QTcpSocket, Daten im ACK



  • Ich habe folgende Kommunikation mitgeschnitten und möchte das nachbilden.
    Was man hier sieht:
    In Frame 299 bekomme ich Daten gesendet, was ich auch Problemfrei lesen kann mit QTcpSocket.
    In Frame 300 wird ein ACK auf Frame 299 gesendet, jedoch (und das ist mein Problem) sind in den Frame Daten eingepflegt.

    0x06
    0x0d
    0x0a
    

    Sende ich diese Daten im Folgenden Frame, wird das von der Anlage nicht angenommen.
    Wie kann ich in den ACK Daten einschmugeln?

    Ich habe was von Dalayed ACK gelesen und von http://de.wikipedia.org/wiki/Nagle-Algorithmus

    Wenn ich das richtig verstehe, geht es unteranderem darum, nicht für jedes Packet ein ACK gesendet werden soll. Desweiteren soll nicht nur ein kleines leeres ACK versendet werden, sondern es sollten sich Daten in der ACK befinden.
    D.h. das währe genau das, was ich suche. Das sei wohl POSIX. Aber wie kann ich das anwenden?

    Hier steht auch was dazu http://doc.qt.nokia.com/4.6/qabstractsocket.html#SocketOption-enum
    aber wie ich das verstehe, ist das bei QT schon an.

    Irgendwie komme ich nicht weiter...

    No.     Time        Source                Destination           Protocol Info
        296 103.122617  192.168.100.240       192.168.100.103       TCP      scp-config > scp-config [SYN] Seq=0 Win=2047 Len=0 MSS=1024
    
    Frame 296 (60 bytes on wire, 60 bytes captured)
        Arrival Time: Jun 14, 2010 16:16:30.838467000
        [Time delta from previous captured frame: 27.824148000 seconds]
        [Time delta from previous displayed frame: 27.824148000 seconds]
        [Time since reference or first frame: 103.122617000 seconds]
        Frame Number: 296
        Frame Length: 60 bytes
        Capture Length: 60 bytes
        [Frame is marked: False]
        [Protocols in frame: eth:ip:tcp]
        [Coloring Rule Name: TCP SYN/FIN]
        [Coloring Rule String: tcp.flags & 0x02 || tcp.flags.fin == 1]
    Ethernet II, Src: Pronet_99:cc:33 (00:20:4a:99:cc:33), Dst: Shuttle_33:91:3e (00:30:1b:33:91:3e)
        Destination: Shuttle_33:91:3e (00:30:1b:33:91:3e)
            Address: Shuttle_33:91:3e (00:30:1b:33:91:3e)
            .... ...0 .... .... .... .... = IG bit: Individual address (unicast)
            .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
        Source: Pronet_99:cc:33 (00:20:4a:99:cc:33)
            Address: Pronet_99:cc:33 (00:20:4a:99:cc:33)
            .... ...0 .... .... .... .... = IG bit: Individual address (unicast)
            .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
        Type: IP (0x0800)
        Trailer: 0000
    Internet Protocol, Src: 192.168.100.240 (192.168.100.240), Dst: 192.168.100.103 (192.168.100.103)
        Version: 4
        Header length: 20 bytes
        Differentiated Services Field: 0x00 (DSCP 0x00: Default; ECN: 0x00)
            0000 00.. = Differentiated Services Codepoint: Default (0x00)
            .... ..0. = ECN-Capable Transport (ECT): 0
            .... ...0 = ECN-CE: 0
        Total Length: 44
        Identification: 0x256b (9579)
        Flags: 0x02 (Don't Fragment)
            0.. = Reserved bit: Not Set
            .1. = Don't fragment: Set
            ..0 = More fragments: Not Set
        Fragment offset: 0
        Time to live: 64
        Protocol: TCP (0x06)
        Header checksum: 0xcab8 [correct]
            [Good: True]
            [Bad : False]
        Source: 192.168.100.240 (192.168.100.240)
        Destination: 192.168.100.103 (192.168.100.103)
    Transmission Control Protocol, Src Port: scp-config (10001), Dst Port: scp-config (10001), Seq: 0, Len: 0
        Source port: scp-config (10001)
        Destination port: scp-config (10001)
        [Stream index: 1]
        Sequence number: 0    (relative sequence number)
        Header length: 24 bytes
        Flags: 0x02 (SYN)
            0... .... = Congestion Window Reduced (CWR): Not set
            .0.. .... = ECN-Echo: Not set
            ..0. .... = Urgent: Not set
            ...0 .... = Acknowledgement: Not set
            .... 0... = Push: Not set
            .... .0.. = Reset: Not set
            .... ..1. = Syn: Set
                [Expert Info (Chat/Sequence): Connection establish request (SYN): server port scp-config]
                    [Message: Connection establish request (SYN): server port scp-config]
                    [Severity level: Chat]
                    [Group: Sequence]
            .... ...0 = Fin: Not set
        Window size: 2047
        Checksum: 0x21cd [validation disabled]
            [Good Checksum: False]
            [Bad Checksum: False]
        Options: (4 bytes)
            Maximum segment size: 1024 bytes
    
    0000  00 30 1b 33 91 3e 00 20 4a 99 cc 33 08 00 45 00   .0.3.>. J..3..E.
    0010  00 2c 25 6b 40 00 40 06 ca b8 c0 a8 64 f0 c0 a8   .,%k@.@.....d...
    0020  64 67 27 11 27 11 c9 ad 0d 96 00 00 00 00 60 02   dg'.'.........`.
    0030  07 ff 21 cd 00 00 02 04 04 00 00 00               ..!.........
    
    No.     Time        Source                Destination           Protocol Info
        297 103.122699  192.168.100.103       192.168.100.240       TCP      scp-config > scp-config [SYN, ACK] Seq=0 Ack=1 Win=64240 Len=0 MSS=1460
    
    Frame 297 (58 bytes on wire, 58 bytes captured)
        Arrival Time: Jun 14, 2010 16:16:30.838549000
        [Time delta from previous captured frame: 0.000082000 seconds]
        [Time delta from previous displayed frame: 0.000082000 seconds]
        [Time since reference or first frame: 103.122699000 seconds]
        Frame Number: 297
        Frame Length: 58 bytes
        Capture Length: 58 bytes
        [Frame is marked: False]
        [Protocols in frame: eth:ip:tcp]
        [Coloring Rule Name: TCP SYN/FIN]
        [Coloring Rule String: tcp.flags & 0x02 || tcp.flags.fin == 1]
    Ethernet II, Src: Shuttle_33:91:3e (00:30:1b:33:91:3e), Dst: Pronet_99:cc:33 (00:20:4a:99:cc:33)
        Destination: Pronet_99:cc:33 (00:20:4a:99:cc:33)
            Address: Pronet_99:cc:33 (00:20:4a:99:cc:33)
            .... ...0 .... .... .... .... = IG bit: Individual address (unicast)
            .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
        Source: Shuttle_33:91:3e (00:30:1b:33:91:3e)
            Address: Shuttle_33:91:3e (00:30:1b:33:91:3e)
            .... ...0 .... .... .... .... = IG bit: Individual address (unicast)
            .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
        Type: IP (0x0800)
    Internet Protocol, Src: 192.168.100.103 (192.168.100.103), Dst: 192.168.100.240 (192.168.100.240)
        Version: 4
        Header length: 20 bytes
        Differentiated Services Field: 0x00 (DSCP 0x00: Default; ECN: 0x00)
            0000 00.. = Differentiated Services Codepoint: Default (0x00)
            .... ..0. = ECN-Capable Transport (ECT): 0
            .... ...0 = ECN-CE: 0
        Total Length: 44
        Identification: 0xdbe6 (56294)
        Flags: 0x02 (Don't Fragment)
            0.. = Reserved bit: Not Set
            .1. = Don't fragment: Set
            ..0 = More fragments: Not Set
        Fragment offset: 0
        Time to live: 128
        Protocol: TCP (0x06)
        Header checksum: 0xd43c [correct]
            [Good: True]
            [Bad : False]
        Source: 192.168.100.103 (192.168.100.103)
        Destination: 192.168.100.240 (192.168.100.240)
    Transmission Control Protocol, Src Port: scp-config (10001), Dst Port: scp-config (10001), Seq: 0, Ack: 1, Len: 0
        Source port: scp-config (10001)
        Destination port: scp-config (10001)
        [Stream index: 1]
        Sequence number: 0    (relative sequence number)
        Acknowledgement number: 1    (relative ack number)
        Header length: 24 bytes
        Flags: 0x12 (SYN, ACK)
            0... .... = Congestion Window Reduced (CWR): Not set
            .0.. .... = ECN-Echo: Not set
            ..0. .... = Urgent: Not set
            ...1 .... = Acknowledgement: Set
            .... 0... = Push: Not set
            .... .0.. = Reset: Not set
            .... ..1. = Syn: Set
                [Expert Info (Chat/Sequence): Connection establish acknowledge (SYN+ACK): server port scp-config]
                    [Message: Connection establish acknowledge (SYN+ACK): server port scp-config]
                    [Severity level: Chat]
                    [Group: Sequence]
            .... ...0 = Fin: Not set
        Window size: 64240
        Checksum: 0x5d23 [validation disabled]
            [Good Checksum: False]
            [Bad Checksum: False]
        Options: (4 bytes)
            Maximum segment size: 1460 bytes
        [SEQ/ACK analysis]
            [This is an ACK to the segment in frame: 296]
            [The RTT to ACK the segment was: 0.000082000 seconds]
    
    0000  00 20 4a 99 cc 33 00 30 1b 33 91 3e 08 00 45 00   . J..3.0.3.>..E.
    0010  00 2c db e6 40 00 80 06 d4 3c c0 a8 64 67 c0 a8   .,..@....<..dg..
    0020  64 f0 27 11 27 11 ff f3 cf fe c9 ad 0d 97 60 12   d.'.'.........`.
    0030  fa f0 5d 23 00 00 02 04 05 b4                     ..]#......
    
    No.     Time        Source                Destination           Protocol Info
        298 103.122884  192.168.100.240       192.168.100.103       TCP      scp-config > scp-config [ACK] Seq=1 Ack=1 Win=2047 Len=0
    
    Frame 298 (60 bytes on wire, 60 bytes captured)
        Arrival Time: Jun 14, 2010 16:16:30.838734000
        [Time delta from previous captured frame: 0.000185000 seconds]
        [Time delta from previous displayed frame: 0.000185000 seconds]
        [Time since reference or first frame: 103.122884000 seconds]
        Frame Number: 298
        Frame Length: 60 bytes
        Capture Length: 60 bytes
        [Frame is marked: False]
        [Protocols in frame: eth:ip:tcp]
        [Coloring Rule Name: TCP]
        [Coloring Rule String: tcp]
    Ethernet II, Src: Pronet_99:cc:33 (00:20:4a:99:cc:33), Dst: Shuttle_33:91:3e (00:30:1b:33:91:3e)
        Destination: Shuttle_33:91:3e (00:30:1b:33:91:3e)
            Address: Shuttle_33:91:3e (00:30:1b:33:91:3e)
            .... ...0 .... .... .... .... = IG bit: Individual address (unicast)
            .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
        Source: Pronet_99:cc:33 (00:20:4a:99:cc:33)
            Address: Pronet_99:cc:33 (00:20:4a:99:cc:33)
            .... ...0 .... .... .... .... = IG bit: Individual address (unicast)
            .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
        Type: IP (0x0800)
        Trailer: 000000000000
    Internet Protocol, Src: 192.168.100.240 (192.168.100.240), Dst: 192.168.100.103 (192.168.100.103)
        Version: 4
        Header length: 20 bytes
        Differentiated Services Field: 0x00 (DSCP 0x00: Default; ECN: 0x00)
            0000 00.. = Differentiated Services Codepoint: Default (0x00)
            .... ..0. = ECN-Capable Transport (ECT): 0
            .... ...0 = ECN-CE: 0
        Total Length: 40
        Identification: 0x256c (9580)
        Flags: 0x02 (Don't Fragment)
            0.. = Reserved bit: Not Set
            .1. = Don't fragment: Set
            ..0 = More fragments: Not Set
        Fragment offset: 0
        Time to live: 64
        Protocol: TCP (0x06)
        Header checksum: 0xcabb [correct]
            [Good: True]
            [Bad : False]
        Source: 192.168.100.240 (192.168.100.240)
        Destination: 192.168.100.103 (192.168.100.103)
    Transmission Control Protocol, Src Port: scp-config (10001), Dst Port: scp-config (10001), Seq: 1, Ack: 1, Len: 0
        Source port: scp-config (10001)
        Destination port: scp-config (10001)
        [Stream index: 1]
        Sequence number: 1    (relative sequence number)
        Acknowledgement number: 1    (relative ack number)
        Header length: 20 bytes
        Flags: 0x10 (ACK)
            0... .... = Congestion Window Reduced (CWR): Not set
            .0.. .... = ECN-Echo: Not set
            ..0. .... = Urgent: Not set
            ...1 .... = Acknowledgement: Set
            .... 0... = Push: Not set
            .... .0.. = Reset: Not set
            .... ..0. = Syn: Not set
            .... ...0 = Fin: Not set
        Window size: 2047
        Checksum: 0x67d2 [validation disabled]
            [Good Checksum: False]
            [Bad Checksum: False]
        [SEQ/ACK analysis]
            [This is an ACK to the segment in frame: 297]
            [The RTT to ACK the segment was: 0.000185000 seconds]
    
    0000  00 30 1b 33 91 3e 00 20 4a 99 cc 33 08 00 45 00   .0.3.>. J..3..E.
    0010  00 28 25 6c 40 00 40 06 ca bb c0 a8 64 f0 c0 a8   .(%l@.@.....d...
    0020  64 67 27 11 27 11 c9 ad 0d 97 ff f3 cf ff 50 10   dg'.'.........P.
    0030  07 ff 67 d2 00 00 00 00 00 00 00 00               ..g.........
    
    No.     Time        Source                Destination           Protocol Info
        299 103.467664  192.168.100.240       192.168.100.103       TCP      scp-config > scp-config [PSH, ACK] Seq=1 Ack=1 Win=2047 Len=24
    
    Frame 299 (78 bytes on wire, 78 bytes captured)
        Arrival Time: Jun 14, 2010 16:16:31.183514000
        [Time delta from previous captured frame: 0.344780000 seconds]
        [Time delta from previous displayed frame: 0.344780000 seconds]
        [Time since reference or first frame: 103.467664000 seconds]
        Frame Number: 299
        Frame Length: 78 bytes
        Capture Length: 78 bytes
        [Frame is marked: False]
        [Protocols in frame: eth:ip:tcp:data]
        [Coloring Rule Name: TCP]
        [Coloring Rule String: tcp]
    Ethernet II, Src: Pronet_99:cc:33 (00:20:4a:99:cc:33), Dst: Shuttle_33:91:3e (00:30:1b:33:91:3e)
        Destination: Shuttle_33:91:3e (00:30:1b:33:91:3e)
            Address: Shuttle_33:91:3e (00:30:1b:33:91:3e)
            .... ...0 .... .... .... .... = IG bit: Individual address (unicast)
            .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
        Source: Pronet_99:cc:33 (00:20:4a:99:cc:33)
            Address: Pronet_99:cc:33 (00:20:4a:99:cc:33)
            .... ...0 .... .... .... .... = IG bit: Individual address (unicast)
            .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
        Type: IP (0x0800)
    Internet Protocol, Src: 192.168.100.240 (192.168.100.240), Dst: 192.168.100.103 (192.168.100.103)
        Version: 4
        Header length: 20 bytes
        Differentiated Services Field: 0x00 (DSCP 0x00: Default; ECN: 0x00)
            0000 00.. = Differentiated Services Codepoint: Default (0x00)
            .... ..0. = ECN-Capable Transport (ECT): 0
            .... ...0 = ECN-CE: 0
        Total Length: 64
        Identification: 0x256e (9582)
        Flags: 0x02 (Don't Fragment)
            0.. = Reserved bit: Not Set
            .1. = Don't fragment: Set
            ..0 = More fragments: Not Set
        Fragment offset: 0
        Time to live: 64
        Protocol: TCP (0x06)
        Header checksum: 0xcaa1 [correct]
            [Good: True]
            [Bad : False]
        Source: 192.168.100.240 (192.168.100.240)
        Destination: 192.168.100.103 (192.168.100.103)
    Transmission Control Protocol, Src Port: scp-config (10001), Dst Port: scp-config (10001), Seq: 1, Ack: 1, Len: 24
        Source port: scp-config (10001)
        Destination port: scp-config (10001)
        [Stream index: 1]
        Sequence number: 1    (relative sequence number)
        [Next sequence number: 25    (relative sequence number)]
        Acknowledgement number: 1    (relative ack number)
        Header length: 20 bytes
        Flags: 0x18 (PSH, ACK)
            0... .... = Congestion Window Reduced (CWR): Not set
            .0.. .... = ECN-Echo: Not set
            ..0. .... = Urgent: Not set
            ...1 .... = Acknowledgement: Set
            .... 1... = Push: Set
            .... .0.. = Reset: Not set
            .... ..0. = Syn: Not set
            .... ...0 = Fin: Not set
        Window size: 2047
        Checksum: 0x0c2e [validation disabled]
            [Good Checksum: False]
            [Bad Checksum: False]
        [SEQ/ACK analysis]
            [Number of bytes in flight: 24]
    Data (24 bytes)
        Data: 33C4233939393918C84E726931434C3030306C40308F0D0A
        [Length: 24]
    
    0000  00 30 1b 33 91 3e 00 20 4a 99 cc 33 08 00 45 00   .0.3.>. J..3..E.
    0010  00 40 25 6e 40 00 40 06 ca a1 c0 a8 64 f0 c0 a8   .@%n@.@.....d...
    0020  64 67 27 11 27 11 c9 ad 0d 97 ff f3 cf ff 50 18   dg'.'.........P.
    0030  07 ff 0c 2e 00 00 33 c4 23 39 39 39 39 18 c8 4e   ......3.#9999..N
    0040  72 69 31 43 4c 30 30 30 6c 40 30 8f 0d 0a         ri1CL000l@0...
    
    No.     Time        Source                Destination           Protocol Info
        300 103.472539  192.168.100.103       192.168.100.240       TCP      scp-config > scp-config [PSH, ACK] Seq=1 Ack=25 Win=64216 Len=3
    
    Frame 300 (57 bytes on wire, 57 bytes captured)
        Arrival Time: Jun 14, 2010 16:16:31.188389000
        [Time delta from previous captured frame: 0.004875000 seconds]
        [Time delta from previous displayed frame: 0.004875000 seconds]
        [Time since reference or first frame: 103.472539000 seconds]
        Frame Number: 300
        Frame Length: 57 bytes
        Capture Length: 57 bytes
        [Frame is marked: False]
        [Protocols in frame: eth:ip:tcp:data]
        [Coloring Rule Name: TCP]
        [Coloring Rule String: tcp]
    Ethernet II, Src: Shuttle_33:91:3e (00:30:1b:33:91:3e), Dst: Pronet_99:cc:33 (00:20:4a:99:cc:33)
        Destination: Pronet_99:cc:33 (00:20:4a:99:cc:33)
            Address: Pronet_99:cc:33 (00:20:4a:99:cc:33)
            .... ...0 .... .... .... .... = IG bit: Individual address (unicast)
            .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
        Source: Shuttle_33:91:3e (00:30:1b:33:91:3e)
            Address: Shuttle_33:91:3e (00:30:1b:33:91:3e)
            .... ...0 .... .... .... .... = IG bit: Individual address (unicast)
            .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
        Type: IP (0x0800)
    Internet Protocol, Src: 192.168.100.103 (192.168.100.103), Dst: 192.168.100.240 (192.168.100.240)
        Version: 4
        Header length: 20 bytes
        Differentiated Services Field: 0x00 (DSCP 0x00: Default; ECN: 0x00)
            0000 00.. = Differentiated Services Codepoint: Default (0x00)
            .... ..0. = ECN-Capable Transport (ECT): 0
            .... ...0 = ECN-CE: 0
        Total Length: 43
        Identification: 0xdc0b (56331)
        Flags: 0x02 (Don't Fragment)
            0.. = Reserved bit: Not Set
            .1. = Don't fragment: Set
            ..0 = More fragments: Not Set
        Fragment offset: 0
        Time to live: 128
        Protocol: TCP (0x06)
        Header checksum: 0xd418 [correct]
            [Good: True]
            [Bad : False]
        Source: 192.168.100.103 (192.168.100.103)
        Destination: 192.168.100.240 (192.168.100.240)
    Transmission Control Protocol, Src Port: scp-config (10001), Dst Port: scp-config (10001), Seq: 1, Ack: 25, Len: 3
        Source port: scp-config (10001)
        Destination port: scp-config (10001)
        [Stream index: 1]
        Sequence number: 1    (relative sequence number)
        [Next sequence number: 4    (relative sequence number)]
        Acknowledgement number: 25    (relative ack number)
        Header length: 20 bytes
        Flags: 0x18 (PSH, ACK)
            0... .... = Congestion Window Reduced (CWR): Not set
            .0.. .... = ECN-Echo: Not set
            ..0. .... = Urgent: Not set
            ...1 .... = Acknowledgement: Set
            .... 1... = Push: Set
            .... .0.. = Reset: Not set
            .... ..0. = Syn: Not set
            .... ...0 = Fin: Not set
        Window size: 64216
        Checksum: 0x64c8 [validation disabled]
            [Good Checksum: False]
            [Bad Checksum: False]
        [SEQ/ACK analysis]
            [This is an ACK to the segment in frame: 299]
            [The RTT to ACK the segment was: 0.004875000 seconds]
            [Number of bytes in flight: 3]
    Data (3 bytes)
        Data: 060D0A
        [Length: 3]
    
    0000  00 20 4a 99 cc 33 00 30 1b 33 91 3e 08 00 45 00   . J..3.0.3.>..E.
    0010  00 2b dc 0b 40 00 80 06 d4 18 c0 a8 64 67 c0 a8   .+..@.......dg..
    0020  64 f0 27 11 27 11 ff f3 cf ff c9 ad 0d af 50 18   d.'.'.........P.
    0030  fa d8 64 c8 00 00 06 0d 0a                        ..d......
    
    No.     Time        Source                Destination           Protocol Info
        301 103.483606  192.168.100.240       192.168.100.103       TCP      scp-config > scp-config [ACK] Seq=25 Ack=4 Win=2047 Len=0
    
    Frame 301 (60 bytes on wire, 60 bytes captured)
        Arrival Time: Jun 14, 2010 16:16:31.199456000
        [Time delta from previous captured frame: 0.011067000 seconds]
        [Time delta from previous displayed frame: 0.011067000 seconds]
        [Time since reference or first frame: 103.483606000 seconds]
        Frame Number: 301
        Frame Length: 60 bytes
        Capture Length: 60 bytes
        [Frame is marked: False]
        [Protocols in frame: eth:ip:tcp]
        [Coloring Rule Name: TCP]
        [Coloring Rule String: tcp]
    Ethernet II, Src: Pronet_99:cc:33 (00:20:4a:99:cc:33), Dst: Shuttle_33:91:3e (00:30:1b:33:91:3e)
        Destination: Shuttle_33:91:3e (00:30:1b:33:91:3e)
            Address: Shuttle_33:91:3e (00:30:1b:33:91:3e)
            .... ...0 .... .... .... .... = IG bit: Individual address (unicast)
            .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
        Source: Pronet_99:cc:33 (00:20:4a:99:cc:33)
            Address: Pronet_99:cc:33 (00:20:4a:99:cc:33)
            .... ...0 .... .... .... .... = IG bit: Individual address (unicast)
            .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
        Type: IP (0x0800)
        Trailer: 000000000000
    Internet Protocol, Src: 192.168.100.240 (192.168.100.240), Dst: 192.168.100.103 (192.168.100.103)
        Version: 4
        Header length: 20 bytes
        Differentiated Services Field: 0x00 (DSCP 0x00: Default; ECN: 0x00)
            0000 00.. = Differentiated Services Codepoint: Default (0x00)
            .... ..0. = ECN-Capable Transport (ECT): 0
            .... ...0 = ECN-CE: 0
        Total Length: 40
        Identification: 0x256f (9583)
        Flags: 0x02 (Don't Fragment)
            0.. = Reserved bit: Not Set
            .1. = Don't fragment: Set
            ..0 = More fragments: Not Set
        Fragment offset: 0
        Time to live: 64
        Protocol: TCP (0x06)
        Header checksum: 0xcab8 [correct]
            [Good: True]
            [Bad : False]
        Source: 192.168.100.240 (192.168.100.240)
        Destination: 192.168.100.103 (192.168.100.103)
    Transmission Control Protocol, Src Port: scp-config (10001), Dst Port: scp-config (10001), Seq: 25, Ack: 4, Len: 0
        Source port: scp-config (10001)
        Destination port: scp-config (10001)
        [Stream index: 1]
        Sequence number: 25    (relative sequence number)
        Acknowledgement number: 4    (relative ack number)
        Header length: 20 bytes
        Flags: 0x10 (ACK)
            0... .... = Congestion Window Reduced (CWR): Not set
            .0.. .... = ECN-Echo: Not set
            ..0. .... = Urgent: Not set
            ...1 .... = Acknowledgement: Set
            .... 0... = Push: Not set
            .... .0.. = Reset: Not set
            .... ..0. = Syn: Not set
            .... ...0 = Fin: Not set
        Window size: 2047
        Checksum: 0x67b7 [validation disabled]
            [Good Checksum: False]
            [Bad Checksum: False]
        [SEQ/ACK analysis]
            [This is an ACK to the segment in frame: 300]
            [The RTT to ACK the segment was: 0.011067000 seconds]
    
    0000  00 30 1b 33 91 3e 00 20 4a 99 cc 33 08 00 45 00   .0.3.>. J..3..E.
    0010  00 28 25 6f 40 00 40 06 ca b8 c0 a8 64 f0 c0 a8   .(%o@.@.....d...
    0020  64 67 27 11 27 11 c9 ad 0d af ff f3 d0 02 50 10   dg'.'.........P.
    0030  07 ff 67 b7 00 00 00 00 00 00 00 00               ..g.........
    

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