PMP450 SM's Dropping Registration

Products PMP
1

We're dealing with some sectors where clients are dropping and registering over and over... but they're not re-reg'ing. Signal and beacon %'s are good on these clients. It's not happening to all clients on the sector, just maybe 1/3rd to half. This seems to have cropped up more with 14.1.1. We've also tried 14.1.2 beta on the AP and it still seems to be happening. The effected SM's all show multi day uptimes and are not being power cycled. Any ideas?

Here are some of the logs from the SM's when they drop and register:

02/16/2016 : 12:06:25 PST : Event: SMSESFAIL, MsgType: SMVCERR, NewState: OOSERVICE, Flag 255
02/16/2016 : 12:08:19 PST : Event: SMSESACTIVATE, NewState: REGISTERING, Flag 0
02/16/2016 : 12:08:19 PST : Event: SMAUTHENMSG, NewState: REGISTERING, Flag 0
02/16/2016 : 12:08:19 PST : Event: SMSESINS, NewState: REGISTERED, Flag 19
02/16/2016 : 12:08:19 PST : Event: SMAUTHORMSG, NewState: REGISTERED, Flag 0

02/16/2016 : 12:06:25 PST : Event: AUTHEN_RESET, NewState: IDLE, Flag 0
02/16/2016 : 12:08:19 PST : Event: AUTHEN_REQ, NewState: AUTHENTICATING, Flag 0
02/16/2016 : 12:08:19 PST : Event: AUTHEN_CHAL, NewState: AUTHENTICATING, Flag 0
02/16/2016 : 12:08:19 PST : Event: AUTHEN_SUC, NewState: AUTHENTICATED, Flag 0

02/16/2016 : 12:06:25 PST : Event: AUTHOR_RESET, NewState: IDLE, Flag 0
02/16/2016 : 12:08:19 PST : Event: AUTHOR_REQ, NewState: AUTHORIZING, Flag 0
02/16/2016 : 12:08:19 PST : Event: AUTHOR_MSG, MsgType: BCASTKEY, NewState: AUTHORIZING, Flag 0
02/16/2016 : 12:08:19 PST : Event: AUTHOR_REQPARAMS, NewState: AUTHORIZING, Flag 0
02/16/2016 : 12:08:19 PST : Event: AUTHOR_CFGPARAMS, NewState: AUTHORIZED, Flag 0
2

Hi Eric, Please send CNUT capture of AP and affected SM’s Are you using RADIUS authentication for SM’s? Thanks, Chitrang

3

Hi there, thanks for the response. NO we're not using RADIUS authentication for SM's. We're just using a pre-shared key and DES encryption. I will send a CNUT to your email Chitrang. Thanks!

4
@Eric Ozrelic wrote:

Hi there, thanks for the response. NO we're not using RADIUS authentication for SM's. We're just using a pre-shared key and DES encryption. I will send a CNUT to your email Chitrang. Thanks!

Eric,

As I emailed you privately we found that these registrations in the specfic capture were due to SNMP reboots of the SMs. Sure would be nice if the SMs would let the AP know when they are rebooting so it could gracefully teardown the connection, so there's a feature request. :)

But lets keep an eye on it but we're not aware of any issues with 14.1.1.

-Charlie

1 Like
5

We've updated the AP's and SM's to 14.1.2 beta on a few of the sectors that seem to have the most reg's and we'll be watching them, along with keeping our network admin from doing any tricky SNMP issued reboots! Thanks for your assistance!

1 Like
6

Did you ever find a solution to this issue? I am having a very similar issue with some of  my PMP450i 900mhz SMs. We are using AES preshared keys and SMs will drop out for 15 minutes and then come back on their own. This is what appears in the log:

08/31/2016 : 08:01:15 HAST : Event: AUTHEN_RESET, NewState: IDLE, Flag 0
08/31/2016 : 08:01:31 HAST : Event: AUTHEN_REQ, NewState: AUTHENTICATING, Flag 0
08/31/2016 : 08:01:40 HAST : Event: AUTHEN_CHAL, NewState: AUTHENTICATING, Flag 0
08/31/2016 : 08:01:43 HAST : Event: AUTHEN_RESET, NewState: IDLE, Flag 0
08/31/2016 : 08:02:00 HAST : Event: AUTHEN_REQ, NewState: AUTHENTICATING, Flag 0
08/31/2016 : 08:02:03 HAST : Event: AUTHEN_FAIL, NewState: IDLE, Flag 0
08/31/2016 : 08:02:22 HAST : Event: AUTHEN_REQ, NewState: AUTHENTICATING, Flag 0
08/31/2016 : 08:02:25 HAST : Event: AUTHEN_FAIL, NewState: IDLE, Flag 0
08/31/2016 : 08:02:44 HAST : Event: AUTHEN_REQ, NewState: AUTHENTICATING, Flag 0
08/31/2016 : 08:02:53 HAST : Event: AUTHEN_CHAL, NewState: AUTHENTICATING, Flag 0
08/31/2016 : 08:02:56 HAST : Event: AUTHEN_RESET, NewState: IDLE, Flag 0
08/31/2016 : 08:03:35 HAST : Event: AUTHEN_REQ, NewState: AUTHENTICATING, Flag 0
08/31/2016 : 08:03:47 HAST : Event: AUTHEN_RESET, NewState: IDLE, Flag 0
08/31/2016 : 08:04:09 HAST : Event: AUTHEN_REQ, NewState: AUTHENTICATING, Flag 0
08/31/2016 : 08:04:12 HAST : Event: AUTHEN_FAIL, NewState: IDLE, Flag 0
08/31/2016 : 08:04:32 HAST : Event: AUTHEN_REQ, NewState: AUTHENTICATING, Flag 0
08/31/2016 : 08:04:35 HAST : Event: AUTHEN_FAIL, NewState: IDLE, Flag 0
08/31/2016 : 08:18:56 HAST : Event: AUTHEN_REQ, NewState: AUTHENTICATING, Flag 0
08/31/2016 : 08:19:08 HAST : Event: AUTHEN_RESET, NewState: IDLE, Flag 0
08/31/2016 : 08:20:10 HAST : Event: AUTHEN_REQ, NewState: AUTHENTICATING, Flag 0
08/31/2016 : 08:20:22 HAST : Event: AUTHEN_RESET, NewState: IDLE, Flag 0
08/31/2016 : 08:22:22 HAST : Event: AUTHEN_REQ, NewState: AUTHENTICATING, Flag 0
08/31/2016 : 08:22:22 HAST : Event: AUTHEN_CHAL, NewState: AUTHENTICATING, Flag 0
08/31/2016 : 08:22:22 HAST : Event: AUTHEN_SUC, NewState: AUTHENTICATED, Flag 0

7

What firmware rev are you using? I believe our issues went away when 14.1.2 was released, and now we've moved on to 14.2. Have you tried using DES instead of AES?

8

I am still on 14.1.1

Have not tried DES instead as I would have to change all connected SMs. 

9

A SM will only drop connection to the AP if the signal level is  <=-75dBi.

Increasing the signal strength to >-69dBi will keep it registered to the AP. Use RF lens or align properly to boost signal strength.

10

The drop outs are from customers whose signals fluctuate, usually from -75 to -82. We don't hook anyone up with a worse signal then a -75, but because we are in the Jungle, trees grow very fast here. So their signals and fluctuate.  

Is the dropping after -75 something that can be changed? Is this something to AP does to conserve bandwidth for other users? My UBNT sectors do not do this, thats why I am wondering. 

We upgraded customers who had -80 with UBNT and then an -80 with PMP450i still. They never got dropped with the UBNT, but now they are getting dropped with the Cambium. 

I am running 15.0.2 now.

11

There was a 900 MHz AP fix in 15.0.2, so I definitely recommend getting that on all 900 MHz systems.

The AP does not drop sessions to conserve bandwidth for other users. 

We are not aware of anymore issues, so we would have to investigate. Do you have interference there as well? 

12

Can you link me to to the 15.0.2 download please?

13
@stepleader wrote:

Can you link me to to the 15.0.2 download please?

https://support.cambiumnetworks.com/files/pmp450i/

14

We upgraded everyone to 15.0.2 but it doesn't help with the marginal signals dropping off. We don't have too much interference. 

15
@ElbowWilham wrote:

We upgraded everyone to 15.0.2 but it doesn't help with the marginal signals dropping off. We don't have too much interference. 

Hi, 

Have you done Spectrum analysis on these SMs? What kind of SNRs do you see on them? Also, how is the signal level on the two polarizations? Since you are shooting through trees, these could be tough shots depending on the how dense the trees are and even low interference can cause problems. 

Thanks,

Sriram

16

SM disconnections are on the the same moment?

For exemple a 80 SM registered in the AP, and 20-30 SM disconnecto in the SAME TIME?

17

SNR is usually 8-10. Signal for both polarity is within a few db. We have done a spectrum analysis. Looks fairly clean. This happens on multiple sectors and the consistent thing is that when the signal gets bad, usually during rain, the SM will drop. Probably nothing you can do, its just a bad signal issue. 

18
@ElbowWilham wrote:

SNR is usually 8-10. Signal for both polarity is within a few db. We have done a spectrum analysis. Looks fairly clean. This happens on multiple sectors and the consistent thing is that when the signal gets bad, usually during rain, the SM will drop. Probably nothing you can do, its just a bad signal issue. 

Ok thanks. SNR of 8 dB is getting down to the 450 SM's limit to maintain a registration. It is possible to go down to 6-7 dB but in reality even 8 dB is pushing it, especially in a nLOS link. Have you considered using the 450d for these tough shots?

19

This is 900mhz

20
@ElbowWilham wrote:

This is 900mhz

Got it. 450d is not an option.