In the CSS containing S7700s with SRUBs installed, the CSS bandwidth is reduced 25% if one of the link connecting the master and slave MPUs is disconnected. Protocol packets of the backup switch must be sent to the master switch through the master MPU. If the link connecting the master and slave MPUs is disconnected, the protocol packets to be forwarded from the backup switch's LPU to the master switch through the chip cannot be sent to the master MPU for processing. To prevent such packets from being lost, avoid using this forwarding chip. A forwarding chip has two CSS links. When the two CSS links become unavailable, the CSS bandwidth is reduced 25%.
After a CSS is established, the master MPU of the master switch becomes the master MPU of the CSS, and the master MPU of the backup switch becomes the slave MPU of the CSS.
