[lwip-users] Slow HTTP put request

[Jochen Strohbeck]

Sorry for the dumb subject but I don't know better...

I implemented a HTTP server using the netconn API on a SAME70 board and
tested ethernet communication using python scripts. Now our customer did
the same with labview on windows and the communication is slow
especially using PUT requests.

I am able to reproduce the same problem using curl on windows and found
out that even a PUT request with only a single byte payload takes about
a second! If I do the same request with python it takes some
milliseconds. Why?

I guess the problem is not directly related to lwip but I do not have
any clue where the problem is located.

I put the wireshark output below. First is the output of the curl
request, second the same request using python.

Any ideas ?

Jochen


13 11.971296 192.168.0.200 192.168.0.100 TCP 66 24773 → 80 [SYN] Seq=0
Win=8192 Len=0 MSS=1260 WS=4 SACK_PERM=1
14 11.971481 192.168.0.100 192.168.0.200 TCP 60 80 → 24773 [SYN, ACK]
Seq=0 Ack=1 Win=2920 Len=0 MSS=1460
15 11.971632 192.168.0.200 192.168.0.100 TCP 54 24773 → 80 [ACK] Seq=1
Ack=1 Win=65520 Len=0
16 11.978719 192.168.0.200 192.168.0.100 TCP 203 24773 → 80 [PSH, ACK]
Seq=1 Ack=1 Win=65520 Len=149 [TCP segment of a reassembled PDU]
17 12.222453 192.168.0.100 192.168.0.200 TCP 60 80 → 24773 [ACK] Seq=1
Ack=150 Win=2771 Len=0
18 13.000423 192.168.0.200 192.168.0.100 HTTP 55 PUT /twi0/66 HTTP/1.1
19 13.001296 192.168.0.100 192.168.0.200 TCP 71 80 → 24773 [PSH, ACK]
Seq=1 Ack=151 Win=2770 Len=17 [TCP segment of a reassembled PDU]
20 13.001480 192.168.0.100 192.168.0.200 HTTP 157 HTTP/1.0 200 OK
(application/json)
21 13.001576 192.168.0.200 192.168.0.100 TCP 54 24773 → 80 [ACK] Seq=151
Ack=122 Win=65400 Len=0
22 13.008113 192.168.0.200 192.168.0.100 TCP 54 24773 → 80 [FIN, ACK]
Seq=151 Ack=122 Win=65400 Len=0
23 13.008330 192.168.0.100 192.168.0.200 TCP 60 80 → 24773 [ACK] Seq=122
Ack=152 Win=2769 Len=0

9 6.245329 192.168.0.200 192.168.0.100 TCP 66 24461 → 80 [SYN] Seq=0
Win=8192 Len=0 MSS=1260 WS=4 SACK_PERM=1
10 6.245554 192.168.0.100 192.168.0.200 TCP 60 80 → 24461 [SYN, ACK]
Seq=0 Ack=1 Win=2920 Len=0 MSS=1460
11 6.245667 192.168.0.200 192.168.0.100 TCP 54 24461 → 80 [ACK] Seq=1
Ack=1 Win=65520 Len=0
12 6.245913 192.168.0.200 192.168.0.100 TCP 224 24461 → 80 [PSH, ACK]
Seq=1 Ack=1 Win=65520 Len=170 [TCP segment of a reassembled PDU]
13 6.246020 192.168.0.200 192.168.0.100 HTTP 55 PUT /twi0/66 HTTP/1.1
14 6.246243 192.168.0.100 192.168.0.200 TCP 60 80 → 24461 [ACK] Seq=1
Ack=172 Win=2749 Len=0
15 6.247102 192.168.0.100 192.168.0.200 TCP 71 80 → 24461 [PSH, ACK]
Seq=1 Ack=172 Win=2749 Len=17 [TCP segment of a reassembled PDU]
16 6.247290 192.168.0.100 192.168.0.200 HTTP 157 HTTP/1.0 200 OK
(application/json)
17 6.247368 192.168.0.200 192.168.0.100 TCP 54 24461 → 80 [ACK] Seq=172
Ack=122 Win=65400 Len=0
18 6.248011 192.168.0.200 192.168.0.100 TCP 54 24461 → 80 [FIN, ACK]
Seq=172 Ack=122 Win=65400 Len=0
19 6.248210 192.168.0.100 192.168.0.200 TCP 60 80 → 24461 [ACK] Seq=122
Ack=173 Win=2748 Len=0