At 6:04 PM +0000 3/20/03, Priscilla Oppenheimer wrote: >Robert Edmonds wrote: >> >> Actually, Multiprotocol Label Switch is MPLS. MLS is >> MultiLayer Switching. >> This refers to a switch that can do not noly what Kiran said >> about L3 >> switching, but can make forwarding decisions based on higher >> level >> protocols, such as tcp, udp, etc. > >Oh dear, this has really gotten funny. > >MLS is neither MPLS nor switching based on multiple OSI layers.
Multiple Listing System, a Real Estate application. > >MLS refers to a route/switch architecture in which the forwarding and >routing jobs (layers or modules) are assigned to two different pieces of >hardware. A router module learns how to reach destinations, handles the >first set of packets to a destination, and then tells a switching module how >to handle subsequent packets for that flow. Some high-end routers do this >(with VIPs, etc.) and some high-end switches can do it also, either with the >help of an outside router or by using built-in feature cards. > >MLS is often used to specifically refer to the architecture and features on >a Cat 5000 and 6000 that enable this division of tasks. There are three >components (or layers) to the MLS architecture on these switches: > >MLS Route Processor (MLS-RP) >MLS Switching Engine (MLS-SE) >Multilayer Switching Protocol (MLSP) > >The router part talks to the switching part using MLSP. This allows the >switching part to develop a cache that enables "shortcut switching" of >packets. See the ongoing drafts in the IETF FORCES Working Group for some general models of this approach. Without getting into vendor-specific areas, however, the most advanced routers in development use higher levels of multiprocessing and multiple processor interactions. > >That's just one way of handling the necessary tasks, however. > >Take the 8500 "switch" as an example of another way of handling the problem. >It can run the entire IOS and act just like a traditional router, only >faster. It has a Switch Route Processor that handles routing functions at >high speeds. Just to confuse matters, it behaves a little differently from >the Route Switch Processor available on other platforms. :-) > >Unfortunately, I don't know much about the Catalyst 4000, which was >mentioned in the original question. But from what I understand about it, >it's basically a router with switch ports. Its architecture is more like the >8500. It runs most of IOS and can do routing protocols, including BGP, OSPF, >etc. It can forward packets at high speeds based on Layer 3 info or Layer 2 >info. It's a router on steroids, whereas a Cat 5000 or 6000 with MLS is a >switch that has been told how to forward packets that normally a router >would handle. > >Which method is better? Neither one, though they have their pluses and >minues. A true point. When I have designed complex networks, on a case-by-case basis, I might find that one or another method was best for the specific circumstances. I am not convinced that another method wouldn't have been "good enough." >Really, you just have to realize that all these options came out >during the dot com craze when Cisco had thousands and thousands of employees >all working to solve the same problem, gobs of money to buy companies with >products that all sovled the same problem, etc. So in true Cisco style, you >can accomplish the exact same thing (fast forwarding of packets) in a bunch >of different ways. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=65910&t=65832 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
