Community discussions

MikroTik App
 
Dixit
newbie
Topic Author
Posts: 34
Joined: Mon Feb 09, 2015 9:00 pm

SXT ACs installed for 200m PTP link, what to do to tweak the speed?

Wed Feb 18, 2015 9:01 pm

I have two SXT ACs installed on a line of sight 200meter link. Below is a video showing a speed test being run using clients on each side (not using the bandwidth test on the SXT) and we getting around 80-85Mbit/sec. Ive tried many different TX powers (the video is shown with both sides set to default) to where its in the -60dBm range and still no change. The band we are using is 5260 on Ceee and there is no one on that band so I feel we are clean there. Ive tried it on 40mhz, same thing. The protocol is NV2 with a passphrase. I tried 802.11 (don't believe I had any security setup, not familiar with how to do that) and that didn't make much of a difference except CCQ was very stable at 95-100%.

I only have 6 firewall rules (to block DHCP broadcast/requests on the link) and with that enabled or disabled, I didn't see any difference in speed.

Any suggestions on what to do? This is my first time using Mikrotik RouterOS products. Btw this link is mainly to connect two houses to share server data between them without having to use the ISP link (each side has their own cable modem).

http://youtu.be/6zl1McJSZFg

Dixit
 
jarda
Forum Guru
Forum Guru
Posts: 7756
Joined: Mon Oct 22, 2012 4:46 pm

Wed Feb 18, 2015 11:17 pm

Lower the power on both sides. -35dbi is too much. If you have enabled firewall on bridge, disable it. You can use fast path without it. Check the profiler what eats cpu during the test. If you can, disable conntrack on the sxt. If you need to block dhcp because you bridged two networks, just cut the bridging port from the bridge on one of main routers and use routing instead bridging. You just need to have different address ranges in both networks. The other routers on the way can also affect the speed, so check them too.
 
Dixit
newbie
Topic Author
Posts: 34
Joined: Mon Feb 09, 2015 9:00 pm

Re: SXT ACs installed for 200m PTP link, what to do to tweak the speed?

Wed Feb 18, 2015 11:40 pm

I turned off the firewall under Bridge settings on both sides and also disabled my 6 rules. My speed increased to about 90-95Meg. However under profile im still seeing firewall showing in the 15-20 range. Before disabling the firewall I was seeing maybe 20-30 on the firewall (where I got 80 to 85Meg link).

I'll try lowering the power but before didn't see much of a difference when I was playing with it before, let me try a few more things.

Issue on the firewall (unless if there is a better way to do this) is that I don't want DHCP requests coming across the link and each network serving a client on the opposite side (I have a 192.168.1.x on one side and 192.168.0.x on the other side), without the firewall rules I was seeing DHCP requests being served by opposite sides.

Dixit
 
User avatar
meconet
Trainer
Trainer
Posts: 101
Joined: Wed Mar 23, 2005 12:02 pm
Location: Germany
Contact:

Re: SXT ACs installed for 200m PTP link, what to do to tweak the speed?

Thu Feb 19, 2015 12:24 am

Hi,

if you have 192.168.1.x on one side and 192.168.0.x on the other, why did you bridge between these Networks? Just use the SXTs as router on each side between both, so you don't need any filter.

Regarding your link performance, I see TX- & RX-Rate switching all the time in a wide range, also CCQ is not okay. Like jarda say, lower down TX-Power and get the most important wireless parameter stable. Also try the same config with NStreme instead of NV2.

Regards
Lutz
 
Dixit
newbie
Topic Author
Posts: 34
Joined: Mon Feb 09, 2015 9:00 pm

Re: SXT ACs installed for 200m PTP link, what to do to tweak the speed?

Thu Feb 19, 2015 1:04 am

I created a bridge mainly because each side (is a house) and each side has its own cable modem and devices for that house. We wanted a network to simple use (this PTP link) to connect to each others servers (we have a windows 2012 server we run and has data on it). So I created this link and didn't want each other's home based routers issuing DHCPs to other side. Each house has just your average home router/gateway like one side has a Linksys E2000 Wifi Router/Gateway hooked to a Cable Modem. The other side has a Netgear R7000 Wifi Router/Gateway also connected to a cable modem. These home based router/gateways are limited in what I can do like creating a vlan and what not to block DHCPs from bleeding across.

We didn't want the link to be used for say internet sharing. That wasn't the intent, just to connect to the other house to share data. I didn't want to use the SXT as the router (say it is the one issuing DHCP).

Im not an expert so I could be horribly wrong on this, as this is about the extend of my networking knowledge. Im not too good with things above your say standard single network.

Dixit
 
Dixit
newbie
Topic Author
Posts: 34
Joined: Mon Feb 09, 2015 9:00 pm

Re: SXT ACs installed for 200m PTP link, what to do to tweak the speed?

Thu Feb 19, 2015 1:31 am

Wanted to also post that after disabling the firewall and all rules, originally I said I was only getting 90-95Meg, turns out the machine I was using somehow didn't negotiate gigabit and only got a 100Meg LAN port, so switched the cable out and got Gigabit. Tried it again and was getting now 125Meg on the link transferring data. Im still seeing firewall on profiler hitting 21 (is this right? Or should it be zero if I have both the firewall disabled on the bridge settings and all rules are disabled?).

My TX power is set to all rates and 1db. Its still showing about -52 to -53dBm.

So sounds like I need to find a better solution for my DHCP issue so I don't have to use the firewall on the SXT and get maximum throughput on the link.

Dixit
 
jarda
Forum Guru
Forum Guru
Posts: 7756
Joined: Mon Oct 22, 2012 4:46 pm

Re: SXT ACs installed for 200m PTP link, what to do to tweak the speed?

Thu Feb 19, 2015 12:35 pm

ok,
first there are some general things: If you start with wifi link, set the regulatory domain and finetune the power by altering antenna gain around real antenna gain value. Check there are no other settings in the bridging devices that could affect the performance. Also check that the traffic is able to flow to and from the bridging devices. You could have bottleneck elsewhere (in your routers, cabling... who knows?).

You should use routing instead bridging in this case, as I told you, cut the bridge on one of the routers port and set routes to both routers to let them know where to send packets that are destined to other network. If you have unmanageable routers, obtain some better ones (for example some mikrotiks) or install some better software inside them if possible. For example OpenWRT.

If you still see 20% of cpu taken by firewall, you have not managed to switch it off. Better to remove configuration to have it clear and set the config fully from scratch.
 
Dixit
newbie
Topic Author
Posts: 34
Joined: Mon Feb 09, 2015 9:00 pm

Re: SXT ACs installed for 200m PTP link, what to do to tweak the speed?

Sun Mar 01, 2015 5:42 am

Just wanted to chime back in here and explain that Ive managed to get this up to 125-130Mbps even with the firewall running. What I did was remove the EoIP tunnel that I originally setup and just ran this as a simple Wireless Bridge as shown in the Wiki http://wiki.mikrotik.com/wiki/Bridging_ ... s_with_SXT

I still have the firewall with just 4 rules now as shown below
/ip firewall filter
add action=drop chain=forward disabled=no dst-port=67 log=yes protocol=udp
add action=drop chain=forward disabled=no dst-port=68 log=yes protocol=udp
add action=drop chain=input disabled=no dst-port=67 log=yes protocol=udp
add action=drop chain=input disabled=no dst-port=68 log=yes protocol=udp
This helps block the DHCP broadcast issue where HouseA ends up serving HouseB with a DHCP client request. This also helps me still keep the network almost like a hybrid single network where UPNP broadcasts pass through and clients like Plex can see all Plex servers (one on each side).

Removing the EoIP tunnel I had setup along increased the speed from 80Mbps to about 125-130Mbps. Now even with a full server to server file transfer test (SXTs not used for speed test as in using Bandwidth Tester tool) Im getting that speed. CPU hits about 50-60% tops on the SXT where before it would hit pretty much 85-95% and firewall in profiler was showing a good 15-30%.

I need to do some more tweaks as far as signal goes (need to final position and mount the SXTs, they still in temporary mounted form). Hope to get even more speed.

Dixit
 
wispwest
Member
Member
Posts: 479
Joined: Tue May 19, 2009 3:48 am

Re: SXT ACs installed for 200m PTP link, what to do to tweak the speed?

Fri Mar 06, 2015 1:18 am

I never achieved much throughput on the SXT's, even the AC models. Replaced them ALL since installment. Not sure if the antenna just has low isolation between the polarities or what, but they've been a nightmare since the first one they put out. Never get really more than 60-70mb.
 
Dixit
newbie
Topic Author
Posts: 34
Joined: Mon Feb 09, 2015 9:00 pm

Re: SXT ACs installed for 200m PTP link, what to do to tweak the speed?

Fri Mar 06, 2015 1:44 am

I had a problem initially if you follow mine from the start. Originally one of the problems was that one of the SXTs didn't negotiate at gigabit, and only got a 100meg for the LAN, after replacing the wire we got it at Gigabit negotiation. Then the problem was the firewall and tunnel I had setup (EOIP). So once I removed that tunnel and kept the firewall I managed to get real world 130-145Mbit on server to server file transfer without using the SXT in built bandwidth test. Right now those numbers are based on the SXT not setup probably for LOS. One antenna was temporarily moved to a different location until we bury the direct burial Cat6 to the area we need. Then we going to mount that SXT to the right spot. Right now my CCQ isn't great, only getting high 50s and low 60s. Mainly due to the fact the signal is going through a big tree. But still impressive Im getting 145Mbit. I hope once its setup at the final spot and CCQ gets up, Id love to see higher levels on my server to server test.

Dixit
 
Dixit
newbie
Topic Author
Posts: 34
Joined: Mon Feb 09, 2015 9:00 pm

Re: SXT ACs installed for 200m PTP link, what to do to tweak the speed?

Sun Mar 08, 2015 4:15 am

Just mounted one of the sides to its final destination on a 1.5" metal pole and used direct burial Cat6 wire and ran all the wiring to the house. Now Im getting even more speed which is great since originally as mentioned it was moved temporarily where there was a tree in the way.

Attached is the latest test. This is a server to server file transfer. So its true real world speed. UDP test on Bandwidth test gets just about 350Mbit/sec. This is definitely going to work for me now.
FileTransferTest.png
This is still with my firewall rules in place. Even on that test I was hitting only 60% CPU. Firewall was only using 5%. Most of it was being used by the Wireless and Bridge according to profiler.

Dixit
You do not have the required permissions to view the files attached to this post.
 
Dixit
newbie
Topic Author
Posts: 34
Joined: Mon Feb 09, 2015 9:00 pm

Re: SXT ACs installed for 200m PTP link, what to do to tweak the speed?

Mon Mar 09, 2015 2:21 am

Just as a final chime in here, Now getting close to 250Mbps consistent. Screenshot shows a little higher but you can see from the chart below it, its pretty solid speed wise. Im definitely happy with this link now.
Speed.png
Dixit
You do not have the required permissions to view the files attached to this post.
 
jarda
Forum Guru
Forum Guru
Posts: 7756
Joined: Mon Oct 22, 2012 4:46 pm

Mon Mar 09, 2015 8:33 am

Congratulations. I knew you would succeed.
 
jarda
Forum Guru
Forum Guru
Posts: 7756
Joined: Mon Oct 22, 2012 4:46 pm

Mon Mar 09, 2015 10:15 am

Anyway, similar speeds are achievable with 2x2 n mimo also.
 
InoX
Forum Guru
Forum Guru
Posts: 1966
Joined: Tue Jan 09, 2007 6:44 pm

Re: SXT ACs installed for 200m PTP link, what to do to tweak the speed?

Mon Mar 09, 2015 12:58 pm

Isn't SXTac an 2x2 mimo device? :D
 
jarda
Forum Guru
Forum Guru
Posts: 7756
Joined: Mon Oct 22, 2012 4:46 pm

Mon Mar 09, 2015 4:25 pm

Sure it is. I just wanted to say that there is no advantage of ac in this case

Who is online

Users browsing this forum: popecix and 29 guests