lonnie... RTS?

[joedan]

Lonnie... I recall a post from you about your success with RTS throughout your network. I can't seem to locate it. Can you give me the numbers again? I remember that you had one number for APs and another for CPEs. What about a CPE that is acting as one end point of a backhaul?

I've got two more clients to put on the new repeater and then we're starting the "bridge to routing" project. I hope I can count on your advise.

Thanks,
~joe

[lonnie]

We will try and be there for you. This is a busy time of year.

We set the AP to 300 or 250, seemed to be about the same. If you have Lucent client cards, they use the number from the AP. Non Lucent clients require you to set the number.

I stress - the AP does not use RTS itself, it is only for clients to reserve a time slot to send a large packet. The key assumption every system has to make is that every client can hear the AP. RTS is to reserve time so that long packets do not get clobbered by another sytem that cannot hear the other client.

The other thing that has helped with throughput is to fix the radio rates at a value which is reasonable and sustainable for the signal levels you have. When a collision occurs, the AP (when in auto fallback mode) assumes there is noise so it drops the speed down. That process takes time and can result in even more collisions. With the speed fixed, a collision just causes a retransmission so it way quicker and you will get much better throughout and stability for your LAN.

[bobbyc]

So you're suggesting to take off auto/11mbps on a noisy AP and set it to 2mbps? And on clients who have a CPE like the wet11, set it to '1 or 2' mbps?
Bob C

[lonnie]

As always, your situation might be different, but it worked for us. The speed you set to is determined by your signal to noise ratio and your signal.

We have one link with very adequate signals but the AP was continually showing speed changes and the customers had packet loss. When we fixed the rate at 11 mbps the packet loss was gone since the AP and clients were not always changing their speed, a process that takes time.

If you have a link where the AP shows the speed jumping all over from 11 mbps to 1 mbps with good signal level, set the speed to fixed 11 mbps. If it sucks, try it at 5 mbps, then 2 mbps, then 1 mbps. If you have poor client speeds at all those settings you have other problems. If it makes the client speed higher and more reliable, then problem fixed.

[bobbyc]

When you say fixed, you mean take it off auto. If auto is checked, it doesn't matter what you have your speed checked to, right? Or is it like this: You have auto checked and 5.5mbps selected, your clients will associate at 5.5 or less mbps?
Bob C

[tony]

That is correct, the 'auto' mode will not exceed your chosen rate.

[kbldawg]

....We have one link with very adequate signals but the AP was continually showing speed changes and the customers had packet loss. When we fixed the rate at 11 mbps the packet loss was gone since the AP and clients were not always changing their speed, a process that takes time.

If you have a link where the AP shows the speed jumping all over from 11 mbps to 1 mbps with good signal level, set the speed to fixed 11 mbps. If it sucks, try it at 5 mbps, then 2 mbps, then 1 mbps. If you have poor client speeds at all those settings you have other problems. If it makes the client speed higher and more reliable, then problem fixed.

Would it be possible for one customer with those symptoms (rate changes) to cause others on that same AP to change rate, packet loss, eratic ping times? I understand that the auto negotiate time the AP requires can cause collision, but I was unsure if it would actually effect other clients rates.

I have one customer that has 20% - 22% quality, with NLOS. His rate has been jumping from 11 - 1 throughout the day, but his ping times and packet loss are acceptable and throughput is good.

However, I just hooked up a new customer that has a 25% - 30% connection quality that is experiencing high packet loss and their rate is also eratic.

If I were to try and fix this with the suggestion above, is it neccessary to have a fixed rate at the AP and do I need to set fixed rates for all clients or just those experiencing problems?

[lonnie]

I would let the AP stay on auto but set all of the clients to 11 mbps.