Phy Mac Loopback Newbie question

Archived from groups: comp.dcom.lans.ethernet (More info?)

Can someone tell me what phy and macloop are and what they are used for?

Thanks,
-Astakhov

--Have humility, Knowledge will follow--
12 answers Last reply
More about loopback newbie question
  1. Archived from groups: comp.dcom.lans.ethernet (More info?)

    I'm stunned that no one has bothered to answer this question! Is it
    such a difficult question to answer? Or are all the so-called
    "experts" too busy to help a newbie?!!

    -Juc

    --Have humility, Knowledge will follow--

    juc_astakhov@yahoo.com (Juc) wrote in message news:<5d73389d.0411241152.1ee4fdfb@posting.google.com>...
    > Can someone tell me what phy and macloop are and what they are used for?
    >
    > Thanks,
    > -Astakhov
    >
    > --Have humility, Knowledge will follow--
  2. Archived from groups: comp.dcom.lans.ethernet (More info?)

    In article <5d73389d.0411241615.3c50e74f@posting.google.com>,
    juc_astakhov@yahoo.com (Juc) wrote:

    > I'm stunned that no one has bothered to answer this question! Is it
    > such a difficult question to answer? Or are all the so-called
    > "experts" too busy to help a newbie?!!
    >

    As a self-declared "newbie", you are probably unaware that Usenet,
    unlike a "chat room", is not geared to real-time interactive
    communications. Your original post appeared (on my news server) at 11:52
    AM Pacific Time on Wednesday; your fervent followup appeared at 4:15 PM
    the same day. That is NOT a lot of time for Usenet. Most people
    (including the so-called experts) are working during those hours. Many
    (most?) Usenet regulars don't check newsgroup postings more than once a
    day. Even worse, today is the day before US Thanksgiving, the busiest
    travel day of the year. I am sure many Usenet regulars are on their way
    to family gatherings.

    >
    > --Have humility, Knowledge will follow--
    >

    Have patience, replies will follow.

    > juc_astakhov@yahoo.com (Juc) wrote in message
    > news:<5d73389d.0411241152.1ee4fdfb@posting.google.com>...
    > > Can someone tell me what phy and macloop are and what they are used for?
    > >

    PHY loopback is just what it sounds like; a method of (internally)
    connecting the transmit output of the PHY (the instantiation of the
    physical layer) to the receive input of the PHY within a network device.
    Similarly, MAC loopback connects the transmit output of the MAC
    controller to the receive input of the MAC controller (bypassing the
    PHY).

    These functions are generally used for test and troubleshooting
    purposes, i.e., to detect whether a fault exists in the communications
    medium or the network device, or to isolate a device fault to the faulty
    component.


    --
    Rich Seifert Networks and Communications Consulting
    21885 Bear Creek Way
    (408) 395-5700 Los Gatos, CA 95033
    (408) 228-0803 FAX

    Send replies to: usenet at richseifert dot com
  3. Archived from groups: comp.dcom.lans.ethernet (More info?)

    Walter Roberson <roberson@ibd.nrc-cnrc.gc.ca> wrote:
    > Perhaps you could be of assistance in helping me to prioritize better?

    Sounds like you need to make more effective use of your "downtime"
    (time that's wasted waiting for a taxi, a bus, a doctor, etc). Is
    there any work-related material that's portable that you could read
    during these times?

    Thanks for giving us this insight. I'm used to seeing you in
    comp.sys.sgi.admin and comp.security.unix, and when I found you in
    here it made me wonder what your life is like. And now I know.

    Damian Menscher
    --
    -=#| Physics Grad Student & SysAdmin @ U Illinois Urbana-Champaign |#=-
    -=#| 488 LLP, 1110 W. Green St, Urbana, IL 61801 Ofc:(217)333-0038 |#=-
    -=#| 4602 Beckman, VMIL/MS, Imaging Technology Group:(217)244-3074 |#=-
    -=#| <menscher@uiuc.edu> www.uiuc.edu/~menscher/ Fax:(217)333-9819 |#=-
    -=#| The above opinions are not necessarily those of my employers. |#=-
  4. Archived from groups: comp.dcom.lans.ethernet (More info?)

    Walter Roberson wrote:

    > Bowels demanded attention, which they got until 15:36.

    And you coudn't have used this time to answer his questions??? ;-)
  5. Archived from groups: comp.dcom.lans.ethernet (More info?)

    In article <co3p3g$o0m$1@news.ks.uiuc.edu>,
    Damian Menscher <menscher+usenet@uiuc.edu> wrote:
    :Sounds like you need to make more effective use of your "downtime"
    :(time that's wasted waiting for a taxi, a bus, a doctor, etc). Is
    :there any work-related material that's portable that you could read
    :during these times?

    Alas, the hidden costs in getting the tape drives repaired are high
    enough that my budget will not be able to handle a Blackberry for me
    for at least another year yet. Management allocated all capital funds
    to buy a new full-body MRI [the one we have is at least 13 years old,
    and it is a key device in our research] so I have to eat the cost of
    the essential new router out of my operational budget which already
    has to stretch to pay for the tapes for the new drive (they may hold
    ~350 Gb each, but we still need a dozen or more for proper tape
    rotation.)


    :Thanks for giving us this insight. I'm used to seeing you in
    :comp.sys.sgi.admin and comp.security.unix,

    These days I'm mostly to be found in comp.dcom.sys.cisco .

    :and when I found you in
    :here it made me wonder what your life is like. And now I know.

    The long long work hours and fairly skewed schedule are unfortunately too
    common. The several "downtime" were nature's way of telling me to slow
    down. I'll gloss over the details and just say that I have good reason
    to expect that less of that "downtime" in the future.
    --
    "[...] it's all part of one's right to be publicly stupid." -- Dave Smey
  6. Archived from groups: comp.dcom.lans.ethernet (More info?)

    In article <E6opd.58232$7i4.38421@bgtnsc05-news.ops.worldnet.att.net>,
    NoSpamForMe <KeepYourSpam@not.here.net> wrote:
    :In the time it took him to write all that drivel, he could've answered the
    :OP's question.

    Someone had -already- answered the question before I had a chance.

    :Truly obnoxious, I'd say.

    Ah, then my posting was effective!

    Steve Martin [yes, -that- Steve Martin] offered some advice to aspiring
    writers in an interview about his book "Pure Drivel": to keep
    practicing and then practice more. Steve said that drivel is one of
    the hardest of all forms of writing [the piece was in the New Yorker
    if I recall correctly.] My practice must finally be starting to pay off.
    --
    Strange but true: there are entire WWW pages devoted to listing
    programs designed to obfuscate HTML.
  7. Archived from groups: comp.dcom.lans.ethernet (More info?)

    "Walter Roberson" <roberson@ibd.nrc-cnrc.gc.ca> wrote in message
    news:co53oi$1m0$1@canopus.cc.umanitoba.ca...
    > In article <E6opd.58232$7i4.38421@bgtnsc05-news.ops.worldnet.att.net>,
    > NoSpamForMe <KeepYourSpam@not.here.net> wrote:
    > :In the time it took him to write all that drivel, he could've answered
    > the
    > :OP's question.
    >
    > Someone had -already- answered the question before I had a chance.
    >
    > :Truly obnoxious, I'd say.
    >
    > Ah, then my posting was effective!
    >
    > Steve Martin [yes, -that- Steve Martin] offered some advice to aspiring
    > writers in an interview about his book "Pure Drivel": to keep
    > practicing and then practice more. Steve said that drivel is one of
    > the hardest of all forms of writing [the piece was in the New Yorker
    > if I recall correctly.] My practice must finally be starting to pay off.
    > --

    Whatever. PLONK
  8. Archived from groups: comp.dcom.lans.ethernet (More info?)

    In article <5ewpd.59415$7i4.909@bgtnsc05-news.ops.worldnet.att.net>,
    NoSpamForMe <KeepYourSpam@not.here.net> wrote:
    :> Steve Martin [yes, -that- Steve Martin]

    :Whatever. PLONK

    Now now, we were discussing Steve Martin. That should have been:

    +-------+
    Whatever. ---+ PLONK +-->


    --
    "No one has the right to destroy another person's belief by
    demanding empirical evidence." -- Ann Landers
  9. Archived from groups: comp.dcom.lans.ethernet (More info?)

    Juc <juc_astakhov@yahoo.com> wrote:
    > juc_astakhov@yahoo.com (Juc) wrote in message
    > > Can someone tell me what phy and macloop are and what
    > > they are used for?

    > I'm stunned that no one has bothered to answer this
    > question! Is it such a difficult question to answer? Or
    > are all the so-called "experts" too busy to help a newbie?!!

    Is this a school homework question?

    -- Robert
  10. Archived from groups: comp.dcom.lans.ethernet (More info?)

    On Thu, 25 Nov 2004 04:01:43 +0000, Walter Roberson wrote:

    > In article <5d73389d.0411241615.3c50e74f@posting.google.com>,
    > Juc <juc_astakhov@yahoo.com> wrote:
    > :I'm stunned that no one has bothered to answer this question! Is it
    > :such a difficult question to answer? Or are all the so-called
    > :"experts" too busy to help a newbie?!!
    >
    > Even "experts" have bosses, and mine tells me that during the day,
    > I should only answer Usenet postings on topics that are directly
    > relevant to my work.
    >
    > [ ... detailed explanation of why self-described newbie couldn't have an
    > answer when it wanted one ...]

    Thank you very much for this description. Have you copyrighted this? I
    don't get the same demands from usenet that you do, but I could definitely
    use this writeup in other parts of my life. So I'm requesting your
    permission to file off the names and times and re-use as if it were my
    own. Sorry if this makes your "drivel" useful. Hope you are able to get
    more than 5/24 hours sleep in the near future.
  11. Archived from groups: comp.dcom.lans.ethernet (More info?)

    In article <pan.2004.11.29.00.54.59.170287@pobox.com>,
    Erik Freitag <erik.freitag@pobox.com> wrote:
    |On Thu, 25 Nov 2004 04:01:43 +0000, Walter Roberson wrote:

    |> [ ... detailed explanation of why self-described newbie couldn't have an
    |> answer when it wanted one ...]

    |Thank you very much for this description. Have you copyrighted this? I
    |don't get the same demands from usenet that you do, but I could definitely
    |use this writeup in other parts of my life. So I'm requesting your
    |permission to file off the names and times and re-use as if it were my
    |own.

    Gosh, if your life resembles mine closely enough that the drivel would
    be useful, then go ahead, as long as you run it through a spelling
    checker first (you can add in your own characterist typos later ;-) )

    On the other hand, if you found that useful, you may wish to read up
    some at bofh.org -- it has some real quality excuses, not the wimpy
    ones like mine that merely have the virtue of being true.

    And for some reason, I have this sense that you would benefit by
    some reading at http://www.actsofgord.com .
  12. Archived from groups: comp.dcom.lans.ethernet (More info?)

    Hello Rich,

    It's really nice of you to take the time to reply (and the free
    admonishment too!). Hope you had a nice thanksgiving.

    Regards,
    -Juc


    Rich Seifert <usenet@richseifert.com.invalid> wrote in message news:<usenet-20C02D.17191624112004@news.isp.giganews.com>...
    > In article <5d73389d.0411241615.3c50e74f@posting.google.com>,
    > juc_astakhov@yahoo.com (Juc) wrote:
    >
    > > I'm stunned that no one has bothered to answer this question! Is it
    > > such a difficult question to answer? Or are all the so-called
    > > "experts" too busy to help a newbie?!!
    > >
    >
    > As a self-declared "newbie", you are probably unaware that Usenet,
    > unlike a "chat room", is not geared to real-time interactive
    > communications. Your original post appeared (on my news server) at 11:52
    > AM Pacific Time on Wednesday; your fervent followup appeared at 4:15 PM
    > the same day. That is NOT a lot of time for Usenet. Most people
    > (including the so-called experts) are working during those hours. Many
    > (most?) Usenet regulars don't check newsgroup postings more than once a
    > day. Even worse, today is the day before US Thanksgiving, the busiest
    > travel day of the year. I am sure many Usenet regulars are on their way
    > to family gatherings.
    >
    > >
    > > --Have humility, Knowledge will follow--
    > >
    >
    > Have patience, replies will follow.
    >
    > > juc_astakhov@yahoo.com (Juc) wrote in message
    > > news:<5d73389d.0411241152.1ee4fdfb@posting.google.com>...
    > > > Can someone tell me what phy and macloop are and what they are used for?
    > > >
    >
    > PHY loopback is just what it sounds like; a method of (internally)
    > connecting the transmit output of the PHY (the instantiation of the
    > physical layer) to the receive input of the PHY within a network device.
    > Similarly, MAC loopback connects the transmit output of the MAC
    > controller to the receive input of the MAC controller (bypassing the
    > PHY).
    >
    > These functions are generally used for test and troubleshooting
    > purposes, i.e., to detect whether a fault exists in the communications
    > medium or the network device, or to isolate a device fault to the faulty
    > component.
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