Cisco Systems 3750E manual Cisco SoftPhone Software Gigabit servers

Chapter 1 Overview

Network Configuration Examples

When an end station in one VLAN needs to communicate with an end station in another VLAN, a router or Layer 3 switch routes the traffic to the destination VLAN. In this network, the Catalyst 3750-E-only switch stack or Catalyst 3560-E switches are providing inter-VLAN routing. VLAN access control lists (VLAN maps) on the switch stack or switch provide intra-VLAN security and prevent unauthorized users from accessing critical areas of the network.

In addition to inter-VLAN routing, the multilayer switches 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.

For prestandard and IEEE 802.3af-compliant powered devices connected to Catalyst PoE switches, IEEE 802.1p/Q QoS gives voice traffic forwarding-priority over data traffic.

Catalyst PoE switch ports automatically detect any Cisco pre-standard and IEEE 802.3af-compliant powered devices that are connected. Each PoE switch port provides 15.4 W of power per port. The powered device, such as a Cisco IP Phone, can receive redundant power when it is also connected to an AC power source. Powered devices not connected to Catalyst PoE switches must be connected to AC power sources to receive power.

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.

With the multilayer switches providing inter-VLAN routing and other network services, the routers focus on firewall services, Network Address Translation (NAT) services, voice-over-IP (VoIP) gateway services, and WAN and Internet access.

Figure 1-7 Catalyst 3750-E-Only Switch Stack in a Collapsed Backbone Configuration

Internet

Cisco 2600 or 3700 routers

Catalyst 3750-E-only

multilayer

StackWise Plus

switch stack

IP	IP
Cisco IP		Aironet wireless
	Workstations	access points
phones
	running

Cisco SoftPhone

software

Gigabit servers

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Catalyst 3750-E and 3560-E Switch Software Configuration Guide

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