My experience with DACs in the wild is they're not worth the trouble. Even if they "work" once you look closer you'll spot that they're not working well. Lots of errors/corrections at higher rates etc. better luck with say 1m or truely active DACs but thing is (Q)SFP(+) was never meant to be more than an interconnect between points on the same board and the signal timing constraints, drive levels and basically every other design decision and constraints reflect that. It's got a very short maximum distance.
On Fri, Dec 1, 2017 at 13:18 Emille Blanc <[email protected]> wrote: > To close this thread, DAC's appear to have been a wash. > Using like-vendor branded optics on both sides, and we have a functioning > 40Gbps link. > > Thanks for the feedback on, and off-list. :] > > -----Original Message----- > From: juniper-nsp [mailto:[email protected]] On Behalf > Of Chuck Anderson > Sent: November-21-17 7:10 AM > To: [email protected] > Subject: Re: [j-nsp] EX3400 or EX4600, and HPE FlexFabric-20/40, QSFP+ > DAC's > > On Tue, Nov 21, 2017 at 06:28:07AM -0800, Emille Blanc wrote: > > Hello folks, > > > > Trudging through the woes that are cross-vendor compatibility issues, > and failing completely at getting a link between an EX3400 or EX4600, and > an HPE FlexFabric-20/40 F8 card in our c7000 enclosure using an HPE branded > QSFP+ 3mtr DAC. That is to say, Juniper on one side, HPE on the other. > > As an added bonus, the HPE module seems to be allergic to Juniper's QSFP > completely. > > > > After the inevitable "It's not us, it's them" back-and-forth between > JTAC and HPE Support, I'm looking for any success (or failure) stories from > the community. > > > > We've been testing with a pair of HPE DACs, and they each work fine when > we loop it to two QSFP+ slots in the same chassis/module. > > > > Has anyone been successful in making such a connection in the wild? > > Buy cheap QSFP+ optics and use fiber? > _______________________________________________ > juniper-nsp mailing list [email protected] > https://puck.nether.net/mailman/listinfo/juniper-nsp > > _______________________________________________ > juniper-nsp mailing list [email protected] > https://puck.nether.net/mailman/listinfo/juniper-nsp > -- "Genius might be described as a supreme capacity for getting its possessors into trouble of all kinds." -- Samuel Butler _______________________________________________ juniper-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/juniper-nsp
