User's Manual

Table Of Contents
244
Users Manual of CS-6306R
Figure 1.3 Uplink Fast
The Uplink Fast
feature adjusts to the slowly convergent SSTP and PVST. In RSTP
and MSTP mode, new root port can rapidly enter the Forwarding state without the
Uplink Fast function.
20.1.1.5 Backbone Fast
The Backbone Fast feature is a supplement of the Uplink Fast technology. The Uplink Fast technology
makes the redundancy line rapidly work in case the direct connection to the designated switch is
disconnected, while the Backbone Fast technology detects the indirect-link network blackout in the
upper-layer network and boosts the change of the port state.
In figure 1.3, Connection L2 between switch C and switch A is called as the direct link between switch C and
root switch A. If the connection is disconnected, the Uplink Fast function can solve the problem. Connection
L1 between switches A and B is called as the indirect link of switch C. The disconnected indirect link is called
as indirect failure, which is handled by the Backbone Fastfunction.
The working principle of the Backbone Fast function is shown in Figure 1.4.