Phy Mac Loopback Newbie question

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--

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 patience, replies will follow.

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

In article , 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?!!

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.

But you, a stranger in another country, probably a different continent, and one whom has [to the best of my knowledge] never contributed anything to make -my- job easier, clearly deserve a more detailed accounting of my time, so here's my explanation. All times are Central Standard (GMT-6):

- Got to bed at 06:08, 24 hours and 3 minutes after I got up yesterday.

- Woke up at 11:17. Peed, grabbed some imitation Shreadies cereal, put some homogonized milk on it and half of a banana, and then immediately went to my home computer and started work for the day, starting work by 11:24. Read through my waiting email, responded briefly to some of it while eating my cereal. Did a quick newsgroup scan, responded to a few postings. Wrote a more detailed reply about our backup hardware problems to one of the vendors who is trying to help us solve a tricky issue. Wrote an update summary to my boss telling him of the few gains we have made with the backups and of the several substantial problems that still remain. We haven't successfully backed up most of our key systems in 5 weeks, 15 weeks for one of our key systems, so this is a high priority item. Finished these messages by 12:13.

Went and found my clothes. Brushed my teeth first, and then shaved while I shat. A bit too much fibre in my diet yesterday, didn't get off the toilet until 12:23. Had a hot shower to try to wake up, but skipped washing my hair, as there wasn't going to be time for it to dry. Another closer shave now that I was more awake, and then back for more shat time (the first one after getting up is usually relatively small, just enough to wake the bowels up; the second can be much longer.) Finished 12:42. Got dressed, dashed off a quick email message, and called for a cab. Accidently notice that the clock I've been using for all of this timing is 9 minutes slow amd that it isn't 12:50 but rather 12:59.

Went outside to wait for cab, which arrived late. First snow was about

36 hours before and all the side streets turned out to be icy so the cab had to drive slowly [the nearest plowed snow route in the right direction is a road that is always very busy.] Arrived at work at 13:25, just after the end time of the short meeting that I was supposed to attend. Discover said meeting had been rescheduled for later the same afternoon... right into the middle of the time I was supposed to be spending with some repair people.

Called the repair people, rescheduled for a later day. Spent 10 minutes looking for the phone number of a sales rep I needed to talk to, called him up and described our needs. He'd never heard of the part before [his company is the only ones who make that part] so I had to explain. At 14:08, did a quick newsgroup scan, answered a few questions. At pretty much the end of the session, saw your posting for the first time [posted at 13:52 central], didn't have an immediate short answer so I flagged it for later attention when I would have time to give you a researched accurate answer instead of a half-assed probably-wrong reply.

14:26, went and talked to a co-worker who knows something about Linux device drivers; he couldn't find what I needed, but that took us through to 15:01. Rescheduled meeting (photo shoot) about to take place, so I combed my hair, took a quick spell on the toilet again [which got the bowels moving again...] and was ready and on location by 15:12. Pictures taken, finished 15:22. Talked briefly to a coworker about the backup system problems, got my things together, locked up, and headed out. Bowels demanded attention, which they got until 15:36. I then walked over a couple of city blocks, hopped on a bus, and sat through several minutes of rush hour traffic. Got out and got to the bank at 15:47 [16:00 official close.]

Did my banking business, finishing at 16:12. Bought a cookie, two 250 ml containers of soy milk, and the slightly better of the two local newspapers. I then spent the next 15 minutes trying to find a public toilet that either didn't have urine on the seat or else at least had toilet paper that I could wipe it up with. More quality time eliminating waste, and out the door at 16:40. Spent the next 7 minutes trying to find a taxi, another 2 waiting for the light to change so I could get -to- the taxi, and was in the taxi at 16;51.

We then got locked into what the taxi driver said was some of the worst congestion he'd ever seen (and from other things he said, he must have been working as a driver for at least 8 years.) Arrived at my destination at 17:19 -- a half hour trip for something that would normally take 9 minutes. Fortunately the doctor's office was still open and there were still people waiting. Doctor wasn't available until

17:39; appointment finished at 17:53. Immediately went to the pharmacy to refill my prescriptions, and was told it would take 1/2 hour. Shopped a bit, ate a small snack, went back and got what I needed. Went out to the bus stop, arrived at 19:01. Walked up to the next stop hoping it would say what time the next bus was, but it did not have a sign either. Bus arrived at 19:16, was home by 19:23.

Put my groceries away, came up to my computer right afterwards, and found that you were already complaining that your question hadn't been answered yet, and that someone else had already answered. Started writing up my accounting of my time, and that takes us to the present.

Perhaps you could be of assistance in helping me to prioritize better? Should I have skipped doing my own high priority work so that I could answer your question the moment I read it? Crossed my legs and clenched my ass tight to keep my innards from explosively coming outwards? Or had my cab driver drive several miles the wrong way on one-way streets so I could dash home and answer your question while I was supposed to be at my appointment, risking missing my appointment and not being able to get a new one until next year ?

In article , snipped-for-privacy@ibd.nrc- cnrc.gc.ca says... [snip]

Walter...truly a classic! :)

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

And you coudn't have used this time to answer his questions??? ;-)

In article , Damian Menscher 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.

In the time it took him to write all that drivel, he could've answered the OP's question.

Truly obnoxious, I'd say.

In article , NoSpamForMe 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

In article , NoSpamForMe wrote: :> Steve Martin [yes, -that- Steve Martin]

:Whatever. PLONK

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

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

Is this a school homework question?

-- Robert

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