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Counter

TCP Retransmissions is a counter of all TCP Retransmissions over a period of time 
per segment. This variable counts the number of retransmitted packets to measure 
excessive retransmission in TCP/IP. A count of all TCP Retransmissions displays in 
the 

 counters of Expert View. A threshold for this counter can be set in 

Expert Alarms. 

Retransmissions are determined by sweeping the capture data periodically to catch 
connections that retransmitted within an interval.

Expert Symptom

TCP Retransmissions are automatically logged as expert symptoms. The 

 field provides information about the well-known ports (WKP) involved, 

including the port number and the IP address. For example:

Between [206.250.228.69]/[TCP/IP WKP:1988] and

[206.250.228.11]/[TCP/IP WKP:197]

Diagnostic Details

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A TCP/IP packet has been retransmitted. There was no ACK from the receiver, 
causing the sender to retransmit the packet.

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1. An ACK sent by the receiver was lost. 
2. The network is overloaded. 
3. The path to the receiving station has long delays. 
4. There may be a problem with the receiver’s TCP/IP stack. 
5. There may be an overloaded switch or router.

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1. Load balance your network.
2. If you see repeated delays and too many retransmissions, your router or switch may 

need upgrading.