I don’t know, I haven’t experienced that problem. I guess start with whatever’s easiest.
I should ask, is this 5.4 or 5.7? I’m not sure it would match the symptoms, but are you taking any DFS hits? If you use the Diagnostic Plotter to look at active channel history, do you see it switching channels? Also I’m confused because you have spikes where the vector error goes to zilch, but most of the time it is good. Also in your first set of screenshots, the current modulation was 64QAM. So are you seeing 2 Mbps all the time, or just during these “events”? If you are seeing 2 Mbps all the time, that seems strange. From: Scott Vander Dussen via Af Sent: Friday, December 12, 2014 5:32 PM To: af@afmug.com Subject: Re: [AFMUG] PTP500 does 2mb/s Ken- Thanks again. This link is not on our network and I don’t have access to SNMP it- here’s the diag plots- about what you expected? Would you concur pigtail replacement on slave side would be a good place to start? Thanks, Scott From: Af [mailto:af-boun...@afmug.com] On Behalf Of Ken Hohhof via Af Sent: Friday, December 12, 2014 15:09 To: af@afmug.com Subject: Re: [AFMUG] PTP500 does 2mb/s Vector error is basically signal to noise ratio, so yes 28 is good and 1.5 is really bad. I would still use the diagnostic plotter to look at vector error over time. It won’t tell you WHY it gets bad, but seeing WHEN it gets bad might help track it down. Or use MRTG/Cacti/etc. to plot the following OIDs: vector error: 1.3.6.1.4.1.17713.5.12.2.0 modulation: 1.3.6.1.4.1.17713.5.12.8.0 Modulation will be a number from 1-15 if I remember right, where 15 is the highest like 64QAM3/4 or whatever and 1 is BPSK. (why do I want to pronounce that “bupkis”?) From: Scott Vander Dussen via Af Sent: Friday, December 12, 2014 4:59 PM To: af@afmug.com Subject: Re: [AFMUG] PTP500 does 2mb/s David/Ken- Thanks for the quick and helpful replies. From the manual: Vector Error The vector error measurement compares the received signal’s In phase / Quadrature (IQ) modulation characteristics to an ideal signal to determine the composite error vector magnitude. The results are stored in an histogram and expressed in dB and presented as: max, mean, min and latest. The max, min and latest are true instantaneous measurements; the mean is the mean of a set of one second means. The expected range for Vector Error would be approximately -1.5 dB (NLOS link operating at sensitivity limit on BPSK 0.50) to –28 dB (short LOS link running 64 QAM 0.83). See Section 7.3.1 “Histogram Data”. I interpret this paragraph that -28db is more desirable than -1.5db. Is that correct? If my min values are circa -28db and that’s bad, what would be an expected good value? I don’t think it’s a noise issue, I set the interference threshold to -63. Here’s each side’s SA. Remote side on bottom. I’d favor the pigtail has water intrusion. Thanks again, Scott From: Af [mailto:af-boun...@afmug.com] On Behalf Of David via Af Sent: Friday, December 12, 2014 14:43 To: af@afmug.com Subject: Re: [AFMUG] PTP500 does 2mb/s Scott, �Have a look at the slave side spectrum manager and see if there is some noise cropping up. If not then you may have some water in a pigtail or defective. Also, may want to do a site walk to see if the antennas may have moved due to weather or something in the path since it was installed. �More often then not the tale tale signature if a bad pig tail is the vector error is all over the place. These things usually dont have grey area when it comes to detailed informational tags like "Limited by WIRELESS conditions" Start with spectrum manager and see what it says then look at Diag plotter for unusual patterns in vector corrections. On 12/12/2014 03:54 PM, Scott Vander Dussen via Af wrote: I�m diagnosing a slow throughput PTP500 link remotely.� This link�s real-world capacity is only about 2mb/s.� Attached is screenshots of the status page.� Anything stick out as weird or wrong?� It was on 15mb/s channels, I tried 10mb/s � there�s plenty of clean spectrum.� It�s not making sense to me that this is only able to move 2mb/s. � Thanks, Scott � �
