Providerbased accounting

1
Provider-based accounting

• Szabolcs Boros Minh van Le
• Aiko Pras Róbert Párhonyi
• 23-11-2000
• ING WU5 meeting, Enschede

2
Overview of the architecture
5. forwarding authorisation
Server ISP
Client ISP
4. config
8. content
auths
6. config
auths
Server Access Router
Client Access Router
7. notification
3. auth
2. authorisation request
1. http request
Client
Server
RC content
RC agent
RC agent
3

Acc-AuthApplication
Browser
4
Server - Agent

• Structure
• webserver
• Java servlets (probably use of Secure HTTP)
• Remark
• possibility to attach a message authorisation
  code in the response (step 2) and after the
  notification (step 7) to verify this code and use
  a detection mechanism.

5
Client - Agent

• Alternatives for structure
• Java applet
• digital signature, operate outside the sand-box
  (sending messages to other addresses), is
  specific to content provider
• MIME type - plug-in
• from trusted site, are there security limits?,
  install once and use often
• lower layer protocol under browser
• difficult to install, can do everything,
  difficult to implement under transport service,
  runs outside web environment
• application layer protocol
• easier to install than lower l.p., can do
  everything, runs outside web environment
  startup automatic or explicit? what kind of
  protocol to use for communication?
• CORBA too difficult

6
Accounting-Authorisation Device

• Structure (is separated from the Access Servers)
• Database management system storage of
  authorisations
• Accounting system
• Manager/configuration system for Access Routers
• Authorisation forwarding mechanism
• Questions
• How to store the authorisations?
• How to configure the Access Router? Are the
  packets marked somehow? Is this necessary?
• What contains the message sent to the Acc-Auth.
  Device at Servers side? Will this include a
  trusted signature (issued by the TTP) of the
  Client ISP?

7
A detailed view of the architecture
1. Get content
Client-side browser
Java Web Server
ConnectionSetupServlet
4. X-MIME params.
2
3
5. Start player application
Transmission service 1
Transmission service 2
9. CONTENT
8. Event dispatch
Port listener Dispatcher service
Auth. msg fwd.
6. ACK control msg.
7. ACK control msg.
8
Current implementation
4. Reaction
Transmission service
3. Generating and dispatching event from the
message
Port listener Dispatcher service
1. ACK, play, stop, pause
Message forwarding service
2. Forwarded message
9
Implementation of the Server-side (1)

• Occupying the necessary ports (2 or 4) for the
  transmission.
• Starts the transmission when requested. It can
  also pause or stop it (TransmissionService).
• When starting the service a listener-service will
  be started for a specific port number. To this
  port will arrive the forwarded messages from the
  clients. The job of this process is to read the
  content of the messages, construct events using
  the information of a message and broadcast the
  event to the running threads of the
  TransmissionService.
• TransmissionService has a listener to be able to
  receive the ACK or other events coming from
  client-side.
• Process the client-side ACK messages and runs a
  timeout mechanism to pause/stop the transmission
  when the ACK messages are late or do not arrive
  at all.

10
Implementation of the Server-side (2)

• Current restrictions
• Uses pre-set port numbers. Thus can serve only
  one client.
• Instability OutOfMemory Exception
• Future tasks
• Implement the destruction of this thread when ACK
  messages have a big delay.
• Synchronization of the acknowledged time and
  media length.
• Should be started by servlet.
• Find out the supported media types. At this
  moment not every mpeg version is supported.

11
Implementation of the Client-side

• Includes a player for the media and a control
  window to be able to control the transmission at
  this side.
• The controls are start, pause, stop.
• It sends automatically every 5 seconds an ACK
  message during playing the media.
• Each message are sent to the forwarding service.
• Current problems
• Image and sound in two different windows.
• Recognizes the video track just every second
  start.
• Timer display control.
• Future tasks
• Design a better interface.
• Possibility to set manually the settings of the
  message forwarder.

12
Implementation of the Message forwarding service

• It is a process that has a listener for a
  specific port-number on the local machine.
• To this port are sent the messages from the
  client.
• Its task is to forward to the server the
  incoming messages.
• Further task
• To store locally the data for accounting from the
  message before forwarding it.

13
Open questions and issues

• Including the ConnectionSetup servlet at the
  server-side.
• Content of messages between the different
  entities. Protocol definition.
• Occupying ports dynamically each entity.
• Extending the capability of the
  TransmissionService to be able to serve more
  clients.
• Having one single window on client-side to play
  both image and sound.
• Start the client-side player automatically from
  browser. Include MIME-type.
• Enable HTTP communication between browser and
  servlet.