Posted: Tue Jan 14, 2020 18:45 Post subject: Reducing jitter in a congested environment.
Hi all!
Having experience my first issue with Jitter, also knows as bufferbloat,
I was wondering on possible steps to take to reduce the issue,
where neighbours all have wifi as well and a mid-day scan
reveals 30+ competing wifi networks.
At different channels, mind you, but a spectral scan
is telling about the congestion around.
One step I think might help is using less powerful antennas
so they capture less surrounding networks. So smaller
antennas and stronger router signal to quiet interference.
Does it make sense? Are there other ways to alleviate
communication in busy airways?
Joined: 16 Nov 2015 Posts: 6447 Location: UK, London, just across the river..
Posted: Wed Jan 15, 2020 8:55 Post subject:
it smells like you'd need to learn/read about a lot of things...
1. do not use auto channel , choose a fixed channel...
either 1, 6, 11 give the best performance for 2.4Ghz
2. use noise immunity - this option is not present on all routers..
3. the other side is, the client side, as some wi-fi clients show a better performance too _________________ Atheros
TP-Link WR740Nv1 ---DD-WRT 55630 WAP
TP-Link WR1043NDv2 -DD-WRT 55723 Gateway/DoT,Forced DNS,Ad-Block,Firewall,x4VLAN,VPN
TP-Link WR1043NDv2 -Gargoyle OS 1.15.x AP,DNS,QoS,Quotas
Qualcomm-Atheros
Netgear XR500 --DD-WRT 55779 Gateway/DoH,Forced DNS,AP Isolation,4VLAN,Ad-Block,Firewall,Vanilla
Netgear R7800 --DD-WRT 55819 Gateway/DoT,AD-Block,Forced DNS,AP&Net Isolation,x3VLAN,Firewall,Vanilla
Netgear R9000 --DD-WRT 55779 Gateway/DoT,AD-Block,AP Isolation,Firewall,Forced DNS,x2VLAN,Vanilla
Broadcom
Netgear R7000 --DD-WRT 55460 Gateway/SmartDNS/DoH,AD-Block,Firewall,Forced DNS,x3VLAN,VPN
NOT USING 5Ghz ANYWHERE
------------------------------------------------------
Stubby DNS over TLS I DNSCrypt v2 by mac913
Joined: 16 Nov 2015 Posts: 6447 Location: UK, London, just across the river..
Posted: Thu Jan 16, 2020 7:40 Post subject:
MasterGoa wrote:
I do not use auto channel. I chose 4 because a site survey shows it is free.
In the 34 networks I see, 7 are channel 1, 5 are #6 and 4 are #11.
To add to the question, is it better to use
less powerfull antennas and use stronger router tx power?
My router had +5db antennas right now, so I suspect it makes
it sensitive to adjacent networks...
smaller antennas will reduce, range and performance..
reducing TX power will do the same...you can take off all the antennas in case you are close to the router...
for best TX power use country domain like Canada...
and channel 11 + lower, short GI, Short preamble and so on..
Io do use my routers in very congested environment,
like 30-40 WiFi networks around, never had a single issue... _________________ Atheros
TP-Link WR740Nv1 ---DD-WRT 55630 WAP
TP-Link WR1043NDv2 -DD-WRT 55723 Gateway/DoT,Forced DNS,Ad-Block,Firewall,x4VLAN,VPN
TP-Link WR1043NDv2 -Gargoyle OS 1.15.x AP,DNS,QoS,Quotas
Qualcomm-Atheros
Netgear XR500 --DD-WRT 55779 Gateway/DoH,Forced DNS,AP Isolation,4VLAN,Ad-Block,Firewall,Vanilla
Netgear R7800 --DD-WRT 55819 Gateway/DoT,AD-Block,Forced DNS,AP&Net Isolation,x3VLAN,Firewall,Vanilla
Netgear R9000 --DD-WRT 55779 Gateway/DoT,AD-Block,AP Isolation,Firewall,Forced DNS,x2VLAN,Vanilla
Broadcom
Netgear R7000 --DD-WRT 55460 Gateway/SmartDNS/DoH,AD-Block,Firewall,Forced DNS,x3VLAN,VPN
NOT USING 5Ghz ANYWHERE
------------------------------------------------------
Stubby DNS over TLS I DNSCrypt v2 by mac913
Joined: 16 Nov 2015 Posts: 6447 Location: UK, London, just across the river..
Posted: Thu Jan 16, 2020 17:52 Post subject:
have you read those links i provided, its explain there... very very well...
it seems you'd like to ask, but not to read...
i cant share all my knowledge in one day...
but you can read about it...
at 2.4 Ghz the full/valid/nonoverlaped channels are 1,6,11 all the rest are shared/overlapped channels
I use 11 and around me, there are at least 5-8 at channel 11 never had an issue...
it wont hurt to read/try before you ask....!! _________________ Atheros
TP-Link WR740Nv1 ---DD-WRT 55630 WAP
TP-Link WR1043NDv2 -DD-WRT 55723 Gateway/DoT,Forced DNS,Ad-Block,Firewall,x4VLAN,VPN
TP-Link WR1043NDv2 -Gargoyle OS 1.15.x AP,DNS,QoS,Quotas
Qualcomm-Atheros
Netgear XR500 --DD-WRT 55779 Gateway/DoH,Forced DNS,AP Isolation,4VLAN,Ad-Block,Firewall,Vanilla
Netgear R7800 --DD-WRT 55819 Gateway/DoT,AD-Block,Forced DNS,AP&Net Isolation,x3VLAN,Firewall,Vanilla
Netgear R9000 --DD-WRT 55779 Gateway/DoT,AD-Block,AP Isolation,Firewall,Forced DNS,x2VLAN,Vanilla
Broadcom
Netgear R7000 --DD-WRT 55460 Gateway/SmartDNS/DoH,AD-Block,Firewall,Forced DNS,x3VLAN,VPN
NOT USING 5Ghz ANYWHERE
------------------------------------------------------
Stubby DNS over TLS I DNSCrypt v2 by mac913
I like reading a lot, but I have to know WHAT to read.
You should have mentionned overlap in your first responce.
I found a great white paper by Cisco explaining proper deployment
of a commercial WLAN implementation.
In that white paper, I found this mention:
This proximity is important because 802.11 specifies the protocol using carrier sense multiple access (CSMA), meaning listen before transmitting. In this case, channel 4 clients refrain from transmitting until the client that is transmitting on channel 1 is finished. In a system with few users, this is probably not a problem. However, as the number of clients increases, so does the possibility of holdoffs.
This scenario also increases the likelihood of collisions, resulting in retries for both clients and decreasing the efficiency of the WLAN. If the cross-channel signal is low enough not to be decoded as a valid 802.11 signal, it is considered noise. This is when collisions start to occur. The noise is strong enough that the desired signal gets corrupted, and the packet needs to be retransmitted. Overall, this is much worse than a holdoff because the device transmits the packet twice (or more) rather than waiting for a clear time and sending it once.
It is counter intuitive, but it is better to be on a crowed, clear channel so that CSMA can work.
I will configure my network accordingly, hopefully, it will help other using DD-WRT
