Nstreme single - rapid connection/disconnection.

RouterOS Wireless Networking
1

Hi,

I have a Point to Multi point setup. One AP communicates with 2 Client Units. The cleint units cannot “hear” each other, so the probability of packet collsions at the AP is high, so I have changed this setup over to Nstreme.

Now I get at the AP:

Sep/29/2010 13:51:48 wireless,debug WAN: 00:80:48:64:6D:4B attempts to associate
Sep/29/2010 13:51:48 wireless,debug WAN: 00:80:48:64:6D:4B in local ACL, accept
Sep/29/2010 13:51:48 wireless,info 00:80:48:64:6D:4B@WAN: connected
Sep/29/2010 13:54:01 wireless,info 00:80:48:64:70:98@WAN: disconnected, extensive data loss
Sep/29/2010 13:54:03 wireless,debug WAN: 00:80:48:64:70:98 attempts to associate
Sep/29/2010 13:54:03 wireless,debug WAN: 00:80:48:64:70:98 in local ACL, accept
Sep/29/2010 13:54:03 wireless,info 00:80:48:64:70:98@WAN: connected
Sep/29/2010 13:54:34 wireless,info 00:80:48:64:6D:4B@WAN: disconnected, extensive data loss
Sep/29/2010 13:54:35 wireless,info 00:80:48:64:70:98@WAN: disconnected, extensive data loss
Sep/29/2010 13:54:35 wireless,debug WAN: 00:80:48:64:6D:4B attempts to associate
Sep/29/2010 13:54:35 wireless,debug WAN: 00:80:48:64:6D:4B in local ACL, accept
Sep/29/2010 13:54:35 wireless,info 00:80:48:64:6D:4B@WAN: connected
Sep/29/2010 13:54:35 wireless,info 00:80:48:64:6D:4B@WAN: disconnected, extensive data loss
Sep/29/2010 13:54:39 wireless,debug WAN: 00:80:48:64:70:98 attempts to associate
Sep/29/2010 13:54:39 wireless,debug WAN: 00:80:48:64:70:98 in local ACL, accept
Sep/29/2010 13:54:39 wireless,info 00:80:48:64:70:98@WAN: connected
Sep/29/2010 13:54:39 wireless,debug WAN: 00:80:48:64:6D:4B attempts to associate
Sep/29/2010 13:54:39 wireless,debug WAN: 00:80:48:64:6D:4B in local ACL, accept
Sep/29/2010 13:54:39 wireless,info 00:80:48:64:6D:4B@WAN: connected
Sep/29/2010 13:54:54 wireless,info 00:80:48:64:6D:4B@WAN: disconnected, extensive data loss
Sep/29/2010 13:54:54 wireless,info WAN: data from unknown device 00:80:48:64:6D:4B, sent deauth
Sep/29/2010 13:54:54 wireless,info WAN: data from unknown device 00:80:48:64:6D:4B, sent deauth
Sep/29/2010 13:54:54 wireless,info WAN: data from unknown device 00:80:48:64:6D:4B, sent deauth
Sep/29/2010 13:54:56 wireless,debug WAN: 00:80:48:64:6D:4B attempts to associate
Sep/29/2010 13:54:56 wireless,debug WAN: 00:80:48:64:6D:4B in local ACL, accept
Sep/29/2010 13:54:56 wireless,info 00:80:48:64:6D:4B@WAN: connected

This occurs every minute or two. AP Noise Floor is -98, Cleint One is connecting -80 and Cleint 2 at -79. Link distance is about 3km. 2.4Ghz B/G

Why does the AP declare a device “unknown”, and then allow it to connect 2 seconds later?

Nstreme settings are:

set WAN comment="" disable-csma=no enable-nstreme=yes enable-polling=yes framer-limit=1500 \
    framer-policy=exact-size

Any suggestions? Any further info required?

Thanks
Brian

2

Sounds like bad signal or noise. Take a look at “/interface wireless registration-table” and see if that data might help. If you have questions about it, please post it.

3

Hi,

Reg table shows:

The connection breaks every minute…

Getting desperate.

Thanks
Brian

4

Those are not good numbers. If you are getting a break every minute, you might try changing frequencies. Long range radar could cause that. I get breaks when specific military aircraft fly over. I am in the approach path to Eglin AFB.

How far is the connection? What antennas are you using?

5

Hi Tim,

I am in Zimbabwe, long range radar is a long way away :slight_smile:

The link is a lot more stable when I turn Nstreme off, without changing frequency. But I thought the polling might take care of the packet collisions that occur because the two CPE’s dont see each other, which is why I am trying Nstreme. Links are approx 3km.

I am using integrated units as pictured below:

15dBi integrated antenna. Rb433 at AP and Rb411 in CPE’s.

Regards
Brian

6

Just to be clear, you have one 15db antenna that connects to two CPEs. Correct? Since the CPEs are “out of range” of each other, are they in the coverage area of the antenna? Anything above 12db starts to get pretty directional. I do the same without the nstreme, but they are “out of range” of each other by obstructions, not angular distance.

7

Tim,

Correct, a hill seperates the two CPE’s, but both see the AP, which is on a mountain some 600m above the CPE’s.

Brian

8

Do you maintain a connection long enough to see the log and signal data in either CPE?

9

Yes, I can sometimes see the signal data before it disconnects, or it reconnects so quickly, that the Winbox doesn’t time out. The log is always there to view when I do get back in.

Signal Strenths look very similar to the readings on the AP.

Regards
Brian

10

What radios are you using? What frequencies have you tried?
What antennas on the CPEs? Any way to increase the antenna gain on that end?

ADD: You really need another 6db to make that connection stable, according to my experience. You can’t get 54m transfer unless you have better than -70db. That is 8 times the gain you have now.

11

Hi,

Radios are Mikrotik R52 MiniPCI Wireless in AP and CPE’s, no way of increasing the antenna gain. I have operated on the one frequency that is clear when scanning from the AP. Problem I think could be, that being a Hi Site, the AP is not alone, and 5 Mhz below and 10Mhz above is a competitors two Ap’s. Maybe I’ll just move this backhaul story to 5.8 and be done with it. Inherited the system 3 months, and this is last niggle I am having, trying to load share across both links down the the CPE’s at the gateways…

Thanks for your time and responses, i really thought that Nstreme was going to be the silver bullet.

Regards
Brian

12

Swap out the radio cards in Ap + Cpe’s get cards with more output