<br>
<br><tt><font size=2>server-devel-bounces@lists.laptop.org wrote on 03/03/2008
02:38:00 AM:<br>
<br>
<br>
> Questions: <br>
> <br>
> <br>
> How many XO's can a single active antenna support? We only have two<br>
> active antennas at the moment. <br>
The answer is always traffic depedent. Given the current status of the
collaboration software on the XO and assuming that the school server's
ejabberd works correctly (shutting off multicast traffic on the XOs), you
should be able to put 30-40 laptops per "active antenna". </font></tt>
<br><tt><font size=2>You should always keep in mind that in "dense"
deployments (classrooms), mesh is sub-optimal compared to standard access
points (assuming that every XO can talk to the AP). That is because, you
have all the path discovery control traffic overhead in mesh mode that
you don't have in infrastructure mode.</font></tt>
<br>
<br>
<br><tt><font size=2>> <br>
> Should we buy extra regular access points to back up our active<br>
> antennas? Again, would love to know if particular AP is preferred
and<br>
> how many XO's one can support. I read in the devel list today that
the<br>
> WRT54G is not preferred. </font></tt>
<br><tt><font size=2>Yes, if you can afford them, APs will give you much
better performance in schools. The issue with the stock firmware in the
WRT54Gs is that it tries to establish WDS peer links with every other WDS
capable node in the vicinity. So if you have a few of them in a school,
you can end up with multiple WDS tunnels between them. Add to that the
multicast traffic from the XOs and you end up with no spectrum at all,
due to multicast/broadcast retransmissions.</font></tt>
<br><tt><font size=2>The solution to that problem is to be able to turn
off WDS. The stock Linksys firmware doesn't do it, however OpenWRT and
its variants can do it.</font></tt>
<br><tt><font size=2>So the answer to whether you should/can use WRT54Gx
APs is "only if you can upgrade them to an OpenWRT variant".</font></tt>
<br>
<br><tt><font size=2>We are working on HostAP support for the active antennas,
so that for small schools, the school server is all that you need. In the
meantime, APs with controllable WDS behavior are recommended.</font></tt>
<br>
<br><tt><font size=2><br>
> <br>
> We will have two pilot schools. One w/ 110 students and the other
w/ 50<br>
> students.<br>
I would use 3 APs on the first and two on the second. In the future 2 and
1 will suffice, however as of now we are wasting a lot of airtime in all
layers of the network stack.</font></tt>
<br>
<br>
<br><tt><font size=2>M.</font></tt>
<br>
<br><tt><font size=2><br>
</font></tt>