Motorola WS5100 1.2.2.11Power Save Polling, 1.2.2.12QoS, 802.11e QoS, 802.1p Support, Voice QoS

1-14WS5100 Series Switch System Reference Guide

When multiple BSSID's are enabled, you cannot tell by snooping the air whether any pair of beacons is sent out by the same physical AP or different physical AP. Hence the term "virtual AP's"- each virtual AP behaves exactly like a single-BSSID AP.

Each BSSID supports 1 Extended Service Set Identifier (ESSID). Sixteen ESSIDs per switch are supported.

1.2.2.11Power Save Polling

An MU uses Power Save Polling (PSP) to reduce power consumption. When an MU is in PSP mode, the switch buffers its packets and delivers them using the DTIM interval. The PSP-Poll packet polls the AP for buffered packets. The PSP null data frame is used by the MU to signal the current PSP state to the AP.

1.2.2.12QoS

QoS provides the user a data traffic prioritization scheme. A QoS configuration scheme is useful in the case of congestion from excessive traffic or different data rates and link speeds.

If there is enough bandwidth for all users and applications (unlikely because excessive bandwidth comes at a very high cost), then applying QoS has very little value. QoS provides policy enforcement for mission-critical applications and/or users that have critical bandwidth requirements when the switch’s total bandwidth is shared by different users and applications.

The objective of QoS is to ensure each WLAN configured on the switch receives a fair share of the overall bandwidth, either equally or as per the proportion configured. Packets directed towards MUs are classified into categories such as Management, Voice and Data. Packets within each category are processed based on the weights defined for each WLAN.

The switch supports the following QoS types:

802.11e QoS

802.11e enables real-time audio and video streams to be assigned a higher priority over regular data. The switch supports the following 802.11e features:

•Basic WMM

•WMM Linked to 802.1p Priorities

•WMM Linked to DSCP Priorities

•Fully Configurable WMM

•Admission Control

•Unscheduled-APSD

•TSPEC Negotiation

•Block ACKQBSS Beacon Element

802.1p Support

802.1p is a standard for providing QoS in 802-based networks. 802.1p uses three bits to allow switches to re-order packets based on priority level. 802.1p uses the Generic Attributes Registration Protocol (GARP) and the GARP VLAN Registration Protocol (GVRP). GARP allows MUs to request membership within a multicast domain, and GVRP lets them register to a VLAN.

Voice QoS

When switch resources are shared between a Voice over IP (VoIP) conversation and a file transfer, bandwidth is normally exploited by the file transfer, thus reducing the quality of the conversation or even causing it to