The Power of the Data-Driven Paradigm
Alan Black: As Hossein mentioned, the key to network agility is having a Database of Record foundation -- a data-driven (e.g. XML) rather than a code-driven model. Any time you want to introduce a new service in a code-dependent model, the underlying software model changes and you need to go back and redo the interfaces.
In an data-driven paradigm, however, as your network changes, everything you modeled previously continues to be supported. All you need to do is extend the XML schema to capture that modest change.
At AT&T, Hossein started with a database of record, one version of the truth. Now without that central foundation, you couldn't begin to consolidate systems because you had all those data flows going to other repositories of truth.
So it's the intersection of the Database of Record and having a data-driven, not code-driven model that gives you multiple vectors of architectural power.
Eslambolchi: If you build that abstraction layer in XML and you put it in a network element system that doesn't know the whole state of the network, it's only a partial fix.
Remember, network equipment vendors -- with all due respect -- like to sell you boxes and element management systems that connect to those boxes. But they don't know the state of the network because the service I offer as a service provider may go across 5 different boxes. But what happens when you try to do fault management, performance management, SLA management, or service delivery across these 5 boxes when the underlying database of record is inaccurate?
I'll tell you what happens: your cycle time takes months. At AT&T, PVC (Private Virtual Circuit) provisioning gobbled up lots of cycle time until we fixed the problem. If the customer already has his physical plant, and he merely wanted to upgrade from a 64 to 128 Kbit circuit, it would take us 8 days to get that done. But once we had a database of record in place, the whole thing took only 3 minutes.
The secret to gaining that power was having a solid foundation -- an accurate database of record. And frankly it's a point I think a lot of service providers really don't understand.