GMPLS Control Plane for MPLS-TP
Transport networks have traditionally been built using Time Division Multiplexed (TDM)
SONET/SDH devices. These have been effective in networks that primarily carry circuit-oriented
traffic, possibly with some packet overlay, but are becoming ineffective and costly in today's
increasingly packet-oriented world.
Packet traffic is exploding exponentially. (According to Cisco , bandwidth
demand will exceed 15 exabytes per month by 2011 and pass 30 exabytes per month by 2013.)
And the traffic mix has shifted from circuit-centric voice to packet-centric applications
such as video, broadcast TV, games, social networking and of course packet voice
(VoIP). Carrying mostly packet traffic over a circuit transport
is not always most efficient.
Similarly, transport device economics have shifted sharply. SONET/SDH equipment has
historically led the way with throughput, but fast packet technology, specifically Ethernet,
now equals or leads SONET/SDH in the capacity race, and moreover can provide this capacity
at a much lower cost. For example, 100GbE looks very attractive compared to 40Gb SONET/SDH.
Given the above drivers of efficiency and cost, service providers are eager
to transition their transport architectures from SONET/SDH to packet.
However, packet technology has not thus far been able to offer the resilience and manageability
of SONET/SDH. This is where MPLS Transport Profile (MPLS-TP) fits in, providing the same QoS,
protection and restoration, and OAM inherent in SONET/SDH, and in a way that has
a familiar look and feel for network operators.
In these evolving packet transport networks, MPLS-TP is the
transport protocol of choice. Work on the technology began in the ITU under the name T-MPLS.
Responsibility now rests with the IETF, and the name has changed to MPLS-TP. It uses the
Generalized MPLS (GMPLS) paradigm to provide deterministic and connection oriented behavior –
making it a more dependable transport protocol. For example, MPLS-TP restricts LSPs to be
bidirectional and co-routed (meaning both directions follow the same path), and removes
complex functions such as LSP Merge and Equal Cost MultiPath (ECMP). Furthermore, MPLS-TP
provides comparable QoS, protection and restoration, and OAM to traditional SONET/SDH
and WDM/DWDM transport networks.
MPLS-TP can operate in two modes – static provisioning of each network element and
dynamic provisioning with a GMPLS control plane. It is anticipated that both modes will
be deployed, depending on network type (core, aggregation, access etc.) and carrier preference.
Equipment vendors will likely offer both options to gain the broadest market.
Using MPLS-TP enables equipment manufacturers to deliver next-generation packet transport
equipment, and because of their cost advantages, such equipment has wider applicability than
the core. With MPLS-TP, service providers can extend the "MPLS edge" to metro and
access networks, and to mobile backhaul – providing a single end-to-end MPLS-TP transport network.
Metaswitch has vast experience
in supplying network software products to communications equipment manufacturers,
helping them build access, aggregation and transport devices.
We are far and away the leaders in portable (G)MPLS solutions and are closely involved in
the MPLS-TP standards process. Our DC-MPLS GMPLS implementation already supports
the necessary features to build a device with an MPLS-TP capable control plane,
and we are adding further enhancements to meet the newest MPLS-TP standards.
This allows our customers to deliver MPLS-TP capable devices at the earliest opportunity.
Features and Benefits
The Metaswitch solution for manufacturers of packet transport devices offers the following
features and benefits.
- Portable, scalable implementations of the MPLS and
IP Routing standards – easily ported
to packet transport devices
- Pre-standard MPLS-TP
technology already supplied and deployed
- Built-in high availability and
in-service software upgrades – ensuring device resilience
- Full protection switching and fast restoration – ensuring network resilience
- Engineering of the very highest quality.
The Metaswitch solution for manufacturers of packet transport devices is based on the following
- MPLS-TP extensions to DC-MPLS (DC-RSVP and DC-LDP),
Metaswitch's widely deployed MPLS signaling products
- DC-MPLS protocol support for (amongst others) multi-segment pseudowire, end-to-end
protection switching and fast restoration
- DC-OAM BFD functionality for monitoring MPLS-TP LSPs and/or PWs
- High Availability Framework (HAF),
Metaswitch's architecture for delivering fault tolerance and reduced downtime
across its range of network software products
- N-BASE, Metaswitch's portable operating environment
for network software products
- Metaswitch professional services, training, and support directly from the
Metaswitch engineering organization.
 "Global Consumer Internet Traffic Forecast",
Cisco, October 2009