AAA Working Group J. Koehler Internet-Draft M. Eklund Category: Standards Track H. Li Cisco Systems, Inc. expires August 2002 February 2002 Diameter NASREQ Application MIB Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. 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." The list of current Internet-Drafts can be accessed at: http://www.ietf.org/ietf/1id-abstracts.txt The list of Internet-Draft Shadow Directories can be accessed at: http://www.ietf.org/shadow.html. Distribution of this memo is unlimited. Copyright Notice Copyright (C) The Internet Society (2001). All Rights Reserved. Abstract This document describes the Diameter application that is used for AAA in a PPP/SLIP Dial-Up and Terminal Server Access environment. This application, combined with the base protocol, satisfies the requirements defined in the NASREQ AAA criteria specification and the ROAMOPS AAA Criteria specification. This draft defines the Management Information Base (MIB) module which describes the minimum amount of objects needed to manage the implementation of the Diameter NASREQ Application. Koehler et al. [Page 1] Internet-Draft Diameter NASREQ MIB February 2002 1. Introduction This memo defines a portion of the Management Information Base (MIB) for use with network management protocols in the Internet community. In particular, it describes managed objects used for managing the Diameter NASREQ Application. The Diameter NASREQ Application is used for AAA in a general dial-up environment and, along with the base protocol, satisfies requirements defined in the NASREQ AAA criteria specification and the ROAMOPS AAA Criteria specification. It is designed to ease the transition from systems that use RADIUS to Diameter by re-using the RADIUS address space, avoiding attribute lookups [16]. 2. The SNMP Management Framework The SNMP Management Framework presently consists of five major components: o An overall architecture, described in RFC 2571 [1]. o Mechanisms for describing and naming objects and events for the purpose of management. The first version of this Structure of Management Information (SMI) is called SMIv1 and described in STD 15, RFC 1155 [2], STD 16, RFC 1212 [3] and RFC 1215 [4]. The second version, called SMIv2, is described in STD 58, RFC 2578 [5], RFC 2579 [6] and RFC 2580 [7]. o Message protocols for transferring management information. The first version of the SNMP message protocol is called SNMPv1 and described in STD 15, RFC 1157 [8]. A second version of the SNMP message protocol, which is not an Internet standards track protocol, is called SNMPv2c and described in RFC 1901 [9] and RFC 1906 [10]. The third version of the message protocol is called SNMPv3 and described in RFC 1906 [10], RFC 2572 [11] and RFC 2574 [12]. o Protocol operations for accessing management information. The first set of protocol operations and associated PDU formats is described in STD 15, RFC 1157 [8]. A second set of protocol operations and associated PDU formats is described in RFC 1905 [13]. o A set of fundamental applications described in RFC 2573 [14] and the view-based access control mechanism described in RFC 2575 [15]. A more detailed introduction to the current SNMP Management Framework can be found in RFC 2570 [17]. Koehler et al. [Page 2] Internet-Draft Diameter NASREQ MIB February 2002 Managed objects are accessed via a virtual information store, termed the Management Information Base or MIB. Objects in the MIB are defined using the mechanisms defined in the SMI. This memo specifies a MIB module that is compliant to the SMIv2. A MIB conforming to the SMIv1 can be produced through the appropriate translations. The resulting translated MIB must be semantically equivalent, except where objects or events are omitted because no translation is possible (use of Counter64). Some machine readable information in SMIv2 will be converted into textual descriptions in SMIv1 during the translation process. However, this loss of machine readable information is not considered to change the semantics of the MIB. 3. Overview The Diameter NASREQ Application is used for AAA in general dial-up and Terminal Server Access environments. It is designed to work in combination with the Diameter base protocol specification [18]. The MIB defined reports objects that are specific to the NASREQ application as defined in [16]. The MIB specification for the Diameter base MIB [18] SHOULD be implemented prior to the implementation of this MIB. 4. Definitions DIAMETER-NASREQ-APPLICATION-MIB DEFINITIONS ::= BEGIN IMPORTS MODULE-IDENTITY, OBJECT-TYPE, OBJECT-IDENTITY, Counter32, Unsigned32, TimeTicks, mib-2 FROM SNMPv2-SMI InetAddressType, InetAddress FROM INET-ADDRESS-MIB SnmpAdminString FROM SNMP-FRAMEWORK-MIB MODULE-COMPLIANCE, OBJECT-GROUP FROM SNMPv2-CONF; diameterMIB MODULE-IDENTITY LAST-UPDATED "200202260000Z" ORGANIZATION "IETF AAA Working Group." CONTACT-INFO " Jay Koehler Cisco Systems, Inc. 10850 Murdock Road Knoxville, TN 37932 US Phone: +1 865 671 0429 EMail: jkoehler@cisco.com Koehler et al. [Page 3] Internet-Draft Diameter NASREQ MIB February 2002 Mark Eklund Cisco Systems, Inc. 10850 Murdock Road Knoxville, TN 37932 US Phone: +1 865 671 6255 Email: meklund@cisco.com Hai Li Cisco Systems, Inc. 10850 Murdock Road Knoxville, TN 37932 US Phone: +1 865 671 0429 EMail: haili@cisco.com" DESCRIPTION "The MIB module is based on the Diameter NASREQ Application, draft-ietf-aaa-diameternasreq-08.txt." ::= { mib-2 119 } diameterNasreqAppMIB OBJECT IDENTIFIER ::= {diameterMIB 2} diameterNasreqAppNotifs OBJECT IDENTIFIER ::= { diameterNasreqAppMIB 0 } diameterNasreqAppObjects OBJECT IDENTIFIER ::= { diameterNasreqAppMIB 1 } diameterNasreqAppConform OBJECT IDENTIFIER ::= { diameterNasreqAppMIB 2 } dnaHostCfgs OBJECT IDENTIFIER ::= { diameterNasreqAppObjects 1 } dnaHostStats OBJECT IDENTIFIER ::= { diameterNasreqAppObjects 2 } dnaHostSessionInfo OBJECT IDENTIFIER ::= { diameterNasreqAppObjects 3 } dnaPeerStats OBJECT IDENTIFIER ::= { diameterNasreqAppObjects 4 } dnaHostAddressType OBJECT-TYPE SYNTAX InetAddressType MAX-ACCESS read-only STATUS current DESCRIPTION "The type of internet address stored in diameterHostAddress." ::= { dnaHostCfgs 1 } dnaHostAddress OBJECT-TYPE SYNTAX InetAddress MAX-ACCESS read-only STATUS current DESCRIPTION Koehler et al. [Page 4] Internet-Draft Diameter NASREQ MIB February 2002 "The IP-Address that corresponds to the Origin-Host AVP." ::= { dnaHostCfgs 2 } dnaRadiusGateway OBJECT-TYPE SYNTAX INTEGER { no(1), yes(2) } MAX-ACCESS read-only STATUS current DESCRIPTION "Tells if this server is acting as a RADIUS/Diameter gateway." ::= { dnaHostCfgs 3 } dnaEapStatsTable OBJECT-TYPE SYNTAX SEQUENCE OF DnaEapStatsEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION Table listing EAP counts." ::= { dnaHostStats 1 } dnaEapStatsEntry OBJECT-TYPE SYNTAX DnaPerPeerStatsEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "A row entry representing an EAP method." INDEX { dnaEapMethodIndex } ::= { dnaEapStatsTable 1 } DnaPerPeerStatsEntry ::= SEQUENCE { dnaEapMethodIndex Unsigned32, dnaEapMethodCount Counter32 } dnaEapMethodIndex OBJECT-TYPE SYNTAX Unsigned32 (1..4294967295) MAX-ACCESS read-only STATUS current DESCRIPTION "A number uniquely identifying the EAP method." ::= { dnaEapStatsEntry 1 } dnaEapMethodCount OBJECT-TYPE SYNTAX Unsigned32 (1..4294967295) MAX-ACCESS read-only STATUS current Koehler et al. [Page 5] Internet-Draft Diameter NASREQ MIB February 2002 DESCRIPTION "The number of EAP requests for each method." ::= { dnaEapStatsEntry 2 } dnaPerPeerStatsTable OBJECT-TYPE SYNTAX SEQUENCE OF DnaPerPeerStatsEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "The table listing the Diameter Nasreq Peer Statistics." ::= { dnaPeerStats 1 } dnaPerPeerStatsEntry OBJECT-TYPE SYNTAX DnaPerPeerStatsEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "A row entry representing a Diameter Peer." INDEX { dnaPeerServerIndex } ::= { dnaPerPeerStatsTable 1 } DnaPerPeerStatsEntry ::= SEQUENCE { dnaPeerServerIndex Unsigned32, dnaPerPeerStatsAARIn Counter32, dnaPerPeerStatsAAROut Counter32, dnaPerPeerStatsDERIn Counter32, dnaPerPeerStatsDEROut Counter32, dnaPerPeerStatsAARDropped Counter32, dnaPerPeerStatsDERDropped Counter32 } dnaPeerServerIndex OBJECT-TYPE SYNTAX Unsigned32 (1..4294967295) MAX-ACCESS not-accessible STATUS current DESCRIPTION "A number uniquely identifying each Diameter Peer with which the host server communicates." ::= { dnaPerPeerStatsEntry 1 } dnaPerPeerStatsAARIn OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "AA-Request in per peer." ::= { dnaPerPeerStatsEntry 2 } Koehler et al. [Page 6] Internet-Draft Diameter NASREQ MIB February 2002 dnaPerPeerStatsAAROut OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "AA-Request out per peer." ::= { dnaPerPeerStatsEntry 3 } dnaPerPeerStatsDERIn OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "Diameter-EAP-Request in per peer." ::= { dnaPerPeerStatsEntry 4 } dnaPerPeerStatsDEROut OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "Diameter-EAP-Answer out per peer." ::= { dnaPerPeerStatsEntry 5 } dnaPerPeerStatsAARDropped OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "AA-Request dropped per peer." ::= { dnaPerPeerStatsEntry 6 } dnaPerPeerStatsDERDropped OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "AA-Request dropped per peer." ::= { dnaPerPeerStatsEntry 7 } dnaHostTotalSessions OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The total number of sessions since uptime." ::= { dnaHostSessionInfo 1 } Koehler et al. [Page 7] Internet-Draft Diameter NASREQ MIB February 2002 dnaHostTotalActiveSessions OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The total number of active sessions." ::= { dnaHostSessionInfo 2 } dnaPerPeerActiveSessionTable OBJECT-TYPE SYNTAX SEQUENCE OF DnaPerPeerActiveSessionEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "The (conceptual) table listing the Diameter Nasreq Active Session Information." ::= { dnaPeerStats 2 } dnaPerPeerActiveSessionEntry OBJECT-TYPE SYNTAX DnaPerPeerActiveSessionEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "An entry (conceptual row) representing a Diameter peer." INDEX { dnaPeerServerIndex, dnaPerPeerSessionIndex } ::= { dnaPerPeerActiveSessionTable 1 } DnaPerPeerActiveSessionEntry ::= SEQUENCE { dnaPerPeerSessionIndex Unsigned32, dnaPerPeerSessionId SnmpAdminString, dnaPerPeerSessionUptime TimeTicks, dnaPerPeerSessionAuthenStatus INTEGER, dnaPerPeerSessionAuthorStatus INTEGER, dnaPerPeerSessionReauthenCount Counter32, dnaPerPeerSessionReauthorCount Counter32, dnaPerPeerSessionAuthorLifetime TimeTicks } dnaPerPeerSessionIndex OBJECT-TYPE SYNTAX Unsigned32 (1..4294967295) MAX-ACCESS read-only STATUS current DESCRIPTION "A number identifying a peer session." ::= { dnaPerPeerActiveSessionEntry 1 } dnaPerPeerSessionId OBJECT-TYPE SYNTAX SnmpAdminString Koehler et al. [Page 8] Internet-Draft Diameter NASREQ MIB February 2002 MAX-ACCESS read-only STATUS current DESCRIPTION "A unique string used to identify a specific session." ::= { dnaPerPeerActiveSessionEntry 2 } dnaPerPeerSessionUptime OBJECT-TYPE SYNTAX TimeTicks MAX-ACCESS read-only STATUS current DESCRIPTION "The total amount of time the session has been up." ::= { dnaPerPeerActiveSessionEntry 3 } dnaPerPeerSessionAuthenStatus OBJECT-TYPE SYNTAX INTEGER { notauthen(1), inprogess(2), authenticated(3) } MAX-ACCESS read-only STATUS current DESCRIPTION "The authentication status of a session." ::= { dnaPerPeerActiveSessionEntry 4 } dnaPerPeerSessionAuthorStatus OBJECT-TYPE SYNTAX INTEGER { notauthor(1), inprogess(2), authorized(3) } MAX-ACCESS read-only STATUS current DESCRIPTION "The authorization status of a session." ::= { dnaPerPeerActiveSessionEntry 5 } dnaPerPeerSessionReauthenCount OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of times this session has been re-authenticated." ::= { dnaPerPeerActiveSessionEntry 6 } dnaPerPeerSessionReauthorCount OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only Koehler et al. [Page 9] Internet-Draft Diameter NASREQ MIB February 2002 STATUS current DESCRIPTION "The number of times this session has been re-authorized." ::= { dnaPerPeerActiveSessionEntry 7 } dnaPerPeerSessionAuthorLifetime OBJECT-TYPE SYNTAX TimeTicks MAX-ACCESS read-only STATUS current DESCRIPTION "The maximum number of seconds of service to be provided to the user before the user is to be re-authenticated and/or re-authorized." ::= { dnaPerPeerActiveSessionEntry 8 } dnaHistorySessionTable OBJECT-TYPE SYNTAX SEQUENCE OF DnaHistorySessionEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "The (conceptual) table listing session history information." ::= { dnaPeerStats 3 } dnaHistorySessionEntry OBJECT-TYPE SYNTAX DnaHistorySessionEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "An entry (conceptual row) representing information for a session." INDEX { dnaHistorySessionIndex } ::= { dnaHistorySessionTable 1 } DnaHistorySessionEntry ::= SEQUENCE { dnaHistorySessionIndex Unsigned32, dnaHistorySessionId SnmpAdminString, dnaHistorySessionUptime TimeTicks, dnaHistorySessionAuthenStatus INTEGER, dnaHistorySessionAuthorStatus INTEGER, dnaHistorySessionReauthenCount Counter32, dnaHistorySessionReauthorCount Counter32, dnaHistorySessionAuthorLifetime TimeTicks } dnaHistorySessionIndex OBJECT-TYPE SYNTAX Unsigned32 (1..4294967295) Koehler et al. [Page 10] Internet-Draft Diameter NASREQ MIB February 2002 MAX-ACCESS not-accessible STATUS current DESCRIPTION "The maximum number of session information to keep." ::= { dnaHistorySessionEntry 1 } dnaHistorySessionId OBJECT-TYPE SYNTAX SnmpAdminString MAX-ACCESS read-only STATUS current DESCRIPTION "A unique string used to identify a specific session." ::= { dnaHistorySessionEntry 2 } dnaHistorySessionUptime OBJECT-TYPE SYNTAX TimeTicks MAX-ACCESS read-only STATUS current DESCRIPTION "The total amount of time the session has been up." ::= { dnaHistorySessionEntry 3 } dnaHistorySessionAuthenStatus OBJECT-TYPE SYNTAX INTEGER { notauthen(1), inprogess(2), authenticated(3) } MAX-ACCESS read-only STATUS current DESCRIPTION "The authentication status of a session." ::= { dnaHistorySessionEntry 4 } dnaHistorySessionAuthorStatus OBJECT-TYPE SYNTAX INTEGER { notauthor(1), inprogess(2), authorized(3) } MAX-ACCESS read-only STATUS current DESCRIPTION "The authorization status of a session." ::= { dnaHistorySessionEntry 5 } dnaHistorySessionReauthenCount OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only Koehler et al. [Page 11] Internet-Draft Diameter NASREQ MIB February 2002 STATUS current DESCRIPTION "The number of times this session has been re-authenticated." ::= { dnaHistorySessionEntry 6 } dnaHistorySessionReauthorCount OBJECT-TYPE SYNTAX Counter32 MAX-ACCESS read-only STATUS current DESCRIPTION "The number of times this session has been re-authorized." ::= { dnaHistorySessionEntry 7 } dnaHistorySessionAuthorLifetime OBJECT-TYPE SYNTAX TimeTicks MAX-ACCESS read-only STATUS current DESCRIPTION "The maximum number of seconds of service to be provided to the user before the user is to be re-authenticated and/or re-authorized." ::= { dnaHistorySessionEntry 8 } -- -- Conformance -- dnaMIBCompliances OBJECT IDENTIFIER ::= { diameterNasreqAppConform 1 } dnaMIBGroups OBJECT IDENTIFIER ::= { diameterNasreqAppConform 2 } -- -- Compliance Statements -- dnaMIBCompliance MODULE-COMPLIANCE STATUS current DESCRIPTION "The compliance statement for diameter base protocol entities." MODULE -- this module MANDATORY-GROUPS { dnaHostCfgGroup } ::= { dnaMIBCompliances 1 } -- -- Units of Conformance -- dnaHostCfgGroup OBJECT-GROUP OBJECTS { dnaHostAddressType, dnaHostAddress, dnaRadiusGateway Koehler et al. [Page 12] Internet-Draft Diameter NASREQ MIB February 2002 } STATUS current DESCRIPTION "A collection of objects providing configuration common to the server." ::= { dnaMIBGroups 1 } END 5. References [1] Harrington, D., Presuhn, R., and B. Wijnen, "An Architecture for Describing SNMP Management Frameworks", RFC 2571, April 2001. [2] Rose, M., and K. McCloghrie, "Structure and Identification of Management Information for TCP/IP-based Internets", STD 16, RFC 1155, May 1990. [3] Rose, M., and K. McCloghrie, "Concise MIB Definitions", STD 16, RFC 1212, March 1991. [4] Rose, M., "A Convention for Defining Traps for use with the SNMP", RFC 1215, Performance Systems International, March 1991. [5] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose, M. and S. Waldbusser, "Structure of Management Information Version 2 (SMIv2)", STD 58, RFC 2578, April 2001. [6] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose, M. and S. Waldbusser, "Textual Conventions for SMIv2", STD 58, RFC 2579, April 2001. [7] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose, M. and S. Waldbusser, "Conformance Statements for SMIv2", STD 58, RFC 2580, April 2001. [8] Case, J., Fedor, M., Schoffstall, M., and J. Davin, "Simple Network Management Protocol", STD 15, RFC 1157, May 1990. [9] Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, "Introduction to Community-based SNMPv2", RFC 1901, January 1996. [10] Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, "Transport Mappings for Version 2 of the Simple Network Management Protocol (SNMPv2)", RFC 1906, January 1996. Koehler et al. [Page 13] Internet-Draft Diameter NASREQ MIB February 2002 [11] Case, J., Harrington D., Presuhn R., and B. Wijnen, "Message Processing and Dispatching for the Simple Network Management Protocol (SNMP)", RFC 2572, April 2001. [12] Blumenthal, U., and B. Wijnen, "User-based Security Model for Version 3 of the Simple Network Management Protocol (SNMPv3)", RFC 2574, April 2001. [13] Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, "Protocol Operations for Version 2 of the Simple Network Management Protocol (SNMPv2)", RFC 1905, January 1996. [14] Levi, D., Meyer, P., and B. Stewart, "SNMP Applications", RFC 2573, April 2001. [15] Wijnen, B., Presuhn, R., and K. McCloghrie, "View-based Access Control Model for the Simple Network Management Protocol (SNMP)", RFC 2575, April 2001. [16] P. Calhoun, W. Bulley, A. Rubens, J. Haag, "Diameter NASREQ Application", draft-ietf-aaa-diameter-nasreq-08.txt, IETF work in progress, November 2001. [17] Case, J., Mundy, R., Partain, D., and B. Stewart, "Introduction to Version 3 of the Internet-standard Network Management Framework", RFC 2570, April 1999. [18] J. Koehler, H. Li, M. Eklund, "Diameter Base Protocol MIB", draft-koehler-aaa-diameter-base-protocol-mib-03.txt, IETF work in progress, February 2002. [19] P. Calhoun, H. Akhtar, J. Arkko, E. Guttman, A. Rubens, G. Zorn, "Diameter Base Protocol", draft-ietf-aaa-diameter-08.txt, IETF work in progress, November 2001. 6. Security Considerations There is a managed object defined in this MIB that has a MAX-ACCESS clause of read-write and/or read-create. Such an object may be considered sensitive or vulnerable in some network environments. The support for SET operations in a non-secure environment without proper protection can have a negative effect on network operations. There is a managed object in this MIB that may contain sensitive information. It is: diameterHostAddress, This can be used to determine the address of the Diameter Koehler et al. [Page 14] Internet-Draft Diameter NASREQ MIB February 2002 host server, with which the servers are communicating. This information could be useful in impersonating the peer server. It is thus important to control GET access to these objects and possibly to even encrypt the values of these object when sending them over the network via SNMP. Not all versions of SNMP provide features for such a secure environment. SNMPv1 by itself is not a secure environment. Even if the network itself is secure (for example by using IPSec), there is no control as to who on the secure network is allowed to access and GET (read) the objects in this MIB. It is recommended that the implementers consider the security features as provided by the SNMPv3 framework. Specifically, the use of the User-based Security Model RFC 2574 [12] and the View-based Access Control Model RFC 2575 [15] is recommended. It is then a customer/user responsibility to ensure that the SNMP entity giving access to an instance of this MIB, is properly configured to give access to the objects only to those principals (users) that have legitimate rights to indeed GET or SET (change/create/delete) them. 7. Authors' Addresses Jay Koehler Cisco Systems, Inc. 10850 Murdock Road Knoxville, TN 37932 Phone: 865-671-0429 EMail: jkoehler@cisco.com Mark Eklund Cisco Systems, Inc. 10850 Murdock Road Knoxville, TN 37932 Phone: 865-671-6255 Email: meklund@cisco.com Hai Li Cisco Systems, Inc. 10850 Murdock Road Knoxville, TN 37932 Koehler et al. [Page 15] Internet-Draft Diameter NASREQ MIB February 2002 Phone: 865-777-1563 EMail: haili@cisco.com 8. Full Copyright Statement Copyright (C) The Internet Society (2001). All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implmentation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns. This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Koehler et al. [Page 16]