Internet DRAFT - draft-yi-cats-hybrid-solution
draft-yi-cats-hybrid-solution
Computing-Aware Traffic Steering X. Yi, Ed.
Internet-Draft R. Pang, Ed.
Intended status: Standards Track China Unicom
Expires: 25 April 2024 H. Shi
Huawei
23 October 2023
Hybrid Computing and Network Awareness and Routing Solution for CATS
draft-yi-cats-hybrid-solution-02
Abstract
Computing-Aware Traffic Steering (CATS) is a traffic engineering
architecture that takes the dynamic changes of computing and network
resources into account when forwarding traffic to appropriate service
instances for processing. For the development of the current
network, it is important to have a solution that meets different
types of service requirements and can be deployed reasonably.
Therefore, this document proposes a hybrid solution to provide
differentiated and flexible traffic streering capabilities for
different service while saving the cost of retrofitting existing
network equipment.
Discussion Venues
This note is to be removed before publishing as an RFC.
Discussion of this document takes place on the Computing-Aware
Traffic Steering Working Group mailing list (cats@ietf.org), which is
archived at https://mailarchive.ietf.org/arch/browse/cats/.
Source for this draft and an issue tracker can be found at
https://github.com/VMatrix1900/draft-yi-cats-hybrid-solution.
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
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Yi, et al. Expires 25 April 2024 [Page 1]
Internet-Draft Hybrid Solution for CATS October 2023
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 25 April 2024.
Copyright Notice
Copyright (c) 2023 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 carefully, as they describe your rights
and restrictions with respect to this document. Code Components
extracted from this document must include Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
1.2. Requirements Language . . . . . . . . . . . . . . . . . . 3
2. Background and Motivation . . . . . . . . . . . . . . . . . . 3
3. Service Flow . . . . . . . . . . . . . . . . . . . . . . . . 4
3.1. Service Overview . . . . . . . . . . . . . . . . . . . . 4
3.2. Workflow Overview . . . . . . . . . . . . . . . . . . . . 5
4. Security Considerations . . . . . . . . . . . . . . . . . . . 5
5. Normative References . . . . . . . . . . . . . . . . . . . . 5
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6
1. Introduction
CATS enables large-scale interconnected collaboration at the edge,
providing optimal service access and load balancing to adapt to
dynamic service. The computing power and network based on the actual
processing delay condition can dynamically process the service
request to switch to the appropriate service node, thereby improving
the quality of service resource utilization and user
experience[I-D.ldbc-cats-framework]. CATS needs to provide
diversified and differentiated service capabilities so that different
service traffic can be forwarded to appropriate service instance.
This document proposes a hybrid solution, on the one hand, it uses
centralized computing information awareness and distributed routing
decision. On the other hand, it can provide the service capability
Yi, et al. Expires 25 April 2024 [Page 2]
Internet-Draft Hybrid Solution for CATS October 2023
of distributed routing or centralized routing for different services
to achieve service differentiation.
1.1. Terminology
1.2. 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 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
2. Background and Motivation
There are three main aspects of CATS 'work: - Computing information
awareness: The network of the resource utilization status and service
status of service instanct needs to be notified, so that the network
can perceive the status of service contact instance. - Select the
optimal service contact instance : The optimal service instance needs
to be calculated based on the status of computing and network. -
Calculate the optimal forwarding path: After determining the optimal
service instance, the optimal forwarding path to the service needs to
be calculated. The optimal forwarding path can be determined based
on network factors such as delay, packet loss rate, and bandwidth.
In the implementation of the above work, CATS still has some
problems: - A number of devices will be upgraded and the cost will be
high, if the computing information needs to be notified between
service instance and engress router. - As business scenarios become
more and more diverse, CATS needs to provide differentiated network
and computing capabilities for different requirements of different
businesses.
This document designs a hybrid solution from two aspects: - Collect
the computing information through the cloud management platform, and
then process and send it to the network device on demand. This kind
of centralized computing information awareness is more easier to
achieve and less costly to deploy compared to collect the computing
information distributedly. - Distributed or centralized routing
decision-making methods for different services. For intelligence
transportation：The location of vehicles is constantly changing when
vehicles are driving normally on the road. CATS needs to re-select
the optimal service instance and the optimal forwarding path
according to the latest vehicle location. In addition, the scenario
of intelligence transportation has very high requirements on delay,
and the delay value will directly affect the driving safety of
vehicles. Therefore, it is recommended that the ingress router of
Yi, et al. Expires 25 April 2024 [Page 3]
Internet-Draft Hybrid Solution for CATS October 2023
CATS makes routing decision, rather than the centralized controller
recalculating and sending to the ingress router. In this way, the
signaling transmission time between the centralized controller and
the ingress router is reduced. Thus, the service quality is
improved. For other scenario such as VR/AR, SDWAN, which generally
prioritize global utilization, it is suitable to use the centralized
routing decision method since the centralized controlller has a
global perspective.
3. Service Flow
+--------------+ +------------------+
| network | | cloud management |
| controller |<------| platform |
+--------------+ +------------------+
/ \
+------------------+ +---------------+
| R2 R3 |------|service instance|
| | +----------------+
Client---|R1(ingress router)|
| | +---------------+
| R4 R5 |------|service instance|
+------------------+ +---------------+
Figure 1: Hybrid-Solution-Arhicteture
3.1. Service Overview
During the deployment of the service, the cloud management platform
or other upper-layer systems collect computing information, process
it, and then send it to the required network devices, which are
generally network ingress router. Then, CATS determines whether to
use the centralized routing decision-making mode or the distributed
routing decision-making mode based on the service type. Generally,
it is recommended that services with strict requirements on time
delay adopt the distributed routing decision making mode, and the
other services adopt the centralized routing decision making mode.
When the distributed routing decision-making mode is adopted, the
CATS ingress router selects the optimal service instance and
calculates the optimal forwarding path according to the status of
computing and network, and then directs the user traffic to the path
towards the service instance.
Yi, et al. Expires 25 April 2024 [Page 4]
Internet-Draft Hybrid Solution for CATS October 2023
When the centralized routing decision-making mode is adopted, the
network controller selects the optimal service instance and
calculates the optimal forwarding path according to the status of
computing and network, and sends the results to the ingress router.
The ingress router directs user traffic to the path towards the
service instance.
3.2. Workflow Overview
1. The service instance reports the computing information to the
cloud management platform.
2. The cloud management platform processes computing information and
send it to the network controller.
3. The network controller collect the network information and
process it along with computing information.
1. Distributed routing decision mode: The network controller
sends computing information to the network ingress router.
The ingress router selects the optimal service instance and
calculates the optimal forwarding path.
2. Centralized routing decision mode: The network controller
selects the optimal service instance, calculates the optimal
forwarding path and sends the result to the ingress router.
4. The ingress router performs traffic steering.
4. Security Considerations
TBD
5. Normative References
[I-D.ldbc-cats-framework]
Li, C., Du, Z., Boucadair, M., Contreras, L. M., Drake,
J., Huang, D., and G. S. Mishra, "A Framework for
Computing-Aware Traffic Steering (CATS)", Work in
Progress, Internet-Draft, draft-ldbc-cats-framework-03, 4
August 2023, <https://datatracker.ietf.org/doc/html/draft-
ldbc-cats-framework-03>.
[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>.
Yi, et al. Expires 25 April 2024 [Page 5]
Internet-Draft Hybrid Solution for CATS October 2023
[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>.
Authors' Addresses
Xinxin Yi (editor)
China Unicom
Beijing
China
Email: yixx3@chinaunicom.cn
Pang Ran (editor)
China Unicom
Beijing
China
Email: pangran@chinaunicom.cn
Hang Shi
Huawei
Beijing
China
Email: shihang9@huawei.com
Yi, et al. Expires 25 April 2024 [Page 6]
