anima J. Zhao, Ed.
Internet-Draft S. Zhang, Ed.
Intended status: Standards Track China Unicom
Expires: 4 September 2025 3 March 2025

Automatic Network Congestion Relief
draft-zhao-anima-automatic-congestion-relief-00

Abstract

This document introduces an automatic congestion relief mechanism
based on intelligent traffic analysis and dynamic regulation. In the
event of congestion caused by fiber optic failures, it can respond
intelligently and self-heal in real time, ensuring the stable
operation of the network.

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This Internet-Draft will expire on 4 September 2025.

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Table of Contents

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Automatic Network Congestion Relief . . . . . . . . . . . . . 2
2.1. Step1: Traffic Modeling . . . . . . . . . . . . . . . . . 3
2.2. Step2: Traffic Monitoring . . . . . . . . . . . . . . . . 3
2.2.1. BGP-LS Utilized Bandwidth TLV . . . . . . . . . . . . 4
2.3. Step3: Intelligent Policy Generation . . . . . . . . . . 4
2.4. Step4: Policy Propagation . . . . . . . . . . . . . . . . 4
2.5. Step5: Policy Reversion . . . . . . . . . . . . . . . . . 5
3. usecase . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1. Pre-deployment Conditions . . . . . . . . . . . . . . . . 5
3.2. Implementation of Automated Mechanism . . . . . . . . . . 5
4. Security Considerations . . . . . . . . . . . . . . . . . . . 7
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
6. Normative References . . . . . . . . . . . . . . . . . . . . 7
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7

1. Introduction

Nowadays, fiber optic failures occur frequently, leading to network
congestion and becoming a common pain point for operators. These
issues necessitate dedicated staff to perform daily traffic
inspections and manually adjust configurations on an hourly basis,
which significantly increases the difficulty of network maintenance.

This draft introduces an automatic congestion relief mechanism based
on intelligent traffic analysis and auto-regulation. In the event of
congestion caused by fiber optic failures, it can intelligently
respond to congestion and initiate real-time self-healing processes,
solving the network congestion and maintenance challenges faced by
operators due to fiber optic failures, and ensuring the stable
operation of the network.

2. Automatic Network Congestion Relief

This second-level congestion relief mechanism is automated through
the intelligent module within the device. Leveraging intelligent
traffic analysis, it precisely calculates the volume of traffic
requiring redistribution. Subsequently, it redirects this traffic to
paired devices via inter-device protocol announcements and the
automatic adjustment of routing priorities.

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+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Traffic Modeling |------>| Traffic Monitoring |---->| Intelligent policy generation |
+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Policy Reversion |<----| Policy Regulation |
+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Figure 1: Mechanism Framework Description

2.1. Step1: Traffic Modeling

The forwarding chip of the device performs real-time traffic sorting
using full-flow data and identifies the top N traffic flows.

The intelligent component of the AI chip subscribes to the BGP RIB-
out (Routing Information Base-outbound) and employs intelligent flow
recognition algorithms to perform AI-based traffic modeling. This
modeling approach, considering factors such as historical traffic
patterns and flow behavior, provides a solid basis for subsequent
traffic detection and regulation.

The intelligent flow feature statistics cover multiple dimensions,
arranged in a logical order from macroscopic to microscopic traffic
characteristics, including flow rate, packet length, the proportion
of TCP/UDP traffic, the proportion of fragmented packets, and the
proportion of SYN packets.

2.2. Step2: Traffic Monitoring

Through the extension of the BGP-LS protocol, the inter-domain link
bandwidth and load changes are obtained by the device in real-time.

When the link bandwidth exceeds the set congestion threshold, the
situation where the link bandwidth exceeds the threshold is reported
quickly.

The interface statistics are collected at a second-level time
interval.

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2.2.1. BGP-LS Utilized Bandwidth TLV

The device uses the Utilized Bandwidth to aggregate the inter-domain
BGP EPE link bandwidth and bandwidth utilization rate. The BGP-LS
Utilized Bandwidth TLV reuses the Maximum Link Bandwidth TLV (Type
1089) [RFC5305] This TLV is used to describe the bandwidth and
bandwidth utilization of inter-domain BGP Egress Peer Engineering
(EPE) links. The format of the BGP-LS Utilized Bandwidth TLV is 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 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Utilized Bandwidth |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Figure 2: BGP-LS Utilized Bandwidth KEY TLV

2.3. Step3: Intelligent Policy Generation

When its utilization exceeds the predefined congestion threshold, the
device launches the intelligent module. The device intelligently
identifies the traffic that needs to be adjusted and generates
policies based on traffic analysis.

One policy is that, considering the traffic characteristics such as
flow rate and type, the device can make a more accurate calculation.
Since the routing prefixes sent to the one network domain (rib-out)
are the same, it is only necessary to change the attributes after
finding the TOP N routing prefixes to be adjusted, and lower the
priority of the faulty plane.

2.4. Step4: Policy Propagation

The device announces the automatic adjustment mechanism of routing
priorities through the BGP RPD protocol and then automatically
allocates the calculated traffic to the lightly-loaded plane. The
end-to-end process is completed within seconds, effectively
alleviating the congestion on the original plane. It can precisely
control neighbors and paths without affecting the existing routing
policies in the network.

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2.5. Step5: Policy Reversion

After the interrupted link recovers, the optimization policies will
be gradually withdrawn. With the revocation of the policies, the
network traffic will progressively return to the load-sharing state
before the failure.

3. usecase

----------------------------------------
| -------- -------- |
| | C2 | Network2 | C1 | |
| -------- -------- |
------|--------------------------|------
| |
| x
| 100GB x 8 x 100GB x 8
| |
-------|--------------------------|------
| +------- -------- |
| | CR2 | Network1 | CR1 | |
| -------- -------- |
----------------------------------------

Figure 3: Intelligent Decision-Making usecase

3.1. Pre-deployment Conditions

Establish topology mapping in Network 1 between CR1 and CR2, and
between CR1/CR2 and C1/C2 in Network 2, clarifying the connection
relationships. Set up BGP-LS peering between CR1 and CR2 to exchange
topology and bandwidth information. Enable BGP EPE functionality via
EBGP peering between CR1 and C1, and between CR2 and C2, to obtain
link state and bandwidth-related information and generate BGP-LS LINK
routes. Activate the BGP RPD neighbor function on CR1 and CR2 to
receive optimized routing policies.

3.2. Implementation of Automated Mechanism

* Step1：AI Traffic Modeling

CR1 and CR2 perform real-time and automatic TOP N traffic modeling
on the link using the built-in automated algorithms. Without
human intervention, they are capable of accurately grasping the
traffic conditions of the link. The system automatically monitors
that the total bandwidth of the traffic channels between CR1-C1
and CR2-C2 is 100 x 8GB, and the current traffic on both paths is
600GB.

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* Step2：Traffic Monitoring

If the CR1 device detects that a total of five links between
CR1-C1 have failed, leaving only three links, the system
automatically determines that congestion will occur on the CR1-C1
link.

* Step3：Intelligent Policy Generation

As the primary adjustment device, the intelligent module of CR1
automatically generates optimization policies based on the
established TOPN traffic model and the real-time collected prefix
information. The entire process does not require human
intervention, which greatly shortens the time from failure
discovery to policy formulation, and enables timely response to
network emergencies to ensure the stable operation of the network.

* Step4: Policy Propagation

After CR1 generates the optimization policies, it automatically
propagates them to C1. Upon receiving the policies, C1
automatically guides the remote routers to adjust their routing
paths.

The system intelligently identifies and then automatically diverts
the two services with the highest priority from the CR1-C1 link to
the CR2-C2 link (through C2) to alleviate the congestion on the
CR1-C1 link. After the policy adjustment, the system
automatically monitors that the traffic on the CR1-C1 link is
reduced to 300G, and the traffic on the CR2-C2 link is increased
to 800G. The automated policy propagation and traffic diversion
process is efficient and accurate, effectively improving the
utilization efficiency of network resources and quickly
alleviating the link congestion problem.

* Step5: Policy Reversion

When the failed links between CR1-C1 are restored, the system
automatically detects the link status change and gradually
withdraws the relevant optimization policies. Upon the automatic
revocation of the policies, the network traffic automatically and
gradually returns to the load-sharing state before the fault.

This automated mechanism ensures that the network can quickly
return to normal operation after the fault is eliminated, reducing
the cost of human intervention and improving the self-healing
ability of the network.

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4. Security Considerations

TBD.

5. IANA Considerations

TBD.

6. Normative References

[RFC5305] Li, T. and H. Smit, "IS-IS Extensions for Traffic
Engineering", RFC 5305, DOI 10.17487/RFC5305, October
2008, <https://www.rfc-editor.org/info/rfc5305>.

Authors' Addresses

Jing Zhao (editor)
China Unicom
Beijing
China
Email: zhaoj501@chinaunicom.cn

Shuai Zhang (editor)
China Unicom
Beijing
China
Email: zhangs633@chinaunicom.cn

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