1-9
Catalyst 2950 Desktop Switch Software Configuration Guide
78-14982-01
Chapter 1 Overview Network Configuration Examples
Bandwidt h alone is not the only c onsiderat ion when d esigning you r network. As you r network t raffic
profiles ev olve, consider providing network services that can support applications such as voice and data
integration and security.
Table 1-3 describes some network dema nds and how you can meet tho se demand s.
Figure 1-1 sh ows configu ration examples of using the Catalyst switches to create these networks:
•Cost-effective wiring closet—A cost-eff ective 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 Gi gaStack GBI C c onnec ti ons. W he n you use a stac k of Ca talyst 295 0G-48 sw itch es, y ou
can co nnect up to 432 us ers. To preser ve swi tch con necti vity i f one swi tch in the s tack fa ils, co nnect
the bottom switch to the top switch to create a GigaStack loopback, and enable cross-stack
UplinkFast on t he c ross-st ack Gigab it uplink s.
Table 1-2 Increasing Network Performance
Network Demands Suggested Design Methods
Too many users on a singl e network segmen t
and a growing number of users accessing the
Internet
•Create smaller network segments so that fewer users share the
bandw idt h, a nd use V LAN s an d I P su bne ts t o pl ace the net work
resources in the same logical network as the users who access those
resources most.
•Use full-duplex operation between the switch and its connected
workstations.
•Increas ed power of new PCs,
workstations, and servers
•High dem an d from n etworked
applications (such as e-mail with large
attached files) and from
bandw idth-i ntensive applic atio ns ( such
as multimedia)
•Connect global resources—such as servers and routers to which network
users require equal access—direct ly to t he Fast Et her net or G iga bit
Etherne t switch ports so that th ey have their own Fast Ethernet or
Gigabit Ethernet segment.
•Use the Fast EtherChannel or Gigabit EtherChannel feature between the
switch and its connected servers and routers.
Table 1-3 Pr oviding Ne tw o rk Services
Netw ork De ma nds Sugge ste d Des ign Metho ds
High dem an d f or mu l tim edia supp ort •Use IGMP and MVR to efficiently forward multicast traffic.
High demand for protecting mission-critical
applications •Use VLANs and prot ected port s to provide sec urity and port isola tion.
•Use VLAN trunks, cross-stack UplinkFast, and BackboneFast for
traffic-lo ad 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 de mand fo r I P te lep hony •Use QoS to prioritize applications such as IP telephony during
congestion an d to help control bo th delay and jitter with in the netw ork.
•Use swit ches that s upport at leas t two que ues per port to priorit ize vo ice
and d ata t raffic as ei the r high- or l ow-prior it y, b ased on 80 2.1 P/Q.
A growing d em and for us ing exis ting
infra struct ure to tran sport data and voice from
a home or off i ce to the Inte rnet or an intranet at
higher speeds
•Use the Catalyst 2950 LRE switches to provide up to 15 Mb of IP
connectivity over existing infrastructure (existing telephone lines).