CCNP ONT Quick Reference Sheets: Exam 642-845

Chapter 6. Wireless Scalability

Wireless LANs (WLAN) are an extension to wired networks using wireless standards, such as 802.11A/B/G. The 802.11 standards take the place of the Ethernet standard, but both data-links support the same types of services. The benefit of WLANs is that it allows users to relocate within the workspace, closer to machinery or conference rooms, for instance.

WLAN QoS

802.11 wireless uses carrier sense multiple access/collision avoidance (CSMA/CA), meaning transmissions are pre-announced, because systems may not be able to hear each other or recognize collisions later. CA uses a Distributed Coordination Function (DCF) to implement timers and delays to ensure cooperation.

Unfortunately, DCF timers interfere with low-latency ...