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New Member

Fiber cores

Hi all,

If i need to connect 2 cisco 2960S switch over fiber with over a distance of 200m, i know if have to use GLC-SX-MM but how many cores do i need ? to be honest i dont have understanding of when we need to use how many cores ?

Can someone help me understand in which case do we need 2 core or 6 core fibers ?

3 ACCEPTED SOLUTIONS

Accepted Solutions
Hall of Fame Super Gold

Fiber cores

1 core = 2 pairs

So you need 1 core fibre. 

VIP Super Bronze

Fiber cores

Ok, I understand now.  6 cores means 6 pairs. So, you need 6 pairs of fiber from each floor to 3rd floor.  This will accommodate up to 6 connections from each floor to 3rd floor. 

Is that clear now?

HTH

VIP Super Bronze

Fiber cores

Sir kindly correct me that always one core (or one pair) is needed for a connection to be made ?? am i right ?

That is correct.  You need a pair for one connection. In that pair, one strand is for tx and the other strand rx.

remember a pair is equal to 2 strands.

HTH

15 REPLIES
Hall of Fame Super Gold

Fiber cores

1 core = 2 pairs

So you need 1 core fibre. 

New Member

Fiber cores

Sir in which case do i need more then 1 core fiber from one location to other ?

VIP Super Bronze

Fiber cores

No sure what you mean by core, but usually the fiber count is by strands or pair.  So to connect 2 switches together you need a pair of fiber which is equal to 2 strands.

HTH

New Member

Fiber cores

Basically Sir, there was a discussion a while back about the design of our headoffice network. We are discussing how many core of fiber we needed from every floor to 3rd floor where the aggregation switch was placed (it was 3560 24 with SFPs). At that time our vendor told us to deploy 6 core fiber from every floor to 3rd floor for uplink purpose.

Thats why i asked,

VIP Super Bronze

Fiber cores

Ok, I understand now.  6 cores means 6 pairs. So, you need 6 pairs of fiber from each floor to 3rd floor.  This will accommodate up to 6 connections from each floor to 3rd floor. 

Is that clear now?

HTH

New Member

Fiber cores

Thanks alot Reza bhai (dont mind if i call you bhai). Sir kindly correct me that always one core (or one pair) is needed for a connection to be made ?? am i right ?

VIP Super Bronze

Fiber cores

Sir kindly correct me that always one core (or one pair) is needed for a connection to be made ?? am i right ?

That is correct.  You need a pair for one connection. In that pair, one strand is for tx and the other strand rx.

remember a pair is equal to 2 strands.

HTH

New Member

Fiber cores

Thanks alot sir. Kindly dont mind about my request.

New Member

Fiber cores

Sir i read an expert saying that you are almost an authority over VSS (outside Cisco). Can you comment on my post on 4500 SUP 8-E

VIP Super Bronze

Fiber cores

Sir i read an expert saying that you are almost an authority over VSS (outside Cisco). Can you comment on my post on 4500 SUP 8-E

Can you copy and paste the URL for that post?

New Member

Fiber cores

VIP Super Bronze

Fiber cores

Unfortunately, I can't common about this, as this sup is pretty new, but I am sure, Marvin has provided you the correct info.

In general and I think, VSS will be supported in all Sups going forward.  Now, if it is not in the current version of software, I am sure it is on road map.

HTH

New Member

Fiber cores

Thanks alot sir, i hope you didnt mind

Silver

Fiber cores

Let's put in writing that

  • in this context "core" is not a proper term to use
  • 1 core is NOT 2 pairs.     2 pairs = 4 strands.
Hall of Fame Super Gold

Fiber cores

1 core = 2 pairs 

Me bad.  It's 2 cores = 1 pair.

"Core" is being used in the Australian jargon.

To make things less confusing, the term "pair" is universal.

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