SLAPP Dan Harkins Partha Narasimhan Subbu Ponnuswarmy

Why CAPWAP? To allow for interoperability between an AC from one vendor and a WTP from another Because there’s a belief that WTPs will become inexpensive, commodity-priced devices and economics will require something like CAPWAP.

Dynamic WLAN Market New technologies being developed as we sit here –802.11r –802.11k Lots of vendor innovation in things like rogue detection, IDS, location services, PMK caching for fast handoffs between WTPs All the innovation is being done in the WLAN switch market, exactly what CAPWAP is addressing

Standards are fun but… Standards are appropriate when the vast majority of the problem space is solvable and the technology is not very fluid. Final part of problem is solved with “vendor extensions” Standardizing on one approach to a snapshot in time of a dynamic environment would stifle innovation and lock everyone into a less-than- ideal common denominator of reduced functionality. The amount of “vendor extensions” would grow as the technology expands and the utility of the standard decreases

Standards are fun but… A control and data tunneling protocol is a good idea but one is pretty much the same as the other– a single approach to a snapshot in time of a dynamic environment. pah-tay-to, poh-tah-to Something else is needed to ensure that innovation and product differentiation is still possible going forward.

SLAPP Negotiable control protocol –One is defined for in the draft but you could easily define a new magic number to be LWAPP’s control and tunneling protocol, or CTP’s control and tunneling protocol, or an control protocol, or…. –Image download feature to provide a bootable image in which a control and tunneling protocol is embedded (could be LWAPP’s, could be CTP’s, could be something proprietary) Image download enables continued innovation in a dynamic technology like

To download an image or not to download an image, that is the question Imagine k is finalized and becomes part of the base standard. What happens if we don’t have image download? –Reconvene the WG to define new standard features for CAPWAP. The WG that never dies!!! –Define vendor specific extensions A vendor that does both AC and WTP makes a proprietary version of “the standard”. Wow! Otherwise vendors must agree on some vendor-specific attributes and wait for them to rev their code and notify your customers of the new matrix of what version of your’’s works with what version of their’s to get k functionality.

To download an image or not to download an image, that is the question Imagine k is finalized and becomes part of the base standard. What happens if we have image download? –If the AC vendor owns code that’s been ported to various WTPs, just do it! –If the AC vendor doesn’t own the code it contacts the WTP vendor to agree on how to extend the proprietary protocol they share. Better than the best case of the “no image download” option because image versions are stored on the AC, no interoperability matrix.

Image download is real Multiple examples exist today where a fat AP from one vendor can be given a brain transplant and turned into a thin AP and controlled by an AC from a different vendor. It requires close co-operation between the AC maker and the WTP maker, right? –To do quickly yes, but so what? Assuming WTPs become commodity priced devices their vendors will happily share the hardware characteristics necessary to port a code base to their WTP. It’s in their best interest after all. –To do less quickly no. But it’s still possible.

SLAPP Technology separation– discovery and authentication step, then media-specific control protocol step– allows SLAPP to be used for other wireless media (e.g ) Supports multiple topologies for connecting WTPs and ACs –Local MAC (bridged and tunneled) –Split MAC (L2 encryption at WTP and L2 encryption at AC)

SLAPP Uses proven technology instead of re- inventing the wheel –DTLS for data protection of entire control protocol (including image download) –GRE for user data encapsulation if SLAPP’s control protocol is used. Satisfies requirements in CAPWAP Objectives Draft

Thank You