44 PowerConnect B-Series FCX Configuration Guide53-1002266-01Configuring basic port parameters2Configuring PHY FIFO Rx and Tx depthPHY devices on PowerConnect B-Series FCX devices contain transmit and receive synchronizingFIFOs to adjust for frequency differences between clocks. The phy-fifo-depth command allows youto configure the depth of the transmit and receive FIFOs. There are 4 settings (0-3) with 0 as thedefault. A higher setting indicates a deeper FIFO.The default setting works for most connections. However, if the clock differences are greater thanthe default will handle, CRCs and errors will begin to appear on the ports. Raising the FIFO depthsetting will adjust for clock differences.Dell recommends that you disable the port before applying this command, and re-enable the port.Applying the command while traffic is flowing through the port can cause CRC and other errors forany packets that are actually passing through the PHY while the command is being applied.Syntax: [no] phy-fifo-depth • is a value between 0 and 3. (0 is the default.)This command can be issued for a single port from the IF config mode or for multiple ports from theMIF config mode.NOTEHigher settings give better tolerance for clock differences with the partner phy, but may marginallyincrease latency as well.Configuring the IPG on PowerConnect Stackable devicesOn PowerConnect B-Series FCX devices, you can configure an IPG for each port. An IPG is aconfigurable time delay between successive data packets.You can configure an IPG with a range from 48-120 bit times in multiples of 8, with a default of 96.The IPG may be set from either the interface configuration level or the multiple interface level.Configuration notes• This section describes the configuration procedures for PowerConnect Stackable devices.• When an IPG is applied to a trunk group, it applies to all ports in the trunk group. When you arecreating a new trunk group, the IPG setting on the primary port is automatically applied to thesecondary ports.• This feature is supported on 10/100/1000M ports.Configuring IPG on a 10/100/1000M portTo configure an IPG of 112 on Ethernet interface 0/1/21, for example, enter the followingcommand.PowerConnect(config)# interface ethernet 0/1/21PowerConnect(config-if-e1000-0/1/21)# ipg 112For multiple interface levels, to configure IPG for ports 0/1/11 and 0/1/14 through 0/1/17, enterthe following commands.PowerConnect(config)# interface ethernet 0/1/11 ethernet 0/1/14 to 0/1/17PowerConnect(config-mif-0/1/11,0/1/14-0/1/17)# ipg 104
