I'm not sure how that would help in this case, Doug, unless you mean that you can take your patch panel ports and cross them yourself. In these lightguides that we got, it's a 12 pair module that has three 4 pair blocks. There are two fibre bundles that connect at the back with very small connectors -- not standard lc connectors at the back. So, because of that, I have no way of switching them around, though I suppose perhaps the whole module could be opened up and rewired somehow.
-Adam On Thu, Oct 11, 2012 at 8:59 PM, Doug Hughes <[email protected]> wrote: > Strange. All of our siemen panels are simplex lc fibers at the back so we > don't run into this problem. > On Oct 11, 2012 8:36 PM, "Robinson, Greg" < > [email protected]> wrote: > >> *UNCLASSIFIED***** >> >> My 2c worth is that all fibre patch panels should be crossed over, as the >> cables to the servers are straight through. All ours are here. We’ve had >> 1 instance where the contractor obviously lost concentration for a while >> and 1 pair out of 24 were straight through!**** >> >> ** ** >> >> Fun happens when you patch to other patch panels. You need an odd number >> in the run, otherwise you need to swap the server cables.**** >> >> ** ** >> >> Greg.**** >> >> ** ** >> >> *From:* [email protected] [mailto:[email protected]] >> *On Behalf Of *Adam Levin >> *Sent:* Friday, 12 October 2012 9:54 AM >> *To:* Jeff Woolsey; [email protected] >> *Subject:* Re: [lopsa-tech] fibrechannel patch panels**** >> >> ** ** >> >> Yeah, thanks. I think it is very strange that nobody had solved this >> common problem, but we ended up breaking them apart and flipping the sides >> after all. It is rough with so many cables at once. >> >> Adam**** >> >> Jeff Woolsey <[email protected]> wrote:**** >> >> On 10/11/12 10:05, Adam Levin wrote:**** >> >> Here's the problem: when we run cables from HBAs (in hosts or in >> >> storage systems) direct to the switches, the Tx and Rx are correct. >> When the lightguide patch is in the middle, the Tx and Rx are reversed.**** >> >> >> >> Some time ago, almost ten years now, when we started hooking things up >> in a newly-renovated server room, it took a while to figure out which >> part of the storage path was borken. Turned out that the connections >> >> between patch panels was straight-through.**** >> >> What I'm not sure about is what is normal for this configuration? Do >> people**** >> >> normally buy "crossover" FC cables to use with a patch panel, >> or do people buy proper patch panels which "uncross" the streams?**** >> >> >> In my opinion, all duplex fiber should be crossover, even the runs in >> walls between patch panels. That way you have a net twist, everything >> >> has Rx connected to Tx. (You will run into a problem if you use any >> passive bulkheads (FDDI had some, SC could too)) >> >> If the panels are straight, then the conections can be kludged in one >> place (of four possibilities, since these were SC-LC cables) by >> >> unclipping either end (and not reclipping to make a straight cable), >> making the problem a little more noticeable. Alas I wasn't in charge >> of that room and nobody ever fixed the parity on the panels, as far as I >> >> know...**** >> >> *IMPORTANT*: This email remains the property of the Department of >> Defence and is subject to the jurisdiction of section 70 of the Crimes Act >> 1914. If you have received this email in error, you are requested to >> contact the sender and delete the email. **** >> >> _______________________________________________ >> Tech mailing list >> [email protected] >> https://lists.lopsa.org/cgi-bin/mailman/listinfo/tech >> This list provided by the League of Professional System Administrators >> http://lopsa.org/ >> >> > _______________________________________________ > Tech mailing list > [email protected] > https://lists.lopsa.org/cgi-bin/mailman/listinfo/tech > This list provided by the League of Professional System Administrators > http://lopsa.org/ > >
_______________________________________________ Tech mailing list [email protected] https://lists.lopsa.org/cgi-bin/mailman/listinfo/tech This list provided by the League of Professional System Administrators http://lopsa.org/
