Shift metro networks into high gear

Keep pace with increasing traffic growth and facilitate the move to cloud services

There was a time when we could safely say that almost all traffic entering a metro network would cross the backbone network en route to an end user site, the Internet or a content source within a service provider’s network. Today, there’s a remarkable shift underway. Growth in video and cloud-based services models is changing the paradigm – and now we have the data to prove it.

We asked Bell Labs to delve into these changing dynamics within metro networks. It wasn’t just to confirm what we already suspected about video and cloud traffic. Instead, the goal of the study “Metro Network Traffic Growth: An Architecture Impact Study“ (PDF) was to understand the impact this will have on a service provider’s network architecture. We used a reference architecture representative of a converged services operator offering residential (Internet, IPTV, VoD), mobile and business/cloud services.

As a service provider who needs to keep pace with increasing traffic growth while supporting emerging cloud service models, you’re probably wondering how these changing trends will impact the metro network. Let me walk you through some of the key findings and their impact on the evolution of metro networks.

(Source: "Bell Labs metro traffic growth: An architecture impact" study)

Implications for Metro Architecture

Finding: Total metro traffic will increase 560% and grow almost 2 times faster than backbone traffic by 2017. Service providers will constantly need to stay ahead of the bandwidth curve. Legacy transport systems are being migrated to next generation packet optimized optical transport systems and IP/MPLS routers are being upgraded. Both are being optimized to support higher speed interfaces (10G/40G and 100G) at scale.Finding: IP video driven by ultra-broadband access (high speed fixed and wireless broadband) is a key contributor to the increase in total metro traffic. The study revealed that video traffic will increase 720% by 2017. Implementing Content Delivery Networks (CDNs) is no longer an exception and instead is becoming the norm with more and more content being cached closer to the end user and within the metro network.Finding: By 2017, 75% of total metro traffic will be terminated within the metro network compared to 57% in 2012. This is due to the increased concentration of traffic sources (data center and video caching) within the metro network. The increased concentration of traffic sources combined with a growing number of ultra-broadband fixed and wireless access nodes (fiber, copper, EPON, 4G LTE and small cells) is resulting in a very large number of end points within the metro network. These endpoints need to be efficiently provisioned and managed across the IP and Optical layers of the metro network. Manual configuration processes, which are error prone and negatively impact OPEX, must be replaced with automated provisioning models.Finding: Cloud and data center (DC) traffic is another key contributor to total metro traffic and forecasted to increase 440% by 2017. Cloud and DC service will have a significant impact on the metro network going forward. Enterprises and data center providers connect their data centers and end users using IP and Carrier Ethernet services from a Service Provider’s (SPs). The Enterprise or Data Center Provider will need to extend the rule sets enforced within their infrastructures into the SPs WAN infrastructure. The SP’s infrastructure, in turn, must support mechanisms for end users to request and program unique network, security or privacy policies and instantiate rapid on-demand network connectivity based on these policy definitions. Examples of policy may be a requirement that specifies one or more of the following:

Network characteristics (bandwidth, QOS, latency, jitter)

Privacy characteristics (primary or rerouted connection stays within a particular region to be compliant with corporate or government laws)

Security characteristics (firewall, intrusion detection, load balancing)

With today’s connectivity services, the framework for defining policies either does not exist or is very complex and cumbersome to implement. Policy and service provisioning is handled with complex IT/OSS systems and, with manual provisioning processes which may take a very long time for service instantiation.

SDN-enabled cloud-optimized network

Software defined networking (SDN) principles are successfully being applied within data center (DC) networks to make intra-DC connectivity instantaneous and boundary-less. The metro network needs to evolve and inherit attributes of existing data center networks where network connections are initiated in seconds or minutes compared to hours or days in most metro/wide area networks today. The data center model can be extended to the metro/wide area network to allow cloud services and applications – like Network Functions Virtualization (NFV) – to consume network connections as quickly and as easily as they consume virtualized compute, storage and network resources within data centers. This will require existing networking equipment (IP and Optical domains) as well as network and service management solutions to be augmented to support these evolving cloud requirements (on-demand, policy driven and rapidly instantiated). The path to multi-layer SDN in the metro/WAN can therefore be viewed as an evolution and not a revolution, since SPs will prefer to leverage and evolve their existing assets to support cloud services delivery.

Move to cloud-optimized metro architecture

The study shows very clearly that big change is coming to the metro. To prepare, service providers should consider a cloud-optimized architecture which will deliver the agility, scale and efficiency to survive and thrive with this change.

Read more about the benefits of cloud-optimized metro network.