Re: RSVP and LDP

Hi Mustafa

LDP over RSVP is the best solution.

I have designed for a big SP network, unicast me i can help you out

Rgds
Phani
Engineer-Network Consulting

2012/2/3 Mustafa Yadav <mustafa.yadav_at_gmail.com>

> Thanks man.it is good info
>
> 2012/2/2, CCIE KID <eliteccie_at_gmail.com>:
> > The order of labels will be VPN label exchanged and the RSVP TE label
> man.
> >
> >
> PE1-------------P3------------------P4----------------P5--------------P6-----------------P7------------------------PE4
> >
> > |
> > |
> >
> > |
> > |
> >
> > |
> > |
> >
> > PE2
> > PE3
> >
> >
> >
> > So in this scenario PE1 ,PE2 to P connections run LDP. From P3 to P7
> > there will be RSVP....From P3 to P7 there will be Targeted LDP
> established
> > to exchange the label for corresponding PE . lets see the thought process
> >
> > Here P7 will form a targeted LDP with P3 and exchange labels for PE3 and
> > PE1 respectively.
> >
> > Now P3 will update PE1 about PE3 via its local label.. and now LSP from
> PE
> > 1 to PE3 will be the LDP label given by P3 and when it reaches P3, it
> > uses the Targeted LDP label recevied from P7 and to reach P7 it uses RSVP
> > label given by P7 when forming the TE tunnel.
> >
> > So P4, P5 and P6 have no idea about PE1 and PE3
> >
> > So Over RSVP there will be LDP and this way it works
> >
> > LDP over RSVP solves the problem of creating many LSPs . For example u
> have
> > to create as many LSPs as number of PE's
> > Lets assume ur POP has 5 PE routers connected to 2 P routers connected to
> > each other in each site. Think there are 7 sites. So totally 35 PE
> routers
> > and 14 P .. So for each PE to PE there will be LSPs created. so in this
> > case 35 PE's so 35*34 LSPs has to be formed
> >
> > When u use LDP over RSVP, there will be only 14*13 LSPs created
> >
> > So it basically avoids number of LSPs
> >
> >
> >
> >
> > 2012/2/2 Mustafa Yadav <mustafa.yadav_at_gmail.com>
> >
> >> This makes sense and. I have found ldp over rsvp is used and there are
> >> 3 labels are used.vpn rsvp and ldp label
> >>
> >> 2012/2/2, CCIE KID <eliteccie_at_gmail.com>:
> >> > Good explanation Hemanth
> >> >
> >> > TE is used to engineer the traffic as u want to go through with the
> >> > prioritized traffic in need of B.W. There many be different LSP's and
> >> you
> >> > assign different treatment for each LSP.
> >> > And also u can do LDP over RSVP where u can do RSVP TE Tunnel from
> one P
> >> to
> >> > another P . So from PE to P u run LDP and have a targeted LDP over ur
> >> RSVP
> >> > So its basically hierarchical LDP over ur RSVP .
> >> >
> >> > On Thu, Feb 2, 2012 at 6:13 PM, HEMANTH RAJ <hemanthrj_at_gmail.com>
> wrote:
> >> >
> >> >> Hi Mustafa
> >> >>
> >> >> LDP has been designed for distributing labels exclusively, But RSVP
> has
> >> >> been a Host based protocol to inform the transit routers that to
> >> >> reserve
> >> >> the bandwidth what the application needs.
> >> >> So here in MPLS TE , RSVP is used as a signalling protocol to
> establish
> >> a
> >> >> BANDWIDTH DEFINED LSP from head end router to your Tail End Router
> >> >>
> >> >> In ur normal LDP , For each prefix u build a particular LSP . These
> >> >> prefixes are distributed by ur CORE IGP. SO basically ur LDP is
> relying
> >> on
> >> >> ur IGP info for setting up a LSP for that prefix
> >> >>
> >> >> But in MPLS TE, RSVP will build a LSP with the Tail End Router with
> >> >> some
> >> >> constraints. So basically it is a Tunnel where ur Head End Router is
> >> >> trying
> >> >> to form with the Tail End and to switch packets on the Tunnel. It is
> a
> >> >> unidirectional Tunnel.
> >> >>
> >> >> TE also uses ur CORE IGP to check whether the requirements to form a
> >> >> tunnel are met. For example , If the TE Tunnel requires 500Kb of
> >> bandwidth
> >> >> ie ur Head End's routers requirement is 500Kbs of B.W end to end (
> >> Assume
> >> >> that there are some users sitting behind Head End Router which
> requires
> >> a
> >> >> 500kb feed from the server which is present behind ur Tail End
> Router )
> >> So
> >> >> now ur Head End has to know the end to end B.W capacity of each
> transit
> >> >> router . This information is fed by our CORE IGP which can be ISIS or
> >> OSPF
> >> >> . ( These r the two protocol in use currently which has the
> capability
> >> to
> >> >> carry MPLS TE extended attributes . OSPF uses Opaque LSA and ISIS
> uses
> >> >> extended TLVS for it )
> >> >>
> >> >> So TE Tunnel will be up only when it is met with these requirements
> and
> >> >> after that it signals the RSVP Path and Tail End will send Reserve
> >> >> Messages
> >> >> to assign Labels ..
> >> >> This is also same as ur LDP where ur Downstream router starts
> assigning
> >> >> labels to the prefixes.
> >> >>
> >> >> So basically LDP is a prefix driven label assignment protocol but
> RSVP
> >> is
> >> >> all about how ur Head End wants the Constraint driven LSP with ur
> Tail
> >> >> End
> >> >> router and ( so u must know ur network and u know there is greedy
> hosts
> >> >> which wants a feed and u configure the TE Tunnel accordingly )
> >> >>
> >> >> Without LDP also, RSVP will work .For RSVP u just need ur CORE IGP to
> >> >> be
> >> >> converged and has the capabilities to carry TE extended information (
> >> >> So
> >> >> no
> >> >> RIP and EIGRP as of now ) RSVP Head End just sends Path message to
> ur
> >> >> Tail
> >> >> End router to signal each and every transit router that this is the
> >> >> requirement
> >> >>
> >> >> Do not confuse between LDP and RSVP. LDP is always Prefix Driven
> From
> >> IGP
> >> >> .. RSVP is basically manually configured Constraint Driven LSP (
> >> >> knowing
> >> >> ur
> >> >> network end to end )
> >> >>
> >> >> Hope this helps :)
> >> >>
> >> >>
> >> >>
> >> >>
> >> >>
> >> >>
> >> >>
> >> >>
> >> >>
> >> >>
> >> >> On Thu, Feb 2, 2012 at 5:43 PM, GAURAV MADAN <
> gauravmadan1177_at_gmail.com
> >> >> >wrote:
> >> >>
> >> >> > I think things are being mixed up here .
> >> >> >
> >> >> > When RSVP is used with TE .. RSVP will do the label distribution .
> >> >> > Hence role of LDP as a protocol for label distibution is eliminated
> >> >> > as
> >> >> you
> >> >> > are doing same thing using RSVP .
> >> >> >
> >> >> > And also ; i believe that in MPLS L3 VPN scenario as well ; running
> >> only
> >> >> > RSVP and no LDP anywhere in core can achieve your goal .
> >> >> >
> >> >> > Regards
> >> >> > Gaurav Madan
> >> >> > CCIE
> >> >> >
> >> >> > On Thu, Feb 2, 2012 at 5:14 PM, Mustafa Yadav <
> >> mustafa.yadav_at_gmail.com
> >> >> > >wrote:
> >> >> >
> >> >> > > so when ldp is going down all te tunnles are going to be down?
> >> >> > >
> >> >> > > but in one of my case ldp goes down but te tunnels did not.
> >> >> > >
> >> >> > > Also I seee ldp neigbor is up for 4 hours but mpls te tunnel up
> for
> >> 8
> >> >> > > hours.and 4 hours ago ldp went down.
> >> >> > >
> >> >> > > On Thu, Feb 2, 2012 at 1:18 PM, sundeep sadhwani <
> >> >> > > sundeep.sadhwani_at_gmail.com
> >> >> > > > wrote:
> >> >> > >
> >> >> > > > Hi Mustafa,
> >> >> > > >
> >> >> > > > RSVP is used for reservation of bandwidth in TE environment( i
> am
> >> >> > giving
> >> >> > > u
> >> >> > > > a very high level view). However plain MPLS-TE is not used in
> >> >> > production
> >> >> > > > scenario as SPs have MPLS-VPN as well. for that purpose we
> >> >> > > > require
> >> >> LDP
> >> >> > as
> >> >> > > > well to distribute IGP labels that will be required for PE to
> PE
> >> >> > > > communication in case of MPLS-VPN.
> >> >> > > >
> >> >> > > > Regards
> >> >> > > > Sundeep
> >> >> > > >
> >> >> > > > On Thu, Feb 2, 2012 at 4:41 PM, Mustafa Yadav <
> >> >> mustafa.yadav_at_gmail.com
> >> >> > > >wrote:
> >> >> > > >
> >> >> > > >> HD0,
> >> >> > > >>
> >> >> > > >>
> >> >> > > >> In a cisco network I have seen mpls traffic engineneering
> >> >> > > >> tunnels
> >> >> are
> >> >> > > >> being
> >> >> > > >> used .So as far as I know rsvp must be configured .But I alos
> >> >> > > >> see
> >> >> that
> >> >> > > ldp
> >> >> > > >> is configured in all boxes.why is that?Is not rsvp enough for
> >> >> > > distrbuting
> >> >> > > >> labels?
> >> >> > > >>
> >> >> > > >>
> >> >> > > >> Blogs and organic groups at http://www.ccie.net
> >> >> > > >>
> >> >> > > >>
> >> >> >
> >> _______________________________________________________________________
> >> >> > > >> Subscription information may be found at:
> >> >> > > >> http://www.groupstudy.com/list/CCIELab.html
> >> >> > >
> >> >> > >
> >> >> > > Blogs and organic groups at http://www.ccie.net
> >> >> > >
> >> >> > >
> >> _______________________________________________________________________
> >> >> > > Subscription information may be found at:
> >> >> > > http://www.groupstudy.com/list/CCIELab.html
> >> >> >
> >> >> >
> >> >> > Blogs and organic groups at http://www.ccie.net
> >> >> >
> >> >> >
> >> _______________________________________________________________________
> >> >> > Subscription information may be found at:
> >> >> > http://www.groupstudy.com/list/CCIELab.html
> >> >> >
> >> >> >
> >> >> >
> >> >> >
> >> >> >
> >> >> >
> >> >> >
> >> >> >
> >> >>
> >> >>
> >> >> --
> >> >> Problems arise because we talk,problems are not solved because we
> don't
> >> >> talk So good or bad talk to your affectionate one's freely.
> >> >>
> >> >> Yours Friendly,
> >> >> H P HEMANTH RAJ
> >> >> CCIE#28593 (R&S)
> >> >> Cisco Systems
> >> >>
> >> >>
> >> >> Blogs and organic groups at http://www.ccie.net
> >> >>
> >> >>
> _______________________________________________________________________
> >> >> Subscription information may be found at:
> >> >> http://www.groupstudy.com/list/CCIELab.html
> >> >>
> >> >>
> >> >>
> >> >>
> >> >>
> >> >>
> >> >>
> >> >>
> >> >
> >> >
> >> > --
> >> > With Warmest Regards,
> >> >
> >> > CCIE KID
> >> > CCIE#29992 (Security)
> >> >
> >>
> >> --
> >> Mobil cihaz}mdan gvnderildi
> >>
> >
> >
> >
> > --
> > With Warmest Regards,
> >
> > CCIE KID
> > CCIE#29992 (Security)
> >
>
> --
> Mobil cihaz}mdan gvnderildi
>
>
> Blogs and organic groups at http://www.ccie.net
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html

Blogs and organic groups at http://www.ccie.net
Received on Fri Feb 03 2012 - 14:45:05 ART