The MPLS-OPS Archive[Date Prev][Date Next][Thread Prev][Thread Next] [Date Index][Thread Index][Author Index][Subject Index] RE: MPLS/VPN question
Hello ! My 2 cents on that as this is a kind of question I often see and get. 1.) the main task of the PE (Ingress/Egress LSR) is to allow the MPLS/VPN based forwarding on the control plane and on the data plane. Regarding QOS the PE as service provider device runs the DIFFSERV model. Typically outside the PE sits an CE which is the USER-Interface. 2.) Things like selection into different VPNs. Address Translation,Protocol Conversion,protocol specific actions and functions.... are IMHO CE functions and not PE ones. So regarding the actual question: if you need different VPNs for the traffic, than separate it on the CE and have more than one (logical) CE-PE connection going into different VPNs. It is also not recommendable for any Service Provider to do customer-specific things on the PE. Generally spoken, does it make sense to convert an existing FR-network to MPLS/VPN ? As always, it depends Despite the wise rule "never change a running system", there maybe some reasons COST, COST,..... Main advantage of MPLS/VPN is an integrated FULL-MESH whereas FR is a circuit point-to-point technology. So if you have to any-to-any connect 100 sites, MPLS/VPN gives you distinct advantage in that case. On the other hand MPLS/VPN as L3-peering-technology has a much higher convergence-time than a direct FR-circuit. .... with best regards Alexander Marhold Senior Consultant PRO IN -----Original Message----- From: Saqib Jang [mailto:saqibj@margallacomm.com] Sent: Tuesday, March 27, 2001 5:50 AM To: raszuk@cisco.com Cc: mpls-ops@mplsrc.com Subject: RE: MPLS/VPN question I think my choice of VoIP (due to the QoS issues surrounding it) as an example may have confused the issue. Assuming a number of sites have set-up a FR based overlay network to forward a specific type of traffic such as HTTP, FTP, or streaming traffic (setting aside the QoS implications for now). Does it make sense for them to look to get rid of the overlay network and use their existing last mile links thats used for all their data traffic in conjunction with an MPLS VPN that supports only (HTTP, ..) the specific type of traffic supported by their existing FR network. Or will MPLS VPNs not work for such a scenario? Saqib -----Original Message----- From: Robert Raszuk [mailto:raszuk@cisco.com] Sent: Monday, March 26, 2001 3:41 PM To: saqibj@margallacomm.com Cc: mpls-ops@mplsrc.com Subject: Re: MPLS/VPN question Saqib, I don't think that the approach of application specific VPNs even makes sense. L2 or L3 VPNs provide you mainly with connectivity (routing information distribution). For application level scheduling guarantees you should be using the right QoS tools available both in each hop as well on ingress. That way you can classify very important traffic (VoIP for example) to be taking the dedicated LLQ resources at each hop. I don't know how building VPNs (routing information disgtribution) may replace basic qos engineering in your network. Also the existance or not of NMPLS-BGP VPNs is orthogonal to the possibiliy of using more complex QoS tools like diffserv aware TE which can be a perfect complement to the VPNs itself, but not a reason for it. R. > Saqib Jang wrote: > > As I understand it, MPLS/BGP VPNs (per RFC2547) enable site-to-site > VPNs at for all traffic flowing between sites in the VPN. Can MPLS > VPNs handle the requirement of creation of VPNs among sites for > specific types of traffic (say e.g. VoIP traffic)? Would this require > a VoIP swtich (other type of allication-aware switches) to be an MPLS edge > router or can a "one size fits all" approach work here (i.e. can standard > MPLS-aware IP routers create application-specific MPLS VPNs). I'm looking > for technical rationale (i.e. not company/product positioning) here. > > TIA, > Saqib > > Saqib Jang > Margalla Communications, Inc. > 3301 El Camino Real, Suite 220 > Atherton, CA 94027 > Ph: 650 298 8462 > Fax: 650 851 1613 > > ------- > 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 ------- The MPLS-OPS Mailing List Subscribe/Unsubscribe: http://www.mplsrc.com/mplsops.shtml Archive: http://www.mplsrc.com/mpls-ops_archive.shtml
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