describes a method for generating an aggregated
pseudowire status message transmitted on a Multi-Protocol Label
Switching (MPLS) Label Switched Path (LSP) to indicate the status of
one or more pseudowires carried on the LSP.
The method for transmitting the pseudowire (PW) status information is
not new, however this protocol extension allows a Service Provider
(SP) to reliably monitor the individual PW status while not
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overwhelming the network with multiple periodic status messages. This
is achieved by sending a single cumulative summary status
verification message for all the PWs grouped in the same LSP.
Table of Contents
1 Introduction ......................................... 3
1.1 Requirements Language ................................ 3
1.2 Terminology .......................................... 3
1.3 Notational Conventions in Backus-Naur Form ........... 4
2 PW status refresh reduction protocol ................. 4
2.1 Protocol states ...................................... 4
2.1.1 INACTIVE ............................................. 5
2.1.2 STARTUP .............................................. 5
2.1.3 ACTIVE ............................................... 5
2.2 Timer value change transition procedure .............. 5
3 PW status refresh reduction procedure ................ 6
4 PW status refresh reduction Message Encoding ......... 6
5 PW status refresh reduction Control Messages ......... 9
5.1 Notification message ................................. 10
5.2 PW Configuration Message ............................. 11
5.2.1 MPLS-TP Tunnel ID .................................... 12
5.2.2 PW ID configured List ................................ 12
5.2.3 PW ID unconfigured List .............................. 13
6 PW provisioning verification procedure ............... 13
6.0.4 PW ID List advertising and processing ................ 14
7 Security Considerations .............................. 14
8 IANA Considerations .................................. 15
8.1 PW Status Refresh Reduction Message Types ............ 15
8.2 PW Configuration Message Sub-TLVs .................... 15
8.3 PW Status Refresh Reduction Notification Codes ....... 16
9 References ........................................... 16
9.1 Normative References ................................. 16
9.2 Informative References ............................... 17
10 Authors' Addresses ................................... 17
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1. Introduction
When PWs use a Multi Protocol Label Switched (MPLS) network as the
Packet Switched Network (PSN), they are setup according to [RFC8077]
static configuration mode and the PW status information is propagated
using the method described in [RFC6478]. There are 2 basic modes of
operation described in [RFC6478] section 5.3: Periodic retransmission
of non-zero status messages, and a simple acknowledge of PW status
(sec 5.3.1 of [RFC6478]). The LSP level protocol described below
applies to the case when PW status is acknowledged immediately with a
requested refresh value of zero (no refresh). In this case the PW
status refresh reduction protocol is necessary for several reasons,
such as:
-i. Greatly increase the scalability of the PW status protocol
by reducing the amount of messages that a PE needs to
periodically send to it's neighbors.
-ii. Detect a remote PE restart.
-iii. If the local state is lost for some reason, the PE needs to
be able to request a status refresh reduction from the
remote PE
-iv. Optionally detect a remote PE provisioning change.
1.1. 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 [RFC2119].
1.2. Terminology
FEC: Forwarding Equivalence Class
LDP: Label Distribution Protocol
LSP: Label Switching Path
MS-PW: Multi-Segment Pseudowire
PE: Provider Edge
PW: Pseudowire
SS-PW: Single-Segment Pseudowire
S-PE: Switching Provider Edge Node of MS-PW
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T-PE: Terminating Provider Edge Node of MS-PW
1.3. Notational Conventions in Backus-Naur Form
All multiple-word atomic identifiers use underscores (_) between the
words to join the words. Many of the identifiers are composed of a
concatenation of other identifiers. These are expressed using
Backus-Naur Form (using double-colon - "::" - notation).
Where the same identifier type is used multiple times in a
concatenation, they are qualified by a prefix joined to the
identifier by a dash (-). For example Src-Node_ID is the Node_ID of
a node referred to as Src (where "Src" is short for "source" in this
example).
The notation does not define an implicit ordering of the information
elements involved in a concatenated identifier.
2. PW status refresh reduction protocol
PW status refresh reduction protocol consists of a simple message
that is sent at the LSP level using the MPLS Generic Associated
Channel.[RFC5586]
A PE using the PW status refresh reduction protocol MUST send the PW
status refresh reduction Message as soon as a PW is configured on a
particular LSP. The message is then re-transmitted at a locally
configured interval indicated in the refresh timer field. If no
acknowledgment is received, the protocol does not reach active state,
and the PE SHOULD NOT send any PW status messages with a refresh
timer of zero as described in [RFC6478] section 5.3.1.
It is worth noting that no relationship is existing between the
locally configured timer for the refresh reduction protocol and the
PW individual status refresh timers.
2.1. Protocol states
The protocol can be in 3 possible states: INACTIVE, STARTUP, and
ACTIVE.
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2.1.1. INACTIVE
This state is entered when the protocol is turned off. This state is
also entered if all PW on a specific LSP are unprovisioned, or the
feature is unprovisioned.
2.1.2. STARTUP
In this state the PE transmits periodic PW status refresh reduction
messages, with the Ack Session ID set to 0. The PE remains in this
state until a PW status refresh message is received with the correct
local session ID in the Ack Session ID Field. This state can be
exited to the ACTIVE or INACTIVE state.
2.1.3. ACTIVE
This state is entered once the PE receives a PW status refresh
reduction message with the correct local session ID in the Ack
Session ID Field within 3.5 times the refresh timer field value of
the last PW status refresh reduction message transmitted. This state
is immediately exited as follows:
-i. A valid PW status refresh reduction message is not received
within 3.5 times the current refresh timer field value.
(assuming a timer transition procedure is not in progress)
New state: STARTUP
-ii. A PW status refresh reduction message is received with the
wrong, or a zero, Ack Session ID field value. New state:
STARTUP
-iii. All PWs using the particular LSP are unprovisioned, or the
protocol is disabled. New state: INACTIVE
2.2. Timer value change transition procedure
If a PE needs to change the refresh timer value field while the PW
refresh reduction protocol is in the ACTIVE state, the following
procedure must be followed:
-i. A PW status refresh reduction message is transmitted with
the new timer value.
-ii. If the new value is greater then the original one the PE
will operate on the new timer value immediately.
-iii. If the new value is smaller then the original one, the PE
will operate according to the original timer value for a
period 3.5 times the original timer value, or until the
first valid PW status refresh reduction message is received.
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A PE receiving a PW status refresh reduction message with a
new timer value, will immediately transmit an acknowledge PW
status refresh reduction message, and start operating
according to the new timer value.
3. PW status refresh reduction procedure
When the refresh reduction protocol, on a particular LSP, is in the
ACTIVE state, the PE can send all PW status messages, for PWs on that
LSP, with a refresh timer value of zero. This greatly decreases the
amount of messages that the PE needs to transmit to the remote PE
because once the PW status message for a particular PW is
acknowledged, further repetitions of that message are no longer
necessary.
To further mitigate the amount of possible messages when an LSP
starts forwarding traffic, care should be taken to permit the PW
refresh reduction protocol to reach the ACTIVE state quickly, and
before the the first PW status refresh timer expires. This can be
achieved by using a PW status refresh reduction Message refresh timer
value that is much smaller then the PW status message refresh timer
value in use. (sec 5.3.1 of [RFC6478])
If the refresh reduction protocol session is terminated by entering
the INACTIVE or STARTUP states, the PE MUST immediately re-send all
the previously sent PW status messages for that particular LSP for
which the session terminated. In this case the refresh timer value
MUST NOT be set to zero, and MUST be set according to the local
policy of the PE router.
4. PW status refresh reduction Message Encoding
The packet containing the refresh reduction message is encoded as
follows: (omitting link layer information)
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MPLS LSP (tunnel) Label Stack Entry |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| GAL |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0 0 0 1|Version| Reserved | 0xZZ PW OAM Message |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Session ID | Ack Session ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Refresh Timer | Total Message Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Checksum | Message Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Last Received Seq Number | Message Type |U C Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Control Message Body ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
This message contains the following fields:
* PW OAM Message.
This field indicates the Generic Associated Channel type in the
GACH header as defined in [RFC5586].
Note: Channel type 0xZZ pending IANA allocation.
* Session ID
A non-zero, locally selected session number that is not preserved
if the local PE restarts.
In order to get a locally unique session ID, the recommended
choice is to perform a CRC-16 giving as input the following data
|Y|Y|M|M|D|D|H|H|M|M|S|S|L|L|L|
Where: YY: are the decimal two last digit of the current year
MM: are the decimal two digit of the current month DD: are the
decimal two digit of the current day HHMMSSLLL: are the decimal
digits of the current time expressed in (hour, minutes, seconds,
milliseconds) If the calculation results in an already existing
Session ID, a unique Session ID can be generated by adding 1 to
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the result until the Session ID is unique. Any other method to
generate a locally unique session ID is also acceptable.
* Ack Session ID
The Acknowledgment Session ID received from the remote PE.
* Refresh Timer.
A non zero unsigned 16 bit integer value greater or equal to 10,
in milliseconds, that indicates the desired refresh interval. The
default value of 30000 is RECOMENDED.
* Total Message Length
Total length in octets of the Checksum, Message Type, Flags,
Message Sequence Number, and control message body. A value of
zero means that no control message is present, and therefore that
no Checksum, and following fields are present either.
* Checksum
A 16 bit field containing the one's complement of the one's
complement sum of the entire message (including the GACH header),
with the checksum field replaced by zero for the purpose of
computing the checksum. An all-zero value means that no checksum
was transmitted. Note that when the checksum is not computed, the
header of the bundle message will not be covered by any checksum.
* Message Sequence Number
An unsigned 16 bit integer number that is started from 1 when the
protocol enters ACTIVE state. The sequence numbers wraps back to
1 when the maximum value is reached. The value of zero is
reserved and MUST NOT be used.
* Last Received Message Sequence Number
The sequence number of the last message received. In no message
has yet been received during this session, this field is set to
zero.
* Message Type
The Type of the control message that follows. Control message
types are allocated in this document, and by IANA.
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* (U) Unknown flag bit.
Upon receipt of an unknown messageor TLV, if U is clear (=0), the
keepalive session MUST be terminated by entering STARTUP state;
if U is set (=1), the unknown message, or message contining a
unknown TLV, MUST be acknowledged and silently ignored and the
following messages, or TLVs, if any, processed as if the unknown
message, or TLV did not exist.
* (C) Configuration flag bit. The C Bit is used to signal the end
of PW configuration transmission. If it is set, the sending PE
has finished sending all it's current configuration information.
* Flags (Reserved)
6 bits of flags reserved for future use, they MUST be set to 0 on
transmission, and ignored on reception.
* Control Message Body
The Control Message body is defined in a section below, and is
specific to the type of message.
It should be noted that the Checksum, Message Sequence Number, Last
Received Message Sequence Number, Message Type, Flags, and control
message body are OPTIONAL. The length field is used to parse how many
optional fields are included. Hence all optional fields that precede
a specific field that needs to be included in a specific
implementation MUST be included if that optional field is also
included.
If any of the above vaules are outside the specified range, a
notification message is returned with a code "PW configuration not
supported.", and the message is ignored.
5. PW status refresh reduction Control Messages
PW status refresh reduction Control messages consist of the Checksum,
Message Sequence Number, Last Received Message Sequence Number,
Message Type, Flags, and control message body.
When there is the need to send a PW status refresh reduction Control
Messages, the system can attach it to a scheduled PW status refresh
reduction or send one ahead of time. In any case PW status refresh
reduction Control Messages always piggy back on normal messages.
A PW refresh reduction message is also called a PW status refresh
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reduction Control Message if it contains a control message
construct.
There can only be one control message construct per PW status refresh
reduction Message. If the U bit is set, and a PE receiving the PW
status refresh reduction Message does not understand the control
message, the control message MUST be silently ignored. However the
message sequence number MUST still be acknowledged by sending a null
message back with the appropriate value in the Last Message Received
Field. If a control message is not acknowledged, after 3.5 times the
value of the Refresh Timer, a fatal notification "unacknowledged
control message" MUST be sent, and the PW refresh reduction session
MUST be terminated.
If a PE does not want or need to send a control message, the
Checksum, and all following fields MUST NOT be sent, and the Total
Message Length field is then set to zero.
5.1. Notification message
The most common use of the Notification Message is to acknowledge the
reception of a message by indicating the received message sequence
number in the "Last Received Sequence Number" field. The notification
message is encoded as follows:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Checksum | Message Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Last Received Seq Number | Type=0x01 |U Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Notification Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The message type is set to 0x01, and the U bit is treated as
described in the above section. The Notification Codes are a 32 bit
quantity assigned by IANA. (see IANA consideration section)
Notification codes are either considered "Error codes" or simple
notifications. If the Notification code is an Error code as indicated
in the IANA allocation registry, the keepalive session MUST be
terminated by entering STARTUP state. The 7 bits of flags are
reserved for future use, they MUST be set to 0 on transmission, and
ignored on reception.
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5.2. PW Configuration Message
The PW status refresh reduction TLVs are informational TLVs, that
allow the remote PE to verify certain provisioning information. This
message contain a series of sub-TLVs in no particular order, that
contain PW and LSP configuration information. The message has no
preset length limit, however its total length will be limited by the
transport network Maximum Transmit Unit (MTU). PW refresh reduction
messages MUST NOT be fragmented. If a sender has more configuration
information to send than will fit into one PW Configuration Message
it may send further messages carrying further TLVs.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Checksum | Message Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Last Received Seq Number | Type=0x02 |U C (Flags) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ ~
| PW Configuration Message Sub-TLVs |
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The PW Configuration Message type is set to 0x02. For this message
the U-bit is set to 1 as processing of these messages is OPTIONAL.
The C Bit is used to signal the end of PW configuration transmission.
If it is set, the sending PE has finished sending all its current
configuration information. The PE transmitting the configuration MUST
set the C bit on the last PW configuration message when all current
PW configuration has been sent.
PW Configuration Message Sub-TLVs have the following generic 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ ~
| Value Continued |
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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5.2.1. MPLS-TP Tunnel ID
This TLV contains the address of the MPLS-TP tunnel ID. When the
configuration message is used for a particular keepalive session the
MPLS-TP Tunnel ID sub-TLV MUST be sent at least once.
The MPLS Tunnel ID address is encoded as follows:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type=0x01 | Length=20 | MPLS-TP Tunnel ID address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ ~
| MPLS-TP Tunnel ID address (20 Octets) |
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The MPLS point to point tunnel ID is defined in [RFC6370] as follows:
Src-Global_Node_ID::Src-Tunnel_Num::Dst-Global_Node_ID::Dst-
Tunnel_Num
Note that a single address is enough to identify the tunnel, and the
source end of the message.
5.2.2. PW ID configured List
This OPTIONAL TLV contains a list of the provisioned PWs on the LSP.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type=0x02 | Length | PW Path ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| PW Path ID |
~ ~
| Continued |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The PW Path ID is a 32 octet pseudowire path identifier specified in
[RFC6370] as follows: AGI::Src-Global_ID::Src-Node_ID::Src-AC_ID::
Dst-Global_ID::Dst-Node_ID::Dst-AC_ID
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The number of PW Path IDs in the TLV will be inferred by the length
of the TLV up to a maximum of 8. The procedure for processing this
TLV will be described in a section below.
5.2.3. PW ID unconfigured List
This OPTIONAL TLV contains a list of the PWs that have been
unprovisioned on the LSP. Note that it is a fatal session error to
send the same PW address in both the configured list TLV , and the
unconfigured list TLV in the same configuration message. If the this
error occurs, an error notification message is returned with the
error code of "PW Configuration TLV conflict" and the session is
terminated by entering STARTUP state.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type=0x03 | Length | PW Path ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| PW Path ID |
~ ~
| Continued |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The PW Path ID is a 32 octet pseudowire path identifier specified in
[RFC6370] as follows: AGI::Src-Global_ID::Src-Node_ID::Src-AC_ID::
Dst-Global_ID::Dst-Node_ID::Dst-AC_ID
The number of PW Path IDs in the TLV will be inferred by the length
of the TLV up to a maximum of 8.
6. PW provisioning verification procedure
The advertisement of the PW configuration message is OPTIONAL.
A PE that desires to use the PW configuration message to verify the
configuration of PWs on a particular LSP, should advertise its PW
configuration to the remote PE on LSPs that have active keepalive
sessions. When a PE receives PW configuration information using this
protocol and it is not supporting or is not willing to use the
information, it MUST acknowledge all the PW configuration messages
with a notification of "PW configuration not supported". In this
case, the information in the control messages is silently ignored. If
a PE receives such a notification it SHOULD stop sending PW
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configuration control messages for the duration of the PW refresh
reduction keepalive session.
If PW configuration information is received, it is used to verify the
accuracy of the local configuration information against the remote
PE's configuration information. If a configuration mismatch is
detected, where a particular PW is configured locally but not on the
remote PE, the following action SHOULD be taken:
-i. The local PW MUST be considered in "Not Forwarding" State.
-ii. The PW Attachment Circuit status is set to reflect the PW
fault.
-iii. An Alarm SHOULD be raised to a network management system.
6.0.4. PW ID List advertising and processing
When configuration messages are advertised along a particular LSP,
the PE sending the messages needs to check point the configuration
information sent by setting the C bit when all currently known
configuration information has been sent. This process allows the
receiving PE to immediately proceed to verify all the currently
configured PWs on that LSP, eliminating the need for a long waiting
period.
If a new PW is added to a particular LSP, the PE MUST place the
configuration verification of this PW on hold for a period of at
least 30 seconds. This is necessary to minimize false positive events
of mis-configuration due to the ends of the PW being slightly out of
sync.
7. Security Considerations
The security considerations of [RFC6478] are adequate for the
proposed mechanism since the operating environment is almost
identical to the one where this protocol would be deployed. It should
also be noted that since this protocol is designed to be deployed
between two adjacent PEs connected by a physical link, it is not
possible to misdirect or inject traffic without compromising the PW
transport link itself. All these situations are covered in the
security considerations of [RFC6478].
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8. IANA Considerations
All the registries in this section are to be created or updated as
appropriate in the Pseudowire Name Spaces (PWE3).
8.1. PW Status Refresh Reduction Message Types
IANA needs to set up a registry of "PW status refresh reduction
Control Messages". These are 8-bit values. Type value 1 through 2 are
defined in this document. Type values 3 through 64 are to be assigned
by IANA using the "Expert Review" policy defined in RFC5226. Type
values 65 through 127, 0 and 255 are to be allocated using the IETF
review policy defined in [RFC5226]. Type values 128 through 254 are
reserved for vendor proprietary extensions and are to be assigned by
IANA, using the "First Come First Served" policy defined in RFC5226.
The Type Values are assigned as follows:
Type Message Description
---- -------------------
0x01 Notification message
0x02 PW Configuration Message
8.2. PW Configuration Message Sub-TLVs
IANA needs to set up a registry of "PW status refresh reduction
Configuration Message Sub-TLVs". These are 8-bit values. Type value 1
through 2 are defined in this document. Type values 3 through 64 are
to be assigned by IANA using the "Expert Review" policy defined in
RFC5226. Type values 65 through 127, 0 and 255 are to be allocated
using the IETF review policy defined in [RFC5226]. Type values 128
through 254 are reserved for vendor proprietary extensions and are to
be assigned by IANA, using the "First Come First Served" policy
defined in RFC5226.
The Type Values are assigned as follows:
sub-TLV type Description
------------ -----------
0x01 MPLS-TP Tunnel ID address.
0x02 PW ID configured List.
0x03 PW ID unconfigured List.
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8.3. PW Status Refresh Reduction Notification Codes
IANA needs to set up a registry of "PW status refresh reduction
Notification Codes". These are 32-bit values. Type value 0 through 7
are defined in this document. Type values 8 through 65536 are to be
assigned by IANA using the "Expert Review" policy defined in RFC5226.
Type values 65536 through 134,217,728, 0 and 4,294,967,295 are to be
allocated using the IETF review policy defined in [RFC5226]. Type
values 134,217,729 through 4,294,967,294 are reserved for vendor
proprietary extensions and are to be assigned by IANA, using the
"First Come First Served" policy defined in RFC5226.
For each value assigned IANA should also track whether the value
constitutes an error as described in Section 5.1. When values are
assigned by IETF Review, the setting of this column must be
documented in the RFC that requests the allocation. For Expert Review
and FCFS assignments, the setting of this column must be made clear
by the requester at the time of assignment.
The Type Values are assigned as follows:
Code Error? Description
---- ------ -----------
0x00000000 No Null Notification.
0x00000001 No PW configuration rejected.
0x00000002 Yes PW Configuration TLV conflict.
0x00000003 No Unknown TLV (U-bit=1)
0x00000004 Yes Unknown TLV (U-bit=0)
0x00000005 No Unknown Message Type
0x00000006 No PW configuration not supported.
0x00000007 Yes Unacknowledged control message.
9. References
9.1. Normative References
[RFC2119] Bradner. S, "Key words for use in RFCs to
Indicate Requirement Levels", RFC 2119, March, 1997.
[RFC8077] "Pseudowire Setup and Maintenance Using the Label
Distribution Protocol (LDP)", L. Martini, G. Heron, RFC8077,
february 2017.
[RFC6478] L. Martini, G. Swallow, G. Heron, M. Bocci "Pseudowire
Status for Static Pseudowires", RFC6478, May 2012
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[RFC6370] M. Bocci, G. Swallow, E. Gray "MPLS-TP Identifiers",
RFC6370, September 2011
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations section in RFCs", BCP 26, RFC 5226, May 2008
9.2. Informative References
[RFC5586] M. Bocci, Ed., M. Vigoureux, Ed., S. Bryant, Ed.,
"MPLS Generic Associated Channel", rfc5586, June 2009
10. Authors' Addresses
Luca Martini
Monoski LLC.
e-mail: lmartini@monoski.com
George Swallow
Cisco Systems, Inc.
300 Beaver Brook Road
Boxborough, Massachusetts 01719
United States
e-mail: swallow@cisco.com
Elisa Bellagamba
Ericsson EAB
Torshamnsgatan 48
16480, Stockholm
Sweden
e-mail: elisa.bellagamba@gmail.com
Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://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
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include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Expiration Date: August 2017
Martini, et al. [Page 18]
