packet loss, as well as application layer acknowledgments to provide
robustness against accounting server failures. SNMP operations with
the exception of InforRequest provide application layer
acknowledgments, and the TCP transport mapping proposed by NMRG
provides robustness against packet loss. Inter-domain operation can
benefit from data object security (which no existing protocol
provides) as well as inter-domain security model enhancements (such
as the KSM).
Where high-value sessions are involved, such as in roaming, Mobile
IP, or telephony, it may be necessary to put bounds on processing
delay. This implies the need to reduce latency. As a result, the
NMRG extensions are required in time sensitive billing applications,
including TCP transport mapping, get-subtree capabilities and OID
compression. High reliability is also required in this application,
implying the need for application layer as well as transport layer
acknowledgments. SNMPv3 with the NMRG extensions and security
scalability improvements such as the KSM can satisfy the requirements
in intra-domain use.
However, in inter-domain use, additional security precautions such as
data object security and receipt support are required. No existing
protocol can meet these requirements. A summary is given in the
table on the next page.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
| Usage | Intra-domain | Inter-domain |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
| Capacity | SNMPv3 & | SNMPv3 &<* |
| Planning | RADIUS #%@ | |
| | TACACS+ @ | |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
| Non-usage | SNMPv3 & | SNMPv3 &<* |
| Sensitive | RADIUS #%@ | |
| Billing | TACACS+ @ | |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
| Usage | | |
| Sensitive | | |
| Billing, | SNMPv3 &>$ | SNMPv3 &<>*$ |
| Cost | TACACS+ &$@ | |
| Allocation & | | |
| Auditing | | |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
| Time | | |
| Sensitive | SNMPv3 &>$ | No existing |
| Billing, | | protocol |
| fraud | | |
| detection, | | |
| roaming | | |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Key
# = lacks confidentiality support
* = lacks data object security
% = limited robustness against packet loss
& = lacks application layer acknowledgment (e.g. SNMP InformRequest)
$ = requires non-volatile storage
@ = lacks batching support
< = lacks certificate support (KSM, work in progress)
> = lacks support for large packet sizes (TCP transport mapping,
experimental)
6. Security Considerations
Security issues are discussed throughout this memo.
7. Acknowledgments
The authors would like to thank Bert Wijnen (Lucent), Keith
McCloghrie (Cisco Systems), Jan Melen (Ericsson) and Jarmo Savolainen
(Ericsson) for useful discussions of this problem space.
8. References
[1] Aboba, B., Lu J., Alsop J., Ding J. and W. Wang, "Review of
Roaming Implementations", RFC2194, September 1997.
[2] Aboba, B. and G. Zorn, "Criteria for Evaluating Roaming
Protocols", RFC2477, January 1999.
[3] Rigney, C., Rubens, A., Simpson, W. and S. Willens, "Remote
Authentication Dial In User Service (RADIUS)", RFC2138, April,
1997.
[4] Rigney, C., "RADIUS Accounting", RFC2139, April 1997.
[5] Shacham, A., Monsour, R., Pereira, R. and M. Thomas, "IP Payload
Compression Protocol (IPComp)", RFC2393, December 1998.
[6] Bradner, S., "Key words for use in RFCs to Indicate Requirement
Levels", BCP 14, RFC2119, March 1997.
[7] Information Sciences Institute, "Transmission Control Protocol",
RFC793, September 1981.
[8] Aboba, B. and M. Beadles, "The Network Access Identifier",
RFC2486, January 1999.
[9] McCloghrie, K., Heinanen, J., Greene, W. and A. Prasad,
"Accounting Information for ATM Networks", RFC2512, February
1999.
[10] McCloghrie, K., Heinanen, J., Greene, W., and A. Prasad,
"Managed Objects for Controlling the Collection and Storage of
Accounting Information for Connection-Oriented Networks", RFC
2513, February 1999.
[11] Frye, R., Levi, D., Routhier, S. and B. Wijnen, "Coexistence
between Version 1, Version 2, and Version 3 of the Internet-
standard Management Framework", RFC2576, March 2000.
[12] Fajman, R., "An Extensible Message Format for Message
Disposition Notifications", RFC2298, March 1998.
[13] Elkins, M., "MIME Security with Pretty Good Privacy (PGP)", RFC
2015, October 1996.
[14] Vaudreuil, G., "The Multipart/Report Content Type for the
Reporting of Mail System Administrative Messages", RFC1892,
January 1996.
[15] Galvin, J., Murphy, S., Crocker, S. and N. Freed, "Security
Multiparts for MIME: Multi-part/Signed and
Multipart/Encrypted", RFC1847, October 1995.
[16] Crocker, D., "MIME Encapsulation of EDI Objects", RFC1767,
March 1995.
[17] Borenstein, N. and N. Freed, "MIME (Multipurpose Internet Mail
Extensions) Part One: Mechanisms for Specifying and Describing
the Format of Internet Message Bodies", RFC1521, December 1993.
[18] Rose, M.T., The Simple Book, Second Edition, Prentice Hall,
Upper Saddle River, NJ, 1996.
[19] Case, J., Mundy, R., Partain, D. and B. Stewart, "Introduction
to Version 3 of the Internet-standard Network Management
Framework", RFC2570, April 1999.
[20] Klyne, G., "Timely Delivery for Facsimile Using Internet Mail",
Work in Progress.
[21] Johnson, H. T., Kaplan, R. S., Relevance Lost: The Rise and Fall
of Management Accounting, Harvard Business School Press, Boston,
Massachusetts, 1987.
[22] Horngren, C. T., Foster, G., Cost Accounting: A Managerial
Emphasis. Prentice Hall, Englewood Cliffs, New Jersey, 1991.
[23] Kaplan, R. S., Atkinson, Anthony A., Advanced Management
Accounting, Prentice Hall, Englewood Cliffs, New Jersey, 1989.
[24] Cooper, R., Kaplan, R. S., The Design of Cost Management
Systems. Prentice Hall, Englewood Cliffs, New Jersey, 1991.
[25] Rigney, C., Willats, S. and P. Calhoun, "RADIUS Extensions", RFC
2869, June 2000.
[26] Stewart, R., et al., "Simple Control Transmission Protocol", RFC
2960, October 2000.
[27] Harrington, D., Presuhn, R., and B. Wijnen, "An Architecture for
Describing SNMP Management Frameworks", RFC2571, April 1999.
[28] Rose, M., and K. McCloghrie, "Structure and Identification of
Management Information for TCP/IP-based Internets", STD 16, RFC
1155, May 1990.
[29] Rose, M. and K. McCloghrie, "Concise MIB Definitions", STD 16,
RFC1212, March 1991.
[30] Rose, M., "A Convention for Defining Traps for use with the
SNMP", RFC1215, March 1991.
[31] McCloghrie, K., Perkins, D. and J. Schoenwaelder, "Structure of
Management Information Version 2 (SMIv2)", STD 58, RFC2578,
April 1999.
[32] McCloghrie, K., Perkins, D. and J. Schoenwaelder, "Textual
Conventions for SMIv2", STD 58, RFC2579, April 1999.
[33] McCloghrie, K., Perkins, D. and J. Schoenwaelder, "Conformance
Statements for SMIv2", STD 58, RFC2580, April 1999.
[34] Case, J., Fedor, M., Schoffstall, M. and J. Davin, "Simple
Network Management Protocol", STD 15, RFC1157, May 1990.
[35] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser,
"Introduction to Community-based SNMPv2", RFC1901, January
1996.
[36] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser, "Transport
Mappings for Version 2 of the Simple Network Management Protocol
(SNMPv2)", RFC1906, January 1996.
[37] Case, J., Harrington D., Presuhn R. and B. Wijnen, "Message
Processing and Dispatching for the Simple Network Management
Protocol (SNMP)", RFC2572, April 1999.
[38] Blumenthal, U. and B. Wijnen, "User-based Security Model (USM)
for version 3 of the Simple Network Management Protocol
(SNMPv3)", RFC2574, April 1999.
[39] Levi, D., Meyer, P. and B. Stewart, "SNMPv3 Applications", RFC
2573, April 1999.
[40] Wijnen, B., Presuhn, R. and K. McCloghrie, "View-based Access
Control Model (VACM) for the Simple Network Management Protocol
(SNMP)", RFC2575, April 1999.
[41] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser, "Protocol
Operations for Version 2 of the Simple Network Management
Protocol (SNMPv2)", RFC1905, January 1996.
[42] Tung, B., Neuman, C., Hur, M., Medvinsky, A., Medvinsky, S.,
Wray, J. and J. Trostle, "Public Key Cryptography for Initial
Authentication in Kerberos", Work in Progress.
[43] Tung, B., Ryutov, T., Neuman, C., Tsudik, G., Sommerfeld, B.,
Medvinsky, A. and M. Hur, "Public Key Cryptography for Cross-
Realm Authentication in Kerberos", Work in Progress.
[44] Hornstein, K. and W. Hardaker, "A Kerberos Security Model for
SNMPv3", Work in Progress.
[45] Brownlee, N. and A. Blount, "Accounting Attributes and Record
Formats", RFC2924, September 2000.
[46] Network Management Research Group Web page,
http://www.ibr.cs.tu-bs.de/projects/nmrg/
[47] Schoenwaelder, J.,"SNMP-over-TCP Transport Mapping", Work in
Progress.
[48] Schoenwaelder, J., "SNMP Payload Compression", Work in Progress.
[49] Sprenkels, R., Martin-Flatin, J.,"Bulk Transfers of MIB Data",
Simple Times, http://www.simple-times.org/pub/simple-
times/issues/7-1.html, March 1999.
[50] Thaler, D., "Get Subtree Retrieval MIB", Work in Progress.
[51] Daniele, M., Wijnen, B., Ellison, M. and D. Francisco, "Agent
Extensibility (AgentX) Protocol Version 1", RFC2741, January
2000.
9. Authors' Addresses
Bernard Aboba
Microsoft Corporation
One Microsoft Way
Redmond, WA 98052
USA
Phone: +1 425 936 6605
EMail: bernarda@microsoft.com
Jari Arkko
Oy LM Ericsson Ab
02420 Jorvas
Finland
Phone: +358 40 5079256
EMail: Jari.Arkko@ericsson.com
David Harrington
Cabletron Systems Inc.
P.O.Box 5005
Rochester NH 03867-5005
USA
Phone: +1 603 337 7357
EMail: dbh@cabletron.com
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