Chapter 2 Switch Installation

Connecting Devices to the Ethernet Ports

Table 2-1

Recommended Ethernet Cables (When Auto-MDIX is Disabled)

 

 

 

 

Device

 

Crossover Cable1

Straight-Through Cable1

Switch to switch

Yes

No

 

 

 

 

Switch to hub

 

Yes

No

 

 

 

Switch to computer or server

No

Yes

 

 

 

Switch to router

No

Yes

 

 

 

Switch to IP phone

No

Yes

 

 

 

 

1.100BASE-TX and 1000BASE-T traffic requires twisted four-pair, Category 5, Category 5e, or Category 6 cable. 10BASE-T traffic can use Category 3 or Category 4 cable.

PoE+ Port Connections

The 10/100/1000 PoE+ ports have the same autonegotiation settings and cabling requirements that are described in the “10/100/1000 Ethernet Port Connections” section on page 2-19. These ports can provide PoE or PoE+ inline power.

PoE inline power supports devices compliant with the IEEE 802.3af standard, as well as prestandard Cisco IP Phones and Cisco Aironet Access Points. Each port can deliver up to 15.4 W of PoE.

PoE+ inline power supports devices compliant with the IEEE 802.3at standard, by delivering up to 30 W of PoE+ power per port to all switch ports.

See Table 1-12 on page 1-18for the power supply modules required to support PoE and PoE+ on 24- and 48-port switches.

For more information about the required power-supply module and the PoE specifications, see the “Power Supply Modules” section on page 1-17and Appendix A, “Technical Specifications.”

Note Many legacy powered devices, including older Cisco IP phones and access points that do not fully support IEEE 802.3af, might not support PoE when connected to the switches by a crossover cable.

Caution PoE faults are caused when noncompliant cabling or powered devices are connected to a PoE port. Use only standard-compliant cabling to connect Cisco prestandard IP Phones, wireless access points, or IEEE 802.3af-compliant devices to PoE ports. A cable or device that causes a PoE fault must be removed from the network.

Warning Voice over IP (VoIP) service and the emergency calling service do not function if power fails or is disrupted. After power is restored, you might have to reset or reconfigure equipment to regain access to VoIP and the emergency calling service. In the USA, this emergency number is 911. You need to be aware of the emergency number in your country. Statement 361

 

 

Catalyst 3650 Switch Hardware Installation Guide

 

 

 

 

 

 

OL-29734-01

 

 

2-21

 

 

 

 

 

Page 45
Image 45
Cisco Systems 3650 manual PoE+ Port Connections, Device Crossover Cable