On Mon, 10 Dec 2001, nrf wrote: > > I presume that you are speaking of L3 MPLS VPN's. Actually, Cisco L3 MPLS > VPN's (RFC 2547) do not behave like Frame-relay or ATM at all. The key > difference is that implementing RFC 2547 assumes IP connectivity at the > customer, whereas FR or ATM makes no such assumption. It is therefore not > really true that ATM/FR can be easily swapped out with RFC 2547, because you > have to make sure that IP is up and running at the customer. For a closer > adherence to ATM/FR, you should look into L2 MPLS VPN's offered by Juniper > and other vendors.
Agreed, but my point was from the customers perspective they are similar in function (Both L2 & L3 configurations are meant to compete with existing ATM/Frame services)...The fact that it (2547) does run over IP could be considered a limitation though. > > > scaleable > > > > Depends on who you listen to:) From the client perspective adding > > additional sites and increasing bandwith should not be an issue. > > L3 MPLS VPN's have both positive and negative overall scalability > implications. Basically, much of the IP routing functionality that used to > be handled by the customer has now been offloaded to the provider. This > means less work for the customer, more for the provider. It is this extra > work for the provider that has caused much alarm in the service-provider > community. IMO, the issue of scalability will cause more providers to > consider offering L2 MPLS VPNs before they offer L3 MPLS VPN's because the > former require less router resources. Both L2 and L3 VPN's have their own issues from a service provider perspective... > Of course, when a provider does offer L2 MPLS VPN's, they probably won't > tell you it's MPLS at all. They'll just tell you that it is ATM or FR and > never mind what is happening in the core. From the perspective of the > customer, it basically is just ATM or FR. If it walks, talks, and acts like > ATM/FR .... > > > > > > > reliable > > > > Will be as reliable as the circuits/provider. > > MPLS VPN's (both L2 and L3) are almost certainly less reliable than regular > VPN's, simply because they are so new and therefore not battle-tested. FR > and ATM have been around forever, and are well established and stable. MPLS > is still going through growing pains. Also, MPLS inter-ops between > different vendors is still problematic (although getting better over time) > > > > > > secure > > > > Although your traffic shouldn't be visible to the providers other > > customers it is not encrypted by the service provider. If you are > > concerned about security, encryption would be appropriate. > > MPLS VPN's are just as secure (or insecure) as ATM and FR. Providers can > sniff your MPLS VPN packets, but they could also sniff your ATM cells and FR > frames. And are equally subject to misconfiguration - ever seen a mystery DLCI on your frame circuits:) > > > > > > flexibility > > > > Adding/revoving remote sites and changing bandwith should not > > be a problem... > > > > > Do you know of any service provider providing similar services? > > > > There are a number of providers that indicate they are running > > MPLS at this point depending on where you are. (ATT, C&W, etc.) > > AT&T and CW are running MPLS in the core to unify their IP and ATM/FR > backbones. But almost nobody is offering widespread MPLS VPN's - Global > Crossing, Equant, NTT, and a few others. Right now they are very much a > niche product, although they should become more widespread in the future > > > > > > > > > > regards > > > jagan Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=28689&t=28655 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
