Packet-Optical
Overview
Service providers are increasingly transitioning their network architectures to packet,
driven by attractive packet device economics and a dramatic rise in packet traffic.
(According to Cisco, bandwidth will exceed 15 exabytes per month
by 2011 and pass 30 exabytes per month by 2013 [1].)
But that transition still has to recognize the large investments made in legacy infrastructure.
The result is that real world networks contain a wide range of technologies.
The network core contains long-haul WDM/DWDM equipment and separate optical crossconnect elements
for switching. These interface with core routers that handle the IP layer.
Metro networks are populated with a mix of WDM, multiservice SONET/SDH and Ethernet equipment.
Given that diversity, service providers are deploying hybrid packet-optical devices
to facilitate an incremental migration to a scalable packet-based infrastructure
augmented by optical. (Heavy Reading expects that by 2014, core packet-optical revenue
will reach $1.66 billion worldwide [2].)
In doing so, they can reduce the number of distinct network element types – to give
very significant reductions in operating and management expenses.
For example, 86 percent of service providers expect packet-optical networks
to save operational expenditures, of which more than two-thirds expect savings of at least
11 percent to over 50 percent [3].
In these evolving packet-optical networks, the MPLS protocol plays a large role. For example
Metaswitch has vast experience in supplying MPLS and IP Routing protocol software products
to communications equipment manufacturers, enabling them to build edge, metro and
core packet-optical devices.
Features and Benefits
The Metaswitch solution for manufacturers of packet-optical devices offers the following
features and benefits.
- Portable, scalable implementations of the MPLS and IP Routing standards –
easily ported to packet-optical devices
- Rich support for pseudowires, layer 2 and layer 3 VPNs, and Traffic Engineering
- GMPLS support for SONET/SDH, WDM/DWDM and G.709 OTN
- Pre-standard MPLS-TP technology already supplied and deployed
- Both static (managed) and dynamic (signaled) LSPs
- Full protection switching and fast restoration – delivering resilience
within the network
- Built-in high availability and software upgrade – delivering resilience
within a network element
- Engineering of the very highest quality.
Solution Elements
The Metaswitch solution for manufacturers of packet-optical devices is based on the following
elements.
- DC-MPLS – including DC-RSVP
and DC-LDP
- DC-IP Routing – including one or more of
DC-BGP,
DC-OSPF,
DC-ISIS,
DC-RIP,
DC-CSPF and
DC-RTM
- DC-MPLS and DC-IP Routing protocol support for (among others)
pseudowires,
layer 2 and
layer 3 VPNs, traffic engineering,
end-to-end protection switching and fast restoration
- MPLS-TP extensions to DC-MPLS
(DC-RSVP and DC-LDP)
- DC-MPLS support for G.709 OTN
- OAM extensions, as currently being developed in the standards bodies
- Metaswitch's Integrated Control Plane,
which can be used to implement a MPLS/GMPLS and IP Routing control plane on a huge range
of network equipment
- High Availability Framework (HAF),
Metaswitch's architecture for delivering fault tolerance and reduced downtime
across the range of network protocols
- N-BASE, Metaswitch's portable operating environment
for network software products
- Metaswitch professional services,
training, and
support directly from the
Metaswitch engineering organization.
[1] "Global Consumer Internet Traffic Forecast",
Cisco, October 2009
[2] "The Core Packet-Optical Transport Evolution",
Heavy Reading, December 2009
[3] "Packet Optical Transport and 40G Represent Big Opportunity",
Infonetics Research, October 2008
[4] Note that the MPLS-TP data plane is packet oriented,
so that where MPLS-TP runs over non-packet sections of the network it utilizes an adaptation layer
(such as packet-over-WDM).