Multi-level client-server network is a modernized form of client-server network for a special reason that is, here different applications and protocols are assigned in individual server. So, if one of the servers is crashed or stopped for a small or long time all the functions do not stop. It means all servers are individually configured such as DHCP server, DNS Server, Mail Server, FTP Server etc. for different purposes. In traditional client-Server Network system a client uses several applications from the same server. If the server is crashed, the total work of that network will be stopped. So, in case of corporate network it is essential to get flawless performance all the time. Corporate offices have their own head office, branch offices and e-commerce customers. To support all of them the corporate office can setup it’s own ISP to support the branch offices as well as the registered customers of the office. For better support without using multi-layer network they can use... Это и многое другое вы найдете в книге Multi-Level Client Server Network and Its Performance Analysis (Mamun Kabir and Mohammad Rashed)