How to tell? MMF or SMF

Discussion in 'Cisco' started by Katanga-Man, May 11, 2004.

  1. Katanga-Man

    Katanga-Man Guest

    Hi,
    Slightly off topic but bear with me. Is there a simple way of telling
    whether a fibre is single mode or multimode without having to wheel out the
    TDR kit? SC or ST can't be it since they are applicable to either type. IS
    there any quick way of finding out that anyone knows of?
    Regards,
    Steve
     
    Katanga-Man, May 11, 2004
    #1
    1. Advertising

  2. In article <7D4oc.84$AL1.4@newsfe1-win>, Katanga-Man <> wrote:
    :Slightly off topic but bear with me. Is there a simple way of telling
    :whether a fibre is single mode or multimode without having to wheel out the
    :TDR kit? SC or ST can't be it since they are applicable to either type. IS
    :there any quick way of finding out that anyone knows of?

    The type and core size is usually printed on the cladding ;-)
    And your SM would likely be thinner than your MM.

    But if all you have available is a patch panel and you can't
    see the fibre itself, time to break out the Fluke.
    --
    This is not the same .sig the second time you read it.
     
    Walter Roberson, May 11, 2004
    #2
    1. Advertising

  3. "Katanga-Man" <> writes:
    >Slightly off topic but bear with me. Is there a simple way of telling
    >whether a fibre is single mode or multimode without having to wheel out the
    >TDR kit? SC or ST can't be it since they are applicable to either type. IS
    >there any quick way of finding out that anyone knows of?


    It should be marked on the jacket or cladding.

    If you have both sides unhooked, you could throw a fiber microscope on
    it, and tell pretty much right away just by looking at the end. While
    the cladding will be the same size on both, you'll be able to see the core
    and what size it is.


    --
    Doug McIntyre
    Network Engineer/Jack of All Trades
    Vector Internet Services, Inc.
     
    Doug McIntyre, May 11, 2004
    #3
  4. On Tue, 11 May 2004 02:35:09 +0100, "Katanga-Man" <>
    wrote:

    >Hi,
    >Slightly off topic but bear with me. Is there a simple way of telling
    >whether a fibre is single mode or multimode without having to wheel out the
    >TDR kit? SC or ST can't be it since they are applicable to either type. IS
    >there any quick way of finding out that anyone knows of?
    >Regards,
    >Steve
    >


    The jacket color may provide a clue. Orange tends to be multimode and
    yellow tends to be singlemode.

    -Terry
     
    Terry Baranski, May 11, 2004
    #4
  5. Katanga-Man

    Dmitri Guest

    It is normally color of the cable's jacket as well as color of the (plastic
    parts of) connectors that can tell the type of fiber:
    The exception is hybrid (both MMF and SMF in the same jacket) cable, where
    you are at mercy of the manufacturer to label it correctly. Sometimes with
    hybrid cables the only way to tell (without actually rolling up the sleeves
    and getting down and dirty with polished type connectors and a scope) is to
    actually call the manufacturer and read them the marking of that cable.
    If you are lucky, and you got indoor cables, then

    SMF cables are yellow
    MMF cables are orange, slate or even aqua (Avaya uses it for their 50/125um
    stuff)
    SM connectors have either white, blue or yellow booths. I've seen red as
    well
    MM connectors have beige, black or slate
    green-colored connector usually denotes either APC (angle-polished
    connector) or a reference cord
    SMF connector adapters are usually blue
    MMF connector adapters are usually beige

    Good luck!


    --
    Dmitri Abaimov, RCDD
    http://www.cabling-design.com
    Cabling Forum, color codes, pinouts and other useful online resources for
    premises wiring users and professionals
    http://www.cabling-design.com/resources/documents/residential.html
    Residential Cabling Guide



    "Katanga-Man" <> wrote in message
    news:7D4oc.84$AL1.4@newsfe1-win...
    > Hi,
    > Slightly off topic but bear with me. Is there a simple way of telling
    > whether a fibre is single mode or multimode without having to wheel out

    the
    > TDR kit? SC or ST can't be it since they are applicable to either type.

    IS
    > there any quick way of finding out that anyone knows of?
    > Regards,
    > Steve
    >
    >
    >
     
    Dmitri, May 17, 2004
    #5
  6. "Dmitri <Cabling-Design.com>" <info@REMOVE_NO_SPAM_cabling-design.com> writes:
    >It is normally color of the cable's jacket as well as color of the (plastic
    >parts of) connectors that can tell the type of fiber:


    Unless you get some of that really anoying fiber that is kind of
    orange, but yet kind of yellow on the jacket, and no markings on the
    jacket as to what it really was.

    I did have to pull out the scope to make sure it was single-mode.
    --
    Doug McIntyre
    Network Engineer/Jack of All Trades
    Vector Internet Services, Inc.
     
    Doug McIntyre, May 17, 2004
    #6
  7. Katanga-Man

    Guest

    On 17 May 2004 21:30:43 GMT, Doug McIntyre <> wrote:

    >"Dmitri <Cabling-Design.com>" <info@REMOVE_NO_SPAM_cabling-design.com> writes:
    >>It is normally color of the cable's jacket as well as color of the (plastic
    >>parts of) connectors that can tell the type of fiber:

    >
    >Unless you get some of that really anoying fiber that is kind of
    >orange, but yet kind of yellow on the jacket, and no markings on the
    >jacket as to what it really was.
    >
    >I did have to pull out the scope to make sure it was single-mode.



    Or you ordered it in a non-typical color. For example, I have MM in
    red, blue, and white outer jackets to segregate networks.

    -Chris
     
    , May 18, 2004
    #7
  8. Katanga-Man

    AnyBody43 Guest

    Doug McIntyre <> wrote in message news:<40a92f03$0$8511$>...
    > "Dmitri <Cabling-Design.com>" <info@REMOVE_NO_SPAM_cabling-design.com> writes:
    > >It is normally color of the cable's jacket as well as color of the (plastic
    > >parts of) connectors that can tell the type of fiber:

    >
    > Unless you get some of that really anoying fiber that is kind of
    > orange, but yet kind of yellow on the jacket, and no markings on the
    > jacket as to what it really was.
    >
    > I did have to pull out the scope to make sure it was single-mode.


    I have a fair bit of experience with fibre (in the UK) and
    I have NEVER found the colour to be an indicator of the cable type.
    Almost all of the installed stuff that I have seen was orange.

    The cables have always been marked with the core diameter
    which is usually marked as OuterDiameter/CoreDiameter. the marking
    are pretty frequent along the fiber.

    The numbers for single mode vary a wee bit but my understanding is
    that this does not matter.

    Note that in my experience the 50 and 62.5 MMF types do not
    interoperate.

    Sizes I think are specified in micro meters, 10E-6m.

    125/62.5 MMF 62.5 core
    125/50 MMF 50 core

    125/9 SMF
    125/8.5 SMF
    125/8 SMF

    Good luck.
     
    AnyBody43, May 18, 2004
    #8
  9. Katanga-Man

    Guest

    On 18 May 2004 02:22:57 -0700, (AnyBody43)
    wrote:

    >Doug McIntyre <> wrote in message news:<40a92f03$0$8511$>...
    >> "Dmitri <Cabling-Design.com>" <info@REMOVE_NO_SPAM_cabling-design.com> writes:
    >> >It is normally color of the cable's jacket as well as color of the (plastic
    >> >parts of) connectors that can tell the type of fiber:

    >>
    >> Unless you get some of that really anoying fiber that is kind of
    >> orange, but yet kind of yellow on the jacket, and no markings on the
    >> jacket as to what it really was.
    >>
    >> I did have to pull out the scope to make sure it was single-mode.

    >
    >I have a fair bit of experience with fibre (in the UK) and
    >I have NEVER found the colour to be an indicator of the cable type.
    >Almost all of the installed stuff that I have seen was orange.
    >
    >The cables have always been marked with the core diameter
    >which is usually marked as OuterDiameter/CoreDiameter. the marking
    >are pretty frequent along the fiber.
    >
    >The numbers for single mode vary a wee bit but my understanding is
    >that this does not matter.
    >
    >Note that in my experience the 50 and 62.5 MMF types do not
    >interoperate.
    >
    >Sizes I think are specified in micro meters, 10E-6m.
    >
    >125/62.5 MMF 62.5 core
    >125/50 MMF 50 core
    >
    >125/9 SMF
    >125/8.5 SMF
    >125/8 SMF
    >
    >Good luck.



    In general, you can mix 50 and 62.5 MM, but you take roughly a 3dB hit
    in power for each transition.

    -Chris
     
    , May 19, 2004
    #9
  10. Katanga-Man

    AnyBody43 Guest

    wrote in message

    > >Note that in my experience the 50 and 62.5 MMF types do not
    > >interoperate.


    > In general, you can mix 50 and 62.5 MM, but you take roughly a 3dB hit
    > in power for each transition.


    Hmmm.

    I only got involved with this once and the details are
    now lost in the mists of time however I doubt that the
    installation that I was working on would have been affected
    by this power loss.

    It was 100M Ethernet, and most likely used FDDI components,
    over a few hundred meters with only a patch lead at each end.
    There was no action until someone decided to
    check the patch leads and found that we had a 50/62.5 missmatch.
    Using matched ones fixed it.

    Maybe all of the missmatched leads were duff, who knows or cares now.
     
    AnyBody43, May 19, 2004
    #10
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. PingPong
    Replies:
    9
    Views:
    1,946
    Gramps
    Aug 19, 2004
  2. Karl Shaw

    How do I tell?

    Karl Shaw, Nov 20, 2004, in forum: Wireless Networking
    Replies:
    10
    Views:
    1,551
    William P.N. Smith
    Nov 22, 2004
  3. John

    Converting wav and mp3 to mmf?

    John, Dec 19, 2004, in forum: Computer Information
    Replies:
    2
    Views:
    2,476
  4. Replies:
    0
    Views:
    590
  5. unix

    Mixing SMF and MMF cables

    unix, Nov 12, 2010, in forum: Cisco
    Replies:
    1
    Views:
    767
Loading...

Share This Page