Internet DRAFT - draft-du-apn6-auto-encapsulation-adjustment
draft-du-apn6-auto-encapsulation-adjustment
Network Working Group Z. Du
Internet-Draft P. Liu
Intended status: Standards Track China Mobile
Expires: 15 April 2023 12 October 2022
Auto-adjustment of Encapsulation Information in APN6
draft-du-apn6-auto-encapsulation-adjustment-03
Abstract
This document introduces a method to adjust the encapsulation
information in Application-aware IPv6 Networking.
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 RFC 2119 [RFC2119].
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 15 April 2023.
Copyright Notice
Copyright (c) 2022 IETF Trust and the persons identified as the
document authors. All rights reserved.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Current Mechanism in APN6 . . . . . . . . . . . . . . . . . . 3
3. Comparisons of Data Plane and Control Plane Programming . . . 4
4. Potential Solutions for Auto-adjustment . . . . . . . . . . . 4
4.1. Triggered by a Timer . . . . . . . . . . . . . . . . . . 5
4.2. Triggered by a Notification Message . . . . . . . . . . . 6
5. Deployment Consideration . . . . . . . . . . . . . . . . . . 6
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
7. Security Considerations . . . . . . . . . . . . . . . . . . . 6
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 7
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
9.1. Normative References . . . . . . . . . . . . . . . . . . 7
9.2. Informative References . . . . . . . . . . . . . . . . . 7
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7
1. Introduction
As the development of 5G and the new emerging Internet services, such
as live video streaming, the networks are facing a larger and larger
SLA requirement difference. For better bearing of the user's
traffic, the networks need to be intelligent and be aware of the user
traffic's demand. An innovative method called APN6 is introduced in
[I-D.li-apn6-problem-statement-usecases] and [I-D.li-apn-framework].
In the mechanism of APN6, the packet can carry the ID information and
SLA requirements of the traffic, and network equipment can get them
in each packet and handle the packet accordingly. It is one kind of
network programming mechanisms on the data plane.
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As the encapsulation information increases in an APN packet, some
bandwidth is kindly wasted in APN6 which contains a larger overhead
in every packet. On one aspect, it is believed that it is necessary
for the evolution to an intelligent network; on the other aspect, it
is recommended that after the network has known the requirements of
the traffic and associated it with a proper policy, the traffic does
not need to resend the same information in every packet again and
again. This document describes the process of the later, and
discusses two potential solutions for the auto-adjustment of the
encapsulation information in APN.
2. Current Mechanism in APN6
As shown in Figure 1, the APN framework [I-D.li-apn-framework]
includes Service-aware App, App-aware Edge Device, App-aware-process
Head-End, App-aware-process Mid-Point, and App-aware-process End-
Point.
Client Server
+-----+ +-----+
|App x|-\ /->|App x|
+-----+ | +-----+ +---------+ +---------+ +---------+ | +-----+
\->|App- | |App-aware|-A-|App-aware|-A-|App-aware|-/
User side |aware|-|process |-B-|process |-B-|process |
/->|Edge | |Head-End |-C-|Mid-Point|-C-|End-Point|-\
+-----+ | +-----+ +---------+ +---------+ +---------+ | +-----+
|App y|-/ \->|App y|
+-----+ --------- Uplink ----------> +-----+
Figure 1: Framework and Key Components in APN6
The data-driven process of APN6 is described below.
The APP or the APP-aware Edge will generate APN packets each carries
the application characteristic information in the encapsulation. In
this document, we also call the APP or the Edge as the encapsulation
node.
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App-aware-process Head-End can read that information and steer the
packets into a given policy which satisfies the application's SLA
requirements. It is supposed that a set of paths, tunnels or SR
policies, exist between the App-aware-process Head-End and the App-
aware-process End-Point. App-aware-process Head-End can find one
existing path or establish a new one for the traffic. In this
document, we also call the Head-End as the mapping node.
3. Comparisons of Data Plane and Control Plane Programming
We can realize the same traffic steering on the control plane. The
control-plane based process, as described below, includes three key
components: the identity of the traffic, policies in Head-End, and
the interface to notify the user requirements.
The APP or the Edge knowing the application characteristic
information needs to report that information to the controller of the
Head-End by some means.
The controller needs to know the traffic requirements and the status
of the network, and generate a policy for the Head-End. The policy
SHOULD include the identity of the traffic and the path that the
traffic should follow.
The Head-End needs to implement the policy, and steer the traffic to
the proper path.
In this mechanism, we do not need to carry extra information in each
packet, but need to generate control messages between the Edge and
the controller, and between the Head-End and the controller.
In the situation that the traffic is small, and simple to handle, a
control-layer decision-loop is not that necessary. By comparison, a
date-driven method is more flexible. In this situation, the Head-End
after steering the traffic needs to report the (summarized) change to
the controller.
4. Potential Solutions for Auto-adjustment
We can find that after the Head-End has selected the policy, the
extra information carried in the following APN6 packets has little
use. Therefore, an auto-adjustment of encapsulation information
mechanism may be helpful for the simplification of the following IPv6
packets.
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According to [I-D.li-apn-framework], the information may include
application-aware identification, such as SLA level, application ID,
user ID, flow ID, etc., and network performance requirements, such as
bandwidth, latency, jitter, packet loss ratio, etc. Hence, at least,
we can send only the application-aware identification information in
the following APN6 packets without network performance requirements
information.
Two methods to reduce the overhead of the APN packets are described
below.
4.1. Triggered by a Timer
One straightforward method is that we firstly send full information
in APN6 packets, and after several seconds, we send APN6 packets that
only contain the necessary information, such as the application-aware
identification information.
After receiving the first APN packet of the traffic from the
encapsulation node, the mapping node can obtain the application
related information from the packet. As talked before, the
information includes the application-aware identification and network
performance requirements, and accordingly the mapping node
establishes a mapping relationship between the traffic and a proper
tunnel or policy.
In this method, we believe that the mapping node can handle the
policy mapping process in the several seconds. For example, it can
be three seconds. The number should be a parameter that can be
adjusted according to the situation of each network. In this
solution, a timer is needed in the encapsulation node. It is started
after the first APN packet of the traffic is sent. When the timer
expires, the encapsulation node will consider that the mapping node
has finished the mapping job.
If all nodes work well, after the several seconds, the mapping node
will receive APN packets of the traffic from the encapsulation node
that contain only the necessary information, for example the
application-aware identification information. In addition, the APN
related information in the packets can only contain the necessary
flow ID information, which is a part of the application-aware
identification information.
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4.2. Triggered by a Notification Message
Another method is that after enabling the policy, the mapping node
can notify the encapsulation node by some means. However, we do not
have a notification mechanism between different nodes on the data-
plane network programming now. We need to notify by using the
control plane again. The control plane sends a message to the
encapsulation node to adjust the encapsulation degree.
This document suggests enabling a simple notification method for the
data-plane network programming if the information is not that
complicated. For example, we can send a "ping" message with a
specific flag to the encapsulation node. The advantage is easy to
inter-operate.
In this solution, the encapsulation node will not need a timer, and
instead it can receive a notification message from the mapping node.
After that, the encapsulation node can make sure that the mapping
node has finished the mapping job between the traffic and a proper
tunnel or policy, and starts to send APN packets of the traffic with
simplified information.
5. Deployment Consideration
In future, with the technical development of network equipments, the
bandwidth may not be the bottleneck anymore, so that a full APN6
encapsulation packet may be used widely to enable the data plane
intelligence. However, the auto-adjustment of encapsulation
information method can help the adoption of the APN6 mechanism by
providing a transit solution. Meanwhile, this document also provides
a feedback mechanism for the data plane programming to enable the
coordination between two nodes.
6. IANA Considerations
TBD.
7. Security Considerations
TBD.
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8. Acknowledgements
TBD.
9. References
9.1. Normative References
[I-D.li-apn-framework]
Li, Z., Peng, S., Voyer, D., Li, C., Liu, P., Cao, C., and
G. S. Mishra, "Application-aware Networking (APN)
Framework", Work in Progress, Internet-Draft, draft-li-
apn-framework-06, 30 September 2022,
<https://www.ietf.org/archive/id/draft-li-apn-framework-
06.txt>.
[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>.
9.2. Informative References
[I-D.li-apn6-problem-statement-usecases]
Li, Z., Peng, S., Voyer, D., Xie, C., Liu, P., Liu, C.,
Ebisawa, K., Previdi, S., and J. N. Guichard, "Problem
Statement and Use Cases of Application-aware IPv6
Networking (APN6)", Work in Progress, Internet-Draft,
draft-li-apn6-problem-statement-usecases-01, 3 November
2019, <https://www.ietf.org/archive/id/draft-li-apn6-
problem-statement-usecases-01.txt>.
Authors' Addresses
Zongpeng Du
China Mobile
No.32 XuanWuMen West Street
Beijing
100053
China
Email: duzongpeng@foxmail.com
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Peng Liu
China Mobile
No.32 XuanWuMen West Street
Beijing
100053
China
Email: liupengyjy@chinamobile.com
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