Month: March 2006

Netopia R-Series

stany

Netopia R-Series routers

Sea-green boxes, eight 10bt ethernet ports on the back in hub configuration (with a switch for cross-over on port 1), space for two expantion daughterboards inside. Serial console port, one additional serial port for external modem. Netopia model line.

Depending on the NVRAM settings, can report itself as an R (router) or D (bridge) model. At one point one could call Netopia technical support, and over the phone recieve a free license key, that would convert an R model into a D model. Last time I’ve called them (Summer of 2003), they were reluctant to provide me with the license codes for two units I was converting to bridging mode.
Their argument was that the serial numbers I’ve provided (and the feature keys are bound by the serial number of the router, which, in turn is locked to it’s MAC) were “too old”, that is, sold to customer over 2 years ago.

Old serial numbers start with 72, new ones start with 80.

These might also correlate to the revision of the logic board inside – older logic boards have two slots for 72 pin RAM soldered on. Newer boards have the pads but no actual sockets.

Out of the box, Netopia unit reports that it has 1 meg of flash and 4 megs of RAM. I’ve attempted to plug in some 4, 8 and 16 meg 72 pin RAM sticks, but each time the router would not report anything over serial console, and eventually would blink all 8 green LEDs corresponding to the 10bt ports about once a second. This might have to do with the type of RAM (I’ve tried double sided RAM, pairs of 8 meg, and singles of 4, 8 and 16) I’ve attempted to use.

Box without any daughtercards inside reports itself as model 1300, so depending on the feature key, it can be either R1300 or D1300.

I’ve handled three types of these units, R7100, R7200 and R9100. The only difference is the daughtercard inside. Otherwise units are identical, with exception of the logic board revisions.

They support firewalling between the hub and the WAN interface, can serve DHCP, and can detect a WAN link failure. If an external modem is connected to the Auxillary serial port, Netopia can be configured to dial out and use PPP as fallback.

Technically they support 10 users, and if one wants more, one has to buy a feature key from Netopia. I’ve never hit the limit, so I am not sure if this is the number of MACs it remembers, or something else.

Technically there are pins on the motherboard where additional hardware can be mounted. Netopia sells a VPN accelerator for these, so it could be a separate encryption module that goes on the inside. VPN accelerator is called TER/XL VPN in Netopia lingo.

R7100 has a single Copper Mountain Networks SDSL daughter card on board. It can synchronise at up to 1.5 megabit to Copper Mountain Equipment. These are the most interesting daughter-cards, as they support back-to-back communication. One unit needs to be configured to set it’s clock source from the network, and the other one to generate a clock source internally, and then, units can be connected over copper pair. I’ve had success synchronizing at 768Kb/sec at a distance of 1.6km over a Bell Canada LDDS circuit (an unbalanced copper pair, primarily used for alarm circuits).

R7200 has a single ATM SDSL daughter card on board. Maximum speed is 2.3 megabit in Nokia Fixed Mode. These can be configured to communicate with various types of DSLAMs, including Nokia and Paradyne gear. I don’t believe that they support setting clock source internally, and thus they can’t be used for private interconnection without a DSLAM.

R9100 has a 10 megabit daughter card, that can be used for routing, or for ATM or IP encapsulation. I have one, but that’s about it. Supposedly these are used to talk to a DSL or cable modem, and do NAT, etc.

R3100 are the same chassis with ISDN daughtercard. Covad used to deploy those with customers. Never handled one myself. Supposedly daughtercards with U, UP and S/T exist.

R5100 are the same chassis with serial V.24/V.35.

R5300 are the same chassis with T1 WAN port. Again, never used myself.

Two daughter cards are installable in a single unit. Daughtercards are identical, and thus if you have two identical routers with a single daughtercard each, card can be removed from one, and added into the other. Model number reported by the firmware changes as a result, and the last two digits of the model number change from 00 to the corresponding daughtercard number.

So, R7272 would have two ATM SDSL daughtercards, D7171 would have two Copper Mountain SDSL daughtercards, etc.
Mixing and matching is possible, and firmware will report things accordingly. If daughtercard is installed in the second slot, first two digits of the model number remain as “13”.

Rxx20 – Has a V.90 analog daughtercard for fallback
Rxx31 – ISDN fallback (or in case of R3131, it would have 2 ISDN ports)

If two identical daughtercards are installed, one might require an IMUX feature key from Netopia. At the last check, Netopia wanted 150 USD for each key. IMUX feature key enables WAN interface bonding, thus, theoretically, if you have two D7171s, both with IMUX keys, and a 4 wire LDDS circuit running between two branch offices, you can bridge the two at 3 megabit. On R9191 and R7272 IMUX feature enables multi-link PPP over ATM as a form of bonding.

“Regular” firmware doesn’t support configuration of second WAN interface out of the box. I theorize that all that IMUX feature key does is it tells firmware to present menus for configuration of the second WAN interface.

Overall, Netopia units can be procured on eBay for ~20 USD a piece, and thus the costs of IMUX feature key are, in my opinion, unreasonable.

Currently latest firmware is 4.11, and Netopia has a list of changes between firmware versions.

Body Posture

stany

Adrian Lima, or so I

I am being told that this is a photo of Adriana Lima.

Beautiful girl. But this is not an article about her beauty, at least not directly. To me this photo is exceptional because it clearly shows her posture.

I guess I should pay more attention to my own body posture, as too much time in school and in front of computer made me hunched over. Not quite a new year’s resolution, but something to keep in mind….

P.S. This photo was shamelessly stolen from here, however I am sure that a goodle search would find many more pictures of her.

Searching options in Mail.app

David Rostenne

I was stumbling through a big pile of mail this morning and wanted to search for all messages whose subject did not contain a certain keyword. It turns out you can do some decent searching in Mail.

Straight from the Help:

When you search entire messages, you can refine your search by using logical symbols to represent “and” (&), “or” ( | ), “not” ( ! ), and parentheses. For example:

“cat & dog” finds messages containing both “cat” and “dog”

“cat | dog” finds messages containing either “cat” or “dog”

“cat ! dog” finds messages containing “cat” but not “dog”

“cat & (dog | newt)” finds messages containing both “cat” and “dog” and messages containing both “cat” and “newt”

Paternity Tests

stany

On a black board in the math tutorial room someone wrote:

“For Paternity Test Results call 1-800-RUMYDAD. www.rumydad.com”

Below it, someone else wrote:

“Translation: Is your family Pareto Optimal? Prune your family game tree at www.rumydad.com”

For some reason, this amused me.

Must be high blood sugar levels, or something.

Things that piss me off (part I)

stany

I am editing video footage that was digitized from a VHS tape. Footage itself is of Wendy Whited Sensei, from 1997 or 1998. I’ve never met Whited Sensei myself, but based on the video, I like her. And I like her style. And she is very very very good. But this is not about my likes.

This is about things that piss me off. Imagine a standard martial arts seminar (I were told that this is a fairely standard martial arts seminar). Instructor, generally a high ranked instructor, was brought in, at big expense and effort to teach.

A part of the idea is to make the money back by the hosting organization (paying for flight, hotel, meals, plus honorarium all add up, and God forbid you need to add rent of the location costs to it too). So hosts invites a bunch of local dojos that kind of do the same thing to send their members over, and hopefully to learn new things.

Usual practice is structured so that Sensei demonstrates something while everyone else is formally sitted, and then folks break into pairs or groups, and try to duplicate what Sensei shows to the best of their ability.

In the meanwhile, Sensei is walking around, and is watching everyone practice, and tries to spot and correct mistakes, explain concept behind the action, and hopefully nudge the practitioner to a higher level of understanding and practice.

Generally, protocol is that on the mat senior instructor is the king and dictator – lives of everyone on the mat are his or her responsibility (this is, after all martial arts, and one can end up breaking wrist, hand, neck, you name it), and when senior instructor demonstrates something, everyone around should stop what they are doing, sit down where they are, and watch. Last bit actually makes sense – if some people are practicing, and there are flying bodies in the air, and some people are sitting, chances are that blending will occure between flying and sitting person, not flying person and a mat.

Also, chances are that everyone is making the same mistake, and instructor is trying to correct it not for just a single person (if that were the case, instructor generally would tell everyone to keep practicing).

So here I am, trying to edit a video tape into somewhat coherent thing, and what do I see?

Two people, from the same dojo (I can tell as they have identical crests on their uniforms) always practice together. Logically, in a seminar setting you would try to pick as a partner someone else each time, if only to get a chance to practice with some higher ranked people, and maybe learn something from how they do their technique, right? Well, maybe these two folks are both higher ranked then the instructor, and know better then her what they are doing? No, they are not second highest ranked people on the mat after senior instructor – far from it. In fact they are not even black belts. Mudansha.

Whenver instructor would try to correct the mistakes of someone in the dojo, these two fellows are the last ones to sit down (if at all) and watch.

When instructor spotted something they were doing that was far from correct (I am not an expert, yet even I could see that what they do was different from what they were shown), and walked over to correct one of them, he started argueing back with her. Mudansha talking back to a 6th degree black belt who practiced longer then this fellow was alive. *blink*

I mean, these two fellows came to the seminar, paid money, got on the mat, only to do what? Practice same way as they practice “at home”, with the same partners? Insult the guest instructor? Not learn anything?

Some minds are forever shut, and one can’t open them even with a crowbar. Upside the head.

Oh, and what do I care? Well, these two fellows parked themselves right in front of the camera during their practice. Every technique. So most of the time, when I were trying to edit the video out, and just keep the bits where Sensei is demonstrating, they kept on obstructing the screen, or shaking the camera. *sigh*

Coming soon: Part II – things that piss me off in filming without script and without clear idea, on filming with cheap hardware that can’t focus properly, on filming without tripod, on zooming in waaaay in, and then panning 180 degrees, and all the other joys of filming, taking pictures, and trying to edit a video together.

Show that if b ∈ R, R is a Eucledian domain and a is a non-zero non-unit, then bR/aR = {r + Ra : r ∈ bR} is an ideal in R/aR.

stany

Suppose that R is a Euclidean domain and a ∈ R is a non-zero non-unit.

For an element b ∈ R consider the subset bR/aR = {r + Ra : r ∈ bR} of R/aR.

Let r + Ra, s + Ra ∈ bR/aR so that r, s ∈ bR, then r + s ∈ bR which gives (r + Ra) + (s + Ra) = (r + s) + Ra ∈ bR/aR.

Let r ∈ Ra ∈ R/aR and s + Ra ∈ bR/aR so that s ∈ bR, then rs ∈ bR implies that (r + Ra) · (s + Ra) = (rs) + Ra ∈ bR/aR.

Hence bR/aR is an ideal in R/aR

Just in case you weren’t sure that it was.

It’s almost 2 am, what do you expect?

Oh, and I goofed while writing a game theory midterm last week, and only got 92/100.

I forgot to do part II of question 1, inspite of the note on the test paper saying “Don’t forget to do part (ii) below”.

Argh!

Oh, and should I do a blurb on the math behind error correction, specifically, as it’s implemented on CDs?

SCSI to ATAPI bridge board

stany 1 Comment

I realize that SCSI is pretty much dead. It makes me cry, as a whole number of my shiny Sun systems, like dara, an Enterprise 4000 server, all take SCSI.

If, for some reason one still wants to hook up an IDE/ATAPI DVD burner or somesuch to a SCSI bus, comrades from the field are recommending Acard Technology AEC-7720U SCSI to IDE bridgeboard.

link, which might die whenever Acard folks decide to change format of their site).

At 69 USD per board, somewhat costly.

As I’ve mentioned before, I also own a Promise UltraTrak TX8, which is an IDE RAID tower with SCSI interface to the host system.

So I wonder if there is a dongle or somesuch that can convert SCSI to firewire, so I could start using my 800 gig storage array with an iBook 🙂

Any suggestions?

Sun Studio 11 (Compilers/Developer Suite) is now free

stany

Alan Coopersmith (whom I’ve never met, yet whom I respect about as much as I respect Casper Dik) mentions that Sun Studio 11 is now free.

Download link is here.
Specifications – Basically Solaris 8 or newer on Solaris SPARC or x86. There is mention of Linux (RH 4 or Suse 9) on the sysreq page too, but I am kind of both disinterested by Leenuks, and somewhat puzzled, as RH 4 is circa 1997 and Sun folks probably mean Fedora 4. Or something.

Here Alan is doing some comparisons between Sun cc and gcc for compiling the X subsystem for Solaris.

I own single license for Sun Studio 6, which I picked up at a dot.com bancropcy auction (it was a box with never registered license codes) for 100 CAD. As part of a deal I got about half a cubic meter of Cisco propoganda for Cisco 25xx routers, but it was worth it.

Owing a license for a Sun’s C compiler for a while made me the coolest kid on the block, as I could compile 64 bit versions of IPF (gcc at the time stood in the corner and nerviously smoked whenever it had to compile 64 bit kernel modules)

Looking for a book of poetry….

stany 2 Comments

Looking for a book of poetry (I can imagine surprized groans now. Poetry? What poetry? stany can read?)
Specifically this one

Mikhail Lermontov: Major Poetical Works by Anatoly Liberman (Editor)

It is an out of print book of poetry translations of Michail Lermontov :

I write to you and truly wonder:
What in the world has made me write?
For you, I’ve gone away and under
And must have forfeited this right.
You know that, though we are asunder,
Your image was too much to lose.
Of course you do! — Such boring news…

Between attacks and other dangers
We live in God-forsaken holes.
But do you care? Our souls are strangers:
Indeed, the normal case for souls.
[…]
(my source only quotes the beginning of this piece. Sorry)

So, here is a funny thing. If I search for this book on Amazon US site, I get two listings for a used book, one for 30$, one for 135$. If I look for it on Amazon Canada site, I get one used book for 284.55 CAD.

Global economy. Go figure.

Oh, and author of the book, Anatoly Liberman, contributes to an Oxford University Press Blog.