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We see "TCP Previous segment not captured" message when Wireshark observes a packet that has TCP SEQ number bigger than we expected in this TCP stream.

For example look at packet No. 134.

It has SEQ of 11704, but we expected SEQ of 10241 (previous packet in this stream had SEQ 10165, and we add segment lenght of 76, so we wanted to see 10165+76).

In your case the packet was actually lost somewhere because we observe subsequent Dup ACKs and Retransmission (receiver and sender reacting to packet loss).

To have an ability to dig deeper we need to know some additional details about network environment you're capturing in and where is the capture point located. And also please capture TCP 3-way handshake if possible (beginning of the connection).

We see "TCP Previous segment not captured" message when Wireshark observes a packet that has TCP SEQ number bigger than we expected in this TCP stream.

For example look at packet No. 134.

It has SEQ of 11704, 11701, but we expected SEQ of 10241 (previous packet in this stream had SEQ 10165, and we add segment lenght of 76, so we wanted to see 10165+76).

In your case the packet was actually lost somewhere because we observe subsequent Dup ACKs and Retransmission (receiver and sender reacting to packet loss).

To have an ability to dig deeper we need to know some additional details about network environment you're capturing in and where is the capture point located. And also please capture TCP 3-way handshake if possible (beginning of the connection).

We see "TCP Previous segment not captured" message when Wireshark observes a packet that has TCP SEQ number bigger than we expected in this TCP stream.

For example look at packet No. 134.

It has SEQ of 11701, but we expected SEQ of 10241 (previous packet in this stream had SEQ 10165, and we add segment lenght of 76, so we wanted to see 10165+76).10165+76). So exactly 1460 Bytes are missing (one-MSS TCP packet).

In your case the packet was actually lost somewhere because we observe subsequent Dup ACKs and Retransmission (receiver and sender reacting to packet loss).

To have an ability to dig deeper we need to know some additional details about network environment you're capturing in and where is the capture point located. And also please capture TCP 3-way handshake if possible (beginning of the connection).