Re: Ethers, Copper, Fiber, Microwaves, Etc.


kwe@bu-it.bu.edu (kwe@bu-cs.bu.edu)
2 Dec 87 19:52:40 GMT


In article <203@wright.EDU> jsloan@wright.EDU (John Sloan) writes:
>
>There are now incredibly cheap (a few thousand $s) microwave systems,
>with dishes that you could put in a briefcase, that could conceivably
>be pushed to 10 Mb/sec over very short distances.

        Now this is something new to me. If you can put them in a
briefcase they must be around 100GHz. That would probably limit the
range to a mile or so. The problem with infrared laser technology is
the atmospheric attenuation of smog, fog, and rain. Sounds like this
new ultra-high freq microwave fills the gap between low freq uwave and
infrared.
>
>Our RBOC bid a optical fiber link. Although their ethernet-to-ethernet
>product (if its not vaporware) was not available by our deadline, this
>too is an interesting idea, not for short distances (a solution which
>has been around for a while) but for long distances, like over five
>miles or more. Managing a geographically dispersed ethernet would be
>challenging, but the functionality is appealing.

        I like fiber. I can't wait to see what happens to FDDI as it
develops. Fiber optic FDDI will be robust, high speed, and simpler
than broadband. I think the ring circumference is around 23 km which
will cover a lot of campuses. Speed is 100/200 Mbps. Of course,
Pronet-80 is here now and works much the same way FDDI will.

        I won't repeat the arguments regarding routers versus bridges
or introduce a new argument about slow routers versus smart/fast
bridges, but I definitely favor routers if we can get some new
hardware architectures that will run thousands of packets per second
in a multi-protocol environment. Multibus and Interlan Enet cards
won't cut it with FDDI and embryonic ISO protocols. Fiber optic token
ring is my preference over a fiber optic monolithic Ethernet. You
should be excited about managing a geographically dispersed internet,
but appalled at the thought of managing a geographically dispersed
(large) Ethernet.--
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