[j-nsp] MPLS fast convergence without link information

[Mark Smith]

Hi

Thanks for help everybody.

One further question: do you have recommendations of tools to perform
network convergence testing? I.e. generally available sw that is
capable of measuring network outage times in the order of magnitude of
milliseconds?

I have traditionally used linux and fping, something like fping -l -p
10 -i 10 -t 10 to get the low-precision measurement of outage in 10
milliseconds. Does this make sense to you?


On Thu, Dec 29, 2011 at 9:36 PM, Phil Mayers <p.mayers at imperial.ac.uk> wrote:
> On 12/29/2011 06:48 PM, Mark Smith wrote:
>
>> I would not expect the L2 service provider to be able to tunnel
>> ethernet OAM (CCM etc) traffic.
>
>
> In general, or in this specific case?

In general at this point. By building your stuff on the assumption
that your "subcontractor" or partner is able to do something
"specific" not mentioned in contract you increase the risk of extra
problems and/or work in case something goes wrong or changes.

For example let's assume you lease L2 lines and notice that OAM
traffic is passed fine. You test and build your network to rely on
this functionality. After some time your L2 provider experiences
hardware failure and they decide to replace the failed component with
different model, config, sw version etc. As a result OAM traffic is
not forwarded anymore and you need to do changes to your
configuration. The provider does not tell you anything, because your
service (L2 line) is restored.

Another example might be that you need to change L2 provider to
different one and again they don't forward OAM.

I have seen things like this happen on several occasions and I would
like to avoid them if possible. Also remember the murphy's law: if
(and when) anything goes wrong, it will happen on the worst possible
moment. I.e. in the middle of midsummer night when you (and your
capable colleagues) are 5 ‰ drunk ;/