To Tweak the OpenWRT for Pure Performance there is no other way than editing config files from Terminal so I hope you actually read Part 3 before.
There are 4 parts to Tweaking the Performance
- Wireless Performance
- Wired Performance
- Web Performance
- QoS (Quality Of Service)
Tweaking Wireless Performance:
Setting to Wireless N with G backward compatibility
The TP-Link WR1043ND Hardware has a 3 Transmit 3 Receive Radio that is only Single Band with 20/40MHZ Frequency. It has Wireless B/G/N Capability.
To fully understand WiFi Standards you need to read up on
IEEE 802.11 standards.
We start by tweaking the Radio.
Wireless N allows backward compatibility with B and G, you need to set it to 802.11g+n.
You can do this by logging into the
Router via Putty using vi editor edit the file called "wireless" in /etc/config/, or do it in LuCI Web Interface(Router Config Page).
Adjusting Channel Width:
Next you need to make sure the Router is using
40MHZ Channel Width, this will allow greater throughput.
You can do this by logging into the
Router via Putty using vi editor edit the file called "wireless" in /etc/config/
config 'wifi-device' 'radio0'
option 'type' 'mac80211'
option 'channel' '7'
option 'macaddr' 'XX:XX:XX:XX:XX:XX'
option 'hwmode' '11ng'
option 'htmode' 'HT40-'
option 'noscan' '1'
option 'country' 'US'
list 'ht_capab' 'SHORT-GI-40'
list 'ht_capab' 'DSSS_CCK-40'
option 'disabled' '0'
option 'txpower' '24'
option 'bursting' '1'
option 'ff' '1'
option 'compression' '1'
config 'wifi-iface'
option 'device' 'radio0'
option 'network' 'lan'
option 'mode' 'ap'
option 'ssid' 'Your_SSID_Here'
option 'frag' '2346'
option 'rts' '2347'
option 'encryption' 'psk2'
option 'key' 'your_secret_key_here'
Note that there are 2 htmodes, HT40+ and HT40- you set them based on the channel available. If you set it wrongly you have to log in to the router via Ethernet Cable and change it back.
By rights 'htmode' is not allowed if there are competing BSSID using that channel (the good neighbor regulation), but you can override that with 'noscan' option. There is also a distance optimization setting which I tested the best values at 20-25.
Below is a graph displaying the difference between 40MHZ Channel Width and 20MHZ Channel Width.
Note that you can define more than 1 Access Point on OpenWRT. You can configure a Second AP as Guest and Fire-walling it from your own LAN.
Higher TXPower (Transmit Power)
There is a catch to set higher transmit power without hacking the source code.
If you set the country to 'US' (United States) or 'CA' Canada, you can increase the Transmit Power to a maximum of
24dbm otherwise you will be limited to 20dbm. However the catch is that
these countries have only channel 1-11 while you can set up to channel 13 for countries like Japan.
Tweaking Wired Performance:
Next you need to make sure the Router Ethernet Performance is adjusted by changing the sysctl variable this will allow greater throughput.
You can do this by logging into the
Router via Putty using vi editor edit the file called "sysctl.conf" in /etc/
kernel.panic=3
net.ipv4.conf.default.arp_ignore=1
net.ipv4.conf.all.arp_ignore=1
net.ipv4.ip_forward=1
net.ipv4.icmp_echo_ignore_broadcasts=0
net.ipv4.icmp_ignore_bogus_error_responses=1
net.ipv4.tcp_ecn=0
net.ipv4.tcp_fin_timeout=30
net.ipv4.tcp_keepalive_time=120
net.ipv4.tcp_syncookies=1
net.ipv4.tcp_timestamps=0
net.core.netdev_max_backlog=30000
net.ipv4.tcp_moderate_rcvbuf=1
net.netfilter.nf_conntrack_checksum=0
net.ipv4.netfilter.ip_conntrack_checksum=0
net.ipv4.netfilter.ip_conntrack_max=16384
net.ipv4.netfilter.ip_conntrack_tcp_timeout_established=3600
net.ipv4.netfilter.ip_conntrack_udp_timeout=120
net.ipv4.netfilter.ip_conntrack_udp_timeout_stream=180
# net.ipv6.conf.all.forwarding=1
# disable bridge firewalling by default
#net.bridge.bridge-nf-call-arptables=0
#net.bridge.bridge-nf-call-ip6tables=0
#net.bridge.bridge-nf-call-iptables=0
# increase TCP max buffer size setable using setsockopt()
# 16 MB with a few parallel streams is recommended for most 10G paths
# 32 MB might be needed for some very long end-to-end 10G or 40G paths
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
# increase Linux autotuning TCP buffer limits
# min, default, and max number of bytes to use
# (only change the 3rd value, and make it 16 MB or more)
net.ipv4.tcp_rmem = 4096 87380 16777216
net.ipv4.tcp_wmem = 4096 87380 16777216
All the TCP tweaks are derived from
ESnet
Note: These
tweaks are not found on OpenWRT How Tos.
Adjusting the Transmit Queue Length.
You can do this by logging into the
Router via Putty using vi editor edit the file called "rc.local" in /etc/
# Put your custom commands here that should be executed once
# the system init finished. By default this file does nothing.
ifconfig eth0 txqueuelen 10500
ifconfig wlan0 txqueuelen 7935
exit 0
Add the 3 lines above to increase the txqueuelen on Ethernet Interface.
eth0.1 is the LAN Port while eth0.2 is the WAN Port.
Also if you have a Windows File Share you want to tell the Router firewall not to monitor SAMBA Packets.
Windows Share also known as SAMBA in Linux uses the Port 445 so you need to tell OpenWRT to stop monitoring Packet Originating from LAN using Port 445.
Tweaking Web Performance:
Web Peformance typically require a lot of DNS Look up so you want to tell OpenWRT to use the Fastest DNS Server available.
You can do this by logging into the
Router via Putty using vi editor edit the file called "dnsmasq.conf" in /etc/
and add the fastest DNS Server closest to you.
Add the Line Below and change the IP of the server to YOUR fastest DNS Server. My Fastest DNS Servers may not be your Fastest DNS Server.
dhcp-option=6,165.21.83.88,8.8.8.8,208.67.222.222
Blue is a Singapore ISP DNS Server, Green is Google DNS Server, Red is OpenDNS Server.
There is no limit of the number of DNS Server you can set on OpenWRT
Install packages that boost performance.
You can do this by logging into the
Router via Putty.
opkg update
opkg install pepsal kmod-ipt-nathelper-extra
Quality of Service
What is Quality of Service?
Quality of Service makes it so that during torrenting, your webpages doesn't take a long time to load even though you are on a 1Mbps Connection.
It does this by prioritizing network traffic, putting webpage network packets in higher importance than torrent packets.
The step to installing QoS is logging into the
Router via Putty then
opkg install luci-app-qos
You set the QoS by setting the Port the Network Originate from and the Priority.
Hopefully you learn a lot from this series of blog post and enjoy the high performance of your Modified Router running on OpenSource Software.
If you run a Windows Share Server when you place the laptop beside the router and do a copy you should be getting insane WiFi Speeds @ 150Mbps at 5m line of sight
Let the numbers speak for themselves!
In case you modified the wrong config files and got lock out the fail safe mode is
here
