[c-nsp] ASR920 "console" port....ugh

Reuben Farrelly reuben-cisco-nsp at reub.net
Sat Jan 16 07:09:15 EST 2016

On 16/01/2016 10:43 PM, Gert Doering wrote:
> Hi,
> On Sat, Jan 16, 2016 at 09:07:00AM +0000, CiscoNSP List wrote:
>> Cheers for the replies guys - I'm really interested in the rational
>> behind moving to USB from traditional RJ45
>> ports....realestate?....boggles the mind.
> Well, if done properly, it's actually easier to the admins than
> having to carry around a usb-to-serial adapter all the time (since
> almost all current machines do not have a built-in serial port
> anymore).
> "properly" implies something else, though, like:
> - the "real" USB console has a mini-b or micro-B plug, so a
> bog-standard USB cable otherwise used to charge your mobile will do
> the job (as for driver installation, well, if you can find a
> USB-to-serial chip that windows supports by default, even better -
> but otherwise, unavoidable misery.  On Linux, it just works with the
> common chipsets)

USB console is a good idea but the execution of this changeover was botched.

As of today we have most routers and switches rolling out with USB 
serial ports and what appears to be USB->Serial chips onboard to do the 
translation.  This required only a standard mini-b to USB cable to work.

Big tick there.  The hardware teams did a good job on their part of the 
job and the implementation of hardware is usually good.

But where Cisco seriously lost all credibility with this was the 
software/driver support.

As of today:

Windows 7 driver - available on CCO and works OK
Windows 8 driver - never supported
Windows 8.1 driver - never supported
Windows 10 driver - seems to be built into Windows 10

Note that the Windows 7 driver did not work on Windows 8.  And in 
practice on every laptop I tried it on the driver got in a messed up 
loop whereby it created 255 COM ports in Windows before deciding that 
there were none left.  This left a right royal mess in device manager to 
clean up.

At least a part of this bug was being tracked under CSCuh52585 which has 
never been made customer visible.

There was some comment on this in:


In the end I just went and bought a decent dongle that did have good 
driver support and haven't had to deal with the problem since.

There are still some routers which don't have USB console ports such as 
the C819G's though.  So it's not quite yet ubiquitous.  But that's the 
exception not the norm.


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