Autobahn WebSocket Testsuite Report
Autobahn WebSocket

websock server - Case 5.20 : Pass - 1003 ms @ 2026-06-02T16:13:29.906Z

Case Description

Same as Case 5.19, but send all frames with SYNC = True. Note, this does not change the octets sent in any way, only how the stream is chopped up on the wire.

Case Expectation

Same as Case 5.19. Implementations must be agnostic to how octet stream is chopped up on wire (must be TCP clean).

Case Outcome

Actual events match at least one expected.

Expected:
{'OK': [('pong', u'pongme 1!'), ('pong', u'pongme 2!'), ('message', u'fragment1fragment2fragment3fragment4fragment5', False)]}

Observed:
[('pong', u'pongme 1!'), ('pong', u'pongme 2!'), ('message', u'fragment1fragment2fragment3fragment4fragment5', False)]

Case Closing Behavior

The spec requires the connection to be failed cleanly here (UNCLEAN)



Opening Handshake

GET /ws HTTP/1.1
User-Agent: AutobahnTestSuite/25.10.1-0.10.9
Host: 127.0.0.1:8888
Upgrade: WebSocket
Connection: Upgrade
Pragma: no-cache
Cache-Control: no-cache
Sec-WebSocket-Key: QNy8xdRt0L5iYhdM+oo7OQ==
Sec-WebSocket-Version: 13
HTTP/1.1 101 Switching Protocols
Date: Tue, 02 Jun 2026 16:13:29 GMT
Connection: Upgrade
Upgrade: websocket
Sec-Websocket-Accept: 55ecOk8OYQTVFE7VF2jlfcKNcz4=


Closing Behavior

KeyValueDescription
isServerFalseTrue, iff I (the fuzzer) am a server, and the peer is a client.
closedByMeTrueTrue, iff I have initiated closing handshake (that is, did send close first).
failedByMeFalseTrue, iff I have failed the WS connection (i.e. due to protocol error). Failing can be either by initiating closing handshake or brutal drop TCP.
droppedByMeFalseTrue, iff I dropped the TCP connection.
wasCleanFalseTrue, iff full WebSocket closing handshake was performed (close frame sent and received) _and_ the server dropped the TCP (which is its responsibility).
wasNotCleanReasonpeer dropped the TCP connection without previous WebSocket closing handshakeWhen wasClean == False, the reason what happened.
wasServerConnectionDropTimeoutFalseWhen we are a client, and we expected the server to drop the TCP, but that didn't happen in time, this gets True.
wasOpenHandshakeTimeoutFalseWhen performing the opening handshake, but the peer did not finish in time, this gets True.
wasCloseHandshakeTimeoutFalseWhen we initiated a closing handshake, but the peer did not respond in time, this gets True.
localCloseCode1000The close code I sent in close frame (if any).
localCloseReasonNoneThe close reason I sent in close frame (if any).
remoteCloseCodeNoneThe close code the peer sent me in close frame (if any).
remoteCloseReasonNoneThe close reason the peer sent me in close frame (if any).


Wire Statistics

Octets Received by Chop Size

Chop SizeCountOctets
11222
47147
1661166
Total4235

Octets Transmitted by Chop Size

Chop SizeCountOctets
818
157105
2441244
Total9357

Frames Received by Opcode

OpcodeCount
11
102
Total3

Frames Transmitted by Opcode

OpcodeCount
04
11
81
92
Total8


Wire Log

000 TX OCTETS: 474554202f777320485454502f312e310d0a557365722d4167656e743a204175746f6261686e5465737453756974652f3235
               2e31302e312d302e31302e390d0a ...
001 RX OCTETS: 485454502f312e312031303120537769746368696e672050726f746f636f6c730d0a446174653a205475652c203032204a75
               6e20323032362031363a31333a32 ...
002 TX FRAME : OPCODE=1, FIN=False, RSV=0, PAYLOAD-LEN=9, MASK=3fa5d24b, PAYLOAD-REPEAT-LEN=None, CHOPSIZE=None, SYNC=True
               fragment1
003 TX OCTETS: 01893fa5d24b59d7b32c52c0bc3f0e
004 TX FRAME : OPCODE=0, FIN=False, RSV=0, PAYLOAD-LEN=9, MASK=6a346ef5, PAYLOAD-REPEAT-LEN=None, CHOPSIZE=None, SYNC=True
               fragment2
005 TX FRAME : OPCODE=9, FIN=True, RSV=0, PAYLOAD-LEN=9, MASK=b723e72a, PAYLOAD-REPEAT-LEN=None, CHOPSIZE=None, SYNC=True
               pongme 1!
006 DELAY 1.000000 sec for TAG None
007 TX OCTETS: 00896a346ef50c460f920751008158
008 TX OCTETS: 8989b723e72ac74c894dda46c71b96
009 RX OCTETS: 8a09706f6e676d65203121
010 RX FRAME : OPCODE=10, FIN=True, RSV=0, PAYLOAD-LEN=9, MASKED=False, MASK=None
               pongme 1!
011 DELAY TIMEOUT on TAG None
012 TX FRAME : OPCODE=0, FIN=False, RSV=0, PAYLOAD-LEN=9, MASK=10a7c4e7, PAYLOAD-REPEAT-LEN=None, CHOPSIZE=None, SYNC=True
               fragment3
013 TX OCTETS: 008910a7c4e776d5a5807dc2aa9323
014 TX FRAME : OPCODE=0, FIN=False, RSV=0, PAYLOAD-LEN=9, MASK=8e79d195, PAYLOAD-REPEAT-LEN=None, CHOPSIZE=None, SYNC=True
               fragment4
015 TX FRAME : OPCODE=9, FIN=True, RSV=0, PAYLOAD-LEN=9, MASK=f21643f4, PAYLOAD-REPEAT-LEN=None, CHOPSIZE=None, SYNC=True
               pongme 2!
016 TX FRAME : OPCODE=0, FIN=True, RSV=0, PAYLOAD-LEN=9, MASK=06ef309d, PAYLOAD-REPEAT-LEN=None, CHOPSIZE=None, SYNC=True
               fragment5
017 CLOSE CONNECTION AFTER 1.000000 sec
018 TX OCTETS: 00898e79d195e80bb0f2e31cbfe1ba
019 TX OCTETS: 8989f21643f482792d939f7363c6d3
020 TX OCTETS: 808906ef309d609d51fa6b8a5ee933
021 RX OCTETS: 8a09706f6e676d65203221
022 RX FRAME : OPCODE=10, FIN=True, RSV=0, PAYLOAD-LEN=9, MASKED=False, MASK=None
               pongme 2!
023 RX OCTETS: 812d667261676d656e7431667261676d656e7432667261676d656e7433667261676d656e7434667261676d656e7435
024 RX FRAME : OPCODE=1, FIN=True, RSV=0, PAYLOAD-LEN=45, MASKED=False, MASK=None
               fragment1fragment2fragment3fragment4fragment5
025 TX FRAME : OPCODE=8, FIN=True, RSV=0, PAYLOAD-LEN=2, MASK=60b6bb7e, PAYLOAD-REPEAT-LEN=None, CHOPSIZE=None, SYNC=False
               0x03e8
026 TX OCTETS: 888260b6bb7e635e
027 TCP DROPPED BY PEER