Subject: [nsc] NLFC: Use Cases

From: <[email-masked]>
Date: Thu, 20 Jun 2013 13:28:09 +0200

Dear all,

It would be useful if we all share the use cases that motivate our interest on this work.

The effort documented in http://tools.ietf.org/html/draft-boucadair-network-function-chaining-00 is mainly motivated by the current work we are investigating to rationalize the Gi interface (mobile context) in the hope to simply the complexity encountered in current deployments. Indeed,
* Plenty of functions are enabled in that segment
* Lack of visibility on dependency between these functions
* Complexity to introduce new function because of the constraint on underlying topology
* Lack of automated means to assess the impact of withdrawing a function from the path
* The connectivity service logic may be frozen because of the dependency on the physical topology

Because we are aware these issues are not specific to our mobile use case, we tried to generalize the motivations space as follows:

   o  Efficiently master the chained activation of network-located
      functions, regardless of the underlying network topology and
      routing policies.
   o  Allow for differentiated packet forwarding by selecting the set of
      network-located functions to be invoked.
   o  Allow to easily change the chronology of the activation of
      network-located functions to be invoked.
   o  Allow to easily change the set of network-located functions to be
      invoked.
   o  Ease withdrawal of network-located functions and minimize any
      subsequent topology upgrade.
   o  Automate the overall process of generating and enforcing policies
      to accommodate a set of network connectivity objectives.

Cheers,
Med