MPLS and GMPLS
Since its introduction in the late 1990s, Multi-Protocol Label Switching (MPLS) has evolved
into a hugely successful and flexible networking technology.
In its original RFC 3031 guise, the fundamental MPLS concept was to switch packets based upon
looking up a label in the packet header. This label is swapped with a different label suitable
for the next hop towards the packet's destination. In this form it has been widely deployed on
routers and switches, under the IP/MPLS moniker.
Subsequently, Generalized MPLS (GMPLS) expanded the concept of a label to include implicit
attributes of the flow, such as wavelength or timeslot. This led to the adoption of GMPLS for
circuit as well as packet switching, and it is widely deployed in such roles today.
MPLS and GMPLS naturally allow layering through the process of label stacking. This leads to
outer labels being used for transport functions and inner labels to define the service.
Thus, the real power of MPLS and GMPLS is the ability to layer any service over any transport,
and to combine multiple services over a common transport, while providing appropriate QoS
for each service.
MPLS transport provides options for traffic engineering, guaranteed QoS, and fast protection
and restoration. It can be used for a variety of technologies including
- Packet transport, including the new MPLS Transport Profile (MPLS-TP) that brings
the QoS and OAM capabilities usually associated with optical transport to
less expensive packet based equipment
- TDM and WDM transport; this includes the next-generation transports of the Optical
Transport Network (OTN), where circuit and packet traffic can be carried efficiently on
the same device.
For more information, see MPLS Transport and
MPLS services include
- Packet IP traffic, including Layer 3 VPNs (a very popular carrier offering)
- Packet Layer 2 traffic (for example the booming Carrier Ethernet market)
- Pseudowires that can carry packet or circuit traffic (which is proving vital for mobile backhaul).
For more information, see MPLS Services.
Whilst the underlying MPLS and GMPLS switching operations typically make use of dedicated
switching hardware, a control plane is used to program this hardware and to perform a wide
range of functions. The Metaswitch control plane is the most widely deployed and most flexible
control plane available.
For more information, see Metaswitch's
Integrated Control Plane and
MPLS and GMPLS Products.
For inquiries about Metaswitch's
MPLS products and expertise contact