Time to Rethink the Metro Network Refresh?
Over the last few years, we have seen a major change in telecom services and the way that these services are being used. This has been driven by three main factors:
1. Ubiquity of IP
IP is the common technology for all services and applications. This ubiquity has meant an explosion in the number of services and applications that are available, with applications being able to easily build of one another. However, it also enables OTT players an easy mechanism to deliver their services over the “standardized” IP network.
A vast number of services and applications have been enriched by including a streamed video component. The need for video drives up capacity, but it also places strict requirements on the network in terms of latency and jitter
3. Cloudification of services
Many services are being moved from client based software to cloud hosted services, with little or no service software on the client machines. We also see many new cloud based services like Amazon Web Services, Facebook, youtube etc. The service provider must provide high capacity, always-up connectivity to support these services.
Telecom networks have evolved to support these new services and consumption models. For example, we have seen core networks move from 10G to 100G and access networks are being continuously refreshed to deliver higher and higher capacities. However, up till now, apart from a move to support increased packet capabilities, metro networks have remained relatively stable and 10G still remains the currency of choice across ring or hub’n’spoke architectures.
We have now reached a point where 10G connectivity is just not cost effective enough to support the amount of cloud and video enabled services that are being demanded. There is an urgent need to move to 100G at the metro edge, with metro architectures supporting the connectivity of multiple 100Gs. Perhaps similar to the point reached by core networks a few years ago, however metro networks are far larger and more complicated than core networks, so any refresh must consider:
- Multiservice and Network consolidation
Any refresh should support network consolidation by supporting the seamless transition of all existing services from the old delivery platforms onto a new integrated IP network. This should allow old product platforms to be retired whilst maintaining support for the services delivered by them. Case in point, some high value customers still like their low-rate TDM services due to their low latency, so the new platform should provide support for these services either natively or by circuit emulation
- Scalability and Flexibility
4K video, augmented reality, big data, IoT and CORD (central office as a re-architected datacenter) are all just around the corner. Any refresh should make it possible to easily scale the metro network to support the increased capacity and connectivity associated with these new services. A little further out we have 5G, the refreshed metro network must provide the flexibility required to support the network slicing that is a fundamental part of the proposed 5G proposals.
- Cost Optimization
The metro network has a huge number of network elements, at least an order of magnitude bigger than the associated core networks, so it is essential to optimize the network elements and network architectures for cost, size and power. This means using the right technology at the right points in the network. In the past, there was discussion about taking full IP switching and routing to the Metro edge and even beyond. However it is now understood that for a cost optimized network it makes sense to perform packet aggregation at the Metro edge rather than full blown switching and routing.
The number of nodes associated with the Metro network means that the management system must offer operational simplification. The management system must make it straightforward and intuitive to provision new services and advanced tools should be provided to identify failures and outages and quickly provide service restoration
- Future Proof
The ultimate aim is to move the network to SDN, any metro refresh should provide an evolution path towards SDN.
Given the rapid evolution of services, service providers cannot afford to wait for SDN, they need to refresh their metro networks now. However this refresh should act as stepping stone to SDN, by providing a cost optimized, multiservice IP platform able to support existing and new services while remaining agile enough to support the new consumption models that SDN will introduce.