Ping jumps over Wi-Fi, mikrotik router. Where to dig?

Question

network hardware

The bottom line is that I encountered mikrotik for the second time in my life.
I set everything up, the Internet works fine on wires, but Wi-Fi lags.
Ping from Wi-Fi client:

Ответ от 95.213.11.146: число байт=32 время=26мс TTL=56
Ответ от 95.213.11.146: число байт=32 время=459мс TTL=56
Ответ от 95.213.11.146: число байт=32 время=26мс TTL=56
Ответ от 95.213.11.146: число байт=32 время=26мс TTL=56
Ответ от 95.213.11.146: число байт=32 время=26мс TTL=56
Ответ от 95.213.11.146: число байт=32 время=26мс TTL=56
Ответ от 95.213.11.146: число байт=32 время=26мс TTL=56
Ответ от 95.213.11.146: число байт=32 время=386мс TTL=56
Ответ от 95.213.11.146: число байт=32 время=26мс TTL=56
Ответ от 95.213.11.146: число байт=32 время=26мс TTL=56
Ответ от 95.213.11.146: число байт=32 время=26мс TTL=56
Ответ от 95.213.11.146: число байт=32 время=26мс TTL=56
Ответ от 95.213.11.146: число байт=32 время=28мс TTL=56
Ответ от 95.213.11.146: число байт=32 время=363мс TTL=56
Ответ от 95.213.11.146: число байт=32 время=26мс TTL=56
Ответ от 95.213.11.146: число байт=32 время=26мс TTL=56
Ответ от 95.213.11.146: число байт=32 время=26мс TTL=56
Ответ от 95.213.11.146: число байт=32 время=26мс TTL=56
Ответ от 95.213.11.146: число байт=32 время=26мс TTL=56
Ответ от 95.213.11.146: число байт=32 время=292мс TTL=56
Ответ от 95.213.11.146: число байт=32 время=26мс TTL=56
Ответ от 95.213.11.146: число байт=32 время=26мс TTL=56
Ответ от 95.213.11.146: число байт=32 время=26мс TTL=56
Ответ от 95.213.11.146: число байт=32 время=26мс TTL=56

Router settings (RB9151G-2HnD):

 > export compact
# dec/09/2016 12:37:22 by RouterOS 6.37.3
# software id = JNKG-S02Y
#
/interface bridge
add admin-mac=6C:3B:6B:03:04:0F auto-mac=no comment=defconf name=bridge
/interface wireless
set [ find default-name=wlan1 ] band=2ghz-onlyn country=russia2 disabled=no distance=indoors frequency=2442 mode=ap-bridge ssid=KVAZAR wireless-protocol=802.11
/interface ethernet
set [ find default-name=ether2 ] name=ether2-master
set [ find default-name=ether3 ] master-port=ether2-master
set [ find default-name=ether4 ] master-port=ether2-master
set [ find default-name=ether5 ] master-port=ether2-master
/interface pppoe-client
add add-default-route=yes disabled=no interface=ether1 name=pppoe-out1 password=MyPass use-peer-dns=yes user=MyLogin
/ip neighbor discovery
set ether1 discover=no
set bridge comment=defconf
/interface wireless security-profiles
set [ find default=yes ] authentication-types=wpa-psk,wpa2-psk mode=dynamic-keys wpa-pre-shared-key=2qvwups8 wpa2-pre-shared-key=2qvwups8
/ip pool
add name=dhcp ranges=10.10.10.10-10.10.10.250
/ip dhcp-server
add address-pool=dhcp disabled=no interface=bridge name=defconf
/interface bridge port
add bridge=bridge comment=defconf interface=ether2-master
add bridge=bridge comment=defconf interface=wlan1
/ip address
add address=10.10.10.1/24 comment=defconf interface=ether2-master network=10.10.10.0
/ip dhcp-client
add comment=defconf dhcp-options=hostname,clientid interface=ether1
/ip dhcp-server lease
add address=10.10.10.10 comment="Server CRM" mac-address=54:04:A6:CD:FF:3A server=defconf
add address=10.10.10.5 client-id=1:38:d5:47:82:47:c0 comment="ASUS RT-N12 Access Point" mac-address=38:D5:47:82:47:C0 server=defconf
add address=10.10.10.25 client-id=1:70:8b:cd:42:f1:11 mac-address=70:8B:CD:42:F1:11 server=defconf
/ip dhcp-server network
add address=10.10.10.0/24 comment=defconf gateway=10.10.10.1 netmask=24
/ip dns
set allow-remote-requests=yes
/ip dns static
add address=10.10.10.1 name=router
/ip firewall filter
add action=fasttrack-connection chain=forward comment="defconf: fasttrack" connection-state=established,related
add action=accept chain=forward comment="defconf: accept established,related" connection-state=established,related
add action=drop chain=forward comment="defconf: drop invalid" connection-state=invalid
add action=drop chain=forward comment="defconf:  drop all from WAN not DSTNATed" connection-nat-state=!dstnat connection-state=new in-interface=ether1
add action=accept chain=input protocol=icmp
add action=accept chain=input connection-state=established
add action=accept chain=input connection-state=related
add action=drop chain=input in-interface=pppoe-out1
add action=accept chain=forward layer7-protocol=*1 src-address=0.0.0.0
/ip firewall nat
add action=masquerade chain=srcnat comment="defconf: masquerade" out-interface=pppoe-out1
/ip upnp
set enabled=yes
/ip upnp interfaces
add interface=bridge type=internal
add interface=pppoe-out1 type=external
/system clock
set time-zone-name=Europe/Moscow
/system leds
set 0 interface=wlan1
/system routerboard settings
set protected-routerboot=disabled
/tool mac-server
set [ find default=yes ] disabled=yes
add interface=bridge
/tool mac-server mac-winbox
set [ find default=yes ] disabled=yes
add interface=bridge

The second access point on the floor below the SSID and WPAKey is the same.
Tried turning it off. All the same.
Frequency (channel) chose the most free. it doesn't even overlap with neighbors across the entire width...
CPU utilization 0-15%, 9% on average.
Mikrotik was taken on purpose so that the network would work stably, but it turns out that there are constant communication problems (IP telephony stutters and gurgles)
Guru Mikrotik, please enlighten me where to dig, what am I doing wrong?

Answer 1

Check if the channels are busy, switch to a freer one and it is very desirable to one of 1,6,11.
You are now at 7th, which is not "best practice".
Take Wi-Fi out of the bridge - make a separate network on it (this will reduce the amount of broadcast traffic), plus prohibit communication between clients in it.
Set up QoS for priority traffic and limit the bandwidth for each specific client (you can do this with the chip parameters).
Well, for SIP, a wire is better, everything is as Artyom wrote