Sự cần thiết cho khả năng mở rộng trong việc thực hiện tính toán hiệu năng cao có hướng xem xét lựa chọn thay thế cho kiến trúc mạng máy tính lớn dựa trên tập trung. Chương này đánh giá công nghệ và kỹ thuật có thể được sử dụng để tối ưu hóa khả năng sống sót và hiệu suất trong một môi trường liên mạng phân phối. | 198 Mission-Critical Platforms Network Platforms The trend in network convergence is having far-reaching effects. In addition to the merging of voice and data traffic over a common network it also implies consolidation of platform form factors. For the first time we are seeing switches that look like servers and servers that look like switches. Many of the principles just discussed pertaining to servers can also apply to network platforms. Network switching and routing platforms contain many of the same elements as a server OS CPU memory backplane and I O ports in some cases storage . But network platforms typically run a more focused application aimed at switching or routing of network traffic. They also must have more versatile network ports to accommodate various networking technologies and protocols. Because they have a more entangled involvement with a network than they do a server host they are subject to higher availability and performance requirements. Routers for instance were known to have availability that was several orders of magnitude lower than carrier class requirements would allow. Much has changed in the last several years. Convergence of voice video and data onto IP-based packet-switching networks and e-commerce and a blurring of the distinction between enterprise and service provider have placed similar high-availability requirements on data networking as on telephony equipment to the point where now these devices must have the inherent recovery and performance mechanisms found in FT FR HA platforms. Switches and routers have become complex devices with numerous configuration and programmable features. Unplanned outages are typically attributed to hardware failures in system controller cards or line cards software failures or even memory leaks. Some of the most major outages in recent years were attributed to problematic software and firmware upgrades. The greater reliance on packet IP networks as a routing fabric for all services has .
