ESP8266 Community Forum

Hi, it was very easy to build and upload the examples to the board (an ESP-01 board), it connected to my WiFi network and the examples worked out of the box (just renaming the ssid and password). Unfortunately after some tests i found that sometimes the browser update took a long time to occur when I made a request to the board, or even get a timeout. I activated wireshark and noticed a lot of dup acks, retransmissions, out of order packets, etc. When it blocks normally I see a lot of rst ack messages from the esp-01 to my laptop.

Attached is a pcap file from wireshark, my laptop has the IP 192.168.3.176, the esp-01 is the 192.168.3.219.

Any idea of what could be the problem? I'm the only one observing this? As I say above, it started working ok, but at the end of a few tests or after some time connected I started observing this erroneous behavior.

Best regards

Fernando

Hi Fernando,

Did you manage to solve this issue?
I also have a problem with TCP retransmissions on my ESP-01 module. Though my pcap (attached) looks different from yours. But the root cause may be similar.
It looks like my ESP stops receiving any TCP packets for some time. ESP starts to retransmit all non-acked packets and I see that host receives them all and sends acks again.
I'll try to sniff the air to see what's going on there.

BR, Eugene.

Hi Eugene

No, in the meantime I've changed to the Sming (https://github.com/anakod/Sming) and at least the basic examples worked with the same hardware (same ESP-01 and same PC). After that I moved to another project and left the esp8266 boards on the shelf. I'll have to pick them again since I will need to add WiFi support to the project I am busy with, and have to decide to go with the Sming or Arduino (or even directly with ESP SDK) for the ESP8266).

Are you still getting the same errors, or have you solve them? It is strange to me that we both have sort of similar errors that are blocking the use of this platform in any real project, but it seems that no one else is having them, there is no any other reply to this issue...

Best regards

Fernando

I have been struggling with this problem for quite some time, and I think I may have found the solution:

wifi_get_phy_mode() returns 3 which is PHY_MODE_11N, but according to SDK Programming Guide v1.0.1 "SP8266 soft-AP only support bg".

After I included wifi_set_phy_mode(PHY_MODE_11B); in my user_init() everything works like a charm.