Monitoring the HotWire DSLAM
7-24 8000-A2-GB20-20
November 1997

Table 7-9. Network Protocol Options (3 of 7)

TCP Data Stats (TCP Data Statistics) B-D-C
Displays a summary of the TCP data activity (packets and bytes transmitted and
received) on all interfaces on the card. The left column is for received data and the right
column is for transmitted data.
The counters increment in real time and you may enter Ctrl-r at any time to reset the
counters.

Left column:

Packets Received – Number of TCP packets received by the card.
Acks – Number of acknowledgements received for transmitted packets. (Also shows the
number of bytes that were acknowledged as received by the remote system.)
Duplicate Acks – Number of duplicate acks received.
Acks For Unsent Data – Number of acks received for data that has not been sent yet.
Pkts/Bytes Received in Sequence – Number of packets/bytes correctly received in
sequence for data that had to be split in multiple TCP packets.
Dupl Pkts/Bytes – Number of duplicate packets/bytes received.
Pkts/Bytes W. Some Dup. Data – Number of packets/bytes with some duplicated data.
(Duplicated data is discarded by TCP.)
Pkts rcvd out-of-order – Packets received out of order.
Pkts of data after window – Packets of data received after our receive window is full.
Window Probes – Packets received looking for space in our receive window.
Window Update Pkts – Packets received from the remote system advertising a new
window size.
Pkts Rcv After Close – Packets received after the (our) TCP connection is shut down.
Discarded for Bad Checksum – Packets that were discarded because the checksum
failed.
Discarded for Bad Header Offset Fields – Packets discarded because the TCP
header was corrupted.
Discarded because Packet Too Short – Packets discarded because the packet was
too short (not a complete TCP header).

Right column:

Packets sent – Number of TCP packets sent by the card.
Data Pkts Retransmit – Number of the sent packets that were data packets instead of
TCP control packets.
Retransmit Pkts/Bytes – Number of packets/bytes that had to be transmitted.
Ack Only Packets – Number of sent packets that contained only an ack of a received
packet and no additional data.
URG only – Number of packets that contained only an Urgent flag and no data.
Window Probe Pkts – Number of packets that were window probes.
Window Update – Number of packets that were advertising our new window size.
Control Pkts – Number of control packets sent (SYN, FIN, or RST flag).