brad@optilink.UUCP (Brad Yearwood) (09/14/89)
In the near future, we will be expanding operations into a second building
located about 300 meters away, across a city street from our present
location. Both properties would be leased from the same owner.
We would like to extend our Ethernet between the two buildings. I
foresee much of the traffic being NFS, which seems to argue for a
10Mbit/sec facility rather than a bridge to something slower, like T1.
I can see several ways of doing this and would appreciate hearing of anybody's
experience with the advantages and problems of each, and of any recommendations
(or condemnations) of equipment and service suppliers:
1. Run fiber optic cable under the street. Does anybody know
what sort of permissions and processes would be necessary to
do this, or is it something that only Pacific Bell can do?
2. Use an air path laser system. This area gets fairly dense fog from
maybe 10PM-10AM several weeks of the year - is this likely to disable
the link?
3. Use a microwave system. Would dense fog disable microwave (maybe at
23GHz)? What are the licensing issues?
Brad Yearwood
Optilink Corp. {pyramid, tekbspa, pixar}!optilink!brad
Petaluma, CA
(707) 795-9444kwe@bu-cs.BU.EDU (kwe@bu-it.bu.edu (Kent W. England)) (09/15/89)
In article <2335@optilink.UUCP> brad@optilink.UUCP (Brad Yearwood) writes: > >In the near future, we will be expanding operations into a second building >located about 300 meters away, across a city street from our present >location. Both properties would be leased from the same owner. > >We would like to extend our Ethernet between the two buildings. I >foresee much of the traffic being NFS, which seems to argue for a >10Mbit/sec facility rather than a bridge to something slower, like T1. > 10M is definitely feasible, but which technique? See below. > 1. Run fiber optic cable under the street. Does anybody know > what sort of permissions and processes would be necessary to > do this, or is it something that only Pacific Bell can do? In Boston, anyone can run a conduit if they coordinate with the Public Improvement Commission. The PIC wants to minimize the street disruption, so they require you to ask their list of concerned companies and accept anyone else's need for conduit in the area. For us, this means we can piggyback on the phone company's construction. This is very useful. You might be able to rent duct from Pac Bell. It depends on their policy. > > 2. Use an air path laser system. This area gets fairly dense fog from > maybe 10PM-10AM several weeks of the year - is this likely to disable > the link? > 300 meters sounds reasonable but fog could be a problem. You would need to get a commitment from a vendor, but it is worth pursuing. There is no license required, or even roof access. You can shoot these things thru windows. Chances are that the fog would be temporarily disruptive and might be acceptable, so long as the link comes back automatically. Beware of equipment that does not squelch noise when the carrier is lost. This can cause grief in the Ethernet, so this should be tested before acceptance. Note that I am not saying this is a problem, just that I wonder about how the vendors deal with carrier loss. No such problem in regular Ethernet. > 3. Use a microwave system. Would dense fog disable microwave (maybe at > 23GHz)? What are the licensing issues? > 23GHz Microwave would work well. You should find a vendor that does turnkey installation, including the requisite FCC licensing. Microwave Bypass of Braintree, MA sells Ethernet on microwave, so you aren't limited to T1 anymore. There are some other vendors, but I am not aware of any other turnkey vendors of Ethernet-on-microwave. Enlighten me. :-) Licensing is not a bad thing. If someone builds something in your way, your FCC license requires them to accomodate you. Infrared does not require a license, so you are out of luck if something "pops up" one day. So, the good news is; you have lots of options. The bad news is; you have to pick one. :-) Kent England, Boston University
boyter@bimbo.UUCP (Maj Brian Boyter) (09/16/89)
In article <2335@optilink.UUCP>, brad@optilink.UUCP (Brad Yearwood) writes: > In the near future, we will be expanding operations into a second building > > 1. Run fiber optic cable under the street. Does anybody know > 2. Use an air path laser system. This area gets fairly dense fog from > 3. Use a microwave system. Would dense fog disable microwave (maybe at 4. use an infrared optical link... it is more immune to the fog than the laser optical link and less expensive than any of the other options. Several manufacturers exist, but I can't think of any off-hand. -- --------------------------------------------------------------- Maj. Brian A Boyter US Army Foreign Science & Technology Center Charlottesville, Va 22901 __ off: (804)980-7362 ( ) home: 973-9440 { } boyter%bimbo.uucp@virginia.acc.virginia.edu ( ) || Nuke'm 'till they glow || ...Then shoot'm in the dark ________< >_______
eli@spdcc.COM (Steve Elias) (09/18/89)
>In article <2335@optilink.UUCP>, brad@optilink.UUCP (Brad Yearwood) writes: >> In the near future, we will be expanding operations into a second building >> >> 1. Run fiber optic cable under the street. Does anybody know another option is to setup a broadband cable running across the street. two 802.3 to 802.4 bridges will then provide you with full speed connectivity -- even if your street is miles wide! (two of the 3 bridges on the market are effectively full speed). -- ... Steve Elias (eli@spdcc.com);6178906844;6179325598; {} /* free email to fax gateway for destinations in metro Boston area. */ /* send email and the destination fax number... */