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Catalyst 2950 Desktop Switch Software Configuration Guide
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Chapter 1 Overview Network Configuration Examples

Collapsed Backbone and Switch Cluster Configuration

Figure 1-3 sh ows a con figura tion for a n etwor k of appro xi mat ely 50 0 employees . Th i s net work u ses a
collapse d back bone and swit ch cluste rs. A colla psed back bone ha s high-ban dwidt h uplinks fr om all
segments and subnetworks to a single device, such as a Gigabit switch, that serves as a single point for
monitori ng and c ontro llin g the network. You can us e a Ca talyst 355 0-1 2T-L3 swit ch, as shown, or a
Catalyst 3508G XL sw it ch t o cr ea te a G igab it ba ck bone. A C at alyst 3550- 12 T-L3 ba ckbo ne swi tch
provides the benefits of inter-VLAN routing and allows the router to focus on WAN access.
The workgroups are created by clustering all the Catal yst switches except the Catalyst 4908G-L3 switch.
Using C MS an d Ci sco switc h cl uste ring techn ology, you can gr oup t he sw itche s in to mu l tiple c lust ers,
as shown, or into a single cluster. You can manage a cluster through the IP address of its active and
standby comm and swit ches, regardless of t he geogra phic loca tion of the cluster mem bers.
This network uses VLA Ns to segment th e network logically into well- defined broadc ast groups and for
security m anagement. Da ta and multime dia traf f ic are conf igured on the same VLAN. Voice traf f ic fro m
the Cisc o IP Phones ar e co nfigured on se para te voice VL AN IDs (VV IDs). You can have up to
four VVIDs per wiring closet. If data, multimedia, and voice traf fic are assigned to the same VLAN, only
one VL AN can be co nfigured per wir ing closet . For any switch port conne cted to Cis co IP Phon es,
802.1P/Q Qo S gives forwarding priority to voice traffic over data traffic.
Grouping servers in a centralized location provides benefits such as security and easier maintenance.
The Gigabit connections to a server farm provide the workgroups full access to the network resources
(such as a call-processing server running Cisco CallManager software, a DHCP server, or an IP/TV
multicast ser ver).
Cisco IP Phones are connected—using s tand ar d s traig ht-t hroug h, twi ste d-p air c ab le with RJ- 45
connectors—to the 10/100 inline-powe r ports on the Catalyst 3524-PWR XL switches and to the
10/100 ports on the Catalyst 2950 switches. These multiservice switch ports automatically detect if an
IP phone i s conn ec ted . Cisc o Cal lMana ge r con trol s c all pr ocessi n g, r outing , a nd IP pho ne fe atu res and
configuration. Users with workstations running Cisco SoftPhone software can place, receive, and control
calls from their PCs. Using Cisc o IP Ph ones, Cisco C allManager so ftware, and Cisc o SoftPhone
software integrate s te lep hony and IP ne tworks, a nd the I P n etwor k support s both voice and d ata .
Each 10/100 inline- po wer port on the Catalyst 3524-PWR XL switches pro vides –48 VDC po we r to the
Cisco I P Phone. The IP pho ne can rec eive redundan t power when it also is connecte d to an AC power
source. I P ph one s n ot c onne cte d to the C atal yst 3 524 -PWR XL sw itche s r eceive power from an AC
power source.