2024-08-19 0

Multi-Rate Ethernet: A Solution to Meet Modern Network Demands

Dingtalk 20240819111915 1 1
Introduction
As digital transformation accelerates and data demands continue to grow, traditional single-rate Ethernet can no longer meet the needs of various applications. The emergence of multi-rate Ethernet technology provides greater flexibility and scalability for networks, making it an essential part of modern network architecture.What is Multi-Rate Ethernet?Multi-rate Ethernet refers to Ethernet interface technology that supports multiple rates, typically including 10 Mbps, 100 Mbps, 1 Gbps, 2.5 Gbps, 5 Gbps, and 10 Gbps. This technology allows network devices to automatically adjust data transmission rates on the same physical port based on demand, better adapting to different application scenarios.

 

The Emergence of Multi-Gigabit Ethernet

The IEEE 802.3an-2006 standard introduced the 10GBASE-T Ethernet standard, designed to support network transmission at speeds up to 10 Gbit/s. Unlike previous Ethernet versions, the rollout of 10GBASE-T was slower due to the high cost per port and the limitations of existing Cat5e/Cat6 cabling, which could not fully support the standard. Upgrading to Cat6a cabling was necessary, presenting significant costs for enterprises needing to replace their existing infrastructure.To address this challenge, industry leaders such as Cisco, Aquantia, NXP, and Intel formed the NBASE-T alliance in 2014. They developed two intermediate speed specifications, 2.5GBASE-T and 5GBASE-T, which have since been ratified by the IEEE and included in the IEEE 802.3bz standard. This new standard allows enterprises to maximize their existing cable investments by upgrading only the devices at each end to those that comply with the IEEE 802.3bz standard, thereby boosting bandwidth by up to five times while continuing to use Cat5e and Cat6 cables.

 

1.MIMO Technology in Multi-Gigabit Ethernet

Multi-Gigabit Ethernet enhances bandwidth by incorporating additional data channels into existing Ethernet hardware. These channels, known as multiple-input multiple-output (MIMO) channels, operate independently, thereby increasing the overall data transmission rate. Furthermore, the technology employs advanced modulation techniques, such as pulse-amplitude modulation with 16 discrete levels (PAM-16), to transmit more data per channel. This enables Multi-Gigabit Ethernet to deliver higher rates than traditional Ethernet using the same physical cabling.

 

2.PHY Technology in Multi-Gigabit Ethernet

To achieve higher data rates while combating increased signal loss and interference, Multi-Gigabit Ethernet relies on more sophisticated digital signal processing algorithms and analog front-end technologies with enhanced bandwidth and linearity. A key element is the use of the low-density parity-check (LDPC) error correction algorithm, which significantly reduces the bit error rate, ensuring a highly reliable link with minimal packet loss. Additionally, to overcome issues associated with traditional decision feedback equalizers (DFE), Multi-Gigabit Ethernet employs Tomlinson-Harashima precoding (THP) and soft decision techniques to further reduce error rates.

 

The transition from PAM-5 modulation in Gigabit Ethernet to PAM-16 in 2.5 Gbit/s and 5 Gbit/s networks allows for more data to be carried per Hz of frequency bandwidth, albeit with stricter requirements on analog front-end linearity and noise performance. Moreover, the adoption of co-frequency co-time full duplex (CCFD) technology enables simultaneous bidirectional signal transmission on the same differential cable pairs, doubling the information transmission efficiency compared to traditional time or frequency division methods.

 

3.PoE Power Supply in Multi-Gigabit Ethernet

A primary application of Multi-Gigabit Ethernet is to provide backhaul for WLAN AP data. In many deployment scenarios, APs are mounted on ceilings or walls, making it challenging to provide them with power. Running separate power cables increases the complexity and cost of campus networks, making Power over Ethernet (PoE) technology critical.PoE enables network cables to simultaneously supply power and transmit data without disrupting normal data flow. There are three PoE standards: IEEE 802.3af (PoE), IEEE 802.3at (PoE+), and IEEE 802.3bt (PoE++). The IEEE 802.3bz standard for Multi-Gigabit Ethernet supports all three PoE standards across all data rates, reducing costs and enhancing network adaptability.

 

Huawei Multi-Gigabit Ethernet Switches

Currently, Multi-Gigabit Ethernet has become the best choice for the transition from Gigabit Ethernet to 10 Gigabit Ethernet, and is developing rapidly.Therefore, Huawei has launched dozens of switches that support the Multi-Gigabit Ethernet standard, such as CloudEngine S5735-S-V2, CloudEngine S5755-H, and CloudEngine S5732-H-V2 series switches. These switches help enterprises upgrade bandwidth without replacing their cable infrastructure. In addition, Huawei Multi-Gigabit Ethernet switches are compatible with multiple IEEE Ethernet Ethernet standards and support Ethernet ports such as 100M/GE/2.5GE/5GE/10GE Base-T ports, implementing flexible rate switching from 100 Mbit/s to 10 Gbit/s.

 

  • CloudEngine S5735-L-V2 series switches: Based on the next-generation high-performance hardware and software platform, CloudEngine S5735-L-V2 series switches stand out with features including intelligent stack (iStack), flexible Ethernet networking, and diversified security control. These switches support multiple Layer 3 routing protocols and provide higher performance and more powerful service processing capabilities. They are widely used in scenarios such as enterprise campus network access and 2.5GE to the desktop.

S5735 L V2

CloudEngine S5735-L-V2 switch

 

  • CloudEngine S5735-S-V2 series switches: Based on the next-generation high-performance hardware and Huawei’s unified software platform, CloudEngine S5735-S-V2 series switches provide enhanced Layer 3 features, easy O&M, flexible Ethernet networking, and mature IPv6 features. They are widely used as access and aggregation switches on enterprise campus networks and access switches on data center networks.

S5735 S V2

CloudEngine S5735-S-V2 switch

 

  • CloudEngine S5755-H series switches: Based on the unified Huawei-developed software platform, CloudEngine S5755-H series next-generation high-quality access switches support VXLAN to implement campus network virtualization and multi-purpose network, and provide free mobility to ensure consistent user experience. A switch provides a maximum of 48 downlink ports and supports MACsec on all ports. They are the best choice of access switches for WLAN APs in the Wi-Fi 6 and Wi-Fi 7 era, and are widely used in healthcare, retail, mining, and Internet industries.

S5755 H

CloudEngine S5755-H switch