Reconfigure Triggered by DHCPv6 Relay Agents
draft-ietf-dhc-triggered-reconfigure-06

DHC Working Group                                           M. Boucadair
Internet-Draft                                               X. Pougnard
Intended status: Standards Track                          France Telecom
Expires: November 07, 2013                                  May 06, 2013

              Reconfigure Triggered by DHCPv6 Relay Agents
                draft-ietf-dhc-triggered-reconfigure-06

Abstract

   This document defines new DHCPv6 messages: Reconfigure-Request and
   Reconfigure-Reply.  Reconfigure-Request message is sent by a DHCPv6
   relay agent to notify a DHCPv6 server about a configuration
   information change, so that the DHCPv6 server can send a Reconfigure
   message accordingly.  Reconfigure-Reply message is used by the server
   to acknowledge the receipt of Reconfigure-Request.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on November 07, 2013.

Copyright Notice

   Copyright (c) 2013 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

Boucadair & Pougnard   Expires November 07, 2013                [Page 1]
Internet-Draft        Relay Triggered Reconfigure               May 2013

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Requirements Language . . . . . . . . . . . . . . . . . . . .   3
   3.  Problem . . . . . . . . . . . . . . . . . . . . . . . . . . .   3
   4.  Proposed Solution . . . . . . . . . . . . . . . . . . . . . .   4
   5.  Link Address Option . . . . . . . . . . . . . . . . . . . . .   6
   6.  Detailed Specification  . . . . . . . . . . . . . . . . . . .   7
     6.1.  Messages Format . . . . . . . . . . . . . . . . . . . . .   7
     6.2.  Messages Validation . . . . . . . . . . . . . . . . . . .   7
       6.2.1.  RECONFIGURE-REQUEST . . . . . . . . . . . . . . . . .   7
       6.2.2.  RECONFIGURE-REPLY . . . . . . . . . . . . . . . . . .   7
     6.3.  Creation and Transmission of RECONFIGURE-REQUEST  . . . .   7
     6.4.  Intermediate Relay Agents Behavior  . . . . . . . . . . .   9
     6.5.  Server Behavior . . . . . . . . . . . . . . . . . . . . .   9
     6.6.  Receipt of RECONFIGURE-REPLY  . . . . . . . . . . . . . .  10
   7.  Rate Limiting Considerations  . . . . . . . . . . . . . . . .  11
   8.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  11
   9.  Security Considerations . . . . . . . . . . . . . . . . . . .  11
   10. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  12
   11. References  . . . . . . . . . . . . . . . . . . . . . . . . .  12
     11.1.  Normative References . . . . . . . . . . . . . . . . . .  12
     11.2.  Informative References . . . . . . . . . . . . . . . . .  12
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  13

1.  Introduction

   This document specifies two new DHCPv6 messages [RFC3315]:
   Reconfigure-Request and Reconfigure-Reply.

   Section 3 describes a typical problem encountered to trigger the
   DHCPv6 server to issue a Reconfigure message when the configuration
   data is supplied by the relay agent.  This problem may be encountered
   in other contexts.  It is out of scope of this document to list all
   these cases.

   Section 4 describes the proposed solution which relies on the use of
   Reconfigure-Request and Reconfigure-Reply messages.  Reconfigure-

Boucadair & Pougnard   Expires November 07, 2013                [Page 2]
Internet-Draft        Relay Triggered Reconfigure               May 2013

   Request message is sent by a DHCPv6 relay agent to notify a DHCPv6
   server about a configuration information change, so that the DHCPv6
   server can send a Reconfigure message accordingly.  Reconfigure-Reply
   message is used by the server to acknowledge the receipt of
   Reconfigure-Request.

   Section 6 provides the detailed specification of the procedure to
   trigger Reconfigure messages by DHCPv6 relay agents.

2.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [RFC2119].

3.  Problem

   [RFC6422] updates the DHCPv6 specification with a new feature to let
   a DHCPv6 relay agent communicate information towards a DHCPv6 client,
   and which is not available at the DHCPv6 server.  This is achieved
   owing to the use of RSOO (Relay-Supplied Options option) which
   carries configuration data to the DHCPv6 server.  The data conveyed
   in an RSOO is then sent back by the DHCPv6 server to the requesting
   DHCPv6 client.

   An example of a RSOO context is shown in Figure 1; only a subset of
   exchanged DHCPv6 and RADIUS messages is represented.  Figure 1 shows
   a broadband network scenario in which the Network Access Server (NAS)
   embeds a DHCPv6 relay agent.

      +-------+                   +-------+                    +-------+
      |DHCPv6 |                   |  NAS  |                    |Radius |
      |Client |                   |(DHCPv6|                    |Server |
      |       |                   | Relay)|                    |       |
      +-------+                   +-------+                    +-------+
          |                           |                            |
          |---Solicit---------------->|                            |
          |                           |---Access-Request---------->|
                                      |<--Access-Accept------------|
                                      |  (e.g. DS-Lite-Tunnel-Name)|
                                    ....
                                      |                        +-------+
                                      |                        |DHCPv6 |
                                      |                        |Server |
                                      |                        |       |
                                      |                        +-------+
                                      |                            |
                                      |---Relay-Forward----------->|

Boucadair & Pougnard   Expires November 07, 2013                [Page 3]
Internet-Draft        Relay Triggered Reconfigure               May 2013

                                      |  (RSOO(OPTION_AFTR_NAME))  |
                                      |                            |
          |                           |<--Relay-Reply--------------|
          |<--Advertise---------------|  (e.g., OPTION_AFTR_NAME)  |
          |  (e.g., OPTION_AFTR_NAME) |
                                     ....

               Figure 1: An Example of the RSOO Option Usage

   The change of the configuration may result in an exchange of CoA
   (Change-of-Authorization, [RFC5176]) messages between the NAS/DHCPv6
   relay agent and Dynamic Authorization Client (DAC) server as shown in
   Figure 2.  In this example, the NAS answers with a CoA-Ack message to
   notify the DAC the CoA-Request is successfully handled.

   Note the change of the configuration in the DHCPv6 relay agent can be
   triggered by any other out-of-band mechanism.

      +-------+                   +-------+                    +-------+
      |DHCPv6 |                   |  NAS  |                    |Radius |
      |Client |                   |(DHCPv6|                    |Server/|
      |       |                   | Relay)|                    |  DAC  |
      +-------+                   +-------+                    +-------+
          |                           |                            |
                                      |<-----CoA-Request-----------|
                                      | (e.g. DS-Lite-Tunnel-Name) |
                                      |------CoA-Ack-------------->|
                                    ....

                     Figure 2: Change of configuration

   Whenever the configuration information sent by the DHCPv6 relay agent
   to the DHCPv6 server change, the DHCPv6 server has no means to detect
   the change so that it can send a Reconfigure message accordingly.  A
   solution is sketched in Section 4.

4.  Proposed Solution

   To solve the problem described in Section 3, this document proposes a
   new DHCP message called Reconfigure-Request.  In the example depicted
   in Figure 3, a Reconfigure-Request message is sent by the DHCPv6
   relay agent to a DHCPv6 server as soon as the configuration data
   conveyed in an RSOO option have changed.  Upon receipt of this
   message, and if it is configured to support such mode, the DHCPv6
   server must build Reconfigure-Reply and Reconfigure messages.
   Reconfigure-Reply is used to acknowledge the receipt of Reconfigure-
   Request.  Reconfigure message encapsulated in Relay-Reply is sent to

Boucadair & Pougnard   Expires November 07, 2013                [Page 4]
Internet-Draft        Relay Triggered Reconfigure               May 2013

   the DHCPv6 relay, which in turn will forward the message to the
   appropriate DHCPv6 client.

   This setup assumes the relay has a record of the client, so that it
   has enough information to send the Reconfigure-Request message to the
   server.  How the state is recorded in the relay is out of scope.  For
   better resilience of the proposed solution, means to recover state in
   failure events (e.g., use of stable storage, DHCPv6 Bulk Leasequery
   [RFC5460]) need to be supported.  These state recovery solutions are
   not discussed in this document.

      +-------+                   +-------+                    +-------+
      |DHCPv6 |                   |  NAS  |                    |Radius |
      |Client |                   |(DHCPv6|                    |Server/|
      |       |                   | Relay)|                    | DAC   |
      +-------+                   +-------+                    +-------+
          |                           |                            |
                                      |<-----CoA-Request-----------|
                                      | (e.g. DS-Lite-Tunnel-Name) |
                                      |                            |
                                      |------CoA-Ack-------------->|
                                    ....
                                      |                        +-------+
                                      |                        |DHCPv6 |
                                      |                        |Server |
                                      |                        |       |
                                      |                        +-------+
                                      |                            |
                                      |---Reconfigure-Request----->|
                                      |<--Reconfigure-Reply--------|
                                      |                            |
          |                           |<--Relay-Reply -------------|
          |<--Reconfigure-------------|   (Reconfigure)            |
          |                           |                            |
                                    ....

              Figure 3: Flow Example with Reconfigure-Request

   The support of Reconfigure-Reply simplifies the retransmission
   procedure of the relay as it provides an explicit indication from the
   server (see Section 6.3 for more details).  An alternative approach
   is the relay monitors Reconfigure messages received from the server
   to conclude whether Reconfigure-Request was successfully handled or
   not.  Nevertheless, this implicit approach may fail to achieve its
   goals in some cases: e.g., the server accepts the request but it
   delays to generate the corresponding Reconfigure messages due to its
   rate-limiting policies, the request was partially failed for some
   clients, etc.  To avoid useless reconfigure cycles (e.g., due to the

Boucadair & Pougnard   Expires November 07, 2013                [Page 5]
Internet-Draft        Relay Triggered Reconfigure               May 2013

   loss of Reconfigure-Reply), the approach adopted in this document
   allows the relay to correct the content of a re-transmitted
   Reconfigure-Request based on some observed events (e.g., the client
   has retrieved the updated configuration).  If the relay has no client
   to be reconfigured, it stops sending Reconfigure-Request messages.

   The Reconfigure-Request message can also be used in other scenarios
   than those that assume the use of RSOO.  It is out of scope of this
   document to describe all these scenarios.

5.  Link Address Option

   Figure 4 shows the format of the Link Address Option.

     0                   1                   2                   3
     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |       OPTION_LINK_ADDRESS     |         option-len            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                                                               |
     |                  link-address (IPv6 address)                  |
     |                                                               |
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

              Figure 4: Message Format of Link Address Option

   The description of the fields are as follows:

      option-code: OPTION_LINK_ADDRESS (To be assigned by IANA, see
      Section 8).

      option-len: 16 (octets).

      link-address: An IPv6 address used by the server to identify the
      link on which the client is located.

   The Link Address Option is used by the relay agent to indicate to the
   server the link on which the client is located.  The relay agent MUST
   use a link-address value that is equivalent to the value used when
   relaying messages from the client to the server.  Two link-address
   values are said to be equivalent if both values are IPv6 addresses
   that are on-link for the network link to which the client is
   connected.  The relay agent SHOULD use the same value that was sent
   to the DHCPv6 server when relaying messages from the client to the
   server, as in Section 20.1.1 of [RFC3315].

Boucadair & Pougnard   Expires November 07, 2013                [Page 6]
Internet-Draft        Relay Triggered Reconfigure               May 2013

6.  Detailed Specification

6.1.  Messages Format

   Two new message type codes are defined:

   o  RECONFIGURE-REQUEST (To be assigned by IANA, see Section 8).

   o  RECONFIGURE-REPLY (To be assigned by IANA, see Section 8).

   RECONFIGURE-REQUEST and RECONFIGURE-REPLY use the same format as
   defined in Section 6 of [RFC3315].

6.2.  Messages Validation

6.2.1.  RECONFIGURE-REQUEST

   Clients MUST silently discard any received RECONFIGURE-REQUEST
   messages.

   Servers MUST discard any received RECONFIGURE-REQUEST messages that
   meet any of the following conditions:

   o  the message does not include a Client Identifier Option [RFC3315].

   o  the message does not include a Link Address Option (Section 5).

   o  the message includes a Server Identifier Option [RFC3315] but the
      contents of the Server Identifier Option does not match the
      server's identifier.

6.2.2.  RECONFIGURE-REPLY

   Clients and Servers MUST silently discard any received RECONFIGURE-
   REPLY messages.

   The relay MUST silently discard any received RECONFIGURE-REPLY
   messages that meet any of the following conditions:

   o  the "transaction-id" field in the message does not match the value
      used in the original message.

   o  the message does not include a Server Identifier Option.

   o  the message does not include a Status Code Option [RFC3315].

6.3.  Creation and Transmission of RECONFIGURE-REQUEST

Boucadair & Pougnard   Expires November 07, 2013                [Page 7]
Internet-Draft        Relay Triggered Reconfigure               May 2013

   For any event (e.g., modification of the configuration information)
   that requires the server to issue a Reconfigure message, the relay
   agent determines the client(s) affected by the change and then builds
   a Reconfigure-Request message: the relay agent sets the "msg-type"
   field to RECONFIGURE-REQUEST, generates a transaction ID and inserts
   it in the "transaction-id" field.

   The relay agent MUST include one or more Client Identifier Options
   [RFC3315] and a Link Address Option (Section 5) so that the DHCPv6
   server can identify the corresponding client and the link on which
   the client is located.

   The relay agent MAY include a Relay Identifier Option [RFC5460].

   The relay agent MAY supply the updated configuration in the RSOO
   [RFC6422].  The relay agent MAY supply a Reconfigure Message Option
   to indicate which form of Reconfigure to use.  The relay agent MAY
   include any option (e.g., Interface Identifier [RFC3315]) which it
   might insert when relaying a message received from a client.

   When several clients on the same link are affected by a configuration
   change, the relay MUST include several Client Identifier Options,
   each of them identifies a specific client.  If including Client
   Identifier Options of all impacted clients exceeds the maximum
   message size (see Section 7), the relay MUST generate several
   RECONFIGURE-REQUEST messages required to carry all Client Identifier
   Options.  Rate-limit considerations are discussed in Section 7.

   The relay sets the destination address of the Reconfigure-Request
   message to the IP address it would have sent a Relay-Forw message
   (see Section 20 of [RFC3315]).

   In case multiple servers are configured to the relay agent, several
   Reconfigure-Request messages are to be built.  The behavior of the
   relay agent to disambiguate responses when multiple servers are
   configured is implementation-specific.  For example, an
   implementation may generate distinct "transaction-id"s per server
   while another implementation may use the content of the "transaction-
   id" field and the Server Identifier Option to disambiguate the
   responses.

   The relay transmits RECONFIGURE-REQUEST messages according to
   Section 14 of [RFC3315], using the following parameters:

Boucadair & Pougnard   Expires November 07, 2013                [Page 8]
Internet-Draft        Relay Triggered Reconfigure               May 2013

   IRT    1 sec
   MRT    10 secs
   MRC    5
   MRD    0

   The relay MAY remove clients from the client identifier list in
   subsequent retransmissions, but MUST NOT add clients to the client
   identifier list.  This decision is local to the relay (e.g., it may
   be based on observed events such as one or more clients were
   reconfigured on their own).

   The relay may receive Reconfigure encapsulated in Relay-Reply before
   Reconfigure-Reply.  The relay SHOULD NOT interpret it as if the
   Reconfigure-Request was successfully handled by the Server.  The
   relay SHOULD use Reconfigure-Reply, not the Reconfigure message, to
   determine if the request was successful.

6.4.  Intermediate Relay Agents Behavior

   The relay agent MUST be configurable to accept or reject RECONFIGURE-
   REQUEST messages received from other relay agents.  If no indication
   is explicitly configured to the relay, the default behavior is to
   accept RECONFIGURE-REQUEST messages.

   If the relay is configured to reject RECONFIGURE-REQUEST, the relay
   MUST silently discard any RECONFIGURE-REQUEST it receives.  If the
   relay is configured to accept RECONFIGURE-REQUEST messages, these
   messages are relayed as specified in Section 20.1.1 of [RFC3315].

6.5.  Server Behavior

   The server MUST be configurable to accept or reject RECONFIGURE-
   REQUEST messages.  If no indication is explicitly configured to the
   server, the default behavior is to reject RECONFIGURE-REQUEST
   messages.

   Upon receipt of a valid Reconfigure-Request message from a DHCPv6
   relay agent (see Section 6.2), the server determines the client(s)
   for which a Reconfigure message is to be sent.

   The server constructs a Reconfigure-Reply message by setting the
   "msg-type" field to RECONFIGURE-REPLY, and copying the transaction ID
   from the RECONFIGURE-REQUEST message into the "transaction-id" field.
   The server includes its server identifier in a Server Identifier
   Option.  The server MUST include a Status Code Option [RFC3315]
   indicating whether the request is successfully processed, failed or
   partially failed.

Boucadair & Pougnard   Expires November 07, 2013                [Page 9]
Internet-Draft        Relay Triggered Reconfigure               May 2013

   o  If the server fails to validate the request, the server MUST set
      the Status Code Option to the appropriate status code (e.g.,
      UnspecFail, NotAllowed, etc.).  In particular,

      *  UnspecFail MUST be returned if Reconfigure-Request message is
         malformed.

      *  NotAllowed MUST be returned if the server is not configured to
         allow Reconfigure-Request.

      *  NotConfigured MUST be returned if the server has no record of
         the link.

   o  If the Reconfigure-Request is successfully validated, the server
      MUST return a Status Code Option indicating "Success".  In
      addition, the server MUST include a list of all the Client
      Identifier Options of the clients to which Reconfigure messages
      will not be sent (e.g., the server has no record of the client or
      the client did not negotiate for Reconfigure support).  Note that
      this means that "Success" will be returned even if Reconfigure
      messages will not be sent to any of the clients.

   If RSOO is supplied, the server MAY use its content to double check
   whether a Reconfigure is required to be sent to the client.  This
   assumes the server stored the content of RSOO it used to generate
   configuration data sent to requesting clients.

   The server MAY use the content of the Reconfigure Message Option
   supplied by the relay agent to determine which form of Reconfigure to
   use.

   Then, the server MUST follow the procedure defined in Section 19.1 of
   [RFC3315] to construct a Reconfigure message.

   Rate-limit considerations are discussed in Section 7.

6.6.  Receipt of RECONFIGURE-REPLY

   Depending on the status code enclosed in a received RECONFIGURE-REPLY
   message, the relay may decide to terminate the request or try a
   different corrected Reconfigure-Request.

Boucadair & Pougnard   Expires November 07, 2013               [Page 10]
Internet-Draft        Relay Triggered Reconfigure               May 2013

   When multiple servers are configured, the relay should expect to
   receive several Reconfigure-Reply messages.  As mentioned in
   Section 6.3, the relay should be able to disambiguate these responses
   and associate them with a given server.  The relay agent assumes the
   request is successfully handled for a client if the corresponding
   Client Identifier Option does not appear in at least one Reconfigure-
   Reply message.

7.  Rate Limiting Considerations

   The relay MUST rate-limit Reconfigure-Request messages to be sent to
   the server.  The relay MUST be configured with required rate-limit
   parameters (i.e., the rate of Reconfigure-Request messages).  The
   maximum Reconfigure-Request packet size SHOULD be configurable and
   the default value MUST be 1280 octets.

   The server MUST rate-limit Reconfigure messages triggered by
   Reconfigure-Request messages.  The server MUST be configured with
   required rate-limit parameters (i.e., the rate of Reconfigure
   messages).

8.  IANA Considerations

   IANA is requested to assign the following new DHCPv6 Message type in
   the registry maintained in http://www.iana.org/assignments/
   dhcpv6-parameters:

      RECONFIGURE-REQUEST

      RECONFIGURE-REPLY

   IANA is requested to assign the following new DHCPv6 Option Codes in
   the registry maintained in http://www.iana.org/assignments/
   dhcpv6-parameters:

      OPTION_LINK_ADDRESS

9.  Security Considerations

   Security considerations elaborated in [RFC3315] (in particular
   Section 21.1) and [RFC6422] must be taken into account.  In addition,
   DHCPv6 servers MAY be configured to reject relayed Reconfigure-
   Request messages or restrict relay chaining (see [RFC5007] for more
   discussion about the rationale of this recommended behavior).
   Section 6.5 specifies the error code to return when the server is
   configured to reject Reconfigure-Request messages.

Boucadair & Pougnard   Expires November 07, 2013               [Page 11]
Internet-Draft        Relay Triggered Reconfigure               May 2013

   Relay agents SHOULD implement appropriate means to prevent using
   Reconfigure-Request messages as a denial-of-service attack on the
   DHCPv6 servers.

   Because Reconfigure-Request message provides a mechanism for
   triggering the DHCP Reconfigure message, and the DHCP Reconfigure
   message can raise security threats (e.g., to control the timing of a
   DHCP renewal), the DHCP server MUST have some mechanism for
   determining that the relay agent is a trusted entity.  A control
   policy based on the content of received Relay Identifier Option MAY
   be enforced by the DHCPv6 server.  Reconfigure-Request messages
   originating from unknown relay agents MUST be silently dropped.

10.  Acknowledgements

   Many thanks to R.  Maglione, A.  Kostur, G.  Halwasia, C.  Jacquenet,
   and R.  Sparks for the comments and review.

   Special thanks to T.  Lemon, B.  Volz and T.  Mrugalski who provided
   a detailed review.

11.  References

11.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC3315]  Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C.,
              and M. Carney, "Dynamic Host Configuration Protocol for
              IPv6 (DHCPv6)", RFC 3315, July 2003.

   [RFC6422]  Lemon, T. and Q. Wu, "Relay-Supplied DHCP Options", RFC
              6422, December 2011.

11.2.  Informative References

   [RFC5007]  Brzozowski, J., Kinnear, K., Volz, B., and S. Zeng,
              "DHCPv6 Leasequery", RFC 5007, September 2007.

   [RFC5176]  Chiba, M., Dommety, G., Eklund, M., Mitton, D., and B.
              Aboba, "Dynamic Authorization Extensions to Remote
              Authentication Dial In User Service (RADIUS)", RFC 5176,
              January 2008.

   [RFC5460]  Stapp, M., "DHCPv6 Bulk Leasequery", RFC 5460, February
              2009.

Boucadair & Pougnard   Expires November 07, 2013               [Page 12]
Internet-Draft        Relay Triggered Reconfigure               May 2013

Authors' Addresses

   Mohamed Boucadair
   France Telecom
   Rennes  35000
   France

   Email: mohamed.boucadair@orange.com

   Xavier Pougnard
   France Telecom
   Lannion
   France

   Email: xavier.pougnard@orange.com

Boucadair & Pougnard   Expires November 07, 2013               [Page 13]