Redundancy Of Stack Links And Stack Ports; Long-Distance Stacking - Huawei S Series White Paper

S Series Switches
iStack Technology White Paper

1.3.4 Redundancy of Stack Links and Stack Ports

Redundancy of Stack Links in a Ring Topology
iStack can implement redundancy of stack links in a ring topology. When a link fails, the ring
topology changes into a chain topology so that services in the stack are not affected.
Redundancy of Stack Ports
As shown in Figure 1-7, iStack uses link aggregation to implement redundancy of stack ports.
Multiple physical links on stack ports can be aggregated to load balance traffic, improving
bandwidth and system performance. Additionally, the physical links back up each other so
that the failure of one link does not affect services in the stack. This improves device
reliability.
Figure 1-7 Redundancy of stack ports
Stack-Port1
Stack-Port2

1.3.5 Long-Distance Stacking

iStack allows remote devices to form a stack. As shown in Figure 1-8, users at each floor
connect to the external network through switches deployed at the corridors. These switches
are connected to form a stack, as if there is only one access switch in each building. This
implementation simplifies network structure. Each building has multiple links to the core
network, improving network robustness and reliability. The configurations of multiple
switches at the corridors are simplified into the configuration of a stack, reducing
management and maintenance costs.
Issue 01 (2013-05-25)
Stack-Port1 Stack-Port2
Stack-Port2 Stack-Port1
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
Stack-Port1
Stack-Port2
iStack Link
Stack-Port
1 Feature Introduction
7