Cisco 2950 Software Configuration Guide - Page 45

Chapter 1 Overview Network Configuration Examples Table 1-4 Providing Network Services Network Demands Suggested Design Methods High demand for multimedia support • Use IGMP and MVR to efficiently forward multicast traffic. High demand for protecting mission-critical applications • Use VLANs and protected ports to provide security and port isolation. • Use VLAN trunks, cross-stack UplinkFast, and BackboneFast for traffic-load balancing on the uplink ports so that the uplink port with a lower relative port cost is selected to carry the VLAN traffic. An evolving demand for IP telephony • Use QoS to prioritize applications such as IP telephony during congestion and to help control both delay and jitter within the network. • Use switches that support at least two queues per port to prioritize voice and data traffic as either high- or low-priority, based on 802.1p or 802.1Q. A growing demand for using existing infrastructure to transport data and voice from a home or office to the Internet or an intranet at higher speeds • Use the Catalyst 2900 LRE XL or Catalyst 2950 LRE switches to provide up to 15 Mb of IP connectivity over existing infrastructure (existing telephone lines). Figure 1-1 shows configuration examples of using the Catalyst switches to create these networks: • Cost-effective wiring closet-A cost-effective way to connect many users to the wiring closet is to connect up to nine Catalyst 2900 XL, Catalyst 2950, Catalyst 3500 XL, and Catalyst 3550 switches through GigaStack GBIC connections. When you use a stack of Catalyst 2950G-48 switches, you can connect up to 432 users. To preserve switch connectivity if one switch in the stack fails, connect the bottom switch to the top switch to create a GigaStack loopback, and enable cross-stack UplinkFast on the cross-stack Gigabit uplinks. You can create backup paths by using Fast Ethernet, Gigabit, Fast EtherChannel, or Gigabit EtherChannel links. Using Gigabit modules on two of the switches, you can have redundant uplink connections to a Gigabit backbone switch such as the Catalyst 3550-12G switch. If one of the redundant connections fails, the other can serve as a backup path. You can configure the stack members and the Catalyst 3550-12G switch as a switch cluster to manage them through a single IP address. • High-performance workgroup-For users who require high-speed access to network resources, use Gigabit modules to connect the switches directly to a backbone switch in a star configuration. Each switch in this configuration provides users with a dedicated 1-Gbps connection to network resources in the backbone. Compare this with the switches in a GigaStack configuration, where the 1-Gbps connection is shared among the switches. With the high speed uplink to the distribution server, the user can efficiently obtain and store data from servers. Using these Gigabit Ethernet modules also provides flexibility in media and distance options: - 1000BASE-T GBIC: copper connections of up to 328 feet (100 meters) - 1000BASE-SX GBIC: fiber connections of up to 1804 feet (550 meters) - 1000BASE-LX/LH GBIC: fiber connections of up to 32,808 feet (10 kilometers) - 1000BASE-ZX GBIC: fiber connections of up to 328,084 feet (100 kilometers) 78-11380-10 Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide 1-11