Community discussions

MikroTik App
 
zhall
Frequent Visitor
Frequent Visitor
Topic Author
Posts: 58
Joined: Fri Aug 20, 2004 6:33 pm
Location: Virginia

Problem with data rate on 5.3GHz link

Tue May 17, 2005 6:36 pm

Hi, just looking for some understanding of why this might be happening. We a PtP link between two sites. Signal strength on both sides is around -59 give or take a little. Frequency is in the 5.3Ghz range. Pings between both sides are around 5ms and for all intents and purposes the spectrum is clear.

What is happening is that the AP data rate locks down around 54Mbps, but the SU data rate will jump to 54Mbps and then go back to 6Mbps. I've reduced the supported rates as low as 12Mbps to see if the SU would lock down there to no effect. The SU just never seems to get a data rate above 6Mbps while the AP is doing fine.

We do have nstreme turned on, but otherwise the link has no special settings.

Anybody have any idea why this would be happening?

Thanks in advance
 
mip
Member Candidate
Member Candidate
Posts: 122
Joined: Fri Jun 04, 2004 8:19 pm
Location: Ráckeve
Contact:

Tue May 17, 2005 11:37 pm

Why is it a problem? Does your link slowing down? Try to leave rate at 54 (or try 48,36), and ping on empty state, 5mbps btw test (tcp, one way), 10mbps, and 15mbps (or even 20mbps). If ping does not grow over 10ms, your link can stand that speed perfekt.
We have some 5,3GHz link, and see what you're talking about, but causes no problem.
https://www.youtube.com/watch?v=j7q0Y_JZMrg - the country you must visit
 
randyloveless
Member Candidate
Member Candidate
Posts: 207
Joined: Thu Sep 30, 2004 10:14 am
Location: california
Contact:

Wed May 18, 2005 10:11 am

hey mip

i am having this issue link is -59 -63 nstream but my issue is ping rates very alot from 5ms to 60ms from ap to station. have asked before no one responds.

any suggestions

Randy
 
zhall
Frequent Visitor
Frequent Visitor
Topic Author
Posts: 58
Joined: Fri Aug 20, 2004 6:33 pm
Location: Virginia

Wed May 18, 2005 8:22 pm

Why is it a problem? Does your link slowing down? Try to leave rate at 54 (or try 48,36), and ping on empty state, 5mbps btw test (tcp, one way), 10mbps, and 15mbps (or even 20mbps). If ping does not grow over 10ms, your link can stand that speed perfekt.
We have some 5,3GHz link, and see what you're talking about, but causes no problem.
Well, it's a problem because we'll be backhauling 3 T1's for a cell phone company over the link. It has to be perfect by a standard that normal IP radio's for ISP's don't have to adhere to. It just makes me uncomfortable to see that both sides aren't balancing at the same data rate.

I just wonder if this is a bug with the mikrotik software, or a problem with setup. I truthfully have no clue. Tomorrow I'll be going out to the towers to run additional tests, so maybe I'll have more information again. But any help/hints would be greatly appreciated.
 
User avatar
stephenpatrick
Forum Veteran
Forum Veteran
Posts: 703
Joined: Fri Aug 20, 2004 12:26 pm
Location: UK
Contact:

Wed May 18, 2005 8:57 pm

Hmm,

Backhauling T1's using WiFi technology isn't generally recommended
Every time the radio "rate adjusts" you will lose some traffic I think.
For cell companies, there is zero tolerance for lost data, as the voice traffic itself is compressed - so the consequences for the user are even worse!

We tested "TDM-over-IP radio" and never got it to work without errors, even in the lab, short range, no interference.
That being said, I remember a post from another user who'd used different TDMoIP boxes and got 2 out of 3 links working.

Would be impressed if this solution can be made to work, anyone else got E1's or T1's over radio working?

I would be kicked off the forum for advocating laser for E1 or T1 backhaul, so I won't :roll: and though that works great, of course they are restricted in distance.

We do have customers who want E1's over radio, but for now, no solution - unless someone has one working - please post-

Regards
CableFree - Wireless Excellence - Microwave, E-band Radios, Free Space Optics, High performance Radios & Routers
http://www.cablefree.net
 
sten
Forum Veteran
Forum Veteran
Posts: 920
Joined: Tue Jun 01, 2004 12:10 pm

Re: Problem with data rate on 5.3GHz link

Wed May 18, 2005 9:55 pm

These are all wild guesses, but i needed a break from what i was doing :)

Try setting the basic rate up to say 12 mbits on each side and stop using 6 mbit alltogheter in the rates. Does it stick at 12mbits?
Just a wild guess but could be that one side sends almost exclusivly broadcast/multicast packets and thus sticks at basic rate.

One thing you could try is to ping the remote end with intensity to see if that changes anything.

Also i've seen this behaviour when the radios/antennas generate alot of noise due to bad hardware. I dont think there is any place that indicates noise on the radio itself. It could be some kind of feedback into the radio. I mean, the radio kind of generates it's own noise when transmitting.
 
randyloveless
Member Candidate
Member Candidate
Posts: 207
Joined: Thu Sep 30, 2004 10:14 am
Location: california
Contact:

Wed May 18, 2005 11:47 pm

sten

ping 192.68.10.11 -t -l 1500 does increase a little from 17ms - 100ms

i am going to change or lock down the freq and thruput see if it changes.

Randy

Who is online

Users browsing this forum: balexiev, erlinden, Google [Bot], sindy, ysha and 60 guests