Does the esp8266 SDK 1.0.0 respond to 802.11 RTS frames?

[tve]

I'm seeing my AP send RTS requests to the esp8266 and I'm not seeing the expected CTS responses. Here is an example of sending the esp an ICMP PING:
- 18:fe:34:9c:cd:43 is the esp
- 00:02:6f:ae:ec:a1 is the AP (an Engenius ECB9500)
- f4:6d:04:ed:62:ca is a linux box sending the pings
What you see is a very long list of RTS from the AP without replies until the AP gives up and sends the packet anyway. The esp then replies and finally the AP ACKs. I've moved the esp closer to the AP but that does not make any difference. This pattern is 100% reproducible.
The capture is made using an AR9271 in monitor mode on yet another linux box that is close to esp, hence the signal level differences.
I can provide more details, but I'm wondering whether the esp simply doesn't respond to RTS or whether there's some other incompatibility? (I've not seen this pattern with other connected clients, which are mostly android devices.)

Code: Select all

07:00:25.274123 83519299us tsft 24.0 Mb/s 2412 MHz 11g -59dB signal antenna 0 RA:18:fe:34:9c:cd:43 TA:00:02:6f:ae:ec:a1 Request-To-Send
07:00:25.275261 83520196us tsft 24.0 Mb/s 2412 MHz 11g -59dB signal antenna 0 RA:18:fe:34:9c:cd:43 TA:00:02:6f:ae:ec:a1 Request-To-Send
07:00:25.275379 83520522us tsft 24.0 Mb/s 2412 MHz 11g -59dB signal antenna 0 RA:18:fe:34:9c:cd:43 TA:00:02:6f:ae:ec:a1 Request-To-Send
07:00:25.275938 83521110us tsft 24.0 Mb/s 2412 MHz 11g -60dB signal antenna 0 RA:18:fe:34:9c:cd:43 TA:00:02:6f:ae:ec:a1 Request-To-Send
07:00:25.277225 83522436us tsft 24.0 Mb/s 2412 MHz 11g -60dB signal antenna 0 RA:18:fe:34:9c:cd:43 TA:00:02:6f:ae:ec:a1 Request-To-Send
07:00:25.277736 83522923us tsft 24.0 Mb/s 2412 MHz 11g -60dB signal antenna 0 RA:18:fe:34:9c:cd:43 TA:00:02:6f:ae:ec:a1 Request-To-Send
07:00:25.278017 83523251us tsft 24.0 Mb/s 2412 MHz 11g -60dB signal antenna 0 RA:18:fe:34:9c:cd:43 TA:00:02:6f:ae:ec:a1 Request-To-Send
07:00:25.278486 83523697us tsft 24.0 Mb/s 2412 MHz 11g -60dB signal antenna 0 RA:18:fe:34:9c:cd:43 TA:00:02:6f:ae:ec:a1 Request-To-Send
07:00:25.279607 83524804us tsft 24.0 Mb/s 2412 MHz 11g -60dB signal antenna 0 RA:18:fe:34:9c:cd:43 TA:00:02:6f:ae:ec:a1 Request-To-Send
07:00:25.280746 83525971us tsft 24.0 Mb/s 2412 MHz 11g -60dB signal antenna 0 RA:18:fe:34:9c:cd:43 TA:00:02:6f:ae:ec:a1 Request-To-Send
07:00:25.281372 83526438us tsft 24.0 Mb/s 2412 MHz 11g -60dB signal antenna 0 RA:18:fe:34:9c:cd:43 TA:00:02:6f:ae:ec:a1 Request-To-Send
07:00:25.282479 83527592us tsft 24.0 Mb/s 2412 MHz 11g -60dB signal antenna 0 RA:18:fe:34:9c:cd:43 TA:00:02:6f:ae:ec:a1 Request-To-Send
07:00:25.282849 83528060us tsft 24.0 Mb/s 2412 MHz 11g -60dB signal antenna 0 RA:18:fe:34:9c:cd:43 TA:00:02:6f:ae:ec:a1 Request-To-Send
07:00:25.283565 83528788us tsft 24.0 Mb/s 2412 MHz 11g -60dB signal antenna 0 RA:18:fe:34:9c:cd:43 TA:00:02:6f:ae:ec:a1 Request-To-Send
07:00:25.284246 83529475us tsft 24.0 Mb/s 2412 MHz 11g -60dB signal antenna 0 RA:18:fe:34:9c:cd:43 TA:00:02:6f:ae:ec:a1 Request-To-Send
07:00:25.285202 83530322us tsft 24.0 Mb/s 2412 MHz 11g -61dB signal antenna 0 RA:18:fe:34:9c:cd:43 TA:00:02:6f:ae:ec:a1 Request-To-Send
07:00:25.285282 83530428us tsft 24.0 Mb/s 2412 MHz 11g -60dB signal antenna 0 RA:18:fe:34:9c:cd:43 TA:00:02:6f:ae:ec:a1 Request-To-Send
07:00:25.286360 83531476us tsft 24.0 Mb/s 2412 MHz 11g -60dB signal antenna 0 RA:18:fe:34:9c:cd:43 TA:00:02:6f:ae:ec:a1 Request-To-Send
07:00:25.287419 83532643us tsft 24.0 Mb/s 2412 MHz 11g -60dB signal antenna 0 RA:18:fe:34:9c:cd:43 TA:00:02:6f:ae:ec:a1 Request-To-Send
07:00:25.287765 83532950us tsft 24.0 Mb/s 2412 MHz 11g -60dB signal antenna 0 RA:18:fe:34:9c:cd:43 TA:00:02:6f:ae:ec:a1 Request-To-Send
07:00:25.288683 83533876us tsft 24.0 Mb/s 2412 MHz 11g -60dB signal antenna 0 RA:18:fe:34:9c:cd:43 TA:00:02:6f:ae:ec:a1 Request-To-Send
07:00:25.289426 83534512us tsft 24.0 Mb/s 2412 MHz 11g -60dB signal antenna 0 RA:18:fe:34:9c:cd:43 TA:00:02:6f:ae:ec:a1 Request-To-Send
07:00:25.289513 83534640us tsft 24.0 Mb/s 2412 MHz 11g -60dB signal antenna 0 RA:18:fe:34:9c:cd:43 TA:00:02:6f:ae:ec:a1 Request-To-Send
07:00:25.290749 83535966us tsft 24.0 Mb/s 2412 MHz 11g -60dB signal antenna 0 RA:18:fe:34:9c:cd:43 TA:00:02:6f:ae:ec:a1 Request-To-Send
07:00:25.291240 83536434us tsft 24.0 Mb/s 2412 MHz 11g -60dB signal antenna 0 RA:18:fe:34:9c:cd:43 TA:00:02:6f:ae:ec:a1 Request-To-Send
07:00:25.292025 83537240us tsft 24.0 Mb/s 2412 MHz 11g -60dB signal antenna 0 RA:18:fe:34:9c:cd:43 TA:00:02:6f:ae:ec:a1 Request-To-Send
07:00:25.293409 83538608us tsft 24.0 Mb/s 2412 MHz 11g -59dB signal antenna 0 RA:18:fe:34:9c:cd:43 TA:00:02:6f:ae:ec:a1 Request-To-Send
07:00:25.294680 83539884us tsft 24.0 Mb/s 2412 MHz 11g -60dB signal antenna 0 RA:18:fe:34:9c:cd:43 TA:00:02:6f:ae:ec:a1 Request-To-Send
07:00:25.294907 83540119us tsft 24.0 Mb/s 2412 MHz 11g -60dB signal antenna 0 RA:18:fe:34:9c:cd:43 TA:00:02:6f:ae:ec:a1 Request-To-Send
07:00:25.295910 83541116us tsft 24.0 Mb/s 2412 MHz 11g -60dB signal antenna 0 RA:18:fe:34:9c:cd:43 TA:00:02:6f:ae:ec:a1 Request-To-Send
07:00:25.296757 83541539us tsft 2412 MHz 11g -66dB signal antenna 0 7.2 Mb/s MCS 0 20 MHz short GI CF +QoS DA:18:fe:34:9c:cd:43 BSSID:00:02:6f:ae:ec:a1 SA:f4:6d:04:ed:62:ca LLC, dsap SNAP (0xaa) Individual, ssap SNAP (0xaa) Command, ctrl 0x03: oui Ethernet (0x000000), ethertype IPv4 (0x0800): 192.168.0.3 > 192.168.0.29: ICMP echo request, id 8063, seq 3, length 64
07:00:25.296861 83541775us tsft 24.0 Mb/s 2412 MHz 11g -60dB signal antenna 0 RA:18:fe:34:9c:cd:43 TA:00:02:6f:ae:ec:a1 Request-To-Send
07:00:25.296932 83541911us tsft 24.0 Mb/s 2412 MHz 11g -60dB signal antenna 0 RA:18:fe:34:9c:cd:43 TA:00:02:6f:ae:ec:a1 Request-To-Send
07:00:25.299300 83543779us tsft short preamble 2.0 Mb/s 2412 MHz 11b -18dB signal antenna 0 BSSID:00:02:6f:ae:ec:a1 SA:18:fe:34:9c:cd:43 DA:f4:6d:04:ed:62:ca LLC, dsap SNAP (0xaa) Individual, ssap SNAP (0xaa) Command, ctrl 0x03: oui Ethernet (0x000000), ethertype IPv4 (0x0800): 192.168.0.29 > 192.168.0.3: ICMP echo reply, id 8063, seq 3, length 64
07:00:25.299569 83544375us tsft short preamble 2.0 Mb/s 2412 MHz 11b -61dB signal antenna 0 RA:18:fe:34:9c:cd:43 Acknowledgment


[Howard]

Sometimes, the sniffer can not catch/record some short packets, which AP has received.
Actually, the AP (00:02:6f:ae:ec:a1) has received the CTS and then sent the Data packet of PING. But the sniffer can not catch the CTS and the ACK after the Data packet of PING.

Yes, there are many RTS packets. I guess some causes:
1) The wireless channel Maybe blocked by other devices, like Bluetooth or other WiFi transmitting, for a while.
2) The antenna on the PCB or the module is not good.
3) The AP or ESP8266 is too close to the sniffer. Try to keep the sniffer 1 meter away from the AP and ESP8266.