Fibre Question

Fibre Question

Post by kAnO » Tue, 15 Jul 2003 05:02:17



When someone refers to "4-core" fibre how does that relate to the number of cables?
Is it four cables, i.e. two pairs (one transmit and one receive in each?)

Thanks

 
 
 

Fibre Question

Post by Phil Partridg » Tue, 15 Jul 2003 16:06:03




Quote:>When someone refers to "4-core" fibre how does that relate to the number of
>cables?
>Is it four cables, i.e. two pairs (one transmit and one receive in each?)

>Thanks

That's right. Although people is this group will shudder at the term
'cable' used for a fibre strand.
*Most* the kit in common use on LAN's will use one fibre for each
direction.
Telco kit and long haul data is a different story. Much of this is
single mode (extended distances, greater bandwidth, to keep it simple)
and some of these systems can send data in both directions on a single
fibre.

HTH
--
Phil Partridge

 
 
 

Fibre Question

Post by James Knot » Tue, 15 Jul 2003 19:44:10



> Telco kit and long haul data is a different story. Much of this is
> single mode (extended distances, greater bandwidth, to keep it simple)
> and some of these systems can send data in both directions on a single
> fibre.

At a company I used to work for, they used one fibre for each direction but
added a 2nd colour to the fibres, with the data running in the opposite
direction and carrying less critical circuits.  If one fibre were to break
and no other path available, the less critical circuits would be dropped,
in favour of the main circuits.

--

Fundamentalism is fundamentally wrong.


james.knott.

 
 
 

Fibre Question

Post by Macy Hallo » Tue, 15 Jul 2003 22:22:49



+---------------

Quote:> When someone refers to "4-core" fibre how does that relate to the number of cables?
> Is it four cables, i.e. two pairs (one transmit and one receive in each?)

4 core means 4 individual fiber optic glass strands under one common sheath.

As a general rule, fiber optic cable is placed into service in pairs,
meaning 2 cores (strands) are required for each equipment to equipment
"connection".

--
 Macy M. Hallock, Jr. - APK Net - Tel:216.241.7166 - Fax:216.241.7522

 
 
 

1. 100Mb/s ethernet over fiber question

The ethernet and cabling FAQs don't appear to have any 100Mb/s ethernet
info in them yet, so I guess I have to ask:

We are installing a 100Mb/sec ethernet interface in a Cisco 7000.  Our
original plan was to run that into a 100baseT hub and hook some servers
up to it.  What we're also interested in doing, however, is extending a
branch off that hub over fiber to another building, and running another
100baseT hub in that location.  (The exact distance is unknown right
now -- something less than 2km; there is a functional 10Mb/s ethernet
going over fiber between these sites right now.)

Is that possible?

What kinds of physical distance limitations are there for 100Mb/s
ethernet over fiber (100baseF?).

Can anyone comment (responses from hardware sales people appreciated as
well) on the type of equipment necessary to provision this?  Our
preference would be two eight or sixteen port 100baseT hubs with fiber
connectors (FOIRL?), one for each building.  The physical distance
involved at each end would be negligible (ie, 2 meter cat5 cables
patched to a handful of workstations on each end).

The only pieces of this equation that have already been purchased are
the Cisco 100Mb/sec ethernet interface, and some Sbus 100baseT cards for
the Suns that will sit on this net.  Everything else is open to
consideration.

Email responses, please.

--
Paul Southworth

2. Procmail

3. 100 Mbps fiber question

4. Merging data from different sources

5. Simple stupid fiber question on Cisco 7301 and 3550 switch

6. ADSL vs T-1 for LAN Connectivity

7. WS-C2924C-XL-EN Cisco Switch Fiber Question

8. ASP connect to SQL Database

9. Single mode fiber question

10. Mechanical splices for fiber-questions

11. Stupid fiber question, I think...

12. Transcontinental Fiber Question

13. Fiber Question