--- alok <alok.dubeAPARA.COM> wrote:
> i have a box infront of node-a and node -b
> its basically a mux....
> it has a seperate signalling channel/timeslots...
> the link is provisioned over the mux (okie ill make
> that 100Mbps to 155Mbps
> so that you call it oc-3 or STM-1)
> the link between boxatnodeA and boxatnodeB is
> STM-1+64k
> in the link between boxatnodeA and boxatnodeB i want
> to use the 64k part
> (muxed out) for signalling..i can tap it out from my
> mux using some serial
> cable and put it onto an interface..
>
> essentially, assume that if the 64k is down the link
> between the 2 boxes is
> down
>
> you might say the last mile on the 64kbps to my
> router is down
> too...fine..very rare..its something one can live
> with...

You may want to look at the proposals of the
deleted draft "draft-ietf-ospf-ppp-flood-" which
defines parallel point-to-point links between two
OSPF routers as equivalent links if they are part
of the same OSPF area.

Only of the equivalent links is required to be fully
adjacent and the others can remain in 2-Way state,
thereby preventing database exchanges and LSA flooding
over the non-adjacent equivalent links.

Also it requires modification of the routing table
calculation as it stores any of the equivalent links
that have least cost as the interface to reach next
hop
which is the directly connected neighbor in this case.

So if the STM-1 link is assumed to have minimum cost
between 64K and STM-1 then SRM-1 link could appear as
the interface to reach the neighbor router in the
forwarding table and IP datagram traffic forwarding
would then happen over the STM-1 link and OSPF DBD,
LSA flooding would be restricted over the 64K link.

However this requires changing the OSPF protocol
operation slightly.

>
> if it flaps..well we had a whole lot of things on
> hitless restart (which now
> seems to be called graceful restart)....and we had
> reduction in LSAs using
> the "triggered updates" ..making LSA refresh timer
> as infiinty etc...
>
> if I can ensure that
> 1. if 64k is up, 155Mbps may be up or down (that is
> possible in my scenario)
> 2.but if 64k is down 155Mbps is down guaranteed
>
> how do i look at this?
>
>
>
> ----- Original Message -----
> From: Manav Bhatia <manavSAMSUNG.COM>
> To: <OSPFDISCUSS.MICROSOFT.COM>
> Sent: Wednesday, February 12, 2003 12:42 PM
> Subject: Re: OSPF---out of band
>
>
> > I think my previous mail was a little ambiguous ..
> expounding more on it
> ..
> >
> > Imagine what will happen when your 64kbps link on
> one end goes down You
> > will be tearing the adjacency and no traffic will
> flow even though you
> have
> > your 100Mbps link alive!
> >
> > ----- Original Message -----
> > From: "alok" <alok.dubeAPARA.COM>
> > To: <OSPFDISCUSS.MICROSOFT.COM>
> > Sent: Wednesday, February 12, 2003 12:29 PM
> > Subject: Re: OSPF---out of band
> >
> >
> > > I could still detect link failures and pass them
> over the 64kbps link?
> > >
> > > I dont think OSPF is needed to detect "link
> failures" ..the kernel
> itself
> > > would do it...?..physical link being up/down is
> kernel's problem...
> > >
> > > as far as L3 failure goes...can you give me a
> "specific" example? where
> > you
> > > say "L3 is down" but "L2 is up"...(assume
> unnumbered
> > interfaces)...mismatch
> > > in config?
> > >
> > > fine, as i said that isnt a concern...i have
> 100Mbps unnumbered (P2P)
> > link
> > > and 64kbps P2P link.
> > >
> > > OSPF hellos mainly would be used to detect
> "routing node" failures which
> > > would anyway be passed over via the other link
> in this case..
> > >
> > >
> > > ----- Original Message -----
> > > From: Yasuhiro Ohara <yasuSFC.WIDE.AD.JP>
> > > To: <OSPFDISCUSS.MICROSOFT.COM>
> > > Sent: Tuesday, February 11, 2003 11:20 PM
> > > Subject: Re: OSPF---out of band
> > >
> > >
> > > > > > assuming there are 2 links between Node A
> and Node B one is 64kbps
> > > other is
> > > > > > 100Mbps...
> > > > > >
> > > > > > i need to use the 64kbps link to establish
> OSPF adjacencies and
> > pass
> > > the LSA
> > > > > > information etc over it.
> > > > >
> > > > > It is can't be done using the vanilla OSPF.
> There has never been a
> > > strong
> > > > > requirement for OSPF to use links other than
> the ones over which
> > > adjacencies
> > > > > are established.
> > > >
> > > > Agree to Acee, and wondered what is the reason
> that you don't want
> > > > the OSPF to run on (or to form an adjacency
> over) the 100Mbps link ?
> > > > I guess the merit which is that any failures
> in L3 can be detected
> > > > is always prefered over the demerit of
> bandwidth consumption.
> > > >
> > > > regards,
> > > > yasu
> > > >
> > >
> >

=====
Somen Bhattacharya
E-Mail : rob_pathyahoo.com

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