Cabletron Systems SmartSwitch 04-0053-01 User Manual

Also see for SmartSwitch 9A100: User guide Upgrade instructions Installation and setup guide

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Cabletron Systems SmartSwitch 04-0053-01 User Manual Manual pdf 106 page image

8-4 SmartSwitch ATM User GuidePort Clock Configuration ATM Filtering and ClockingBy default, the clock mode for all SmartSwitch 6500 ports is local. Use the set portclockmode command to changea ports clocking source. For example, the following sets port 5a3 into loopback mode.SmartSwitch # set portclockmodePortNumber(ALL) : 5a3PortClkMode(local) : loopSmartSwitch #Note Never configure two connecting port to both be in loopback mode. Without atleast one of the connecting ports generating a clocking signal, connectivity will goout of sync and communication will be lost.8.2.1 Network ClockingNetwork clocking allows your SmartSwitch 6500 to obtain an external, high-quality, precise clocking signal and makeit available for use by all ports. Typically, network clocking is configured when a high-quality clock signal is available(for example from a service provider connection) and the SmartSwitch is supporting traffic from applications that aretime-sensitive, such as voice and video. The port connected to the high-precision clock signal is specified as thenetwork source using the set networkclock command. When set, the port is essentially placed in loopback mode,however, the port also places the incoming, high-precision signal on the SmartSwitch 6500’s backplane, where itbecomes available to all other ports.The following is an example of network clocking configuration. It is assumed in this example that the SmartSwitch6500 is connected through port 7a1 to a service provider’s switch that produces a high-precision clocking signal.1. Use the set networkclock command to specify the port through which the network clocking signalis to be obtainedSmartSwitch # set networkclockPortNumber(none) : 7a1SmartSwitch #2. Use the set portclockmode command to instruct ports (either all ports or on a per-port basis) to usethe clocking signal obtained from port 7a1SmartSwitch # set portclockmodePortNumber(ALL) : — In this example, we set all ports to use the network clockPortClkMode(local) : networkSmartSwitch #Once the set portclockmode command is entered with the PortClkMode parameter set to network, the ports specifiedon the SmartSwitch 6500 now use the clocking signal received on port 7a1 as their port clock source.