nanog mailing list archives

RE: While we're complaining about wacky wild Cisco ASR Stuff?


From: "LJ Wobker (lwobker) via NANOG" <nanog () lists nanog org>
Date: Wed, 6 Aug 2025 20:08:07 +0000

Today must be my lucky day... I was around (though much less directly) for these conversations as well.  Here goes (and 
sadly it's sort of the same tune with different lyrics)...

Pretty much every damn system I've helped design in the last 2 decades has started an internal fight about exactly 
which ports we put where, what connectors we use, and why.  This little guy (your ASR920) I'm sure is no exception.  

These little boxes NEVER have enough faceplate area available for all the ports (plus empty space for airflow) we want 
(larger is always better, right?) -- we have to squeeze in every damn management, timing, BITS, some other management, 
serial, aux, auxiliary-serial, breakfast-cereal, ethernet both optical AND copper... AAAARGH IT NEVER F-ING ENDS..... 
Anyway, that's my trauma, not yours.  

Here, I do not have an answer as to why we picked that super weirdo USB-A to USB-A pin mapping.  MAYBE at the time 
people thought it wasn't that weird.  God knows that we've been caught making a component or connector choice that SURE 
AS HELL looked for six months that it would be common, but then died a quick death and 15 years later we're stuck.  
ANYWAY... 

I DO know at least in a few cases we wanted to avoid the USB-micro because we had One Or Two Very Specific Requests 
From Very Very Large Customers that their onsite techs often played rough and the USB micro connector is pretty brittle.

It's totally possible (and I do not know about this specific one, but more generally) that some Very Very Large 
Customer wanted the alarm connector to be an RJ-45, and they didn't give a shit what the other ports that they weren't 
going to use looked like.  So we did what they wanted and sacrificed other things.  This is *shockingly* common.

It's worth mentioning (warning: lame-ass excuse coming here!) that in the Service Provider market (and even more so now 
since the hyperscalers drive everything) we might be selling a Very Substantial Percentage of a box like this to A Very 
Short List Of Customers.  If you're going to buy 10,000 of these to stick on your cell towers or in your neighborhood 
or at your agg sites, and you want the thing painted magenta instead of lavender... Cisco will do that for you If 
You're A Large Enough Customer For Said Special Router.


--lj

-----Original Message-----
From: Dan Mahoney (Gushi) via NANOG <nanog () lists nanog org> 
Sent: Wednesday, August 6, 2025 3:50 PM
To: nanog () lists nanog org
Cc: Dan Mahoney (Gushi) <danm () prime gushi org>
Subject: While we're complaining about wacky wild Cisco ASR Stuff?

Note: This is an attempt at Humor that I hope to make my fellow graybeards go "wait, really?".  It gave me a fun story 
to tell.  But it may just read as old-man-yells-at-cloud-hardware-vendor.

While we're posting fun problems about SNMP polling, where the "S" stands for "Simple" (?), and we're trying to walk 
10's of megs of data out of a system, but the protocol only ever uses UDP, even though TCP is totally in the spec...

Can someone please tell me which engineer at Cisco decided that the serial ports on some of their ASR920 would be:

* not in an RJ45 shell (as we've seen since the C2501 days)...

* nor a USB-micro that presents PL2032 serial port controller internally, that connects with a micro-to-usb-A (like 
everyone has lying around to charge their old stuff?), and like every other cisco device has had for 10 years.

But instead, would be your choice of:

* A usb "A" port, that presents a virtual serial port to the host PC, but which then requires a USB-A-TO-USB-A cable 
that nobody has, and is next to, and identical to, (but distinct from) the USB port where one can plug in flash 
drives...

OR

* A totally different port on the other side of the main ports that has 
the usual TXD, RXD, GND, CTS, RTS -- but ALSO inside a USB-A header, so 
you need some special kind of unobtanium breakout box (And another of 
those for the AUX connector.)

===

WHAT?

If you don't believe me, go look up pictures of the Cisco ASR-920-24TZ-M

I've had to walk people on the datacenter floor through splicing a serial 
console together with twisted wires, (stripped with the teeth as the lord 
intended), because of this, over a bad facetime connection -- because of 
course that's where the cellular and wifi signal's worst, inside the 
building with thousands of 10G connections to the internet.

By cutting these corners, Cisco saved space for the RJ45 sitting right 
there for an "ALARM" connector, I'm sure that's a crucial thing that 
everyone who needs a small router like this will use. (My ASR9000's had 
it, my ASR1001X's didn't, but a 920...sure?)

Clearly Cisco hired someone from the iPhone headphone port division (let's 
be "brave" and delete it!).  Or the APC UPS DE-9 port division, where 
connecting a straight-through cable would cause it to drop the load.

This is as bad as the ham radio a friend sent me, that has a USB charger 
that puts out 12V.  (That one got some hot glue to make it a perma-cable, 
it's an otherwise fine radio).

i've known some awesome people who worked at Cisco (including one of 
dayjob's board members, who just passed away.  We miss you, Fred!). 
Jim Houts in the TME lab and Xander Thujis have been incredibly kind and 
helpful to us, in a bygone era.

But this here, this is some temu-level stuff.

I'll be here all week, try the veal.

-Dan/W3ZUL

-- 


--------Dan Mahoney--------
Techie,  Sysadmin,  WebGeek
Gushi on efnet/undernet IRC
FB:  fb.com/DanielMahoneyIV
LI:   linkedin.com/in/gushi
Site:  http://www.gushi.org
---------------------------

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