Cisco Switch and Multimode fiber question

Posted on 2015-01-23
Medium Priority
Last Modified: 2016-05-05

If I currently have two buildings connected to the Central office via multimode fiber using the following Gbic:

S-G5484  1000BASE-SX "Short Wavelength" Gbic Multimode

And I need to replace the existing 3560 switches with a:
WS-C3850-48P-S       Cisco       Catalyst 3850X 48 Port PoE+ w 715WAC PS, IP Base feature set

Will the existing fiber work?  And do I need new gbics or reterminate the fiber ends?

Thanks ahead for your time.
Question by:lawemcsd
LVL 50

Expert Comment

by:Don Johnston
ID: 40567691
That model switch has 48 10/100/1000 ports.  No SFP ports so it's copper only.

3850 Data Sheet
LVL 57

Accepted Solution

giltjr earned 1000 total points
ID: 40568160
The 3850 line has some 12 and 24 port switches that support SFP's.

The CS-G5484 uses a SC connector and no SFP's have that type of interface anyway.  So unless you get anotehr switch that supports GBIC interface you are going to either need to run a new cable or get a converter of some type.

Since the model 3850 you are looking at only supports copper you could look for a multimode fiber to Copper converter that supports SC connectors.   This would allow you to keep your current fiber and use the new switch.  The costs run anywhere from just over $100 to just under $200.  If this is your only link between the two locations I would suggest you get the best quality one you can find.

Author Comment

ID: 40568842
Would there be a better model switch to use?  I'm not tie to that particular switch.  Just looking for a replacement and notice that that was the latest in the 3xxx series.  I'm open to use other lines also, like the 4000 series.

Thanks for helping out.
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Author Comment

ID: 40569035
I was going buy one of these :

to insert into the unit
LVL 57

Expert Comment

ID: 40569761
If you don't need 10Gbps you may want to look at C3850-NM-4-1G, which has 4 1GB SFP  ports.  You will still need a SC to LC pig tail.

Assisted Solution

ajeab earned 1000 total points
ID: 40580861
you can get patch fiber that SC-LC on each end.

the SFP-10G-LR= is for single mode fiber.  if you are looking to 10G option, you have to be aware of the distance.  
it's depend on what type of MM fiber you have, you can get
SFP-10G-SR (work with OM3 and OM4) 300meter  or
SFP-10G-LRM work with OM1-4 but limit is 220meter.

with 10G, there is no fall back. it is either connect at 10G or not connect at all.
LVL 51

Expert Comment

ID: 40651825
Also both ends need to support 10G if you go that route.

The  4-port 1gb management module is what you want.

SFP should be GLC-SX-MMD

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