ZyXEL Communications MSC1000G Series, Руководство пользователя

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Chapter 13 Switch Screens
Management Switch Card User’s Guide
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Figure 365
MSTP Configuration Example: Port
8
For switch B, configure the same general MSTP settings and VLAN-to-MST mappings as switch A for
the subtending ports.
9
Set the subtending port priorities on switch B to allow MSTP to forward traffic to the corresponding
link.
In MSTID1, set the subtending port 1 priority to 0 and subtending port 2 priority to 240.
In MSTID2, set the subtending port 1 priority to 240 and subtending port 2 priority to 0.
Note: Devices belonging to the same MST region must have the same settings in the
Config Name and Revision Level fields and VLAN-MST instance mapping(s).
13.13 Switch Port
This section describes the switch port features and parameters.
13.13.1 Uplink and Subtending Modes
The Gigabit Ethernet SFP slots and ports can function in either subtending or uplink mode. Connect
a port in uplink mode to an backbone Ethernet switch or router. The management switch card
allows traffic between the ports in uplink mode and the DSL ports on the line cards.
Use the subtending mode to daisy-chain other Ethernet switches. With subtending mode, the
management switch card allows traffic between the ports in subtending mode and the ports in
uplink mode. The management switch card does not allow traffic between the ports in subtending
mode and the DSL ports on the line cards.
13.13.2 Flow Control
A concentration of traffic on a port decreases port bandwidth and overflows buffer memory causing
packet discards and frame losses. Flow control is used to regulate transmission of signals to match
the bandwidth of the receiving port.
The MSC uses IEEE 802.3x flow control in full duplex mode and back pressure flow control in half
duplex mode.