Internet DRAFT - draft-li-6man-apn-ipv6-encap
draft-li-6man-apn-ipv6-encap
Network Working Group Z. Li
Internet-Draft S. Peng
Intended status: Standards Track Huawei Technologies
Expires: 5 September 2024 C. Xie
China Telecom
S. Zhang
China Unicom
4 March 2024
Application-aware IPv6 Networking (APN6) Encapsulation
draft-li-6man-apn-ipv6-encap-00
Abstract
Application-aware IPv6 Networking (APN6) makes use of IPv6
encapsulation to convey the APN Attribute along with data packets and
make the network aware of data flow requirements at different
granularity levels. The APN attribute can be encapsulated in the APN
header. This document defines the APN header and its encapsulation
in the IPv6 data plane.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on 5 September 2024.
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Please review these documents carefully, as they describe your rights
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Requirements Language . . . . . . . . . . . . . . . . . . . . 3
3. Terminologies . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Problem statement and Requirements . . . . . . . . . . . . . 3
5. Usage scenarios . . . . . . . . . . . . . . . . . . . . . . . 4
6. APN Header . . . . . . . . . . . . . . . . . . . . . . . . . 4
7. APN ID . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
8. APN Parameters . . . . . . . . . . . . . . . . . . . . . . . 6
9. The APN Option . . . . . . . . . . . . . . . . . . . . . . . 8
10. Locations for the APN Option . . . . . . . . . . . . . . . . 9
10.1. IPv6 Hop-by-Hop Options Header (HBH) . . . . . . . . . . 9
10.2. IPv6 Destination Options Header (DOH) . . . . . . . . . 9
11. APN TLV for the SRH . . . . . . . . . . . . . . . . . . . . . 10
12. Implementation Status . . . . . . . . . . . . . . . . . . . . 10
13. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
13.1. APN ID Types . . . . . . . . . . . . . . . . . . . . . . 11
13.2. APN Parameter Types . . . . . . . . . . . . . . . . . . 12
13.3. IPv6 Header Option . . . . . . . . . . . . . . . . . . . 12
13.4. SRH TLV Type . . . . . . . . . . . . . . . . . . . . . . 12
14. Security Considerations . . . . . . . . . . . . . . . . . . . 13
15. References . . . . . . . . . . . . . . . . . . . . . . . . . 13
15.1. Normative References . . . . . . . . . . . . . . . . . . 13
15.2. Informative References . . . . . . . . . . . . . . . . . 14
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14
1. Introduction
Application-aware Networking (APN) conveys an attribute with data
packets in the network and makes the network aware of fine-grained
requirements at appropriate level.
Such an attribute is acquired, constructed in a structured value, and
then encapsulated in the packets. Such a structured value is treated
as an opaque object in the network, to which the network operator
applies policies in various nodes/service functions along the path
and provides corresponding services.
This structured attribute can be encapsulated in various data planes
adopted within a Network Operator's controlled and limited domain,
e.g. MPLS, VXLAN, SR/SRv6 and other tunnel technologies.
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This document defines the application-aware networking (APN) header
and its encapsulation in the IPv6 data plane.
2. 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 RFC 2119 [RFC2119] RFC 8174 [RFC8174] when, and only when, they
appear in all capitals, as shown here.
3. Terminologies
APN: Application-aware Networking
APN6: Application-aware IPv6 Networking, i.e., the data plane of APN
is IPv6
APN Attribute: Application-aware information. It is added at the
edge devices of an APN domain along with any tunnel encapsulation.
APN ID: Application-aware Networking ID
APN Para: Application-aware Networking Parameters
SRH: Segment Routing Header RFC 8754 [RFC8754]
4. Problem statement and Requirements
In a network operator controlled domain, the ingress edge devices
usually have access to rich information, such as VLAN/QinQ, VPN ID,
and access interface, which is used to classify the packets into fine
granular virtual groups of flows at the edge.
However, after the packets enter the network operators domain, all
such information is not immediately visible at transit nodes. It may
be hidden inside encapsulation, masked by encryption, mapped to other
protocol fields, or stripped from the packets completely.
Furthermore, many mapping schemes, where they are used, lose some
level of granularity from the information available at the network
edge. For example, when the information is mapped into small fields
like DSCP (6 bits) or MPLS EXP (3 bits) the result is that only
relatively coarse grained QoS treatment can be provided. MPLS EXP
bits are sometimes insufficient to carry what an operator needs, even
the DSCP is really too small.
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On the other hand, the identification of single application or user
is not needed in the network either. Besides the commitment of
privacy protection, the traffic running in the network is aggregated
and the network does not have such capability nor the necessity of
processing such extremely fine granularity.
Therefore, the capability of offering appropriate level of
granularity is desired by operators in order to provide fine-grained
services.
5. Usage scenarios
The packet treatments needed may vary at different parts of the path
within the domain, and enough information is needed to determine
these treatments such as steering, triggering, and identifying in an
efficient way, that is, to efficiently realize a composite network
service provisioning along the path. For example, at the headend to
steer into corresponding path at the midpoint to collect
corresponding performance measurement data at the service function to
execute particular policies flexibly.
Furthermore, when the packet traversing through multiple technology
domains of a single operator, where each domain is controlled
independently without a hierarchical controller being deployed and
each has its own SLA mechanism, in this case, it is difficult to
achieve end-to-end consistency in service provisioning (e.g.
visualization) due to lack of information to indicate the granularity
of traffic flow across multiple domains. The ACL configuration at
the following domains edge devices are very complex and dynamic.
This information can be carried directly in the packet or achieved
through a mapping from an opaque tag. Existing protocols such as
SFC/NSH, SR/SRv6, MPLS, VXLAN, and IPv6, can be taken as
implementation basis, but in each case the protocol may need
extensions. This draft focuses on the extensions in the IPv6 data
plane.
6. APN Header
A common header, i.e. APN Header, is defined and can be used in
different data planes. The common header carries the APN attribute
that is composed of APN ID and APN parameters.
This document defines three types of APN ID:
- Type 1 APN ID: it is 32 bits.
- Type 2 APN ID: it is 64 bits.
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- Type 3 APN ID: it is 128 bits.
According to the types of APN ID, three types of APN headers are
defined and follow the same format 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| APN-ID-Type | Flags | APN-Para-Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| APN-ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Intent (Optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| APN-Para (Optional) |
......
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1. APN Header Format
APN-ID-Type: An 8-bit identifier, indicates the type of APN ID.
Flags: An 8-bit field. The possible flags will be defined in the
future versions of this document.
APN-Para-Type: A 16-bit map that specifies which APN parameters are
specified for the APN ID. The APN-Para-Type value is a bitmap. The
packing order of the APN parameters follows the bit order as
specified in the APN-Para-Type bitmap field. The following bits are
defined in this document, with details on each bit described in
Section 8.
Bit 0 (Most significant bit) When set, indicates the presence of the
bandwidth requirement.
Bit 1 When set, indicates the presence of the delay requirement.
Bit 2 When set, indicates the presence of the jitter requirement.
Bit 3 When set, indicates the presence of the packet loss rate
requirement.
APN-ID: A 32-bit identifier.
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Intent: A 32-bit identifier, represents a set of service requirements
to the network.
APN-Para: A variable field including APN parameters. The presence of
the APN parameters is indicated by the APN-Para-Type.
7. APN ID
The APN ID is suggested to be divided into three parts:
APP-Group-ID: Application Group ID
USER-Group-ID: User Group ID
Reserved: The reserved field.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| APP-Group-ID | USER-Group-ID | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2. Structure of APN-ID
The lengths of the APP-Group-ID and the USER-Group-ID are variable.
Their lengths must be configured and consistent within a specific APN
domain.
The APN ID can be configured by using a template [I-D.peng-apn-yang].
8. APN Parameters
In the APN Header, the APN-Para-Type is a bit field to indicate the
presence of corresponding APN parameters. When the bit is set, the
corresponding APN parameter MUST exist in the APN Header. The length
of each APN parameter is 32 bits. Thus it is easy to skip over
unknown requirements.
Typical APN parameters are the parameters related with the network
performance requirements as follows:
1. Bandwidth Requirement
This Bandwidth Requirement parameter indicates the minimum acceptable
bandwidth for the APN traffic. The format of this parameter is shown
in the following diagram:
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Bandwidth |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3. Bandwidth Requirement Parameter
where:
Bandwidth: This 32-bit unsigned integer field carries the bandwidth
requirement in Mbps along the path.
2. Delay Requirement
This Delay Requirement parameter indicates the maximum acceptable
delay. The format of this parameter is shown in the following
diagram:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| RESERVED | Delay |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4. Delay Requirement Parameter
where:
RESERVED: This field is reserved for future use. It MUST be set to 0
when sent and MUST be ignored when received.
Delay: This 24-bit field carries the delay requirements in
microseconds, encoded as an unsigned integer value. When set to the
maximum value 16,777,215 (16.777215 sec), then the delay is not
constrained. This value is the highest delay that can be tolerated.
3. Delay Variation Requirement
This Delay Variation Requirement parameter indicates the maximum
acceptable delay variation. The format of this parameter is shown in
the following diagram:
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| RESERVED | Delay Variation |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5. Delay Variation Parameter
where:
RESERVED: This field is reserved for future use. It MUST be set to 0
when sent and MUST be ignored when received.
Delay Variation: This 24-bit field carries the delay variation
requirements in microseconds, encoded as an unsigned integer value.
4. Packet Loss Rate Requirement
This Packet Loss Rate Requirement parameter indicates the maximum
acceptable packet loss rate. The format of this parameter is shown
in the following diagram:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| RESERVED | Packet Loss Rate |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 6. Packet Loss Rate Sub-TLV
where:
RESERVED: This field is reserved for future use. It MUST be set to 0
when sent and MUST be ignored when received.
Packet Loss Rate: This 24-bit field carries packet loss rate
requirement in packets per second as an unsigned integer. This value
is the highest packet-loss rate that can be tolerated.
9. The APN Option
To support Application-aware IPv6 networking, one IPv6 Header option
RFC 8200 [RFC8200], the APN option, is defined.
The APN option has the following format:
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Opt Type = TBD1| Opt Data Len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. .
. APN Header (Variable) .
. .
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 7. The APN Option
where:
o Opt Type: Type value is TBD1 (suggested value 0x13), an 8-bit
unsigned integer. Identifier of the type of this APN Option.
o Opt Data Len: An 8-bit unsigned integer. Length of the Option Data
field of this option, that is, length of the APN header.
o APN Header: Option-Type-specific data. It carries the APN header.
Variable-length field as specified in Section 6.
10. Locations for the APN Option
The APN IPv6 Header option can be placed in two locations in an IPv6
packet header RFC 8200 [RFC8200] depend upon the scenario and
implementation requirements. These are defined in the subsections
below.
10.1. IPv6 Hop-by-Hop Options Header (HBH)
The APN option can be carried in the IPv6 Hop-by-Hop Options Header.
By using the HBH Options Header, the information carried can be read
by every node along the path.
10.2. IPv6 Destination Options Header (DOH)
The APN option can be carried in the IPv6 Destination Options Header.
By using the DOH Options Header, the information carried can be read
by the destination node but would not normally be seen by other nodes
along the path.
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11. APN TLV for the SRH
[RFC8754] defines the segment routing header (SRH) and the SRH TLV.
The SRH TLV provides meta-data for segment processing. The APN
header can be placed in the SRH as the value of one type of SRH TLV
following the Segment List. By using the SRH, the information
carried can be read by the specified segment destinations along the
SRv6 path.
The APN TLV is OPTIONAL and has the following format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = TBD2 | Length |D| RESERVED |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. .
. APN Header (Variable) .
. .
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 8. The APN SRH TLV
where:
o Type: TBD2 (suggested value 0x13).
o Length: The length of the variable length data in bytes.
o D: 1 bit. When it is set, it indicates the Destination Address
verification is disabled due to use of a reduced segment list.
o RESERVED: 15 bits. MUST be 0 on transmission and ignored on
receipt.
o APN Header: It carries the APN header as specified in Section 6. A
variable-length field.
12. Implementation Status
Huawei:
Huawei hardware platforms supports APN with current status as
follows:
o Huawei ATN with VRPV8 shipping code.
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o Huawei CX600 with VRPV8 shipping code.
o Huawei NE40E with VRPV8 shipping code.
o Huawei ME60 with VRPV8 shipping code.
o Huawei NE5000E with VRPV8 shipping code.
o Huawei NE9000 with VRPV8 shipping code.
o Huawei NE8000 with VRPV8 shipping code.
Tshinghua University:
o Linux
BUPT (Beijing University of Posts and Telecommunications):
o P4
13. IANA Considerations
These IANA Considerations conform to [RFC8126].
IANA is requested to create the following new registries on a new
"Application-Aware Networking (APN)" webpage.
13.1. APN ID Types
IANA is requested to create the following registry on the
Application-Aware Networking (APN) Attribute webpage:
Name: APN ID Types
Registration Procedure: IETF Review
Reference: [this document]
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Value Description Reference
----- ------------- ---------------
0 reserved
1 Type 1 APN ID [this document]
2 Type 2 APN ID [this document]
3 Type 3 APN ID [this document]
4-254 unassigned
255 reserved
13.2. APN Parameter Types
IANA is requested to create the following registry on the
Application-Aware Networking (APN) Attribute webpage:
Name: APN Parameter Types
Registration Procedure: IETF Review
Reference: [this document]
Bit Description Reference
--- ----------------------- ---------------
0 Bandwidth requirement [this document]
1 Delay requirement [this document]
2 Jitter requirement [this document]
3 Packet loss requirement [this document]
4-15 unassigned
13.3. IPv6 Header Option
IANA is requested to assign an IPv6 Header Option as follows:
Hex Binary Value
Value act chg rest Description Reference
----- --- --- ----- ---------------------------- ---------------
0x13 00 0 10011 Application-aware Networking [this document]
13.4. SRH TLV Type
IANA is requested to assign an SRH TLV Type from the range of type
values for TLVs that do not change en route (2-127) as follows:
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Value Description Reference
----- ---------------------------- -----------------
0x13 Application-aware Networking [this document]
14. Security Considerations
In the APN work, in order to reduce the privacy and security issues,
the APN attribute MUST be conveyed along with the tunnel information
in the APN domain. The APN attribute is encapsulated and removed at
the edge of the APN domain. The APN ID MUST be acquired from the
existing available information in the packet header without
interference into the payload.
According to the above specifications, the APN attribute is only
produced and used locally within the APN domain without the
involvement of the host/application side.
In order to prevent the malicious attack through the APN attribute,
the following policies can be configured at the network devices of
the APN domain. If the APN attribute is conveyed without the tunnel
information, the packet MUST be dropped. If the APN attributes are
not known to the APN domain, it should trigger the alarm information.
The packet can be forwarded without being processed or dropped
depending on the local policy. If the network service requirements
exceed the specification for the specific APN ID, it should trigger
the alarm information. The packet should be discarded to prevent
abusing of the resources. There should be rate-limiting policy at
the edge of the APN domain to prevent the traffic belonging to a
specific APN ID from exceeding the preset limit.
15. References
15.1. 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>.
[RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", STD 86, RFC 8200,
DOI 10.17487/RFC8200, July 2017,
<https://www.rfc-editor.org/info/rfc8200>.
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[RFC8754] Filsfils, C., Ed., Dukes, D., Ed., Previdi, S., Leddy, J.,
Matsushima, S., and D. Voyer, "IPv6 Segment Routing Header
(SRH)", RFC 8754, DOI 10.17487/RFC8754, March 2020,
<https://www.rfc-editor.org/info/rfc8754>.
15.2. Informative References
[I-D.peng-apn-yang]
Peng, S. and Z. Li, "A YANG Model for Application-aware
Networking (APN)", Work in Progress, Internet-Draft,
draft-peng-apn-yang-03, 9 May 2023,
<https://datatracker.ietf.org/doc/html/draft-peng-apn-
yang-03>.
Authors' Addresses
Zhenbin Li
Huawei Technologies
Beijing
100095
China
Email: lizhenbin@huawei.com
Shuping Peng
Huawei Technologies
Beijing
100095
China
Email: pengshuping@huawei.com
Chongfeng Xie
China Telecom
China
Email: xiechf@chinatelecom.cn
Shuai Zhang
China Unicom
China
Email: zhangs366@chinaunicom.cn
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