B. Beser
Internet Draft                                                     3Com
Document: draft-ietf-dhc-packetcable-00.txt                 March 2000
Category: Informational


         DHCP Option for PacketCable VoIP Client Configuration


Status of this Memo

   This document is an Internet-Draft and is NOT offered in accordance
   with Section 10 of RFC2026 [1], and the author does not provide the
   IETF with any rights other than to publish as an Internet-Draft

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1. Abstract

   The Voice over IP work carried over in the PacketCable project
   conducted by CableLabs. The configuration of the PacketCable Voice
   over IP client is achieved using DHCP messaging.

   This document contains the definition of PacketCable VoIP  Client
   configuration option.


2. Conventions used in this document

   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 RFC-2119 [2].

3. DHCP Terminology

   o "DHCP client"

     A DHCP client or "client" is an Internet host using DHCP to obtain
     configuration parameters such as a network address.
Internet Draft   draft-beser-dhcp-packetcable-00.txt        March 2000


   o "DHCP server"

     A DHCP server of "server"is an Internet host that returns
     configuration parameters to DHCP clients.


   o "binding"

     A binding is a collection of configuration parameters, including
     at least an IP address, associated with or "bound to" a DHCP
     client.  Bindings are managed by DHCP servers.


4. Introduction

   PacketCable is a project conducted by Cable Television Laboratories,
   Inc. (CableLabs) and its member companies aimed at identifying,
   qualifying, and supporting Internet-based voice and video products
   over cable systems. These products will represent new classes of
   services utilizing cable-based packet communication networks. New
   service classes include telephone calls and videoconferencing over
   cable networks and the Internet. The services would be delivered
   using the basic Internet Protocol (IP) technology that is used to
   send data via the Internet.

   PacketCable project produced specifications of VoIP elements which
   can be found in www.packetcable.com. The PacketCable VoIP Client
   uses DHCP for configration. Due to specific needs of PacketCable
   client a new DHCP option is needed. The new option is designed to
   have a number of sub-information which is laid down in DHCP option
   fashion [3].

5. PacketCable VoIP Client Configuration Option

   The code for this option is TBD.

   PacketCable VoIP Client Configuration option is used for PacketCable
   VoIP clients to identify a list of valid PacketCable network
   servers.

   The option contains sub-fields to contain information regarding
   these servers. The option looks as depicted below at the DHCP OFFER.

   --------------------------------------------------------
   | TBD | Length | PacketCable VoIP Client Configuration |
   --------------------------------------------------------

   A client that recognizing the sub-fields sees the option as:

   -------------------------------------------------------------
   | TBD | Length | Subfield 1 | Subfield 2 | ... | Subfield n |
   -------------------------------------------------------------
Internet Draft   draft-beser-dhcp-packetcable-00.txt        March 2000

   Each sub-field is in the form of:

   ---------------------------------------------------
   | Sub-field Number | Length | Subfield information |
   ---------------------------------------------------

   Each sub-field of PacketCable VoIP Client Configuration identifies a
   particular type of PacketCable server. Sub-field 1 identifies the
   PacketCable network DHCP server, sub-field 2 identifies the
   PacketCable service provider's SNMP entity, and sub-field 3 and 4
   identifies the primary and secondary PacketCable network DNS
   servers. The Sub-fields are summarized below:

   --------------------------------------------------------------------
   |Option |Sub-field | Description and Comments                      |
   ====================================================================
   | TBD   |     1    | Telephony Service Provider DHCP Server Address|
   |       |-----------------------------------------------------------
   |       |     2    | Telephony Service Provider SNMP Server Address|
   |       |-----------------------------------------------------------
   |       |     3    | Telephony Service Provider Network Primary    |
   |       |          | Domain Name Server                            |
   |       |-----------------------------------------------------------
   |       |     4    | Telephony Service Provider Network Secondary  |
   |       |          | Domain Name Server                            |
   --------------------------------------------------------------------

6. PacketCable VoIP Client option Sub-field Definitions

   The following parts provide detailed descriptions of each sub-field
   of DHCP PacketCable VoIP Client option. Note that UDP port numbers
   are normally standard values as defined in [4].  However, the format
   of the sub-field data fields defined here have a provision to
   optionally include port numbers for these systems if a port number
   other than the standard is required. If no port number is specified,
   the standard port number based on the definitions [4] is assumed.
   For example, the standard DNS UDP port number is 42/udp.

6.1. Telephony Service Provider's DHCP Server Address

   The Telephony Service Provider's DHCP Server Address identifies the
   DHCP server that will be used to obtain an MTA-unique IP address for
   a given telephony service provider's network administrative domain.
   This address can be configured as either an FQDN or as an IPv4
   address.

   The encoding of sub-field 1 is as follows:

   --------------------------------------------------------------------
   |Sub-field | Value         | Description and Comments              |
   ====================================================================
   |     1    |[x.y.z.y]:port | Either the IP address or the FQDN will|
   |          |---------------| be configured. The port number is to  |
Internet Draft   draft-beser-dhcp-packetcable-00.txt        March 2000
   |          | FQDN:port     | be used only if different than well   |
   |          |               | port number is to be used.            |
   --------------------------------------------------------------------

6.2. Telephony Service Provider's SNMP Entity Address

   The Telephony Service Provider's SNMP Entity Address is the network
   address of the default server for a given telephony service
   provider's network administrative domain. The Telephony Service
   Provider's SNMP Entity Address component MUST be capable of
   accepting SNMP traps. This address can be configured as either an
   FQDN or as an IPv4 address.

   The encoding of sub-field 2 is as follows:

   --------------------------------------------------------------------
   |Sub-field | Value         | Description and Comments              |
   ====================================================================
   |     2    |[x.y.z.y]:port | Either the IP address or the FQDN will|
   |          |---------------| be configured. The port number is to  |
   |          | FQDN:port     | be used only if different than well   |
   |          |               | port number is to be used.            |
   --------------------------------------------------------------------

6.3. DNS system

   The Telephony Service Provider's DNS server is required to resolve a
   PacketCable device's FQDN into an IPv4 address. The DNS server's
   address MUST be specified in the IPv4 format.

   Sub-field 3 is the address of the network's primary DNS server and
   MUST be specified if sub-field 1 or sub-field 2 is in FQDN format.
   Sub-field 4 is the address of the network's secondary DNS server.
   Sub-field 4 MAY be specified to identify a redundant or backup DNS
   server.

   The encoding syntax for sub-field 3 and sub-field 4 is as follows:

   --------------------------------------------------------------------
   |Sub-field | Value         | Description and Comments              |
   ====================================================================
   |     3    |[x.y.z.y]:port | Either the IP address of the telephony|
   |          |---------------| service providers primary DNS server. |
   |          | FQDN:port     | Port will be defined only if different|
   |          |               | than well-known port.                 |
   --------------------------------------------------------------------
   |     4    |[x.y.z.y]:port | Either the IP address of the telephony|
   |          |---------------| service providers secondary DNS server|
   |          | FQDN:port     | Port will be defined only if different|
   |          |               | than well-known port.                 |
   --------------------------------------------------------------------

6.4. Procedure for adding call control server types
Internet Draft   draft-beser-dhcp-packetcable-00.txt        March 2000
   A vendor may add a new sub-field by issuing an internet draft that
   contains the new sub-field.  The new sub-field code MUST be labeled
   "TBD."  This draft will then be submitted to the DHC working group,
   and, if accepted for inclusion in the DHCP specification, a sub-
   option field code is assigned and the sub-option specification is
   published as an RFC which updates this RFC.

7. Security Considerations

   DHCP currently provides no authentication or security
   mechanisms.  Potential exposures to attack are discussed
   is section 7 of the protocol specification [5].


9. References

   1. Bradner, S., "The Internet Standards Process -- Revision 3", BCP
   9, RFC 2026, October 1996.

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

   3. Alexander, S. and R. Droms, "DHCP Options and BOOTP Vendor
   Extensions", RFC-2132, March 1997.

   4. Reynolds, J., Postel, J., _ASSIGNED NUMBERS_, RFC 1340, July
   1992.

   6. Droms, R., "Dynamic Host Configuration Protocol", RFC-2131, March
   1997.


10.  Acknowledgments

   I would like to extend a heartfelt thanks to all those who
   contributed to the development of PacketCable Provisioning
   specification. Particular thanks are given Sasha Medvinsky, Raj
   Deshpande (Motorola), Angela Lyda, Rick Morris (Arris Interactive);
   Steven Bellovin (AT&T); Jiri Matousek (Bay Networks); Klaus
   Hermanns, Azita Kia, Michael Thomas, Rich Woundy (Cisco); Deepak
   Patil (Com21); Jeff Ollis, Rick Vetter (General Instrument); Roger
   Loots (Lucent); Roy Spitzer (Telogy), Aviv Goren (Terayon); and
   Prithivraj Narayanan (Wipro).


11. Author's Addresses

   Burcak Beser
   3Com
   Mount Prospect, IL  60056
   Email: Burcak_Beser@3com.com
Internet Draft   draft-ietf-dhcp-packetcable-00.txt        March 2000