Why this Binding request got no response and see "STUN method 0x1 ignored" on TURN server?

[TChen]

Hello,

I have a strange issue when testing coturn TURN server.

A “coturn” TURN server running on 10.113.54.60 is started as following:
#turnserver -v -f --min-port=32355 --max-port=65535 --no-auth

I run two TURN client applications on 10.113.54.61 but have different results: App1 always receive no response and I can see “STUN method 0x1 ignored” on Turn Server side while App2 always got OK response with XOR-Mapped-address. I captured Bind Request sent by both on server but I can not tell the difference. Can someone tell me why the 1st Bind request from App1 got no response from TURN server?

1.    Failed Bind request from App1 that got “1506: handle_turn_command: STUN method 0x1 ignored” error
0000  00 0c 29 34 d0 b4 00 05 a6 0e 04 c3 08 00 45 00   ..)4..........E.
0010  00 5c 00 00 40 00 40 11 b9 36 0a 71 36 3d 0a 71   .\..@.@..6.q6=.q
0020  36 3c 92 06 0d 96 00 48 fd a6 00 01 00 2c 21 12   6<.....H.....,!.
0030  a4 42 d2 9d f7 c0 b1 a6 3e ba 60 1f c8 0a 80 22   .B......>.`...."
0040  00 28 72 65 54 55 52 4e 20 53 79 6e 63 20 43 6c   .(reTURN Sync Cl
0050  69 65 6e 74 20 30 2e 33 20 2d 20 52 46 43 35 33   ient 0.3 - RFC53
0060  39 2f 74 75 72 6e 2d 31 32                                   89/turn-12

2.    Successful Bind request from App2 that got Ok response with XOR-Mapped_address
0000  00 0c 29 34 d0 b4 00 05 a6 0e 04 c3 08 00 45 00   ..)4..........E.
0010  00 60 00 00 40 00 40 11 b9 32 0a 71 36 3d 0a 71   .`..@.@..2.q6=.q
0020  36 3c a7 9b 0d 96 00 4c b0 28 00 01 00 30 21 12   6<.....L.(...0!.
0030  a4 42 5a 10 34 a1 7b 2a 76 60 c3 f2 14 94 80 22   .BZ.4.{*v`....."
0040  00 2c 72 65 54 55 52 4e 20 41 73 79 6e 63 20 43   .,reTURN Async C
0050  6c 69 65 6e 74 20 30 2e 33 20 2d 20 52 46 43 35   lient 0.3 - RFC5
0060  33 38 39 2f 74 75 72 6e 2d 31 32 20 20 20             389/turn-12  

[TChen]

Wow, both have same issue now. There seems to have an issue in turnserver source code, the no_stun flag might not be initialized.
Need to add --no-stun=1 to turnserver startup script, then my TURN client works correctly.