The MPLS-OPS Archive

Cell Relay Retreat>MPLS-OPS Archive>month:2002-Dec> msg00120



[Date Prev][Date Next][Thread Prev][Thread Next]  
  [Date Index][Thread Index][Author Index][Subject Index]

Fwd: Re: Re: Labels per link...

  • From: Roger Clark Williams <rogerw@nordlink.com>
  • Date: Tue, 10 Dec 2002 15:05:57 -0500
  • Resent-Date: Tue, 10 Dec 2002 16:40:26 -0500
  • To: MPLS-ops Mailing List <mpls-ops@mplsrc.com>
  • X-Sender: rogerw@together.net@207.69.200.148

Customer routers, in the normal MPLS model, do not use labels. They are not 
PEs or P routers

Roger Williams
>From: "alok" <alok.dube@apara.com>
>To: "Roger Clark Williams" <rogerw@nordlink.com>
>Subject: Re: Re: [MPLS-OPS]: Labels per link...
>Date: Tue, 10 Dec 2002 16:04:57 +0530
>X-Mailer: Microsoft Outlook Express 5.00.2615.200
>
>are A and C customer routers or PE routers?
>
>----- Original Message -----
>From: Roger Clark Williams <rogerw@nordlink.com>
>To: MPLS-ops Mailing List <mpls-ops@mplsrc.com>
>Sent: Tuesday, December 10, 2002 1:21 PM
>Subject: Fwd: Re: [MPLS-OPS]: Labels per link...
>
>
> > Gopal is correct, at least as far as I know. Perhaps I can clarify, if
>this
> > drawing comes across well enough.
> >
> > A---\
> >         C-----D
> > B---/
> >
> >
> > Frame mode, or platform-wide labeling:
> > Router C will advertise to D 2 routes; a route to A using one label, and a
> > route to B using another label.
> > Going the other direction, Router C will advertise to both A and B a route
> > to D, sending the same label to both A and B.
> >
> > Cell-mode (a bunch of MPLS-aware ATM switches for instance):
> > In the first instance, C would advertise to D 2 routes using two labels,
> > just as before
> > In the second instance however, C would advertise the route to D using two
> > different labels, sending one to A and the other to B.
> >
> > This is  because C would likely have two different VCs to D, which is
> > effectively two completely different paths, each requiring a separate
>label.
> >
> > I hope this helps.
> >
> > Roger Williams
> >
> > >Resent-Date: Tue, 10 Dec 2002 01:30:54 -0500
> > >X-Authentication-Warning: host.secure4-hosting.net: mplsrc12 set sender
>to
> > >mpls-ops-request@mplsrc.com using -f
> > >Date: Mon, 9 Dec 2002 21:57:13 -0800 (PST)
> > >From: "Gopal@Yahoo" <gnaganab@yahoo.com>
> > >Subject: Re: [MPLS-OPS]: Labels per link...
> > >To: nitin p <nitin_panj@yahoo.com>, alok <alok.dube@apara.com>,
> > >    mpls-ops@mplsrc.com, ppvpn@lyris.nortelnetworks.com
> > >Resent-From: mpls-ops@mplsrc.com
> > >X-Mailing-List: <mpls-ops@mplsrc.com> archive/latest/4956
> > >X-Loop: mpls-ops@mplsrc.com
> > >Resent-Sender: mpls-ops-request@mplsrc.com
> > >
> > >Nitin, That is incorrect. Pls forward me if there is a
> > >doc that supports your data.
> > >In frame mode labels are unique to the router. There
> > >is one big label space per router. Router assigns
> > >labels to the prefixes in the routing table from this
> > >space.
> > >
> > >If a prefix P is learned from neighbors on 2 different
> > >interfaces(or we advertise to 2 neighbors on 2
> > >differnt interfaces), router assigns one unique label
> > >to that prefix(it is often refered as local label).
> > >
> > >In label or local label = Label that router assigns to
> > >a prefix. This label is one unique to the router, no
> > >matter how many sources we learn from or, to how many
> > >neighbors we advertise.
> > >
> > >Out label or remote label(s) = label this router
> > >received from the neighbors. there can be more than
> > >one remote/out label for a prefix(advertised by
> > >different neighbors).
> > >
> > >You can play with your boxes to see this behaviour
> > >indeed.
> > >
> > >rgds,
> > >gopal
> > >
> > >
> > >--- nitin p <nitin_panj@yahoo.com> wrote:
> > > > Gopal,
> > > >
> > > > Adding to this discussion..
> > > > Don't we have the concept of having global and local
> > > > labels. Global when there is one label pool in a
> > > > router and all the interfaces are assigned labels
> > > > from
> > > > this pool so label values at two interafces on the
> > > > same router will never be same.
> > > > Local, is the one in which each interface has it
> > > > pool
> > > > of labels and two interface on the same box maight
> > > > have same label values.
> > > > Please correct me on this.
> > > >
> > > > Thanks,
> > > > Nitin
> > > >
> > > > --- "Gopal@Yahoo" <gnaganab@yahoo.com> wrote:
> > > > >
> > > > > --- alok <alok.dube@apara.com> wrote:
> > > > > > Hi All
> > > > > >
> > > > > > i need to know what is the standard
> > > > implementation
> > > > > > practice on labels for
> > > > > > multipoint interfaces.
> > > > > >
> > > > > > If  i have an ethernet network between routers,
> > > > P
> > > > > > routers connected to
> > > > > > multiple P via ethernet...
> > > > > >
> > > > > > is a label unique +ACI-per neighbour+ACI- or
> > > > > > +ACI-per interface+ACI- in this case
> > > > >
> > > > > What is ACI?
> > > > > In frame-mode, (local)Label is unique to a
> > > > > router(LSR).
> > > > >
> > > > > >
> > > > > > for example, P-a, P-b and P-c are on the same
> > > > > > ethernet LAN
> > > > > >
> > > > > > can u have label 111 between P-a and P-b for
> > > > > egress
> > > > > > trafficbetween a and b,
> > > > > > and 111 between P-a and P-c for egress traffic
> > > > > > between a and c?
> > > > >
> > > > > Yes.
> > > > >
> > > > > If router-A is the Egress for a prefix, net-A and
> > > > if
> > > > > local label for Net-A is 111. Then rtr-A adv 111
> > > > to
> > > > > both rtr-b and rtr-c.
> > > > >
> > > > > Then, both rtr-b and rtr-c will have 111 as the
> > > > > out-label for the prefix, net-A.
> > > > >
> > > > >
> > > > > >
> > > > > > -rgds
> > > > > > Alok
> > > > > >
> > > > > > -------
> > > > > > The MPLS-OPS Mailing List
> > > > > > Subscribe/Unsubscribe:
> > > > > > http://www.mplsrc.com/mplsops.shtml
> > > > > > Archive:
> > > > > http://www.mplsrc.com/mpls-ops_archive.shtml
> > > > >
> > > > >
> > > > > __________________________________________________
> > > > > Do you Yahoo!?
> > > > > Yahoo! Mail Plus - Powerful. Affordable. Sign up
> > > > > now.
> > > > > http://mailplus.yahoo.com
> > > > >
> > > > > -------
> > > > > The MPLS-OPS Mailing List
> > > > > Subscribe/Unsubscribe:
> > > > > http://www.mplsrc.com/mplsops.shtml
> > > > > Archive:
> > > > http://www.mplsrc.com/mpls-ops_archive.shtml
> > > >
> > > >
> > > > __________________________________________________
> > > > Do you Yahoo!?
> > > > Yahoo! Mail Plus - Powerful. Affordable. Sign up
> > > > now.
> > > > http://mailplus.yahoo.com
> > > >
> > > > -------
> > > > The MPLS-OPS Mailing List
> > > > Subscribe/Unsubscribe:
> > > > http://www.mplsrc.com/mplsops.shtml
> > > > Archive:
> > >http://www.mplsrc.com/mpls-ops_archive.shtml
> > >
> > >
> > >__________________________________________________
> > >Do you Yahoo!?
> > >Yahoo! Mail Plus - Powerful. Affordable. Sign up now.
> > >http://mailplus.yahoo.com
> > >
> > >-------
> > >The MPLS-OPS Mailing List
> > >Subscribe/Unsubscribe:  http://www.mplsrc.com/mplsops.shtml
> > >Archive: http://www.mplsrc.com/mpls-ops_archive.shtml
> >
> > -------
> > The MPLS-OPS Mailing List
> > Subscribe/Unsubscribe:  http://www.mplsrc.com/mplsops.shtml
> > Archive: http://www.mplsrc.com/mpls-ops_archive.shtml
> >

-------
The MPLS-OPS Mailing List
Subscribe/Unsubscribe:  http://www.mplsrc.com/mplsops.shtml
Archive: http://www.mplsrc.com/mpls-ops_archive.shtml