SD-WAN can use transport media that lack the same geographic restrictions as MPLS and can be deployed more quickly and cheaply. This enables expensive, high-performance bandwidth (like MPLS links) to be reserved for application traffic that requires these features, while less important traffic (like web browsing) is routed over less expensive links.īy decreasing an organization’s dependence on MPLS circuits, SD-WAN not only decreases costs but also improves network flexibility. SD-WAN appliances aggregate various transport media (broadband, MPLS, mobile networks, etc.) and select routes based upon application-specific policies. Rather than relying on dedicated links, SD-WAN works by optimizing the use of available transport media. However, these benefits come at a significant cost and force organizations to accept the limitations of MPLS.Īs these MPLS drawbacks begin to hinder the achievement of business goals, Software-defined WAN (SD-WAN) is an MPLS alternative that allows organizations to more cheaply and easily create a flexible, high-performance, and reliable corporate WAN. MPLS is designed to implement a high-performance, reliable WAN. While MPLS links are not encrypted, they are partitioned from the rest of the Internet, providing security similar to a virtual private network ( VPN). However, it does have some security benefits as well. The primary goal of MPLS is to improve the performance and reliability of network traffic. These paths are unidirectional, and return traffic is sent over its own LSP. The FEC defines routing criteria that are used to create a predetermined path to route traffic through the MPLS network, which is called a label-switched path (LSP). A 1-bit bottom of the stack field that, when set, indicates the packet has reached the end of the MPLS network.īy encapsulating data, MPLS separates forwarding mechanisms that can be used to create forwarding tables for any underlying protocol.A 3-bit field originally named Experimental that today is used for QoS priority and ECN (Explicit Congestion Notification).A 20-bit label that determines where the packet is to be forwarded.The MPLS header or label stack contains 4 fields: This assigns a forwarding equivalence class (FEC), indicated by appending a short bit sequence (the label) to the packet. 2005, IETF.When traffic enters the MPLS network, an ingress MPLS router will add an MPLS header to it. Lang, "Link Management Protocol (LMP)", RFC 4204, Oct. Rekhter, "OSPF Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)", RFC 4203, Oct. Yeung, "Traffic Engineering (TE) Extensions to OSPF Version 2 Architecture", RFC 3630, Sep. Berger, "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource Reservation Protocol-Traffic Engineering (RSVP-TE) Extensions", RFC 3473, Jan. Swallow, "RSVP-TE: Extensions to RSVP for LSP tunnels", RFC 3209, Dic. Journal of Optical Communications and Networking. "Modeling WDM wavelength switching systems for use in GMPLS and automated path computation". Multiple Types of Switching and Forwarding Hierarchies" Mannie, "Generalized Multi-Protocol Label Switching (GMPLS) architecture", RFC 3945, Oct. Automatic switched-transport network (ASTN).Wavelength switched optical network (WSON).Open Shortest Path First with Traffic Engineering extensions ( OSPF-TE) routing protocol.Resource Reservation Protocol with Traffic Engineering extensions ( RSVP-TE) signaling protocol.GMPLS is composed of three main protocols: The Generalized Label can also carry a label that represents a generic MPLS label, a Frame Relay label, or an ATM label. The Generalized Label is a label that can represent either (a) a single fiber in a bundle, (b) a single waveband within fiber, (c) a single wavelength within a waveband (or fiber), or (d) a set of time-slots within a wavelength (or fiber). These changes and additions impact basic label-switched path (LSP) properties: how labels are requested and communicated, the unidirectional nature of LSPs, how errors are propagated, and information provided for synchronizing the ingress and egress LSRs. The support for the additional types of switching has driven GMPLS to extend certain base functions of traditional MPLS and, in some cases, to add functionality.
For instance, GMPLS is the de facto control plane of wavelength switched optical network (WSON). Generalized MPLS differs from traditional MPLS in that it extends support to multiple types of switching such as TDM, wavelength and fiber (port) switching. Generalized Multi-Protocol Label Switching ( GMPLS) is a protocol suite extending MPLS to manage further classes of interfaces and switching technologies other than packet interfaces and switching, such as time-division multiplexing, layer-2 switching, wavelength switching and fiber-switching.ĭifferences between MPLS and GMPLS
0 kommentar(er)
