flowcontrol

To set the send or receive flow-control value for an interface, use the command flowcontrol in Interface Configuration Mode.

If flowcontrol send is on for a device and if it detects any congestion at its end, then it notifies the link partner or the remote device of the congestion by sending a pause frame.
If flowcontrol receive is on for the remote device and it receives a pause frame, then it stops sending any data packets. This prevents any loss of data packets during the congestion period.
PAUSE is a flow control mechanism that is implied on full duplex Ethernet link segments. The mechanism uses MAC control frames to carry the PAUSE commands.

flowcontrol { {send | } { receive} } { {on | } { off | } { desired} }

Parameters

Parameter	Type	Description
`send`		Enter to set the interface to send flow control packets to a remote device.
`receive`		Enter to set the interface to receive flow control packets from a remote device.
`on`		Enter for “on” option. If used with “receive”, it allows an interface to operate with the attached device to send flow control packets. If used with “send”, the interface sends flowcontrol packets to a remote device if the device supports it.
`off`		Enter to turn-off the attached devices (when used with receive) or the local ports (when used with send) ability to send flow-control packets to an interface or to a remote device respectively.
`desired`		Enter to allow a local port to operate with an attached device that is required to send flow control packets or that may send the control packets, when used with receive option. Allows the local port to send administrative status to a remote device if the remote device supports it, when used with send option

Interface Configuration Mode

Interface must first be made administratively down before setting flow control status.

The default flow control for the interfaces are

iS5Comm# (config-if)# flowcontrol send on