I think sync over power and gigabit should not be used together. Sync over power, while a bit hacky, is fine when the power lines do nothing else, but trying to couple pulsating voltage with low-voltage really-high-speed data in an RF/EMI- prone environment like on towers just seems like a recipe for headaches. On Oct 3, 2016 4:06 PM, "Chuck McCown" <[email protected]> wrote:
> I have tried to avoid publically singling out a manufacturer, but a > certain manufacturer we all love does have something goofy with the sync > over power. It has some nasty risetime glitches and overshoots that cause > many surge suppressors to conduct -thus causing data glitches and the drop > from Gig to 100 Mbps. It is proportional to cable lengths I believe but I > have not proven that. > > It is also something relatively new. Perhaps because Gig interfaces on > their radios are relatively new. > > So, I just made the surge suppressor eat the overshoot. Belt, suspenders, > now flack jacket. Triple protection. It really made the whole design that > much better. > > I have added the spike eater to all products going forward. There are not > many in the pipeline yet, and you really don’t need it unless you want to > use that particular sync over power product... > > > > *From:* George Skorup > *Sent:* Monday, October 03, 2016 2:00 PM > *To:* [email protected] > *Subject:* Re: [AFMUG] 450i Problems maintaining gigabit. > > It happens on the regular 450 AP too. 1000Base-T does not work at all with > GigE-APC-HV's in line. It is 100% the sync pulse causing the SS to clamp. > > I won't speak for Chuck, but he sent me some stuff to test and it works. > This was a yet unused 5GHz 450 AP at a site with ~220 feet of Shireen > DC-1021. No SS on top. GigE PowerInjector+Sync fed with regulated 24v. > > I have GigE-APCs on tons of POE and non-POE gigabit links *without a sync > pulse* and they work perfectly fine. It would not surprise me if other > brands of suppressors are doing the same thing because of the sync pulse. > Maybe it takes the right conditions like temperature, power draw, etc. It's > just immediately obvious with the GigE-APCs because they are moar betterer. > > On 10/3/2016 12:45 PM, Forrest Christian (List Account) wrote: > > We have very recently started getting a whole bunch of support queries > which are from customers maintaining a gigabit link on a 450i. The link > seems to come up at gig, then some time later drops back to 100Mb/s. > > So far, we haven't nailed down a cause. Some seem to be related to the > sync pulse, others are completely unaffected by this. Some seem to be > related to the addition of a surge suppressor to the link (even a good > quality one), some not. I'm even aware of quite a few cases where > replacement of our gear with a stock cambium injector doesn't fix the > problem - so I'm pretty comfortable in feeling that something other than > our power injection equipment is the root cause. > > The commonality of most of these are longer cable runs. All of the normal > things have been tried (swapping cables, reterminating ends, validating > cables, etc.). I also suspect that these are newer 450i's. (I'm not sure > if we've seen this on a 450 or not). > > So, what I'm hoping for from the list is to determine if this problem is > widespread, and if there seems to be any relation to how old the 450i is, > or a firmware version update, or something else so I can help fix this for > my customers. Any information would be helpful. > > -- > *Forrest Christian* *CEO**, PacketFlux Technologies, Inc.* > Tel: 406-449-3345 | Address: 3577 Countryside Road, Helena, MT 59602 > [email protected] | http://www.packetflux.com > <http://www.linkedin.com/in/fwchristian> <http://facebook.com/packetflux> > <http://twitter.com/@packetflux> > > >
