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2 full-duplex flow control, 2 packet statistics – Comtech EF Data OM20 User Manual

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OM20 Universal Outdoor Modem

Web Browser/Remote Protocol

MN-OM20– Revision 5

6–61

When available buffer space is almost gone, the OM20 will force a collision on the input port
when it senses an incoming packet. This collision will cause the transmitting station to back off
and retry the transmission.

The OM20 will stop forcing collisions as soon as free buffer space becomes available.

6.4.1.2

Full-Duplex Flow Control

In full-duplex mode, the OM20 implements IEEE 8802.3x flow control as follows:

When available buffer space is almost gone, the OM20 sends out a pause frame with the
maximum pause time to stop the remote nodes from transmitting.

The OM20 sends out another pause frame with the pause time set to zero as soon as free buffer
space becomes available.

6.4.2 Packet Statistics

The following statistics are available under the Monitor Menu when the Ethernet Data Interface is
selected:

Total Packets: This Counter displays the total number of Ethernet packets received from the
satellite.

Error Packets: This counter displays the total number of Ethernet packets received from the
satellite that had errors.

Packet Error Rate: This displays the Ethernet Packet Error Rate (PER) from the satellite.

Packet Statistics Reset: Allows the user to reset the Ethernet Total Packets and Ethernet Error
Count by pressing .