North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: IEEE 40GE & 100GE
"Chris Cole" <[email protected]> writes: > The 10km reach Transceivers will require no attenuators to operate from > 1m to 10km. Sweet. As an operator, this is exactly what I'm looking for. > The 40km reach Transceivers will probably require attenuators for > reaches below 10km, similar to restrictions on 10GBASE-ZR 80km modules > today. That stands to reason... > Also, I have enclosed an article that was published in this month's IEEE > Communications Magazine on 100GE Technologies which may give you more > details on the types of solutions that will be forthcoming. Wow, I had no idea that the NANOG mailing list accepted attachments. Someone oughta fix that, heh. Thanks, ---Rob > > Chris > > -----Original Message----- > From: Robert E. Seastrom [mailto:[email protected]] > Sent: Wednesday, December 12, 2007 11:20 AM > To: Chris Cole > Cc: Justin M. Streiner; [email protected] > Subject: Re: IEEE 40GE & 100GE > > > "Chris Cole" <[email protected]> writes: > >> One of the points made by Ted Sealy from Sprint is that they take >> advantage of the extra link budget in 10GBASE-LR 10km link budget to >> account for extra connector loss, etc. > > Ted Seely and I are of the same mind on this. 2 dB sounds like plenty > for connector loss right up until you have to deal with multiple patch > bays in a structured system with amateurishly applied mechanical > splices. The difference between noting that the loss is a little high > but the link still works so you roll with it, and having to spend time > on the phone arguing with someone who thinks 24 dB link loss is A-OK, > will make the slight additional up front cost for the better grade > optics look very inexpensive indeed... > >> From this discussion it sounds to me like we should stick with 10km >> initially, and then later come back with an additional specification >> optimized for low cost, perhaps covering 2km. > > I'm on board with that as far as it goes, but has the scenario of > adjustable launch powers so that you don't ever need attenuators plus > the economy of scale that would come from having *one* type of > interface for 1m-10km runs been considered? It seems to me based on > what I've seen of the optics market that once you make something a > mass-produced commodity the price falls awfully far - suppose the > price difference was $250 vs. $375, that's a big difference on a > percentage basis but pocket change on an absolute basis. > > ---rob > >> >> Chris >> >> -----Original Message----- >> From: Robert E. Seastrom [mailto:[email protected]] >> Sent: Wednesday, December 12, 2007 5:06 AM >> To: Justin M. Streiner >> Cc: [email protected]; Chris Cole >> Subject: Re: IEEE 40GE & 100GE >> >> >> "Justin M. Streiner" <[email protected]> writes: >> >>> I haven't read the draft spec yet to see what's being proposed for a >>> link budget at 3/4/10km, but that's just as important as the physical >>> distance. >> >> That's a really good point, and one which I didn't originally consider >> pre-coffee. :-) >> >> Link budget information on page 4, here: >> http://www.ieee802.org/3/hssg/public/reach/Matsumoto_r1_1207.pdf >> Relative cost estimates on page 5. >> >> Suppositions for ingredients to link budget are here: >> > http://grouper.ieee.org/groups/802/3/hssg/public/nov07/cole_01_1107.pdf >> (page 3) >> >> I'm kind of looking longingly at that extra 3dB, given the slight >> marginal extra cost and my knowledge of the trained chimp quality >> mechanical splices that are rife in certain <cough> data centers. >> >> ---Rob |