Small To Medium-Sized Network Using Catalyst 2928 Switches - Cisco Catalyst 2928 Software Configuration Manual

Chapter 1 Overview
Network Configuration Examples

Small to Medium-Sized Network Using Catalyst 2928 Switches

Figure 1-3 shows a configuration for a network of up to 500 employees. This network uses Catalyst 2928
switches with high-speed connections to two routers. This ensures connectivity to the Internet, WAN,
and mission-critical network resources in case one of the routers fails. The switches are using
EtherChannel for load sharing.
The switches are connected to workstations and local servers. The server farm includes a call-processing
server running Cisco CallManager software. Cisco CallManager controls call processing, routing, and
Cisco IP Phone features and configuration. The switches are interconnected through Gigabit interfaces.
This network uses VLANs to logically segment the network into well-defined broadcast groups and for
security management. Data and multimedia traffic are configured on the same VLAN. Voice traffic from
the Cisco IP Phones are configured on separate VVIDs. If data, multimedia, and voice traffic are
assigned to the same VLAN, only one VLAN can be configured per wiring closet.
When an end station in one VLAN needs to communicate with an end station in another VLAN, a router
routes the traffic to the destination VLAN. In this network, the routers are providing inter-VLAN
routing. VLAN access control lists (VLAN maps) on the switch provide intra-VLAN security and
prevent unauthorized users from accessing critical areas of the network.
In addition to inter-VLAN routing, the routers provide QoS mechanisms such as DSCP priorities to
prioritize the different types of network traffic and to deliver high-priority traffic. If congestion occurs,
QoS drops low-priority traffic to allow delivery of high-priority traffic.
Cisco CallManager controls call processing, routing, and Cisco IP Phone features and configuration.
Users with workstations running Cisco SoftPhone software can place, receive, and control calls from
their PCs. Using Cisco IP Phones, Cisco CallManager software, and Cisco SoftPhone software integrates
telephony and IP networks, and the IP network supports both voice and data.
The routers also provide firewall services, Network Address Translation (NAT) services, voice-over-IP
(VoIP) gateway services, and WAN and Internet access.
Catalyst 2928 Switch Software Configuration Guide
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