LIU cisco

[MelBel]

Hi, there,
I have some question about Line Interface Unit, some questions are pretty foundamental.
would you please post some link that I can read, I couldnt find some on the Internet.

thanks,


mel.

 

[youcandoit]

i think of Liu as "light interconnect unit" for fiber.

can you give us a context?

 

[MelBel]

Thanks,
I am not sure what that stand for, all I know is that there are boxes that right above our distribution layer switches and have label called LIU-XXX where XXX is the number used by our own.
The boxes have many fiber-like calbe connected to our distribtion layer switches which 4900 series.

any idea?

thanks,

Mel

 

[youcandoit]

It sounds to me mel like you are talking about a "light interconnect unit". This is a junction point for fiber either multimode or singlemode.In MDF from the liu the distribution layer switches will feed access layer switchs in IDF or independant distribution frame. the access layer switches feed the desktops most likely via 100baset.

The LIU is most likely a Siecor or Corning product. these can be rack mount or wall mount. sounds like your talking rack mount. The fiber like cables are orange and multimode.

takes 2 strands to complete the circuit transmt and recieve.
for redundancy you may have 4 strands feeding one device. 2 strands each to 2 redundant distribution switches. transmit and recieve.

without a manufacturer or part number couldnt really point to any relevant web docs for more detailed info.

try google.com


Goodluck!

 

[MelBel]

youcandoit:
You are absolutely right. all the things you're talking about fit the fact that i observed.
We have about 4 4900 switches at the distribution layer and a 6500 at core.

So the junction point is kind of relay, and the ethernet on it remains unchanged, except the speed is faster. is this understanding correct?

thanks,

M.

 

[youcandoit]

you understanding is kinda correct.
the junction point or LIU is considered the terminaton point of the channel or back bone connection between your mdf and idf. the bandwidth of what fiber can carry is limited mainly by the type of hardware you have connected to it for example 10(ethernet)/100(fast ethernet)/1000(gigethernet)/10000 in the future. the data is converted into light waves and transmited via LED or LASER at specified wavelengths long distances and then converted back to data by like equipment at the other end. the speed may only be 100baset between your eqiupemnt unless you have gbic interfaces. hope this helps.

 

[youcandoit]

oh and this should be in the cable forum.

 

[MelBel]

Youcandoit,
thanks,
How can I identify a calbe is a LX/SX/LH?
when I plug it into a transceiver, is there any order as to which socket is used for which end?

best

m.

 

[youcandoit]

not sure about lx/sx/lh what are these?

lc/sc/st/mtrj are various connector types. you can use google to identify which connector is called what.

transciever? are you converting to utp with this transciver.

the transciever wont work (no LInk) if you have the polarity wrong. transmit must go to recieve and receive to transmit. someone correct if im wrong.

 

[MelBel]

I'll start a new thread. Please look at it.
thanks,
M.B.