Designing OSS to cope with greater transience (part 2)

This is the second episode discussing the significant change to OSS thinking caused by modern network models. Yesterday’s post discussed how there has been a paradigm shift from static networks (think PDH) to dynamic / transient networks (think SDN/NFV) and that OSS are faced with a similar paradigm shift in how they manage modern network models.

We can either come up with adaptive / algorithmic mechanisms to deal with that transience, or mimic the “nailed-up” concepts of the past.

Let’s take Carrier Ethernet as a basis for explanation, with its E-LAN service model [We could similarly analyse E-Line and E-Tree service models, but maybe another day].

An E-Line is a point-to-point service between an A-end UNI (User-Network Interface) and a Z-end UNI, connected by an EVC (Ethernet Virtual Connection). The EVC is a conceptual pipe that is carried across a service provider’s network – a pipe that can actually span multiple network assets / links.

In our OSS, we can apply either:

1. Abstract Model – Just mimic the EVC as a point-to-point connection between the two UNIs
2. Specific Model – Attempt to tie network assets / links associated with the conceptual pipe to the EVC construct

The abstract OSS can be set up just once and delegate the responsibility of real-time switching / transience within the EVC to network controllers / EMS. This is the simpler model, but doesn’t add as much value to assurance use-cases in particular.

The specific OSS must either have the algorithms / policies to dynamically manage the EVC or to dynamically associate assets to the EVC. This is obviously much more sophisticated, but provides operators with a more real-time view of network utilisation and health.