Network Working Group B. Cheng
Internet-Draft D. Wiggins
Intended status: Standards Track MIT Lincoln Laboratory
Expires: February 3, 2019 L. Berger
LabN Consulting, L.L.C.
August 2, 2018
DLEP Traffic Classification Data Item
draft-ietf-manet-dlep-traffic-classification-00
Abstract
This document defines a new DLEP protocol Data Item that is used to
support traffic classification. Traffic classification information
is used to identify traffic flows based on frame/packet content such
as destination address. The Data Item is defined in an extensible
and reusable fashion. It's use will be mandated in other documents
defining specific DLEP extensions. This document aloas introduces
DLEP sub data items, and sub data items are defined to support
DiffServ and Ethernet traffic classification.
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
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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 February 3, 2019.
Copyright Notice
Copyright (c) 2018 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
(https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
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carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
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described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Key Words . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Traffic Classification . . . . . . . . . . . . . . . . . . . 3
2.1. Traffic Classification Data Item . . . . . . . . . . . . 4
2.1.1. Traffic Classification Sub Data Item . . . . . . . . 6
2.2. DiffServ Traffic Classification Sub Data Item . . . . . . 6
2.2.1. Router Receive Processing . . . . . . . . . . . . . . 8
2.3. Ethernet Traffic Classification Sub Data Item . . . . . . 8
2.3.1. Router Receive Processing . . . . . . . . . . . . . . 9
3. Compatibility . . . . . . . . . . . . . . . . . . . . . . . . 10
4. Security Considerations . . . . . . . . . . . . . . . . . . . 10
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
5.1. Data Item Values . . . . . . . . . . . . . . . . . . . . 10
5.2. DLEP Traffic Classification Sub Data Item Registry . . . 10
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 11
6.1. Normative References . . . . . . . . . . . . . . . . . . 11
6.2. Informative References . . . . . . . . . . . . . . . . . 11
Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . 12
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12
1. Introduction
The Dynamic Link Exchange Protocol (DLEP) is defined in [RFC8175].
It provides the exchange of link related control information between
DLEP peers. DLEP peers are comprised of a modem and a router. DLEP
defines a base set of mechanisms as well as support for possible
extensions. DLEP defines Data Items which are sets of information
that can be reused in DLEP messaging. The base DLEP specification
does not include any flow identification beyond DLEP endpoints. This
document defines DLEP Data Item formats which provide flow
identification on a more granular basis. Specifically it enables
traffic sent by a router to use traffic flow classification
information provided by the modem to identify which traffic flows.
In this case, a flow is identified based on information found in a
data plane header and one or more matches are associated with a
single flow. (For general background on traffic classification see
[RFC2475] Section 2.3.) Credit windows may be shared or dedicated on
a per flow basis. The Data Item is structured to allow for reuse of
the defined traffic classification information with applications such
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as credit window control, such as found in
[I-D.ietf-manet-dlep-da-credit-extension]
This document defines traffic classification based on a DLEP
destination and flows identified by either DiffServ [RFC2475] DSCPs
(differentiated services codepoints) or IEEE 802.1Q
[IEEE.802.1Q_2014] Ethernet Priority Code Points (PCP). The defined
mechanism allows for flows to be described in a flexible fashion and
when combined with applications such as credit window control, allows
credit windows to be shared across traffic sent to multiple DLEP
destinations and flows, or used exclusively for traffic sent to a
particular destination and/or flow. The extension also supports the
"wildcard" matching of any flow (DSCP or PCP). Traffic
classification information is provided such that it can be readily
extended to support other traffic classification techniques, or be
used by non-credit window related extensions, such as
[I-D.ietf-manet-dlep-pause-extension] or even 5-tuple IP flows.
This document defines support for traffic classification using a
single new Data Item in Section 2.1 for general support and two new
sub Data Items are defined to support identification of flows based
on DSCPs and PCPs.
1.1. Key Words
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. Traffic Classification
The Traffic Classification Data Item is used to represent a list of
flows that may be used at the same time for traffic sent from a
router to a modem. The data plane information used to identify each
flow is represented in a separate sub Data Item. The Data Item and
Sub Data Item structure is intended to be independent of any specific
usage of the flow identification, e.g., flow control. The Sub Data
Item structure is also intended to allow for future traffic
classification types, e.g., 5-tuple flows. While the structure of
the Data Items is extensible, actual flow information is expected to
be used in an extension dependent manner. Support for DSCP and PCP-
based flows are defined via individual sub Data Items below. Other
types of flow identification, e.g., based on IP protocol and ports,
may be defined in the future via new sub Data Items.
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The list of flows contained in the Data Item can be used per sender
or shared across multiple senders. Each list of flows is identified
using a "Traffic Classification Identifier" or "TID" and is expected
to represent a valid combination of data plane identifiers that may
be used at the same time. Each flow is identified via a "Flow
Identifier" or "FID". Each FID is defined in a sub Data Item which
carries the data plane identifier or identifiers used to associate
traffic with the flow. A DLEP destination address is also needed to
complete traffic classification information used in extensions such
as flow control. This information is expected to be provided in an
extension specific manner. For example, this address can be provided
by a modem when it identifies the traffic classification set in a
Destination Up Message using the Credit Window Associate Data Item
defined in [I-D.ietf-manet-dlep-credit-flow-control]. The scope of
TID and FID values is a modem.
2.1. Traffic Classification Data Item
This sections defines the Traffic Classification Data Item. This
Data Item is used by a modem to provide a router with traffic
classification information. When an extension requires use of this
Data Item the Traffic Classification Data Item SHOULD be included by
a modem in any Session Initialization Response Message, e.g., see
[I-D.ietf-manet-dlep-da-credit-extension]. Updates to previously
provided traffic classifications or new traffic classifications MAY
be sent by a modem by including the Data Item in Session Update
Messages. More than one Data Item MAY be included in a message to
provide information on multiple traffic classifiers.
The set of traffic classification information provided in the data
item is identified using a Traffic Classification Identifier, or TID.
The actual data plane related information used in traffic
classification is provided in a variable list of Traffic
Classification Sub Data Items.
The format of the Traffic Classification Data Item is:
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Traffic Class. Identifier (TID)| Num SDIs | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Traffic Classification Sub Data Item 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: ... :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Traffic Classification Sub Data Item n |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: TBA1
Length: Variable
Per [RFC8175] Length is the number of octets in the Data Item,
excluding the Type and Length fields.
Traffic Classification Identifier (TID):
A 16-bit unsigned integer identifying a traffic classification
set. There is no restriction on values used by a modem, and there
is no requirement for sequential or ordered values.
Num SDIs:
An 8-bit unsigned integer indicating the number of Traffic
Classification Sub Data Items included in the Data Item. A value
of zero (0) is allowed and indicates that no traffic should be
matched against this TID.
Reserved:
MUST be set to zero by the sender (a modem) and ignored by the
receiver (a router).
Traffic Classification Sub Data Item:
Zero or more Traffic Classification Sub Data Items of the format
defined below MAY be included. The number MUST match the value
carried in the Num SDIs field.
A router receiving the Traffic Classification Data Item MUST locate
the traffic classification information that is associated with the
TID indicated in each received Data Item. If no associated traffic
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classification information is found, the router MUST initialize a new
information set using the values carried in the Data Item. When
associated traffic classification information is found, the router
MUST update the information using the values carried in the Data
Item. In both cases, a router MUST also ensure that any data plane
state, e.g., [I-D.ietf-manet-dlep-credit-flow-control], that is
associated with the TID is updated as needed.
2.1.1. Traffic Classification Sub Data Item
All Traffic Classification Sub Data Items share a common format that
is patterned after the standard DLEP Data Item format, see [RFC8175]
Section 11.3. There is no requirement on, or meaning to sub Data
Item ordering. Any errors or inconsistencies encountered in parsing
sub Data Items are handled in the same fashion as any other Data Item
parsing error encountered in DLEP.
The format of the Traffic Classification Sub Data Item is:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub Data Item Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Value... :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Sub Data Item Type:
A 16-bit unsigned integer that indicates the type and
corresponding format of the Sub Data Item's Value field. Sub Data
Item Types are scoped within the Data Item in which they are
carried, i.e., the Sub Data Item Type field MUST be used together
with the Data Item Type to identify the format of the Sub Data
Item. Traffic Classification Sub Data Item Types are managed
according to the IANA registry described in Section 5.2.
Length: Variable
Copying [RFC8175], Length is a 16-bit unsigned integer that is the
number of octets in the sub Data Item, excluding the Type and
Length fields.
2.2. DiffServ Traffic Classification Sub Data Item
The DiffServ Traffic Classification Sub Data Item is used to identify
the set of DSCPs that should be treated as a single flow, i.e.,
receive the same traffic treatment. DSCPs are identified in a list
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of DiffServ fields. An implementation that does not support DSCPs
and wants the same traffic treatment for all traffic to a destination
or destinations would indicate 0 DSCPs.
The format of the DiffServ Traffic Classification Sub Data Item is:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Must be one (1) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flow Identifier (FID) | Num DSCPs | DS Field 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DS Field 2 | ... | DS Field n |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Length: Variable
Length is defined above. For this Sub Data Item, it is equal to
three (3) plus the value of the Num DSCPs field.
Flow Identifier (FID):
A 16-bit unsigned integer representing the data plane information
carried in the sub Data Item that is to be used in identifying a
flow. The value of 0xFFFF is reserved and MUST NOT be used in
this field.
Num DSCPs:
An 8-bit unsigned integer indicating the number of DSCPs carried
in the sub Data Item. A zero (0) indicates a (wildcard) match
against any DSCP value.
DS Field:
Each DS Field is an 8-bit whose definition is the same as
[RFC2474].
0 1 2 3 4 5 6 7
+---+---+---+---+---+---+---+---+
| DSCP | CU |
+---+---+---+---+---+---+---+---+
DSCP: differentiated services codepoint
CU: currently unused, MUST be zero
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2.2.1. Router Receive Processing
A router receiving the Traffic Classification Sub Data Item MUST
validate the information on receipt, prior to using the carried
information, including potentially updating the data behavior as
determined by the extension requiring the use of the Sub Data Item.
Validation failures MUST be treated as an error as described above.
Once validated, the receiver MUST ensure that each DS Field value is
listed only once across the whole Traffic Classification Data Item.
Note, this check is across the Data Item and not the individual sub
Data Item. If the same DS Field value is listed more than once
within the same Traffic Classification Data Item, the Data Item MUST
be treated as an error as described above.
2.3. Ethernet Traffic Classification Sub Data Item
The Ethernet Traffic Classification Sub Data Item is used to identify
the VLAN and PCPs that should be treated as a single flow, i.e.,
receive the same traffic treatment. Ethernet Priority Code Point
support is defined as part of the IEEE 802.1Q [IEEE.802.1Q_2014] tag
format and includes a 3 bit "PCP" field. The tag format also
includes a 12 bit VLAN identifier (VID) field. PCPs are identified
in a list of priority fields. An implementation that does not
support PCPs and wants the same traffic treatment for all traffic to
a destination or destinations would indicate 0 PCPs. Such an
implementation could identify a VLAN to use per destination.
The format of the Ethernet Traffic Classification Sub Data Item is:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Must be two (2) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flow Identifier (FID) |NumPCPs| VLAN Identifier (VID) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Pri. 1| Pri. 2| ..... | ..... | ..... | Pad |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Length: Variable
Length is defined above. For this Sub Data Item, it is equal to
four (4) plus the number of octets needed to carry the carried
Priority fields is indicated by the NumPCPs field. Note that as
length is in octets and each Priority field is 4 bits, the
additional length is the value carried in the NumPCPs field
divided by two and rounded up to the next higher integer quantity.
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Flow Identifier (FID):
A 16-bit unsigned integer representing the data plane information
carried in the sub Data Item that is to be used in identifying a
flow. The value of 0xFFFF is reserved and MUST NOT be used in
this field.
Num PCPs:
A 4-bit unsigned integer indicating the number of Priority fields
carried in the sub Data Item. A zero (0) indicates a (wildcard)
match against any PCP value.
VLAN identifier (VID):
A 12-bit unsigned integer field indicating the VLAN to be used in
traffic classification. A value of zero (0) indicates that the
VID is to be ignored and any VID is to be accepted during traffic
classification.
Priority:
Each Priority Field is 4-bits long and indicates a PCP field
defined in [IEEE.802.1Q_2014]. Note that zero (0) is a valid
value for either PCP or DEI.
0 1 2 3
+---+---+---+---+
| PCP |DEI|
+---+---+---+---+
PCP: Priority code point
DEI: currently unused, MUST be zero
Pad:
A 4-bit long field included when NumPCPs is an odd number. This
field MUST be set to zero when added, and MIST be ignored on
receipt.
2.3.1. Router Receive Processing
A router receiving the Traffic Classification Sub Data Item MUST
validate the information on receipt, prior to the using the carried
information, including potentially updating the data behavior as
determined by the extension requiring the use of the Sub Data Item.
Validation failures MUST be treated as an error as described above.
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Once validated, the receiver MUST ensure that each Priority Field
value is listed only once across the whole Traffic Classification
Data Item. Note, this check is across the Data Item and not the
individual sub Data Item. If the same Priority Field value is listed
more than once within the same Traffic Classification Data Item, the
Data Item MUST be treated as an error as described above.
3. Compatibility
The formats defined in this document will only be used when
extensions require their use.
4. Security Considerations
This document introduces finer grain flow identification mechanisms
to DLEP. These mechanisms do not inherently introduce any additional
threats above those documented in [RFC8175]. The approach taken to
Security in that document applies equally to the mechanism defined in
this document.
5. IANA Considerations
This document requests the assignment of several values by IANA. All
assignments are to registries defined by [RFC8175].
5.1. Data Item Values
This document requests the following new assignments to the DLEP Data
Item Registry named "Data Item Type Values" in the range with the
"Specification Required" policy. The requested values are as
follows:
+-----------+------------------------+
| Type Code | Description |
+-----------+------------------------+
| TBA1 | Traffic Classification |
+-----------+------------------------+
Table 1: Requested Data Item Values
5.2. DLEP Traffic Classification Sub Data Item Registry
Upon approval of this document, IANA is requested to create a new
DLEP registry, named "Traffic Classification Sub Data Item Type
Values". The registry shall identify the type code value, the Data
Item which may use the value, and a description of the value. While
the same value may be reused in different Data Items, this is not
recommended at this time.
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The following table provides initial registry values and the
[RFC8126] defined policies that should apply to the registry:
+-------------+---------------------------------+
| Type Code | Description |
+-------------+---------------------------------+
| 0 | Reserved |
| | |
| 1 | DiffServ Traffic Classification |
| | |
| 2 | Ethernet Traffic Classification |
| | |
| 3-65407 | Specification Required |
| | |
| 65408-65534 | Private Use |
| | |
| 65535 | Reserved |
+-------------+---------------------------------+
Table 2: Initial Registry Values
6. References
6.1. 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>.
[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>.
[RFC8175] Ratliff, S., Jury, S., Satterwhite, D., Taylor, R., and B.
Berry, "Dynamic Link Exchange Protocol (DLEP)", RFC 8175,
DOI 10.17487/RFC8175, June 2017,
<https://www.rfc-editor.org/info/rfc8175>.
6.2. Informative References
[I-D.ietf-manet-dlep-credit-flow-control]
Cheng, B., Wiggins, D., and L. Berger, "DLEP Credit-Based
Flow Control Messages and Data Items", draft-ietf-manet-
dlep-credit-flow-control-02 (work in progress), June 2018.
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[I-D.ietf-manet-dlep-da-credit-extension]
Cheng, B., Wiggins, D., and L. Berger, "DLEP DiffServ
Aware Credit Window Extension", draft-ietf-manet-dlep-da-
credit-extension-05 (work in progress), May 2018.
[I-D.ietf-manet-dlep-pause-extension]
Cheng, B., Wiggins, D., and L. Berger, "DLEP Control Plane
Based Pause Extension", draft-ietf-manet-dlep-pause-
extension-04 (work in progress), June 2018.
[IEEE.802.1Q_2014]
IEEE, "IEEE Standard for Local and metropolitan area
networks--Bridges and Bridged Networks", IEEE 802.1Q-2014,
DOI 10.1109/ieeestd.2014.6991462, December 2014,
<http://ieeexplore.ieee.org/servlet/
opac?punumber=6991460>.
[RFC2474] Nichols, K., Blake, S., Baker, F., and D. Black,
"Definition of the Differentiated Services Field (DS
Field) in the IPv4 and IPv6 Headers", RFC 2474,
DOI 10.17487/RFC2474, December 1998,
<https://www.rfc-editor.org/info/rfc2474>.
[RFC2475] Blake, S., Black, D., Carlson, M., Davies, E., Wang, Z.,
and W. Weiss, "An Architecture for Differentiated
Services", RFC 2475, DOI 10.17487/RFC2475, December 1998,
<https://www.rfc-editor.org/info/rfc2475>.
[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>.
Appendix A. Acknowledgments
The sub Data Item format was inspired by Rick Taylor's "Data Item
Containers". He also proposed the separation of credit windows from
traffic classification at IETF98. Many useful comments were received
from contributors to the MANET working group. This document was
derived from [I-D.ietf-manet-dlep-da-credit-extension] as a result of
discussions at IETF101.
Authors' Addresses
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Bow-Nan Cheng
MIT Lincoln Laboratory
Massachusetts Institute of Technology
244 Wood Street
Lexington, MA 02421-6426
Email: bcheng@ll.mit.edu
David Wiggins
MIT Lincoln Laboratory
Massachusetts Institute of Technology
244 Wood Street
Lexington, MA 02421-6426
Email: David.Wiggins@ll.mit.edu
Lou Berger
LabN Consulting, L.L.C.
Email: lberger@labn.net
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