Multiprotocol Label Switching (MPLS )
MPLS or short for Multiprotocol Label Switching, an IETF initiative that integrates Layer 2 information about network links (bandwidth, latency, utilization) into Layer 3 (IP) within a particular autonomous system–or ISP–in order to simplify and improve IP-packet exchange. It is a mechanism in high-performance telecommunications networks that directs data from one network node to the next based on short path labels rather than long network addresses, avoiding complex lookups in a routing table. The labels identify virtual links (paths) between distant nodes rather than endpoints. MPLS can encapsulate packets of various network protocols. MPLS supports a range of access technologies, including T1/E1, ATM, Frame Relay, and DSL.
MPLS works by prefixing packets with an MPLS header, containing one or more labels. This is called a label stack. Each label stack entry contains four fields:
- A 20-bit label value. A label with the value of 1 represents the router alert label.
- A 3-bit Traffic Class field for QoS (quality of service) priority (experimental) and ECN (Explicit Congestion Notification).
- A 1-bit bottom of stack flag. If this is set, it signifies that the current label is the last in the stack.
- An 8-bit TTL (time to live) field.
Cisco IOS Multiprotocol Label Switching (MPLS) enables Enterprises and Service Providers to build next-generation intelligent networks that deliver a wide variety of advanced, value-added services over a single infrastructure. This economical solution can be integrated seamlessly over any existing infrastructure, such as IP, Frame Relay, ATM, or Ethernet. Subscribers with differing access links can be aggregated on an MPLS edge without changing their current environments, as MPLS is independent of access technologies.
Cisco IOS MPLS delivers highly scalable, differentiated, end-to-end IP services with simple configuration, management, and provisioning for providers and subscribers. A wide range of platforms support this solution, which is essential for both Service Provider and Enterprise networks.
The Benefits of MPLS Networks:
- Improve Uptime
- Create Scalable IP VPNs
- Improve User Experience
- Improve Bandwidth Utilisation
- Hide Network Complexity
- Reduce Network Congestion
MPLS is particularly well suited for use in Carrier Networks and corporate Wide Area Networks. Multi-Protocol Label Switching is particularly useful for situations where…
- Multiple types of traffic share a data connection, with some types of traffic requiring priority over others
- Uptime is important, key locations have multiple connections so that alternative paths always exist
- Network congestion occurs sometimes on some connections
- New sites will need to be able to connect to many different locations, while being entirely invisible to many other sites on the network.
- It’s also very popular with organizations that need a scalable WAN that can carry both voice (phone calls) and data.