Impact of SAN multi-protocol on future router development

At present, SAN multi-protocol is widely used. So I have studied the impact of SAN multi-protocol on the future development of routers. I would like to share with you here, hoping to help you. This great career of Kumar Malavalli originated from his comparison and Investigation of the world's popular network technologies represented by Ethernet and the channel technologies represented by SCSI.

The basic starting point for the creation of the optical fiber channel protocol is to create an advanced network architecture that combines the advantages of the network routing technology and the advantages of the channel technology. Because Fiber Channel learned the network technology at that time, the advantages of the channel technology were eliminated, and engineers with various network technology backgrounds were competing to take the network they knew, the channel protocol was rewritten to the fourth layer (FC-4) of the fiber channel. At that time, the protocols that were standardized to FC-4 were SCSI, IP, ATM, FICON (ESCON's fiber channel version) and so on. Over the past 10 years, fiber channel SCSI has evolved into a mainstream multi-protocol for the storage of Local Area Network SAN. FICON has also become the mainstream of the Mainframe (Mainframe) storage protocol. The IP Technology Based on Fiber Channel is applied to the management of fiber channel switches.

The SAN Multi-Protocol Based on Fiber Channel can transmit data at a high speed of 200 MB/sec. An important difference between an optical fiber channel and other network protocols is its data transfer bandwidth utilization. In an Optical Fiber Channel architecture, the bandwidth utilization can easily reach more than 99%. This is incomparable to other existing network protocols. Fiber Channel can extend the SAN multi-protocol connection distance to over 100 kilometers. If the protocol conversion technology (for example, the conversion from the fiber channel to the SONET and the conversion from the fiber channel to the IP address) is supplemented, the connection distance of the SAN multi-protocol can reach the global scale. A Fabric consisting of fiber channel switches connected to each other can connect 239 fiber channel switches with up to 24-bit device address space. Compared with Ethernet, fiber channel data transmission in the same Fabric is device-to-device, while data transmission in the same Ethernet Subnet is broadcast. This is the main reason why fiber channel bandwidth usage is several times higher than that of Ethernet. It is precisely because the data transmission device of the Optical Fiber Channel in the same Fabric is opposite to the device, and the optical fiber channel stipulates a strict system to constitute a management system. In the management system of this system, the access and removal of devices, including fiber channel switches, are broadcast to devices that communicate with the access and removal devices in the form of broadcast.

The more fiber channel switches in a Fabric, the larger the SAN multi-protocol network. There are more opportunities for Device Access and migration. As a result, more information is sent to the outbound broadcast. Although such broadcast information is insignificant compared with the data broadcast storm in Ethernet, it cannot be ignored for the high availability level and network management required by the storage network.

In various disaster recovery systems, once the local and remote SAN multi-protocols are connected, a large Fabric is formed. However, long-distance bare fiber or IP connections that connect local and remote SAN protocols are often the weakest link in this Fabric. If the local and remote SAN protocols belong to the same Fabric, if the connection between them is unstable, Fabric reconfiguration, which affects the SAN multi-protocol architecture, will occur ). This is an important cause of unstable disaster recovery systems.

The Disaster Tolerance System is at a historical development stage from traditional disaster tolerance between two points to mutual disaster tolerance between multiple data centers and the provision of disaster tolerance as a service to multiple customers. The traditional isolated Fabric Structure of fiber channel can no longer meet the requirements of Multi-Point Disaster Tolerance and make disaster tolerance a service. Today, there are already hundreds of thousands of SAN multi-protocol islands in the world. Users often need to integrate these SAN multi-protocol islands. If this integration is integrated into a Fabric, the customer will face complicated operations such as adjusting the Fiber Channel switch parameters and rewriting the system composition files on some servers. In many cases, the customer cannot even arrange enough scheduled downtime to complete such system integration.

Different functional departments in the company objectively need to have the storage network development space and freedom of their own departments. The storage network of other departments should not be affected by the expansion of the multi-protocol SAN of a department. However, it is difficult to achieve this when all the company's server memory is in the same Fabric.