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Re: TE metric and graceful restart
Zafar and Don,
> >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.
Zero b/w advertisement is optional with the current spec, as "should" has
to do with setting unreserved b/w to 0, and not with originating a TE LSA.
The spec doesn't say that a node *should* originate a TE LSA upon the restart.
Yakov.
>
> 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.
> > >
> > >
>
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> Content-Type: text/html; charset="us-ascii"
>
> <html>
> <font size=3>At 01:01 PM 5/1/2002 -0400, Don Fedyk wrote:<br>
> <blockquote type=cite cite>Yakov,<br>
> <br>
> I think the text is correct since it is "should ... until it can
> determine<br>
> the amount of reserved..." Logically a node might never advertise
> zero <br>
> because it knows its resources. However, I do prefer *may* in place of
> the <br>
> first *should* which implies zero bandwidth advertisement is
> optional. </font></blockquote><br>
> Dear Yakov, <br>
> <br>
> I agree with Don. Switching the "should" to "may"
> will clarify the text greatly. <br>
> <br>
> Thanks<br>
> <br>
> Regards... Zafar <br>
> <br>
> <br>
> <blockquote type=cite cite><font size=3>Thanks,<br>
> Don<br>
> <br>
> <br>
> Yakov Rekhter wrote:<br>
> > <br>
> > Don,<br>
> > <br>
> > > Kireeti, Zafer:<br>
> > > <br>
> > > I think that Zafer picked up on my earlier point that just
> because<br>
> routing<br>
> > > is gracefully restarting an implementation may have an
> independent <br>
> > > LSP system that can function just fine so why be forced to
> penalize <br>
> > > it? On the other hand, you may have an LSP system that is
> linked <br>
> > > to routing such it must restart as well and then I would agree
> that <br>
> > > zeroing bandwidth may well be necessary( but somewhat less
> "graceful").<br>
> > > I'm not convinced changing Metrics is required at all. <br>
> > > <br>
> > > So I would agree with Zafer the wording should be such that
> either <br>
> > > case is allowed,<br>
> > <br>
> > Here is the current text:<br>
> > <br>
> > When a restarting node is going to originate its
> TE LSAs, the TE LSAs<br>
> > containing Link TLV should be originated with 0
> unreserved bandwidth,<br>
> > and if the Link has LSC or FSC as its Switching
> Capability then also<br>
> > with 0 as Max LSP Bandwidth, until the node is
> able to determine the<br>
> > amount of unreserved resources taking into account
> the resources<br>
> > reserved by the already established LSPs that have
> been preserved<br>
> > across the restart. Once the restarting node
> determines the amount of<br>
> > unreserved resources, taking into account the
> resources reserved by<br>
> > the already established LSPs that have been
> preserved across the<br>
> > restart, the node should advertise these resources
> in its TE LSAs.<br>
> > <br>
> > First of all note that the node advertises 0 unreserved b/w<br>
> > *only* "until the node is able to determine the<br>
> > amount of unreserved resources taking into account the
> resources<br>
> > reserved by the already established LSPs that have been
> preserved<br>
> > across the restart." <br>
> > <br>
> > Second, note that originating TE LSA with 0 unreserved b/w<br>
> > is *should*, not *must*.<br>
> > <br>
> > With this in mind, don't you think that the text is ok ?<br>
> > Or do you still want to change "should" in the first
> sentence above<br>
> > into "may" ?<br>
> > <br>
> > Yakov.<br>
> > <br>
> > </font></blockquote></html>
>
> --=====================_15224191==_.ALT--
>