Autobahn WebSocket Testsuite Report
Autobahn WebSocket

websock server - Case 5.20 : Pass - 1002 ms @ 2026-06-23T08:24:07.608Z

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: ny5WZPR7StoEoVB+FG3fOw==
Sec-WebSocket-Version: 13
HTTP/1.1 101 Switching Protocols
Date: Tue, 23 Jun 2026 08:24:07 GMT
Upgrade: websocket
Connection: Upgrade
Sec-Websocket-Accept: 7BoXjBv8wGcbqXUt1OYv3L4Y/2M=


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: 485454502f312e312031303120537769746368696e672050726f746f636f6c730d0a446174653a205475652c203233204a75
               6e20323032362030383a32343a30 ...
002 TX FRAME : OPCODE=1, FIN=False, RSV=0, PAYLOAD-LEN=9, MASK=a3607ecc, PAYLOAD-REPEAT-LEN=None, CHOPSIZE=None, SYNC=True
               fragment1
003 TX OCTETS: 0189a3607eccc5121fabce0510b892
004 TX FRAME : OPCODE=0, FIN=False, RSV=0, PAYLOAD-LEN=9, MASK=df925106, PAYLOAD-REPEAT-LEN=None, CHOPSIZE=None, SYNC=True
               fragment2
005 TX FRAME : OPCODE=9, FIN=True, RSV=0, PAYLOAD-LEN=9, MASK=5fe9ec93, PAYLOAD-REPEAT-LEN=None, CHOPSIZE=None, SYNC=True
               pongme 1!
006 DELAY 1.000000 sec for TAG None
007 TX OCTETS: 0089df925106b9e03061b2f73f72ed
008 TX OCTETS: 89895fe9ec932f8682f4328ccca27e
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=d054b51b, PAYLOAD-REPEAT-LEN=None, CHOPSIZE=None, SYNC=True
               fragment3
013 TX OCTETS: 0089d054b51bb626d47cbd31db6fe3
014 TX FRAME : OPCODE=0, FIN=False, RSV=0, PAYLOAD-LEN=9, MASK=ad276c32, PAYLOAD-REPEAT-LEN=None, CHOPSIZE=None, SYNC=True
               fragment4
015 TX FRAME : OPCODE=9, FIN=True, RSV=0, PAYLOAD-LEN=9, MASK=341b85ee, PAYLOAD-REPEAT-LEN=None, CHOPSIZE=None, SYNC=True
               pongme 2!
016 TX FRAME : OPCODE=0, FIN=True, RSV=0, PAYLOAD-LEN=9, MASK=c02cbc6a, PAYLOAD-REPEAT-LEN=None, CHOPSIZE=None, SYNC=True
               fragment5
017 CLOSE CONNECTION AFTER 1.000000 sec
018 TX OCTETS: 0089ad276c32cb550d55c042024699
019 TX OCTETS: 8989341b85ee4474eb89597ea5dc15
020 TX OCTETS: 8089c02cbc6aa65edd0dad49d21ef5
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=2d9f6bed, PAYLOAD-REPEAT-LEN=None, CHOPSIZE=None, SYNC=False
               0x03e8
026 TX OCTETS: 88822d9f6bed2e77
027 TCP DROPPED BY PEER