Creating a Circuit ID Format

William Herrin bill at
Mon Aug 21 21:24:48 UTC 2017

On Mon, Aug 21, 2017 at 4:26 PM, Colton Conor <colton.conor at>

> We are building a new fiber network, and need help creating a circuit ID
> format to for new fiber circuits.
> I am sure anything will work as long as you keep track of it, but any
> advice would be great!

Hi Colton,

The key thing a circuit ID should inherently identify is whether or not the
circuit is one of yours.  Typically this is a two or three letter code in a
particular position whose absence allows a tech to immediately realize that
the ID the customer read out refers to something else.

You might also consider putting a simple checksum in the circuit ID like
the credit card companies do so that you can detect when an ID has been

Finally, structure it with breaks (slashes, commas, spaces) so it can be
read out over the phone without a high probability of error. It's easy to
lose your place in a 20 digit number one digit after another after another.
And when you write the database software, make sure the UI provides and
accepts those breaks!

Beyond that, there's no great value in not simply counting up by one. Your
network's architecture will change over time so any architecture-based
scheme will end up with confusing exceptions. Locality-based schemes aren't
a whole lot better.

Finally, there's a database principle called normalization: it means don't
put the same information two places because inevitably one will end up
disagreeing with the other. Put the customer's configuration (such as
speed) in your database and leave it out of the circuit id.

Bill Herrin

William Herrin ................ herrin at  bill at
Dirtside Systems ......... Web: <>

More information about the NANOG mailing list