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""Chris White"" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > On Mon, 10 Dec 2001, Jagan Krishnaraj wrote: > > > One Telco service provider claims that they are using MPLS (Cisco Powered > > Network) at his back bone, which enable substantial saving to the clients. > > All the remote sites are able to connect to the central site via the > service > > provider's MPLS cloud. Each remote site site is connected to the MPLS cloud > > directly and the central site is connected to the MPLS cloud via a huge > pipe. > > > > > > I've the following concerns which need your advise: > > From the client perspective a MPLS VPN will look similar to using > frame relay (From a cost perspective ATM/Frame is a good reference > as well) . Think of the MPLS VPN as a virtual network running > on top of the service providers network. Unlike frame relay the > VPN can not reach beyond the providers network (technically it > is possible but I have not heard of any providers offering this > at this point) which may or may not be a concern depending on > the provider and the locations you need to connect. > > http://www.cisco.com/warp/public/732/Tech/mpls/ 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. > > > 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. 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. > > > 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=28674&t=28655 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
