As noted previously, several media types are used for campus networks. It is common to run UTP to end stations, use multiple multimode uplinks from access to distribution, and use single-mode fiber for longer-distance and higher-bandwidth links. Table 6-7 provides a summary comparison of these media.
Table 6-7 Campus Transmission Media Comparison
| Factor | Copper/UTP | Multimode Fiber | Single-Mode Fiber |
| Bandwidth | Up to 10 Gbps | Up to 10 Gbps | Up to 10 Gbps |
| Distance | Up to 100 m | Up to 2 km (Fast Ethernet) | Up to 100 km (Fast Ethernet) |
| Up to 550 m (Gigabit Ethernet) | Up to 5 km (Gigabit Ethernet) | ||
| Up to 300 m (10 Gigabit Ethernet) | Up to 40 km (10 Gigabit Ethernet) | ||
| Price | Inexpensive | Moderate | Moderate to expensive |
| Recommended use | End stations | Building access to distribution switch uplinks; peer-to-peer switch links | Long-distance links |
Power over Ethernet (PoE)
Power over Ethernet (PoE) is commonly used for powering IP phones and wireless access points (WAPs) over UTP. Other devices are increasingly being supplied power, such as video cameras, point-of-sale (PoS) machines, access control readers, and LED luminaries.
Standards-based PoE is defined in the IEEE 802.3af (2003) and IEEE 802.3at (2009) specifications. IEEE 802.3af provides 15.4 watts at the power sourcing equipment (PSE) side (LAN switch); due to power dissipation, only 12.95W is assured to the powered device (PD). IEEE 802.3at (known as PoE+) provides up to 30W on the PSE side, with 25.5.W assured to the PD. PoE and PoE+ provide power using two pairs: pins 1 and 2 and pins 3 and 6.
Cisco has developed Universal Power over Ethernet (UPOE) to provide power to higher-level devices, such as telepresence systems, digital signage, and IP turrets. Cisco UPOE uses four twisted pairs (instead of two pairs for PoE) to provide additional power. Cisco UPOE provides 30W + 30W = 60W of PSE power over Category 5e UTP, assuring 51W to the PD. Cisco UPOE+ provides 45W + 45W = 90W of PSE power over Category 6a UTP cabling, assuring 71.3W of power to the PD. Table 6-8 compares PoE capabilities.
Table 6-8 Cisco PoE and UPOE Comparison
| Category | PoE | PoE+ | Cisco UPOE | Cisco UPOE+ |
| Minimum cable type | CAT 5e | CAT 5e | CAT 5e | CAT 6a |
| IEEE standard | 802.3af | 802.3at | Cisco proprietary | Cisco proprietary |
| Maximum power to the PSE port | 15.4W | 30W | 60W | 90W |
| Maximum power to the PD | 12.95W | 25.5.W | 51W | 71.3W |
| UTP pairs | 2 | 2 | 4 | 4 |
| Distance | 100 m | 100 m | 100 m | 100 m |
Wake on LAN (WoL)
When a PC shuts down, the NIC still receives power and is able to listen to the network. WoL allows an administrator to remotely power up sleeping machines in order to perform maintenance updates. WoL sends specially coded network packets, called magic packets, to systems equipped and enabled to respond to these packets. If you send WoL packets from remote networks, the routers must be configured to allow directed broadcasts.