[c-nsp] Fractional DS3, dsu bandwidth statement and circuit interruption

[Justin M. Streiner]

On Mon, 8 Dec 2014, papaia wrote:

> Need to change the bandwidth statement in the DSU line item config (up-ing
> the available bandwidth for a fractional DS3), for a router placed remotely
> from my office. Lacking an off-band access to this router, I am wondering
> if that change would trigger a circuit connectivity drop, and if so, if
> there would be a recovery of such, on its own, or if I would be better off
> with feet (and hands) on the ground, to reload or even fix.

Is this an actual fractional DS3, where you have to turn up a specific 
number of DS1 channels at each end, or is this a full DS3 that the carrier 
is rate-limiting to a certain speed?

What module are you using for the physical DS3 termination at the remote 
router?

It's been a while since I worked with DS3 interfaces, but:

If you're talking about the "bandwidth XXX" statement in the interface 
config, that has nothing to do with the actual bandwidth of the circuit. 
That's just used for things like route cost calculations if you're running 
a routing protocol like OSPF.  Changing that could force your IGP's SPF 
algorithm to re-run, but that would not cause the protocol adjacency to 
drop.  Since it sounds like this is a single-homed site, this should be a 
non-issue for you.

If you're referring to anything under the T3 controller config itself (if 
the module you're using has that), that will probably need remote hands 
because there is a chance that those config changes will cause the link to 
drop.

jms