RFC 1672 (rfc1672) - Page 2 of 3

Accounting Requirements for IPng

RFC 1672            Accounting Requirements for IPng         August 1994


   responsible, i.e., willing to pay for, a packet. It would initially
   be set by the host which originates the packet, hence at that stage
   the tag would identify the user who sent it.

   A tag could be changed at various points along a packet's path. This
   could be done as part of the routing policy processing so as to
   reflect changes of the party responsible over each section of the
   path. For example:

        user - provider           tag identifies user
        provider A - provider B   tag identifies provider A

   The tag could be used by accounting meters to identify the party
   responsible for a traffic flow, without having to deduce this using
   tables of rules. This should considerably simplify accounting for
   transit traffic across intermediate networks.

Higher-layer (Session and Application) Accounting

   At higher layers there is a clear need to measure accounting
   variables and communicate them to various points along a packet's
   path, for example an application server may wish to inform a client
   about its usage of resources. A tag containing this information could
   be read by meters at any point along the packet's path for charging
   purposes, and could also be used by the client to inform the user of
   charges incurred.

   It would make the collection of accounting data much simpler if this
   information was carried in a standard tag within each packet, rather
   than having different protocols provide this service in differing
   ways.

   For 'old' applications which remain unaware of the tag field, a meter
   could be placed at a gateway for the application's host. This
   'gateway' meter could determine what the application is by watching
   its streams of packets, then set an appropriate value in thir tag
   fields.

Structure of the accounting tag

   The two uses of tags outlined above must be able to coexist. Since
   many - indeed most - of the packets will only carry a voucher, it
   seems simplest to keep this as part of the routing tuple (see below).

   For the application variables, a separate tag seems sensible. This
   would simply contain a list of the variables.  Having two tags in
   this way would keep separate the management of routers and meters.




Brownlee