Spanning Tree Protocol (Stp); Rapid Stp; Stp Terminology; Table 12 Stp Path Costs - ZyXEL Communications ZyXEL ZyAIR G-3000H User Manual

G-3000H User's Guide
Table 11 ToS and IEEE 802.1d to WMM QoS Priority Level Mapping
DSCP VALUE
a
96, 0
64, 32
a. The ZyAIR also uses best effort for any DSCP value for which another
WMM QoS priority is not specified (255, 158 or 37 for example).

5.4 Spanning Tree Protocol (STP)

STP detects and breaks network loops and provides backup links between switches, bridges or
routers. It allows a bridge to interact with other STP-compliant bridges in your network to
ensure that only one route exists between any two stations on the network.

5.4.1 Rapid STP

The ZyAIR uses IEEE 802.1w RSTP (Rapid Spanning Tree Protocol) that allow faster
convergence of the spanning tree (while also being backwards compatible with STP-only
aware bridges). Using RSTP topology change information does not have to propagate to the
root bridge and unwanted learned addresses are flushed from the filtering database. In RSTP,
the port states are Discarding, Learning, and Forwarding.

5.4.2 STP Terminology

The root bridge is the base of the spanning tree; it is the bridge with the lowest identifier value
(MAC address).
Path cost is the cost of transmitting a frame onto a LAN through that port. It is assigned
according to the speed of the link to which a port is attached. The slower the media, the higher
the cost - see the following table.

Table 12 STP Path Costs

Path Cost
Path Cost
Path Cost
Path Cost
Path Cost
Path Cost
62
WMM QOS PRIORITY LEVEL
besteffort
background
RECOMMENDED
LINK SPEED
VALUE
4Mbps 250
10Mbps 100
16Mbps 62
100Mbps 19
1Gbps 4
10Gbps 2
RECOMMENDED ALLOWED
RANGE RANGE
100 to 1000 1 to 65535
50 to 600 1 to 65535
40 to 400 1 to 65535
10 to 60 1 to 65535
3 to 10 1 to 65535
1 to 5 1 to 65535
Chapter 5 Wireless Configuration