[PATCH 13/19] P2PS: add p2ps_supported_cpt configuration property

Stepanov, Max Max.Stepanov
Tue Jun 16 09:15:39 PDT 2015

On Tue, June 16, 2015 at 17:10, Jouni Malinen wrote:
>This would make the priority list global to the P2P Device, i.e., this would apply
>to all services. Would that really cover the cases where multiple services are
>available? I would expect that different services could have different
>preferences for CPT especially since the current designs would likely only
>support the UDP option while some newer services may end up expecting the
>MAC option to be used.
>Should this be done as a per-service (P2P_SERVICE_ADD,
>P2P_ASP_PROVISION_RESP, P2P_ASP_PROVISION) parameter instead of an
>extension to the global P2P_SET?

Good question. According to WFDS spec: " The ASP on a device communicates with the ASP on a peer device to manage ASP sessions between the two devices".
E.g. in general the supported session coordination protocol relates to a single ASP service, not to services.

By default only UDP transport is enabled, and setting of p2ps_supported_cpt is needed only for new services that may require MAC. Also ASP service may decide which ASP coordination protocol transport to use for a specific service. Both P2P_ASP_PROVISION and P2P_ASP_PROVISION_RESP commands allow ASP to specify 'feature_cap' parameter and explicitly set CPT value of a provision discovery request frame. On the other hand the CPT values of p2ps_supported_cpt are used mainly for provision discovery request verification and CPT value selection returned in a provision discovery response frame.

So, it looks like reasonable to have a set of the supported CPTs as a global ASP related P2P property.


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