Ethernet Switch

Introduction

The Ethernet is the most commonly used network architecture, and most well known used by most users. The data rate was originally 10 Mbps, it is now currently working up to 100 Mbps, and 1000 Mbps data rate is common to use from local area network (LAN) to metropolitan area network (MAN) infrastructures. In the Ethernet network, in order to share and transmit data, the sharing hub is becoming one of the most important equipments as a node of network connections, due to the increasing demanding of data rate and efficiency, hubs is not able to afford anymore, the switches with more efficient performance is becoming popular in the market.

Unlike a hub, a switch checks every received data packet, and processes each packet appropriately. In a physical network environment, a switch has two major functions. The first is to divide the existing network into several subnets, so any expansion subnets are all reside in valid distances, and then more network nodes could be supported. The second function is to isolate traffics to prevent any collisions and crowded conditions in networks.

There are two switching techniques used in a switch: a straightforward “cutting through” method, and a “store and forward” method to verify and control packets passing through the switch. “Cutting through” only checks the header of the packets, then delivers the packets to the destination address indicated in the header of the packets. “Store and forward” receives the entire packet and verifies its correctness before sending the packets toward the destination path.

Standard

  • 802.1-High Level Interface
  • 802.2-LLC(Logical Link Control)
  • 802.3-CSMA/CD
  • 802.4-Token BUS
  • 802.5-Token Ring
  • 802.6-DQDB (Distributed Queue Dual Bus) 802.7-Broadband Technical Advisory Group
  • 802.8-Fiber Optic Technical Advisory Group
  • 802.9-Integrated Voice and Data LAN working Group
  • 802.10-LAN Security working Group
  • 802.11-Wireless LAN
  • 802.12-100VG-AnyLAN
  • 802.13-CATV
  • 802.1Qbv
  • 802.1AS
  • 802.1CB
  • 802.1Qci
  • 802.1Qch
  • 802.1br
  • 802.1p

Application

 

The switches of the metropolitan network can be divided into the switches used by Core Network, Aggregation Network and Access Network. Core Network’s switches mainly send/receive data to the backbone line, and do not do any processing on the data. The Aggregation Network switch takes the data from the Core Network switch and sends it to the path where the correct Access Network switch is located, or aggregates the data from the Access Network switch and uploads it to the Core Network. Access Network switches are used on the user side.
The types of LAN switches can be roughly and simply divided into enterprise-level Enterprise switches and family-level SOHO (Small Office / Home Office) switches based on the scope of use. If it is classified by functional category, it can be divided into Layer 3 switches, Layer 2 switches with management functions, and general switches. The main considerations are network management capabilities, especially quality, traffic, strategy, and management on virtual networks. In recent years, with the addition of radio technology, the port of WiFi access point is developing towards Multi-Gigbit level. We can also see that the demand for 2.5G, 5G, and 10G is also rapidly increasing.
The rise of cloud computing and scale-out data centers has driven the recent development of Ethernet speed. Stimulated by the demand for higher network performance, 10G port servers and 40G branch-backbone data center architectures have shown tremendous growth. As the huge amount of data continues to increase, the number of virtual machines continues to grow, and cloud workloads are becoming increasingly heavier, the network backbone layer of large cloud operators has gradually switched to 100G/400G architecture.
The requirement of long-distance high-speed transmission makes time synchronization IEEE 1588, TSN gradually become the key technology of the next generation of Ethernet switch products. TSN stands for “Time Sensitive Network”. It incorporates whether data can arrive at the destination on time into the transmission protocol of the Ethernet network. It continuously synchronizes the frequency and phase of time with the master clock, and can choose to synchronize multiple time domains at the same time. Under the requirements of the application, allowing data to be delivered at the correct time is a key technology that is essential for applications that emphasize “real-time”.
With the determinism, accuracy, guaranteed delivery and low latency characteristics of TSN Ethernet, it is sufficient to provide the best solutions in the following four markets:
Automobile industry
Fully autonomous vehicles need TSN Ethernet switches that comply with 802.11Qci and 802.1CB in the IEEE specification. These cars need a switch that can provide network integrity with zero packet loss, and have deterministic, fast response times to successfully execute peer-to-peer communications and road sensing infrastructure applications every time.
Telecom/Wireless Base Station
Under the 5G system settings, TSN Ethernet can achieve “real-time” performance under the MIMO architecture. TSN, especially when the packet is congested, can ensure the transmission of data packets through the characteristics of low delay and low jitter, and bring more bandwidth to each wireless node to process the transmitted traffic.
TSN Ethernet definition provides 802.1Qch and 802.1Qbu/802.3br based on IEEE specifications 1588v2 and 802.1AS-REV for packet management protocol for timing and synchronization, and also provides 5G with how to use TSN Ethernet in MIMO waves IEEE 802.1CM solution of the new model.
Automated industry
TSN Ethernet can enable industrial networks to safely, reliably and deterministically connect to large computing centers residing in the cloud of large data centers. TSN can process a large amount of data from multiple input sources such as data analysis cloud and Internet of Things (IoT) to make immediate decisions to improve real-time efficiency.
Professional audio/video
The professional audio/video industry also requires real-time and realistic requirements through the universal Ethernet ecosystem to complete real-time connections across multimedia data centers. TSN switches can be used to provide the ultra-high-quality 4k and 8k resolutions required by professional audio/video studios. TSN Ethernet supports IEEE specification 802.1CB, as well as 1588v2 and 802.1AS-REV for timing and synchronization. Used to provide redundancy for lossless synchronized video for real-time editing of 4K/8K resolution streams.
As chip technology advances to support 100G/400G connections, providing higher bandwidth, richer specifications, and deeper temporary memory, the Ethernet connection in the cabinet needs to be better than 40G The solution is 25G. 100G, like 40G (CAUI-4, 100GBASE-CR4, 100GBASE-SR4), uses four physical channels to communicate with connected devices, but now the rate of each channel is higher, which can reach 25Gbit/s, so according to single channel In principle of capacity expansion, multiple 25G ports can be used between the server/storage endpoint and the top-of-rack switch.

Architecture