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Bug
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Resolution: Done
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Medium
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1.13.0, Aluminium SR3
When NETCONF messages are sent from ODL controller to a simulated device, there is a delay of around 40 miliseconds during transmitting packets through network. This happens when smaller segments are sent, from ODL controller, for which it does not receive ACK right away, but sometimes after some delay of about 40 miliseconds.
Part of packet trace, which is included as an attechment:
352 18.452697180 127.0.0.1 → 127.0.0.1 HTTP 306 HTTP/1.1 204 No Content 353 18.454299387 127.0.0.1 → 127.0.0.1 HTTP 24778 POST /restconf/operations/ncmount:write-routes HTTP/1.1 (application/json) 354 18.462870957 127.0.0.1 → 127.0.0.1 TCP 374 53014 → 17830 [PSH, ACK] Seq=910075 Ack=18803 Win=65536 Len=308 TSval=1956095973 TSecr=1956095955 355 18.467105704 127.0.0.1 → 127.0.0.1 TCP 294 17830 → 53014 [PSH, ACK] Seq=18803 Ack=910383 Win=1171456 Len=228 TSval=1956095977 TSecr=1956095973 356 18.468011857 127.0.0.1 → 127.0.0.1 TCP 358 53014 → 17830 [PSH, ACK] Seq=910383 Ack=19031 Win=65536 Len=292 TSval=1956095978 TSecr=1956095977 357 18.475131627 127.0.0.1 → 127.0.0.1 TCP 294 17830 → 53014 [PSH, ACK] Seq=19031 Ack=910675 Win=1171456 Len=228 TSval=1956095985 TSecr=1956095978 358 18.496973379 127.0.0.1 → 127.0.0.1 TCP 66 8181 → 38312 [ACK] Seq=1920 Ack=222409 Win=65536 Len=0 TSval=1956096007 TSecr=1956095964 359 18.499013130 127.0.0.1 → 127.0.0.1 TCP 32902 53014 → 17830 [PSH, ACK] Seq=910675 Ack=19259 Win=65536 Len=32836 TSval=1956096009 TSecr=1956095985 360 18.506765555 127.0.0.1 → 127.0.0.1 TCP 65549 53014 → 17830 [ACK] Seq=943511 Ack=19259 Win=65536 Len=65483 TSval=1956096017 TSecr=1956095985 361 18.508246260 127.0.0.1 → 127.0.0.1 TCP 66 17830 → 53014 [ACK] Seq=19259 Ack=1008994 Win=1145856 Len=0 TSval=1956096018 TSecr=1956096009 362 18.508259159 127.0.0.1 → 127.0.0.1 TCP 255 53014 → 17830 [PSH, ACK] Seq=1008994 Ack=19259 Win=65536 Len=189 TSval=1956096018 TSecr=1956096018 363 18.552865326 127.0.0.1 → 127.0.0.1 TCP 66 17830 → 53014 [ACK] Seq=19259 Ack=1009183 Win=1171456 Len=0 TSval=1956096063 TSecr=1956096018 364 18.552891630 127.0.0.1 → 127.0.0.1 TCP 14234 53014 → 17830 [PSH, ACK] Seq=1009183 Ack=19259 Win=65536 Len=14168 TSval=1956096063 TSecr=1956096063 365 18.552973144 127.0.0.1 → 127.0.0.1 TCP 66 17830 → 53014 [ACK] Seq=19259 Ack=1023351 Win=1171456 Len=0 TSval=1956096063 TSecr=1956096063 366 18.577113026 127.0.0.1 → 127.0.0.1 TCP 294 17830 → 53014 [PSH, ACK] Seq=19259 Ack=1023351 Win=1171456 Len=228 TSval=1956096087 TSecr=1956096063 367 18.577786589 127.0.0.1 → 127.0.0.1 TCP 294 17830 → 53014 [PSH, ACK] Seq=19487 Ack=1023351 Win=1171456 Len=228 TSval=1956096088 TSecr=1956096063 368 18.578334159 127.0.0.1 → 127.0.0.1 TCP 66 53014 → 17830 [ACK] Seq=1023351 Ack=19715 Win=65536 Len=0 TSval=1956096089 TSecr=1956096087 369 18.583169095 127.0.0.1 → 127.0.0.1 HTTP 306 HTTP/1.1 204 No Content
There is a delay between sending packet number 362 an receiving ACK in packet 363.
Time interval between sending packet with data and it's acknowledgment is about 52 miliseconds. Next packet with data is sent only after receiving acknowledgment for previously sent data.
This is probably caused by combination of ACK delay and Nagel's algorithm.
