RE: TE metric and graceful restart

[Zafar Ali <zali@cisco.com>]

At 01:01 PM 5/1/2002 -0400, Don Fedyk wrote:
> Yakov,
>
> I think the text is correct since it is "should ... until it can
> determine
> the amount of reserved..." Logically a node might never advertise
> zero 
> because it knows its resources. However, I do prefer *may* in place of
> the 
> first *should* which implies zero bandwidth advertisement is
> optional.  

Dear Yakov, 

I agree with Don. Switching the "should" to "may"
will clarify the text greatly. 

Thanks

Regards... Zafar 


> Thanks,
> Don
>
>
> Yakov Rekhter wrote:
> > 
> > Don,
> > 
> > > Kireeti, Zafer:
> > > 
> > > I think that Zafer picked up on my earlier point that just
> because
> routing
> > > is gracefully restarting an implementation may have an
> independent 
> > > LSP system that can function just fine so why be forced to
> penalize 
> > > it? On the other hand, you may have an LSP system that is
> linked 
> > > to routing such it must restart as well and then I would agree
> that 
> > > zeroing bandwidth may well be necessary( but somewhat less
> "graceful").
> > > I'm not convinced changing Metrics is required at all. 
> > > 
> > > So I would agree with Zafer the wording should be such that
> either 
> > > case is allowed,
> > 
> > Here is the current text:
> > 
> >    When a restarting node is going to originate its
> TE LSAs, the TE LSAs
> >    containing Link TLV should be originated with 0
> unreserved bandwidth,
> >    and if the Link has LSC or FSC as its Switching
> Capability then also
> >    with 0 as Max LSP Bandwidth, until the node is
> able to determine the
> >    amount of unreserved resources taking into account
> the resources
> >    reserved by the already established LSPs that have
> been preserved
> >    across the restart. Once the restarting node
> determines the amount of
> >    unreserved resources, taking into account the
> resources reserved by
> >    the already established LSPs that have been
> preserved across the
> >    restart, the node should advertise these resources
> in its TE LSAs.
> > 
> > First of all note that the node advertises 0 unreserved b/w
> > *only* "until the node is able to determine the
> > amount of unreserved resources taking into account the
> resources
> > reserved by the already established LSPs that have been
> preserved
> > across the restart." 
> > 
> > Second, note that originating TE LSA with 0 unreserved b/w
> > is *should*, not *must*.
> > 
> > With this in mind, don't you think that the text is ok ?
> > Or do you still want to change "should" in the first
> sentence above
> > into "may" ?
> > 
> > Yakov.
> > 
> >