ForCES Library Draft

Joel M. Halpern

joel@stevecrocker.com

Purpose

• To build a ForCES implementation that does anything, we need a set of LFB Class definitions

• There will be multiple documents that provide these

• This is intended to provide a good starting point

Structure

• I have grouped the Classes into sections– Groupings are fairly arbitrary

• Connectivity LFBs

• Packet Valdiation & Manipulation LFBs

• Classifier LFBs

• Packet Control LFBs

• Queue & Scheduler LFBs

Connectivity LFBs

• These LFBs represent the connectivity (very generally) to the external world.

• This includes provision for stacking connectivity (PPP stacked on Serial Line, Frame Relay, or Ethernet)

• Redirect LFB for FE-CE redirect packets

• Tagged Data is envisioned for backplanes that can carry meta-data.

Packet Valdiation & Manipulation

• Validators, trimmers, markers, and updaters

• Separates validation from classification– Some implementations will not want to

validate packets being forwarded

• Updaters possibly should be folded into next hop selection LFBs

Classifier LFBs

• Cover the different kinds of classifiers• Currently, one that considers incoming

LFB port, and matches field contents from meta-data and packet contents

• Separate LPM classifier– Trying to fold LPM into the general classifer

structure hurt my head

• Should we have different classifiers?– One that used metadata, one for packet fields

Packet Control LFBs

• A catch all for odd functions

• These may be better dealt with by the CE for the first release

• They may exercise some useful features

• ICMP, ARP related functions

Queue & Scheduler LFBs

• Need to store and send packets

• Separating queue and scheduler has been found useful in other models

• Need to model the relationship

• Rather awkward approach. Suggestions would be appreciated.