The mindmap always evolving and we will continue to add content.
Multi Protocol Label Switching. The MPLS protocol defines a process by which core network providers traffic engineer their infrastructure based on optimal use of packet forwarding paths and routing. At a high level, label switching allows routers (via the packet header data) to make routing decisions quickly by examining the packets header label rather than performing an entire lookup of the routing table which adds delay. Each packet is forwarded to a pre-determined LSP - Label Switched Path (know and LSPs). Alternative LSPs are made available for traffic packet routing forwarding in the event packets cannot reach the designated route.
Labels are assigned to the header (using Cisco routers as an example) by use of the LDP protocol (Label Distribution Protocol) which enables LSR (Label Switched Routers) to actually exchange the labels information when sending packets on a hop by hop basis. Without an LDP protocol, there would be no means of releasing a labels important information to other routers within the network. The protocol allows discovery of other peer routers together with the ability to exchange a labels information. Ultimately, the LDP really is the building blocks for MPLS service routing and VPNs.
Managed MPLS services are inherently secure due when talking about private VPN services. Each provider customer VPN is secured by use of separated routing tables (VRF - Virtual Router Forwarding table). As label switching occurs, traffic is only sent into a particular clients VPN.
VPLS offers the capability to extend LAN capability across geographical distance. When organisations operate protocols which are not supported by layer 3 VPN services, a layer 2 VPLS product will allow an organisation to control layer 3 protocols and their distribution. We have written several articles on VPLS, at a high level and company with a requirement to simplify their network into LAN segments should consider products. There are numerous reasons why this might a requirement.
Interested in learning more?
Packet - A Cisco article on packet switching
Legacy services - ATM (Asynchronous Transfer Mode) and Frame Relay. ATM was one of the first WAN services to introduce the concept of QoS (Quality of Service) by use of VRBr, ABR which aligns to current CoS (Class of Service) policies found in MPLS and VPLS networks today.
Multiprotocol LSPs - An article on packet forwarding / switching across label switched paths.
Multiprotocol PE - Provider Edge routers - LSPs are run between PE to PE devices.
CE - Customer Edge routers - The customer edge CE routers do not run MPLS. The LSPs are operated across traffic between PE to PE routers.
Routing - A cisco article, a routing handbook.
Internet IPSec VPNs - Cisco article on IPSec
VPN Switching - An overview of switching from Cisco vs layer 3 routing.
Layer 2 VPNs - More detail on layer 2 of the OSI model
Layer 3 VPNs - More detail on layer 3 of the OSI model
GMPLS - GMPLS (General MPLS)
Packet header - an article explaining packet headers.
RSVP - The resource reservation protocol forms a key component of MPLS.
CoS / QoS across circuits - Real time, mission critical and best effort.
MSP - Managed Services Provider