DHC Working Group Internet Draft Murali Achanta Document: draft-achanta-dhc-ap-options-00.txt Cisco Systems Expires: December 2005 June 2005 DHCP Option for Radio Configuration Parameters to Mobile Access Points Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. 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All Rights Reserved. Abstract This document defines a DHCP option that contains Radio specific Parameters for Mobile Access Points, Like Transmit Power, Country code, reserved RF channels. Murali Achanta Expires - December 2005 [Page 1] Internet-Draft June 2005 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 [i]. Table of Contents 1. Motivation.....................................................2 2. Mobile access point radio Configuration parameters option format3 2.1 Radio transmit power sub-option............................3 2.2 Radio IOS 3166 country code sub-option.....................3 2.3 Radio reserved RF channels sub-option......................4 3. IANA Considerations............................................4 4. Security Considerations........................................4 References........................................................4 Acknowledgments...................................................5 Author's Addresses................................................5 1. Motivation Dynamic Host Configuration Protocol provides necessary mechanism for device configuration. However, there is no provision for Mobile access points to get their radio configuration information elements. With Introduction of portable mobile Access points, users can take these mobile access points along with them where ever they go to extend wired network to wireless network. Problem is when multiple users take multiple access points to a Motel then there will be overlapping radio cells, because one radio cell may go across multiple motel rooms. One way to solve this problem is to configure lower transmit power levels on these access points. However users will not proactively configure lower transmit powers on their access points. 802.11h TPC is only to control transmit power of 802.11 clients not for the access points. We need a way to automatically set the transmit power from wired network, that way network admin can configure lower transmit powers to decrease the radio cell size depending on the room sizes, so that multiple rooms can have their own cell without interfering other radio cells. Mobile access points may get radio specific configuration parameters for this network from DHCP server, to determine what is the max transmit power allowed, which country this mobile portable access point has been plugged into, what are the recommended RF channels not to be used while connected to this network. Murali Achanta Expires - December 2005 [Page 2] Internet-Draft June 2005 2. Mobile access point radio Configuration parameters option format The option begins with a tag octet containing the option code(TBD). A length octet following the tag octet. The value of the length octet does not include itself or the tag octet. This option layout is depicted below: +------+--------+--------------+--------------+---+--------------+ | TBD |Length | Sub-option 1 | Sub-option 2 |...| Sub-option n | +------+--------+--------------+--------------+---+--------------+ A sub-option begins with a tag octet containing the sub-option code. A length octet follows the tag octet. The value of the length octet does not include itself or the tag octet. The length octet is followed by "length" octets of sub-option information. The sub-ption layout is depicted below: +-------------------+--------+------------------------+ | Sub-option Code | Length | Sub-option information | +-------------------+--------+------------------------+ 2.1 Radio transmit power sub-option This sub-option provides a Max allowed Transmit power in unit of dBm. It is a one octet value. Code Len 802.11 wireless transmit power +-----+-----+---------------+----- | 1 | 1 | power in dBm | +-----+-----+---------------+----- 2.2 Radio IOS 3166 country code sub-option This sub-option provides the country code of the network in which this mobile access point is connected to. This information MUST be used to derive the RF channel list this access point is supposed to operate as per regulatory requirements. Code Len 802.11 wireless A2 IS0 3166 country code +-----+-----+-----+-----+-----+-----+-- | 2 | 2 | c1 | c2 | +-----+-----+-----+-----+-----+-----+-- County code values are to be taken from valid ISO 3166 standard. Alpha-2 code elements MUST be used in this option. c1 and c2 are the two characters for a given country code. Murali Achanta Expires - December 2005 [Page 3] Internet-Draft June 2005 http://www.iso.org/iso/en/prods-services/iso3166ma/02iso-3166-code- lists/list-en1.html 2.3 Radio reserved RF channels sub-option This sub-option provides a list of channel a mobile access point not supposed to operate in order to avoid interference to the native devices operating in the network. Code Len 802.11 wireless reserved channels +-----+-----+----------+-----------+----------+--- | 3 | n | channel1 | channel2 | channel3 | . . . . . +-----+-----+----------+-----------+----------+--- Channel[1..n] is 4 digit representation of the radio frequency in MHz. Example: 2412 MHz, 2462 MHz, 5180 MHz. 3. IANA Considerations IANA is requested to assign an option code for radio configuration parameters for mobile access points. 4. Security Considerations These DHCP options may be used by intruder DHCP server to mislead the mobile access points to operate in country domain other than the existing country and provide wrong power levels. References [1]Bradner, S., "Intellectual Property Rights in IETF Technology", BCP 79, RFC 3668, Feb. 2004 [2] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997 [3] Droms, R., "Dynamic Host Configuration Protocol", RFC 2131, March 1997. Murali Achanta Expires - December 2005 [Page 4] Internet-Draft June 2005 Acknowledgments Author's Addresses Murali Achanta Cisco Systems, Inc. 170 W Tasman Drive San Jose, CA 95134, USA Email: achanta@cisco.com Murali Achanta Expires - December 2005 [Page 5]