软路由+ap, 内网设备间 iperf3 测速低于任何一台设备单独访问互联网?

拓扑大概是这个样子，两个设备都通过 AP 连接，有线部分都是超六类线

使用测速网测得
PC：319/62Mbps
手机：351/38Mbps
宽带 300/30Mbps ，每个设备访问互联网速度都是正常的，

然而设备间访问速度就很慢，无论是 smb 、ftp 、qrcp 传文件，只有 10-20MBps 左右。起初以为是软件优化问题没在意，后怀疑是设备的问题，使用 iperf3 测速，结果让我大吃一惊，内网传输速度竟然比访问互联网还慢？

PC：

sky96111@SurfaceSUSE ~> iperf3 -s
-----------------------------------------------------------
Server listening on 5201 (test #1)
-----------------------------------------------------------
Accepted connection from [phoneip], port 44408
[  5] local [laptopip] port 5201 connected to [phoneip] port 44420
[ ID] Interval           Transfer     Bitrate
[  5]   0.00-1.00   sec  7.67 MBytes  64.3 Mbits/sec                  
[  5]   1.00-2.00   sec  11.1 MBytes  92.8 Mbits/sec                  
[  5]   2.00-3.00   sec  15.3 MBytes   128 Mbits/sec                  
[  5]   3.00-4.00   sec  10.5 MBytes  88.2 Mbits/sec                  
[  5]   4.00-5.00   sec  15.1 MBytes   127 Mbits/sec                  
[  5]   5.00-6.00   sec  14.3 MBytes   120 Mbits/sec                  
[  5]   6.00-7.00   sec  16.6 MBytes   139 Mbits/sec                  
[  5]   7.00-8.00   sec  13.9 MBytes   116 Mbits/sec                  
[  5]   8.00-9.00   sec  16.7 MBytes   140 Mbits/sec                  
[  5]   9.00-10.00  sec  14.6 MBytes   122 Mbits/sec                  
[  5]  10.00-10.05  sec   539 KBytes  84.3 Mbits/sec                  
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate
[  5]   0.00-10.05  sec   136 MBytes   114 Mbits/sec                  receiver

Phone:

u0_a173@localhost ~> iperf3 -c surfacesuse.lan
Connecting to host surfacesuse.lan, port 5201
[  5] local [phoneip] port 44420 connected to [laptopip] port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  8.25 MBytes  69.2 Mbits/sec   91    143 KBytes
[  5]   1.00-2.00   sec  11.2 MBytes  94.1 Mbits/sec    0    229 KBytes
[  5]   2.00-3.00   sec  15.1 MBytes   127 Mbits/sec    0    308 KBytes
[  5]   3.00-4.00   sec  10.9 MBytes  91.5 Mbits/sec    0    354 KBytes
[  5]   4.00-5.00   sec  14.6 MBytes   122 Mbits/sec    0    409 KBytes
[  5]   5.00-6.00   sec  14.8 MBytes   124 Mbits/sec    0    456 KBytes
[  5]   6.00-7.00   sec  16.1 MBytes   135 Mbits/sec    0    505 KBytes
[  5]   7.00-8.00   sec  14.1 MBytes   118 Mbits/sec    0    542 KBytes
[  5]   8.00-9.00   sec  16.8 MBytes   141 Mbits/sec    0    584 KBytes
[  5]   9.00-10.00  sec  14.5 MBytes   122 Mbits/sec    0    618 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec   136 MBytes   114 Mbits/sec   91             sender
[  5]   0.00-10.05  sec   136 MBytes   114 Mbits/sec                  receiver

iperf Done.

尝试过：

• 增大 iperf3 线程数，丢包重发更多，速度更慢了
• 重启路由器 /AP
• AP 位接入交换机，PC 使用有线连接
  均无成效。还有什么排查的方法吗？