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3km link in the city (B2B)

Posted: Sun Nov 14, 2004 7:14 pm
by gianluca
I would like to set up 3 links between 2 big buildings in a city, complete LOS (a lot higher then other buildings), distance is about 3 km and need at least 40 Mb/s.

I am pretty used with MK (traffic shaping and firewalling but not wireless)

I suppose the solution goes through having a PCI card installed on the routerboards, using 11a and a big antenna, but I would like to have some more detailed info:

- which card to mount on the routerboard ? where to buy it or which supplier ?
- is routerboard enough to have a link like this?
- which antenna is reccomended ?

many thank for the input

Posted: Sun Nov 14, 2004 7:25 pm
by mip
Post it only one place.

Yo have alreadyposted it there.

Posted: Sun Nov 14, 2004 7:34 pm
by gianluca
my apologise, after posting I saw it interesting to open a new subject collecting the doubts a lot of people have.

A short summary of how to set up a link with MK.

Any help?

Posted: Sun Nov 14, 2004 8:34 pm
by stephenpatrick
Hi GianLuca,

Saw your post ...

CPU speed is a big problem if you want 40Mbps throughput. As well, you need high signal levels, and low interference on channel-bonded "turbo" mode. Choose good antennas, the 23dBi's on MT get good write-ups.

RB-type boards with 266MHz CPUs (there are several about) offer about 25Mbps throughput flat out - 100% CPU utilisation.

We cracked it some weeks back using 1GHz CPUs, 5.3 or 5.8GHz using Turbo and Nstreme, and you can get 74Mbps TCP and 83Mbps UDP using BW tester in the lab - just a bit slower at 3km I think - I would love to hear what other users have achieved.

Another user was "a bit annoyed" to my last post helping others with exactly the same problem - we've developed a complete product that does all this, but despite lots of really interested people who mailed me, it's of course not ettiquette to advertise on another's forum ... so I won't repeat the contents - have search on this forum-
BTW, we make products, we're not an operator/provider, so that's where we fit in.

I personally agree with the support comment, some "out of the box" guidelines are needed for the most common configs. We hope to get these together shortly to support our products.

I'm just back from holiday, so need to catch up ...

Best regards


Posted: Sun Nov 14, 2004 9:11 pm
by gianluca
what's teh maximum bandwidth (more or less) with the routerboard ? and which card you suggest to use fo rthe link?

many many thanks for the help
and welcome back!

Posted: Sun Nov 14, 2004 9:35 pm
by stephenpatrick
Lots of previous posts say that RB gives 24Mbps half duplex, with all "non essential" features turned off.

I've personally used MT's 5211 and 5212. No problems with either.

Hope that helps -


Posted: Sun Nov 14, 2004 9:47 pm
by gianluca
thanks again, but what are the MT's 5211 and 5212 ?

Posted: Sun Nov 14, 2004 10:47 pm
by stephenpatrick
Have a look here

I think they removed either 5211 or 5212 and replaced with 5213 now - need to read the datasheets carefully.

Hope that helps

Best regards